i     i.:.-..;.-,..-..-.v----.: 


Columbia  ©nibersJitp;^^'^ 
in  tf)c  Citp  of  Mt\3}  ^orfe*^°  V7 

COLLEGE  OF  PHYSICIANS 
AND   SURGEONS 


Reference  Library 

Given  by 


A  MANUAL 


PRACTICAL  JIYCIENI'^ 


STUDENTS,  PHYSICIANS,  AND  HEALTH  OmCERS. 


BY 


CHARLES   HARRINGTON,   M.D., 

Late  Professor  of  Hygiene  in  the  Medical  School  of  Harvard  University. 


FOURTH  EDITION,  REVISED  AND  ENLARGED. 


BY 

MARK   WYMAN   RICHARDSON,   M.D., 

Secretary  to  the  State  Board  of  Health  of  Massachusetts. 


ILLUSTRATED  WITH  TWELVE   PLATES  IN  COLORS  AND  MONOCHROME, 
AND  ONE  HUNDRED  AND  TWENTY-FOUR  ENGRAVINGS. 


LEA  &  FEBIGER, 

PHILADELPHIA   AND   XEW   YORK. 
1911. 


Entered  uccordiiig  to  Act  of  Cougress,  in  the  year  1911,  by 

LEA   &   FEBIGEK, 

In  the  Office  of  the  Librarian  of  Congress.    All  rights  reserved. 


WtSTCOTT    fc    THOMSON, 
CLCCTROTYPERS,    PHILAOA. 


WILLIAM    J.    DORNAN, 
PRINTER,   PHILAOA. 


PREFACE  TO  THE  FOURTH  EDITION. 


Prior  to  his  doparturc  for  Kn<ijl;in(l  in  1908,  where  he  difd  un- 
expectedly, Dr.  Karri n_<>t()ii  had  boon  preparinfj^  for  a  revision  oi"  his 
Hygiene,  the  demand  for  which  he  foresaw.  He  had  tlieu  largely 
completed  the  chapters  on  Milk  and  Disinfection.  His  manuscript, 
as  well  as  the  remainder  of  the  volume,  have  been  brought  to  date  by 
the  present  writer.  Dr.  Harrington's  work  had  won  its  way  to  an 
enviable  position  in  the  literature  of  one  of  the  most  important 
branches  of  human  knowledge.  No  eifort  has  been  spared  to  main- 
tain its  usefulness  as  an  authoritative  guide  for  all  classes  of  readers 
interested  in  hygiene  and  sanitation. 

It  is  a  pleasure  to  the  writer  to  extend  his  thanks  to  those  who 
have  been  of  service  to  him  in  getting  out  this  new  edition,  and 
especially  to  Mr.  H.  W.  Clark,  chemist  in  charge  at  the  Lawrence 
Experiment  Station,  for  his  assistance  in  revising  the  section  on 
Sewage  Disposal. 

M.  ^y.  R. 

144  State  Hoxise,  Boston, 
1911. 


Digitized  by  the  Internet  Archive 

in  2010  with  funding  from 

Open  Knowledge  Commons 


http://www.archive.org/details/manualofpractica1911harr 


CONTENTS. 


CHAPTER  I. 

FOODS 17 

SkCTION    1.    GlCNKHAL    CONSIDERATIONS 17 

The  nutritive  value  of  food.s,  17.  Amount  of  food  necessary,  18.  Com- 
position of  foods,  1*.).  Protciids,  19.  J'ats,  22.  Carbohydrates,  22. 
Organic  acids,  24.     Inorganic  salts,  24. 

Section  2.  Animal  Foods:    Meats,  Fish,  Eggs,  and  Meat  Products 24 

Meats,  25.  Digestibility,  2.5.  Flavor,  25.  Texture,  26.  Effects  of 
cooking,  26.  Characteristics  of  good  meat,  27.  Comparative  digesti- 
bility of  meats,  28.  Composition  of  meats,  28.  Beef,  29.  Pork,  .30. 
Veal,  31.  Mutton,  31.  Lamb,  31.  Poultry,  32.  Horse  meat,  32. 
Meat  preparations,  33.  Sausages,  33.  Fish,  35.  Digestibility,  36. 
Keeping  qualities,  36.  Composition,  38.  Meat  and  fish  and  parasitic  dis- 
eases, 38.  Transmission  of  disease  by  meat,  fish,  and  vegetables,  44. 
Tuberculosis,  46.  Relation  between  human  and  bovine  tuberculosis,  50. 
Typhoid  fever  and  cholera,  58.  Poisoning  by  meat  and  fish,  64.  Due  to 
substances  normally  present  in  the  living  organism,  64.  Due  to  bacterial 
products  in  meats  and  fish,  65.  Signs  pointing  to  an  epidemic,  68.  Onset 
and  course  of  symptoms,  68.  Nature  symptoms,  69.  Post-mortem 
appearances,  69.  Character  of  meats  which  cause  poisoning,  70.  Cases 
illustrative  of  poisoning  by  fish  and  meat,  72.  Poisoning  by  mussels,  72. 
Poisoning  by  herrings,  73.  Poisoning  by  salmon,  74.  Poisoning  by  pike, 
75.  Poisoning  by  oysters,  75.  Poisoning  by  veal,  76.  Poisoning  by  pork, 
78.  Poisoning  by  beef,  84.  Poisoning  bj^  horse  meat,  86.  Poisoning  by 
sausages,  87.  Poisoning  by  kid  meat,  89.  Meat  inspection  and  slaughter- 
ing, 89.     Eggs,  91.     Lard,  94.     United  States  standards,  94. 

Section  3.     Milk  and  Milk  Products 95 

United  States  standard,  95.  Composition  of  milk,  96.  Fat,  97.  Milk- 
sugar,  98.  Proteids,  99.  Mineral  matter,  99.  Specific  gravity  of  milk, 
99.  Reaction,  99.  Appearance,  99.  Taste,  100.  Koumiss  and  kefir, 
101.  Colostrum,  102.  Consistence  of  milk,  102.  Fennents  of  milk,  103. 
Trypsin  or  galactose,  104.  Pepsin,  104.  Diastase  or  amj-lase,  104. 
Lipase,  104.  Salol-splitting  ferment,  105.  Oxj-dases,  105.  Reductases, 
105.  Bacteria  in  milk,  105.  Lactic  ferments,  106.  Peptonizing  ferments, 
107.  ButjTic  ferments,  107.  Number  of  bacteria  in  milk,  107.  Preserva- 
tion of  milk,  114.  Cold,  114.  Heat,  pasteurization,  and  steriUzation,  114. 
Objections  to  heat,   115.     Chemicals,   118.     Boric  acid  and  borax,   118. 

7 


8  CONTENTS. 

PAGE 

Formaldehyde,  US.  Adulteration  of  milk,  122.  Cream,  12-4.  United 
States  standard,  124.  Condensed  milk,  124.  Milk  as  a  factor  in  the 
spread  of  disease,  125.  Poisonous  milk,  125.  Milk  from  diseased  cows,  127. 
Milk  contaminated  from  without  with  organisms  related  to  human  diseases, 
136,  Analysis  of  milk,  14G.  Determination  of  specific  gravity,  147. 
Determination  of  fat,  14S.  Determination  of  total  solids,  151.  Determina- 
tion of  milk-sugar,  152.  Determination  of  ash,  153.  Determination  of 
proteids,  153.  Detection  of  added  water,  154.  Coloring  matters,  158. 
Detection  of  preservatives,  160.  Methods  of  distinguishing  between  raw 
and  cooked  milk,  162.  Detection  of  gelatin  in  cream,  163.  Detection 
of  sucrate  of  lime  in  cream,  164.  Butter,  164.  United  States  standard, 
164.  Butter  as  a  carrier  of  disease,  167.  Analysis  of  butter,  169.  Deter- 
mination of  the  nature  of  the  fat,  169.  Cheese,  173.  Composition,  175. 
Adulteration  of  cheese,  175.  Analysis  of  cheese,  176.  Cheese  as  a  cause  of 
poisoning,  175. 

Section  4.     Vegetable  Foods 177 

Farinaceous  seeds,  178.  Cereals,  178.  Wheat,  178.  Composition  of 
wheat,  179.  Wheat  flour,  179.  Preparations  of  wheat  flour,  180.  Bread, 
180.  Composition  of  wheat  bread,  183.  Adulteration  of  flour,  184. 
Bleaching  of  flour,  185.  Rye,  185.  Barley,  186.  Oats,  186.  Corn,  187. 
Rice,  189.  Buckwheat,  189.  Legumes,  190.  Peas,  191.  Beans,  191. 
Lentils,  192.  Farinaceous  preparations,  193.  Sago,  193.  Tapioca,  193. 
Arrowroot,  193.  Fatty  seeds,  193.  Almonds,  194.  Cocoanuts,  194. 
Wahiuts,  194.  Peanuts,  194.  Chestnuts,  194.  Vegetable  fats,  195.  Olive 
oil,  195.  United  States  standard,  195.  Cotton-seed  oil,  196.  Tubers 
and  roots,  196.  Potatoes,  196.  Sweet  potatoes,  199.  Artichokes,  199. 
Roots,  199.     Herbaceous  articles,  200.    Fruit,  products  used  as  vegetables, 

201.  Fruits,   201.     Apples,   201.     Pears,   202.     Peaches,   202.     Apricots, 

202.  Plums,  202.     Cherries,  202.     Oranges,  202.     Grapes,  203.     Melons, 

203.  Bananas,  204.  Figs,  204.  Berries,  204.  Edible  fungi,  205. 
Mushrooms,  205.  Saccharine  preparations,  206.  Cane-sugar,  205.  Maple 
sugar,  206.  Glucose,  dextrose,  206.  Molasses,  207.  Honey,  208.  Con- 
fectionery, 209.     Jellies  and  jam,  210. 

Section  5.     Beverages 210 

Stimulant  beverages  containing  alkaloids,  210.  Tea,  210.  Adulteration 
of  tea,  212.  Coffee,  213.  Cocoa,  215.  Milk  chocolate,  217.  Fermented 
alcoholic  beverages,  217.  Beer,  217.  Process  of  manufacture  of  beer,  219. 
Substitutes  for  barley  malt,  220.  Substitutes  for  hops,  221.  Physical 
properties  and  chemical  composition  of  beer,  222.  Adulteration  of  beer, 
222.  Analysis  of  beer,  223.  Determination  of  beer,  223.  Table  showing 
percentage  of  alcohol  by  weight  and  by  volume,  224.  Analysis  of  beer,  229. 
Determination  of  methyl  alcohol,  229.  Determination  of  extract,  232. 
Detection  of  preservatives,  233.  Salicylic  acid,  233.  Fluorides,  233. 
Method  of  Hefelmann  and  Mann,  233.  Brand's  method,  233.  Other 
determinations,  233.  Total  acidity,  233.  Fixed  and  volatile  acidity,  233. 
Ash,  234.  Wines,  234.  Classification  of  wines,  235.  Composition  of 
wines,  236.  Adulteration  of  wines,  236.  Analysis  of  wines,  238.  Deter- 
mination of  alcohol,  238.  Detection  of  coal-tar  colors,  239.  Detection 
of  preservatives,  salicylic  acid,  240.  Formaldehyde,  240.  Sulphites,  240. 
Cider,  240.  Perry,  241.  Distilled  alcoholic  beverages,  241.  Brandy,  242. 
Whiskey,  243.     Rum,  245.     Gin,  245.     Liqueurs,  245. 


(JON'VI'lN'l'H.  9 

FAOa 

SkOTION    0.       CfJNDIMKNTH,    Rf'KJEH,    AND    HaKKKh'    i\\\VM\V,K\M 246 

Vincf^iir,  24('».  (Jidcr  viiicwir,  247.  IJiiilcd  Hl.uicH  Hlandiinl,  247.  Wiru; 
virioKar,  247.  Mult,  vific^^ar,  247.  Siif^ar  v'mcKur,  247.  CJIiif,oH<;  vinc«itr, 
248.  MoluHH(!H  viruiKur,  248.  AdulUTiUionH  of  \\\\v.v^,i.v,  248.  Kxamina- 
tion  of  vitionar,  248.  Acidii.y,  248.  Lcmon-juicfi  and  litnf-juicc;,  249. 
Adulteration,  249.  Salt,  249.  MuHturd,  2.'')().  I'cfjpcjr,  250.  Clov<«,  2r,0. 
Cinnamon  and  casHia,  251.  AllHpicc,  niii^cr,  nutmeg,  mace,  Cayenne 
pc!i)|)('r,  251.     Hiikiiiff  powd(!rH,  252. 

Section  7.     Food  Putoservation 253 

Cold,  254.  Drying,  254.  Salting,  2.54.  Smoking,  254.  Canning,  2.54. 
Chemical  treatment,  250.  Horie  aeid  and  borax,  2.58.  Salieylie  aeid,  261. 
Sulphites,  2()2.  I<\)rnia,ld(hyde,  202.  Hydrogen  peroxide,  20.'i.  Sodium 
fluoride,  204.     Sodium  biearhonate,  264. 

Section  8.     Contamination  of  Foodh  by  Metals 264 

Copper,  264.  Lead,  266.  Zinc,  267.  Nickel,  267.  Tin,  267.  Metallic 
Contamination  from  kitchen  utensils,  267. 


CHAPTER  II. 

AIR 269 

Oxygen,  269.  Nitrogen,  271.  Argon,  272.  Hydrogen,  272.  Carbon 
dioxide,  272.  Ozone,  274.  Ammonia,  275.  Nitrogen  acids,  275.  Aqueous 
vapor,  276.  Dust  and  micro-organisms,  278.  Carbon  monoxide,  etc.,  280. 
"Sewer  gas,"  282.  Organic  matters,  286.  Effects  of  vitiated  air,  286. 
The  air  as  a  carrier  of  infection,  290.  Influence  of  fog,  297.  Examination  of 
air,  297.  Determination  of  aqueous  vapor,  298.  Direct  determination 
of  moisture  by  weighing,  298.  Determination  of  relative  humidity  by 
the  wet  and  dry  thermometer  bulbs,  299.  Glashier's  table,  300.  Table  of 
tensions,  301.  Determination  of  carbon  dioxide,  303.  Solutions  required, 
303.  Process  of  analysis,  304.  Corrections,  307.  Example  of  method  of 
reckoning  CO,  309.  Determination  of  CO  by  Wolpert's  method,  309. 
Determination  by  Fitz's  method,  310.  Determination  of  carbon  monoxide, 
311.  Determination  of  ozone,  312.  Determination  of  dust,  313.  Bacte- 
riological examination,  314. 

CHAPTER  III. 

THE  SOIL 316 

Constituents  of  the  soil,  318.  Physical  properties  of  soils,  319.  Per- 
meability of  soils,  320.  Capacity  for  water  and  water-retaining  capacity, 
324.  Soil  temperature,  326.  Changes  in  the  character  of  soils  due  to 
chemical  and  biological  agencies,  32S.  Soil-air,  329.  Soil  water,  332. 
Sources  of  soil-water,  335.  Loss  of  moisture  by  evaporation,  335.  In- 
fluence of  vegetation  on  soil  moisture,  336.  Other  effect  of  vegetation 
upon  the  soil,  337.  Pollution  of  the  soil,  338.  Bacteria  of  the  soil, 
340.  Soil  and  disease,  342.  Soil  dampness  and  disease  in  general,  342. 
Soil  and  pulmonary  tuberculosis,  343.  Typhoid  fever,  343.  Cholera,  346. 
Bubonic  plague,  346.     Diphtheria,  347.     Malaria,  348.     Yellow  fever,  348. 


1 0  CONTE^'TS. 

PAGE 

Tetanus  and  malignant  edema,  348.  Anthrax,  349.  Uncinariasis,  350. 
Goitre,  353.  Epidemic  diarrhea,  354.  Examination  of  soils,  354.  Per- 
meability to  air,  356.  Permeability  to  water,  357.  Water  capacity,  359. 
Capillarity,  359.  Moisture,  359.  Organic  and  volatile  matters,  360. 
Determination  of  CO  in  soil-air,  360.  Bacteriological  examination  of  soil, 
362. 

CHAPTER  IV. 

WATER 364 

Rain,  363.  Surface  waters,  364.  Ground-waters,  365.  Phj'sical  and 
chemical  characteristics  of  water,  367.  Appearance,  368.  Reaction,  369. 
Odor,  369.  Taste,  371.  Substances  found  normally  in  water,  371.  Gases, 
371.  Carbon  dioxide,  372.  Organic  matter,  372.  Albuminoid  ammonia, 
375.  Nitrates  and  nitrites,  375.  Mineral  matters,  377.  Hardness,  378. 
Bacteria  in  water,  379.  Water  supplies,  382.  Stored  rain,  382.  Surface 
waters,  384.  Ground-waters,  385.  Driven  wells,  387.  Bored  wells,  388. 
Drainage  area  of  wells,  391.  Pollution  of  wells,  391.  Filter  galleries,  393. 
Classification  of  waters  from  the  sanitary  standpoint,  394.  Purification 
of  water,  396.  Oxidation,  396.  Dilution,  397.  Sedimentation,  397. 
Bacterial  action,  397.  Vegetation,  397.  Methods  of  purification,  398. 
Boihng  and  distillation,  404.  Filtration,  404.  Domestic  filters,  404. 
Filtration  of  public  supplies,  406.  Mechanical  filtration,  412.  Destruc- 
tion of  Algae,  412.  Removal  of  hardness,  413.  Removal  of  iron,  414. 
Action  of  water  on  lead  and  other  metals,  414.  Action  on  iron,  418. 
Action  on  zinc,  418.  Action  on  tin,  419.  Water  and  disease,  420.  Dis- 
orders connected  with  mineral  matter,  421.  Disorders  connected  with  or- 
ganic pollution,  423.  Typhoid  infection  of  water  supplies,  425.  Influence 
of  introduction  of  public  water  supplies  on  typhoid  rates,  426.  Examples 
of  typhoid-fever  epidemics  and  of  limited  outbreaks  traced  to  infected 
water,  429.  Epidemic  at  Lausanne,  Switzerland,  429.  The  Plymouth,  Pa., 
epidemic,  430.  Outbreak  at  Uvemet,  431.  Epidemic  at  Ashland,  Wis- 
consin, 431.  Epidemic  at  Luneberg,  432.  Epidemic  at  Zehdenick,  433, 
etc.  Asiatic  cholera,  436.  The  propagation  of  cholera  in  India,  438. 
Parasites  and  drinking-water,  438.  Parasites  and  drinking-water,  441. 
Ice,  443.  Chemical  examination  of  water,  444.  Collection  of  samples, 
444.  Determination  of  free  ammonia  and  albuminoid  ammonia,  445. 
Solutions  required,  445.  Apparatus  required,  446.  Nesslerizing  tubes, 
447.  Determination,  447.  Precautions,  448.  Permanent  ammonia, 
standards,  449.  Determination  of  other  nitrogen  compounds,  4,50.  Deter- 
mination of  nitrogen  as  nitrates,  450.  Permanent  nitrate  standards,  451. 
Determination  of  nitrogen  as  nitrates,  451.  Determination  of  chlorine, 
4.52.  Determination  of  residue,  453.  Determination  of  hardness,  453. 
Solutions  required,  453.  Determination  of  "oxygen  required,"  454. 
Solutions  required,  454.  Determination  of  color,  455.  Determination  of 
odor,  455.  Determination  of  reaction,  455.  Determination  of  turbidity, 
456.  Detection  and  determination  of  lead,  456.  Detection  of  zinc,  458. 
Detection  of  tin,  459.  Detection  and  determination  of  iron,  459.  Infer- 
ences as  to  character  of  water  from  the  results  of  sanitary  chemical  analysis, 
459.  Bacteriological  examination  of  water,  462.  Collection  of  samples, 
463.  Planting  the  samples,  463.  Quantitative  determination,  464.  Quali- 
tative determination,  465.  Comparative  value  of  chemical  and  bacte- 
riological analysis  of  drhikmg-water,  467. 


CONTh'N'/'S.  11 

PAOB 

TIAIUTA^IMONS,  SCHOOLS,   I'l'IXJ 470 

SiO(!'i'i()N   I.     (j!knioiiai,  (  !()Nsii)KI{ath)Nh 470 

Ah|)(!(!I,,  470.  (lon.sl.nuil.iori  nrul  !irrririK(!rri(!n(,,  470.  (Inn-  of  liabitationH, 
471.  S(!1k)()Im,  471.  SrIiodI  IHr  nil  luc,  472.  CliuirH,  47'2.  DcKkH,  472. 
IJIackhoiinlH,  47;{. 

Hioc'i'ioN  2.     Vi'iNTrfiATioN   ANr)   IIkatino 473 

Aiiiounl,  of  splice  required  for  noml  ventilation,  47r).  Natural  forc-oH  in 
V(Mitiliiiioii,  47().  DilTusion  ;i.ii(l  fi;r;i,vily,  470.  perflation  and  aHpiration, 
47i).  Natural  veiH  iliil Ktii,  4Sl.  iiilet.s  and  oulIetH,  4H2.  Mwlianical 
V(Miiilati()n,  4S.^).  Artidtnal  lieatJng  in  its  relation  to  ventilation,  4H.'i. 
Radiation,  4S().  Conduction,  4.S(3.  Convection,  480.  Method.s  of  wann- 
ing, 487.  ()|)en  fires,  487.  Stoves,  487.  Furnaee^s,  489.  Hot-water 
pijjcs,  48'.).  Steam  pipes,  489.  llegulation  of  temperature,  490.  Nccf*- 
sity  of  providing  moisture,  491.  Filtration  of  air,  493.  Determination  of 
rates  of  ventilation,  493. 

Section  3.     LicniTiNfi 495 

Natural  lighting,  495.  Artificial  lighting,  497.  Luminosity  of  flame,  497. 
Gas  burners,  498.  Varieties  of  illuminating  gas,  499.  Coal  gas,  499. 
Water-gas,  499.  Acetylene  gas,  500.  Impurities  given  off  in  lighting,  .501. 
Gas  pipes,  501.     Fixtures,  502.     Electric  lighting,  502. 

Section  4.     Plumbing 502 

The  soil-pipe  and  main  drains,  504.  Waste  pipes,  509.  Traps,  510.  Ix)ss 
of  seal,  516.  Non-siphoning  traps,  518.  Water-closets,  520.  The  pan 
closet,  523.  The  plunger  or  plug  closet,  524.  Hopper  closet,  525.  Open 
wash-out  closets,  525.  Siphon  closets,  526.  Flushing  apparatus,  528. 
Water-closet  connections,  529.  Urinals,  530.  Wash-basins,  530.  Bath- 
tubs, 532.  Sinks,  534.  House-maids'  sinks,  535.  Laundry  tubs,  535. 
House  service  tanks,  535.     Service  pipes,  536.     Testing  plumbing,  537. 

CHAPTER  VI. 

DISPOSAL  OF  SEWAGE 538 

Methods  of  sewage  disposal,  540.  Discharge  into  the  sea,  541.  The  pail 
system,  541.  Sedimentation  and  chemical  precipitation,  542.  Sewage 
irrigation,  544.  Influence  of  sewage  irrigation  on  health,  545.  The 
Waring  system  of  irrigation,  547.  Sewage  filtration,  548.  Contact  filtra- 
tion, 550.  Trickling  filters,  551.  The  Cameron  septic  tank,  554.  Septic 
tanks  for  the  digestion  of  sludge  only,  554. 

CHAPTER  VH. 
DISPOSAL  OF  GARBAGE 556 

Reduction,  559. 

CHAPTER   Vni. 

DISINFECTANTS  AND  DISINFECTION 560 

Pliysical  agents,  560.  Light,  560.  Heat,  563.  Steam.  565.  BoiUng 
water,   568.     Cold,   569.     Chemical  agents,   571.     Non-metallic  elements 


12  CONTE^'TS. 

PAGE 

and  their  compounds,  572.  Oxygen,  572.  Ozone,  573.  Hydrogen  per- 
oxide, 574.  Chlorine,  574.  "Chloride  of  lime,"  bleaching  powder,  chlorin- 
ated lime,  575.  Sodium  hypochlorite  solution,  577.  Hypochlorous  acid, 
577.  Iodine,  577.  Bromine,  577.  Sulphur  dioxide,  577.  Sodium  car- 
bonate, 579.  Sodium  carbonate  or  washing-soda,  579.  Lime,  quicklime, 
5S0.  MctaUic  salts,  581.  Ferrous  sulphate,  581.  Ferric  sulphate,  581. 
Ferric  chloride,  581.  Zinc  chloride,  581.  Aluminum  chloride,  581.  Potas- 
sium permanganate,  582.  Copper  sulphate,  582.  Mercuric  chloride  or  cor- 
rosive sublimate,  582.  Mercuric  cyanide,  584.  Sublamin,  584.  Silver 
compounds,  584.  Sodium  aurate,  585.  Mineral  acids,  585.  Carbolic  acid 
and  cresol  preparations,  586.  Cresols,  587.  Liquor  crcsolis  compositus, 
588.  Creohn,  589.  Lysol,  589.  Bacillol,  590.  Saprol,  590.  Solveol, 
590.  Sulfonaphthol,  590.  Alcohol,  591.  Essential  oils,  593.  Soaps,  594. 
Medicated  soaps,  596.  Lj'soform,  598.  Paralysol,  598.  Metakaline,  598. 
Formaldehj'de,  598.  Methods  of  use  and  apparatus,  599.  Germicidal 
properties,  606.  Conditions  favoring  action,  607.  Toxicity,  607.  Amount 
necessary  for  room  disinfection,  608.  Disadvantages,  60S.  Technic  of 
room  disinfection,  609.  Other  apphcations  of  formaldehyde,  609.  Pre- 
vention of  dissemination  of  infectious  material;  practical  disinfection,  609. 
Disinfection  of  feces,  610.  Urine,  610.  Sputum,  611.  Discharges  from 
mouth,  etc.,  611.  Eating  utensils,  etc.,  611.  Bed-linen  and  clothing,  611. 
Hands,  611.  Air,  612.  Room  disinfection,  612.  Disinfection  of  books, 
616.     Disinfection  of  water-closets,  616. 

CHAPTER  IX. 

MILITARY  HYGIENE 617 

The  recruit,  619.  Examination  of  the  recruit,  625.  Chest  capacity,  626. 
Grounds  for  rejection,  626.  The  hygiene  of  the  soldier,  627.  Personal 
cleanliness,  627.  Contentment  and  cheerfulness,  627.  Clothing  of  the 
soldier,  628.  Wool,  628.  Cotton  and  linen,  628.  Shoddy,  629.  Color, 
629.  Military  dress  coats,  629.  Trousers,  629.  Gaiters  and  leggings, 
629.  Head  covering,  630.  Stockings,  630.  Boots,  630.  Underclothing, 
631.  Abdominal  bands,  632.  Water-proof  blankets,  632.  The  soldier's 
exercise  and  work,  633.  Marching,  633.  Care  of  the  feet  on  the  march, 
638.  Care  of  other  parts,  639.  The  soldier's  food:  "rations,"  639.  Garri- 
son ration,  640.  Field  ration,  641.  Travel  ration,  641.  Alcohol  in  the 
ration,  643.  Preparation  of  food,  644.  Is  the  United  States  ration  suited 
to  the  tropics?  645.  Posts  and  camps,  649.  Sites,  651.  Barracks,  652. 
Tents,  653.  Huts,  656.  Sewerage,  657.  Sinks  and  latrines,  658.  In- 
spections, 659.  Sanitary  police,  660.  The  diseases  of  the  soldier,  665. 
Typhoid  fever,  667.  Dysentery,  malaria,  668.  Measles,  669.  Diarrheal 
diseases  in  general,  669.     Sunstroke,  669.     Venereal  diseases,  670. 

CHAPTER  X. 

NAVAL  AND  MARINE  HYGIENE 671 

Naval  recruits,  671.  The  naval  ration,  672.  Water  supply,  675.  The 
sailor's  sleeping  quarters,  676.  The  diseases  of  sailors,  677.  Ventilation 
of  vessels,  677.     General  hygiene  of  ships,  679. 

CHAPTER  XI. 

TROPICAL  HYGIENE 681 

The  soldier  and  the  civilian  in  the  tropics,  681.     Residence,  683.     Habitg 


aON'I'HM'S.  13 

CAOB 

of  lifo,  (583.  Tfic!  UH(!  of  .-ihioliol  in  Ui<;  (,roi)if;H,  OSo.  ("lothirij,?,  0H7.  ('un; 
of  the  pcrHon,  GS8.     'IVopical  (liH(!iwcH,  (JHS. 

(JIIAPTKK    XII. 

THE  RELATION  Ol''  INSI'XnS  TO  HUMAN   DISEASES 091 

FIi(!H,  m\.  MciiH,  (■.04.  iicdhiijrH,  (ior,.  Ar:i(;lini(lH,  (iOC.  TirkH,  (JOfi. 
liody  l()iiH(!,  (\S){).  ]VIoH(|uit.o(;H,  ()'.)().  Mfwfiiiit.ocs  aii'l  inaljiria,  (»07.  Tlir; 
lualari.'il  parani(.(^,  700.  I'lcvcuitivc.  rnnaHiiroH,  700.  .MoHfiuitocH  and  y»"llow 
fcvor,  707.  Tlu^  yellow  fcvor  iiioHqui(,o,  709.  I'rfivciitivf  rnc-iwurcH,  711. 
Mosquitocvs  and  filarial  discu.S(;,  712.     MoH(jui(,o(;H  and  dengue,  714. 

CHAPTER  XIII. 

hy(J11':n!o  of  occupation 716 

Classifioal.ion  of  occupations,  721.     Occupations  involving  exposure  to  air 

vitiated  by  rcspiratjon,  72:5.  ()o(!Miiations  involviii^  exposure  1o  irritating 
and  poisonous  f^ases  and  fumes,  72)5.  IrritaliuK  ^\VH^'H  and  fumes,  724. 
Poisonous  frases  and  fumes,  72.^).  Occupation  involving  exposure  to  jKji.son- 
ous  and  irritating  dusts,  729.  Poisonous  dusts,  720.  Irritating  dusts,  7;i2. 
Occupations  involving  exposure  to  infective  matter  in  dust,  735.  Occupa- 
tions involving  tiie  inhalation  of  ofTcsnsive  gases  and  vapors,  73G.  (Jccufia- 
tions  involving  exposure  to  extreme  of  heat,  737.  Occupations  involving 
exposure  to  dampness,  737.  Occupations  involving  exposure  to  abnormal 
atmospheric  pressure,   737.     0(H',upations  involving  constrained  attitufle, 

738.  Occupations  involving  sedentary  life,  730.     Prophylaxis  in  general, 

739.  Employment  of  women  and  children,  740. 

CHAPTER  XIV. 

VITAL  STATISTICS 742 

The  census,  743.  Estimated  population,  745.  Increase  of  population,  746. 
Population  constitution,  746.  Registrar's  returns,  747.  Marriage  rates, 
748.  Birth-rates,  749.  Death-rates,  751.  Influence  of  sex,  751.  In- 
fluence of  age,  751.  Influence  of  race,  752.  Other  influences,  753.  In- 
fluence of  density,  753.  Weekly  death-rates,  etc.,  754.  Z.\Tnotic  death- 
rate,  754.  Infantile  death-rate,  754.  Death-rates  of  children,  756. 
High  and  low  death-rates,  756.  Correction  of  death-rate,  757.  Classifica- 
tion of  cause  of  death,  758.  Registration  of  sickness,  7.58.  Duration  of 
life,  759.  Probable  duration  of  life,  759.  Mean  duration  of  life,  759. 
Expectation  of  life,  or  mean  after-life-time,  760.     Life  tables,  760. 

CHAPTER  XV. 
PERSONAL  HYGIENE 762 

Section  1.     C.\re  of  the  Person 762 

Section  2.     Regitlation  of  the  Diet 764 

Section  3.     Rest  and  Recreation 764 

Section  4.     Physical  Exercise 765 

Effects  of  active  exercise,  765.  Circulation  and  respiration.  765.  Skin, 
766.  Nervous  system,  766.  Digestive  apparatus,  767.  Ividnej-s,  767. 
Effect  of  exercise  on  weight,  767.  Amount  of  exercise  required.  768.  I\ind 
of  e.xercise,  769.  Golf,  769.  Wheeling,  770.  Tennis,  etc.,  770.  Rowing, 
770. 


14  CONTENTS. 

PAGE 

Section  o.     Clothing 770 

Color,  770.  Texture,  770.  Hoat  comluctivity,  771.  Hygroscopicity,  771. 
Materials,  771.  ^^'ool,  772.  Silk,  773.  Cotton,  774.  Linen,  775. 
Rubber,  leather,  77G.  Fur,  776.  Felt,  776.  Adulteration  of  clothing, 
776.  .  Chemical  analysis,  777.  Microscopical  exaniination,  777.  Poisonous 
dyes,  777.  .  Selection  of  clothing,  778. 

CHAPTER  XVI. 

INFECTION,  SUSCEPTIBILITY,  IMMUNITY 780 

Exciting  causes  of  disease,  780.  Channels  of  infection,  780.  Infection  and 
contagion,  781.  Suscoiitibility,  781.  Ehrlich's  theory,  783.  Toxins  and 
antitoxins,  783.  Bacteriolysis,  788.  Hemolysis,  789.  Complements,  793. 
Immune  bodies,  795.  Agglutinins,  796.  Wassermann's  reaction  for 
syphilis,  800.  Metschnikoff's  theory,  801.  Opsonins,  802.  Practical 
applications  of  the  results  of  studies  in  immunity,  802.  Diphtheria,  804. 
Tetanus,  805.  Hay-fever,  805.  Dysentery,  806.  Typhoid  fever,  807. 
Asiatic  cholera,  808.  Bubonic  plague,  809.  Antistreptococcus  serums, 
811.     Tuberculosis,  811.     Cerebrospinal  meningitis,  812. 

CHAPTER  XVn. 
VACCINATION  AND  SMALLPOX 814 

CHAPTER  XVIII. 

QUARANTINE 820 

Quarantine  law  of  1893,  822.  Interstate  quarantine,  826.  State  quaran- 
tine, 826.  Sanitary  cordon,  828.  Municipal  quarantine,  828.  Camps 
of  detention,  829. 

CHAPTER  XIX. 

DISPOSAL  OF  THE  DEAD 830 

Earth  burial,  830.  Sites  for  cemeteries,  832.  Cremation,  832.  History 
of  modem  cremation,  834. 


PRACITICJAL  HYGIENE. 


C  11  APT  Eli   I. 

FOODS. 

Section  1.     GENERAL   CONSIDERATIONS. 

Foods  may  be  said  to  include  everything  taiven  into  the  system 
capable  of  being  utilized  directly  or  indirectly  to  build  up  normal 
structure,  repair  waste,  or  produce  energy  in  any  form,  but  in  the 
common  ac(teptatiou  of  the  term  they  include  only  those  substances 
which  can  be  oxidized  in  the  system,  thus  excluding  water  and  air, 
without  which  the  functions  of  the  body  can  not  be  performed.  Diet 
is  a  mixture  of  food  materials  of  various  kinds  habitually  taken  in  such 
quantity  as  is  needed  to  maintain  or  improve  the  condition  of  the  system. 

The  Nutritive  Value  of  Foods. 

The  potential  energy  of  food  is  measured  by  the  amount  of  heat 
which  can  be  obtained  by  its  complete  combustion,  and  is  expressed  in 
units  of  heat  or  calories.  The  amount  of  energy  required  to  raise  the 
temperature  of  1  kilogram  of  water  1°  C.  is  known  as  a  large  calorie; 
that  required  to  raise  the  temperature  of  1  gram  to  the  same  extent 
is  laiown  as  a  small  calorie;  thus,  1  large  calorie  equals  1000  small 
calories.  When  the  term  is  used  without  qualification,  large  calories 
are  understood.  These  heat  units  correspond  to  425.5  units  of  work  ; 
that  is  to  say,  the  same  amount  of  energy  required  to  raise  the  tempera- 
ture of  the  given  weight  of  water  1°  C.  is  sui!icient  to  raise  425.5 
times  the  weight  one  meter.  The  amount  of  work  done  is  expressed 
in  kilogram-meters. 

The  heat  unit  of  the  English  system  is  the  amount  of  energy  required 
to  raise  the  temperature  of  a  pound  of  water  1°  F.,  and  its  mechanical 
equivalent  is  772  imits  of  work  ;  that  is  to  say,  the  Siime  amount  of 
energy  will  raise  772  pounds  one  foot.  According  to  the  English 
method,  work  done  is  expressed  in  foot  tons  rather  than  in  foot 
pounds. 

The  calorimetric  values  of  different  food  materials  express  also  their 

2  17 


18  FOODS. 

physiological  values  as  nutriment.     Rubner*   determined    the  calori- 
metric  value  of  the  proximate  principles  as  follows  : 

One  gram  of  proteids  ^=  4.1  calories. 

One  gram  of  carbohydrates  =  4.1       " 
One  gram  of  fat  =  9.3       " 

In  the  system,  the  carbohydrates  and  fats  are  burned  completely  to 
carbonic  acid  and  water,  but  the  proteids  leave  a  residue  of  urea  incapa- 
ble of  still  further  oxidation.  It  is  estimated  that  the  ])iiysiological 
value  of  the  proteids  averages  only  about  75  per  cent,  of  their  calori- 
metric  value. 

The  calorimetric  value  of  different  foods  of  the  several  classes  is 
not  to  be  understood  as  bemg  exactly  the  same.  Thus,  two  kinds  of 
sugar  or  two  kinds  of  fat,  or  two  kmds  of  proteid  have  not  exactly  the 
same  calorimetric  values,  and  the  figures  above  given  are  to  be  under- 
stood only  as  fair  averages.  Rubner^  has  determined  by  actual  ex- 
perimentation the  relative  calorimetric  values  of  certain  food  materials, 
and  has  shown  that  100  grams  of  fat  are  equivalent  to  225  of  syntonin, 
or  232  of  starch,  or  234  of  cane  sugar,  or  243  of  muscle  fiber,  or  256  of 
grape  sugar.  In  other  words,  these  several  amounts  of  food  material  are 
isodynamic. 

Amount  of  Food  Necessary. 

For  the  maintenance  of  a  proper  degree  of  health  and  strength,  the 
individual  must  ingest  an  amount  of  food  sufficient  to  meet  the  daily 
loss  of  nitrogen  and  carbon.  This  must  necessarily  vary  according  to 
circumstances,  and  hence  no  rule  can  be  laid  down  to  fit  all  cases.  The 
best  that  can  be  done  is  to  make  certain  general  rules  based  on  the 
amount  of  Avork  performed,  for  the  greater  the  amount  of  work  done, 
the  greater  the  amount  of  food  required  to  meet  the  necessary  consump- 
tion of  fuel  and  to  repair  the  tissues.  When  performing  heavy  labor, 
the  naturally  increased  desire  for  food  is  shown  j)articularly  in  the 
direction  of  fats,  and  secondarily  of  proteids. 

For  many  years  Voit's  esthnate,  that  a  man  of  154  to  165  pounds, 
working  at  moderately  hard  labor  9  or  10  hours  a  day,  requires  118 
grams  of  proteid,  56  of  fat,  and  500  of  carbohydrates,  the  whole  yield- 
ing 3054.6  calories,  has  been  generally  accepted  as  correct.  Recently, 
however,  Chittenden^  has  demonstrated  conclusively  by  experiments 
extending  over  many  months,  the  subjects  being  men  engaged  in  intel- 
lectual pursuits,  soldiers,  and  athletes  in  training,  that  half  the  stated 
amount  of  proteids  is  ample  for  the  real  physiological  needs  of  the  body 
under  ordinary  conditions  of  life,  and  that  a  fuel  value  of  3000  cal- 
ories is  not  necessary,  the  diminution  in  the  proteid  intake  requiring  no 
additional  amount  of  non-nitrogenous  substances. 

Knowing  the  composition  of  a  given  article  of  food,  the  proteid,  fat, 
and  carbohydrate  value  of  a  given  weight  can  easily  be  determined ; 
and  thus  one  can  construct  standard  dietaries  for  the  various  conditions 

1  Lehrbuch  der  Hygiene,  Leipsic,  1900,  p.  438.  "''  Ibidem,  p.  430. 

^  Physiological  Economy  in  Nutrition,  New  York.  1904. 


COMI'OSITION   O/-'   I'OODS.  \'.) 

of"  l)iir(!  .sul>,sis(('ii(!c,  rest,  aixl  pcrronn.'iiicc  of  v.'irioiis  ;itin)iiiit-  of"  (|;iily 
labor.  IJ|>  i'O  tl"'  pi'csciil,  fimc,  it,  Iiuk  been  (Misloiniiry  lo  \)Vi-M;r\\)(t  llnj 
constituents  ol"  i\u\  ,st!iii(l;ir<l  diets  in  tlic  foliowin/i;  projiorlioiis  :  Vor 
each  part  of  protcids,  two-thirds  of  u  pai  t  of"  fiit,  i\\rvv,  and  oiic'-Hixtli 
parts  of  curholjy<l rates,  and  one-f'ourtli  of"  a  j»art  of  mineral  inatt(;r, 
tlu!  proportion  of  1  part  of  nitro^(;n  (o  15  of  carbon  bein^  inaintiiine-d 
as  nearly  as  possible.  In  vi(!\v,  however,  <»f  ("hittenden's  resnlts,  tln'so 
proportions  should  be  ehaufxed,  not  <Mdy  on  aeeoinit  of  the  f;u!t  that  an 
excess  of  proteids  is  a  bin'dcin  to  the  system,  but  also  for  e(;onomic{il 
administration,  since  tlie  nitro<2;enous  f"oods  are,  as  a  (;las.-,  by  far  the 
most  cx|)(!iisivc. 

.  In  any  dietary^  nutritive  vahu;  must  not  be  the  sole  consideration, 
for  taste  and  variety  are  highly  important  and  the  palate  must  be  flat- 
tered. 

Composition  of  Foods. 

The  constituents  of  food  materials  are  partly  organic  and  partly  in- 
organic. The  organic  constituents  include  j)roteids,  fats,  carbohy<lrates, 
and  organic  acids ;  the  inorganic  include  water  and  mineral  salts. 

Proteids. — The  proteids  are  the  most  important  constituents  of  both 
animal  and  vegetable  foods,  and  their  presence  is  necessary  for  the 
carrying  on  of  all  the  phenomena  of  life.  They  are  very  complex 
colloid  substances  composed  of  carbon,  oxygen,  liydrogcn,  nitrogen,  and 
sulphur,  possessing  common  properties  and  connected  in  very  close 
genetic  relationship.  They  are  divided  into  animal  proteids  and  vege- 
table proteids,  but  between  the  members  of  the  one  class  and  those  of 
the  other  there  are  no  important  chemical  differences,  and  they  are 
about  equal  in  nutritive  value.  Some  of  the  vegetable  proteids  are  not 
colloids,  for  according  to  Schmiedeberg,  Weyl,  Maschka,  and  others, 
they  are  found  in  crystalline  form  in  the  tissues  of  certain  plants,  and 
notably  in  the  bean,  pea,  lentil,  and  various  nuts. 

Proteids  when  completely  split  up  by  acids  yield  as  end  products 
ammonia,  nitrogen,  organic  bases,  and  amido  acids.  They  are  never 
completely  absent  from  animal  and  vegetal)le  tissues,  but  tlieir  amount 
in  different  substances  is  very  widely  variable,  some  foods  being  very 
rich  in  them,  while  in  others  they  exist  only  in  traces. 

Ingested  in  great  excess  of  the  needs  of  the  system,  thev  are  likely 
to  cause  general  disturbance,  diarrha?a  and  albuminuria,  while  a  diet 
from  which  they  are  practically  excluded  will  cause  rapid  loss  of 
strength,  aniemia,  great  prostration,  and  greatly  diminished  resistance 
to  invasion  by  specific  diseases,  especially  tuberculosis  and  pneumonia. 

The  animal  proteids  are  more  rapidly  digested  than  the  vegetable 
proteids,  some  of  which  are  largely  wasted  through  imperfect  digestion. 
The  proteids,  whatever  their  source,  yield  in  the  main  the  same  prod- 
ucts of  digestion,  and  consequently  may  replace  each  other  in  the 
diet. 

The  most  recent  and  most  satisfactory  classification  of  proteids  is 


20  FOODS. 

that  made  by  a  combined  cominitteo  of  the  American  Society  of  Bio- 
logical Chemists  and  the  American  Physiological  JSociety.^ 

The  recommendations  are  as  follows  : 

First :  The  word  ])roteid  should  be  abandoned. 

Second  :  The  word  protein  should  designate  that  group  of  substances 
which  consists,  so  far  as  at  present  is  known,  essentially  of  combina- 
tions of  a-amino  acids  and  tiieir  derivatives,  c.  (/.,  a-amino-acetic  acid 
or  glycocoll,  a-amino-propionic  acid  or  alanine ;  phenyl-a-amino  pro- 
pionic acid  or  ]ihenylalanine,  guanidine-amino-valerianic  acid  or  argi- 
nine,  etc.,  and  are,  therefore,  essentially  polypejitides. 

Third  :  That  the  following  terms  be  used  to  designate  the  various 
groups  of  proteins  : 

I.  The  Simple  Proteins. 

Protein  substances  which  yield  only  a-amino  acids  or  their  deriva- 
tives on  hydrolysis. 

Although  no  means  are  at  present  available  whereby  the  chemical 
individuality  of  any  protein  can  be  established,  a  number  of  simple 
proteins  have  been  isolated  from  animal  and  vegetable  tissues  which 
have  been  so  well  characterized  by  constancy  of  ultimate  composition 
and  uniformity  of  physical  properties  that  they  may  be  treated  as 
chemical  individuals  until  further  knowledge  makes  it  possible  to  char- 
acterize them  more  definitely. 

The  various  groups  of  simple  proteins  may  be  designated  as  follows  : 

(a)  Albumins.  Simple  proteins  soluble  in  pure  water  and  coagula- 
ble  by  heat. 

(6)  Globulins.  Simple  proteins  insoluble  in  pure  water,  but  soluble 
in  neutral  solutions  of  salts  of  strong  bases  with  strong  acids. ^ 

(c)  Glutelins.  Simple  proteins  insoluble  in  all  neutral  solvents,  but 
readily  soluble  in  very  dilute  acids  and  alkalies.^ 

(f/)  Alcohol-soluble  proteins.  Simple  proteins  soluble  in  relatively 
strong  alcohol  (70  to  80  per  cent.),  but  insoluble  in  water,  absolute 
alcohol,  and  other  neutral  solvents.* 

(e)  Albuminoids.  Simple  proteins  which  possess  essentially  the  same 
chemical  structure  as  the  other  proteins,  but  are  characterized  by  great 
insolubility  in  all  neutral  solvents.^ 

(/)  Histones.  Soluble  in  water  and  insoluble  in  very  dilute  ammo- 
nia and,  in  the  absence  of  ammonium  salts,  insoluble  even  in  an  ex- 
cess of  ammonia ;  yield  precipitates  with  solutions  of  other  proteins, 

^  American  Journal  of  Physiology,  21,  1908,  p.  xxvii. 

*  The  precipitation  limits  -with  ammonium  sulphate  should  not  be  made  a  basis  for 
distinguisliinjj  the  albumins  from  the  globulins. 

3  Such  substances  occur  in  abundance  in  the  seeds  of  cereals,  and,  doubtless,  repre- 
sent a  well-defined  natural  group  of  simple  proteins. 

*  The  sub-classes  defined  (a,  h,  c,  d)  are  exemplified  by  proteins  obtained  from  both 
plants  and  animals.  The  use  of  appropriate  prefixes  will  suffice  to  indicate  tlie  origin 
of  the  compounds,  e.  g.,  ovoglol)ulin,  myoalbumin,  etc. 

5  The.se  form  the  principal  organic  constituents  of  the  skeletal  structure  of  animals, 
and  also  their  external  covering  and  its  appendages.  This  definition  does  not  jirovide 
for  gelatin,  which  is,  however,  an  artificial  derivative  of  collagen. 


aoMi'osirioN  OF  foods.  21 

jukI  m.  (U);i!j;iiliim  on  licnIiiiL;  wliidi  is  casih'  :-iiliil)|c  in  v<tv  <liliilr!  lu-idn. 
On  hydrolysis  iJu^y  yield  ;i  hir^c  niiinlxr  ni'  .•iiniiio-iicid-.  aiiiKrij.';  wliicli 
ilu!  I)asi(;  oihjs  prcdoiiiinali'. 

(</)  I'roiiunincs.  Simpler  pulyixplidiv-  lli;iii  tlie  [iroleins  iiieliided 
in  tlu!  |)i'('(;odiii<2;  eronps.  Tliey  arc;  soliihle  in  water,  un('(»a^ulal»le  l»y 
licut,  liavo  IIk!  |)r()|>ei(y  ol"  precipitating;  atpieoiis  solutions  (>[  other 
pr()t(!ins,  |)oss(!SS  stronjj;  basic,  |)roper(ies,  and  form  stai)l(!  saltH  with 
strong  niincnil  acids.  I'lx'y  yi'^ld  comparatively  lew  amino-acids, 
among  which  the  basic  amino-acids  greatly  |iredoiniiiat<;. 

11.    CoNJIKiATKD    J'lU/rKINS. 

Substances  which  contain  the  ])rotein  mohicnie  united  (o  some  other 
molccuh^  or  molecules  otherwise;  than  as  a  salt. 

[a)  Nncleoproteins.  Compounds  of"  one  or  more  j>rotein  moIecule.H 
with  micleic!  acid. 

(A)  Glycoproteins.  Compounds  ((ftlie  j)rotein  molecule  with  a  sub- 
stance or  substances  containing  a  carbohydrate  group  other  than  a 
nu(!leic  acid. 

((t)  Phosphorproteins.  Compounds  of  tlie  protein  nioleenle  with 
some,  as  yet  undefined,  ])hosphorns-(!ontaining  substance  other  than 
a  nucleic  acid  or  lecithins.' 

(d)  Hiemoglobins.  Compounds  of  the  protein  molecule  with  hema- 
tin  or  some  similar  substance. 

(e)  Lecithoproteins.  C^ompounds  of  the  protein  molecule  with 
lecithins  (lecithaus,  phosphatides). 

III.  Derived  Proteins. 

1.  Primary  Protein  Derivatives.  Derivatives  of  the  protein  molecule 
apparently  formed  through  hydrolytic  changes  which  involve  only  slight 
alterations  of  the  protein  molecule. 

(a)  Proteins.  Insoluble  products  which  apparently  result  from  the 
incipient  action  of  water,  very  dilute  acids,  or  enzymes. 

(6)  Metaproteins.  Products  of  the  further  action  of  acids  and  alka- 
lies whereby  the  molecule  is  so  far  altered  as  to  form  products  solul)le 
in  very  weak  acids  and  alkalies,  but  insoluble  in  neutral  fluids. 

This  group  will  thus  include  the  familiar  "  acid  proteins "  and 
"alkali  proteins,"  not  the  salts  of  proteins  with  acids. 

(c)  Coagulated  proteins.  Insoluble  products  will  result  from  (1)  the 
action  of  heat  on  their  solutions  or  (2)  the  action  of  alcohols  on  the  protein. 

2.  Secondary  Protein  Derivatives.-  Products  of  the  further  hydro- 
lytic cleavage  of  the  protein  molecule. 

(a)  Proteoses.  Soluble  in  water,  uncoagulated  by  heat,  and  pre- 
cipitated by  saturating  their  solutions  with  ammonium  or  zinc  sulphate.^ 

^  The  aconmulated  chemical  evidence  distinctly  points  to  the  propriety  of  classify- 
ing the  phosphoproteins  as  conjvic:aled  comjiounds,  )'.  €.,  they  are  possibly  esters  of  some 
phosphoric  acid  or  acids  and  protein. 

^  The  term  secondary  hydrolytic  derivatives  is  used  because  the  formation  of  the 
primary  derivatives  usually  precedes  the  formation  of  these  secondary  derivatives. 

•*  As  thus  defined,  this  term  does  not  strictly  cover  all  the  protein  derivatives  com- 
monly called  proteoses,  e.  g.,  heteroproteose  and  dyproteose. 


22  FOODS. 

(b)  Peptones.  Soluble  in  water,  iincoagulated  by  beat,  but  not  pre- 
cipitated by  saturating  tbeir  solutions  -with  ammonium  sulphate/ 

(c)  Peptides.  Definitely  characterized  combinations  of  two  or  more 
amino-acids,  the  carboxyl  group  of  one  being  united  with  the  amino 
group  of  the  other  witli  the  elimination  of  a  molecule  of  water.^ 

The  albumins  are  not  precipitated  by  alkaline  carbonates,  common 
salt,  or  dilute  acids,  but  they  are  coagulated  by  being  heated  to  65°- 
73°  C.  Casein,  legumin,  conglutin,  syntonin,  and  albuminates,  on  the 
contrary,  are  not  coagulable  by  heat,  but  are  precipitated  by  common 
salt,  sodium  acetate,  and  trisodium  phosphate.  The  albumoses  are 
widely  distributed  throughout  the  vegetable  kingdom,  and  are  found 
largely  m  the  cereals.  In  the  animal  kingdom,  they  are  intermediate 
products  of  the  action  of  pepsin  on  ordinary  proteids,  becoming  even- 
tually converted  to  peptones.  The  collageus  are  very  rich  in  nitrogen, 
but  have  an  inferior  nutritive  value.  Gelatin,  for  instance,  contains 
17—18  per  cent.,  while  the  albumins  contain  but  16. 

Fats. — The  fats  are  compounds  of  the  triatomic  alcohol,  glycerin, 
with  fatty  acids,  mainly  stearic,  palmitic,  and  oleic.  These  several 
compounds  are  known  as  stearin,  palmitin,  and  olein.  The  two  first 
mentioned  are  solids  at  usual  temperatures,  while  olein  is  a  liquid. 
Most  fats  are  combinations  of  two  or  all  of  these  substances,  and  some, 
as,  for  example,  butter,  contain  additional  glycerides  in  small  amount. 
Stearin  and  palmitin  being  solids,  and  olein  liquid,  the  consistency  of 
a  fat  is  dependent  upon  the  proportions  in  which  these  substances  are 
present.  Stearin  is  a  component  of  most  animal  fats,  but  never  is 
found  in  vegetable  fats.  The  chief  constituent  of  animal  fats  is  pal- 
mitin, and  this  occurs  also  in  nearly  all  vegetable  fats.  Olein  exists 
in  both.  Butyrin,  caprin,  caproin,  and  caprylin  are  glycerides  of 
volatile  fatty  acids  present  m  the  fat  of  milk. 

Fats  consist  of  carbon,  hydrogen,  and  oxygen,  and  contain  no  nitro- 
gen. The  hydrogen  and  oxygen  are  not  present  in  the  proportions  in 
which  they  exist  in  water  and  in  carbohydrates,  the  oxygen  being  de- 
ficient. 

As  taken  in  food,  fats  are  chiefly  in  the  form  of  neutral  substances, 
but  more  or  less  free  fatty  acid  is  always  present,  and  in  some  foods 
which  have  been  kept  for  a  time,  particularly  in  well-ripened  cheese, 
fatty  acids  may  be  present  in  a  free  state  in  quite  large  proportion. 

The  fats  play  an  important  part  in  the  maintenance  of  animal  heat 
and  mechanical  energy.  When  hard  labor  is  being  performed,  an  excess 
of  fat  is  mstinctively  taken. 

Carbohydrates. — The  carbohydrates  include  the  starches,  sugars, 
and  cellulose. 

The  Starches,  though  presenting  very  different  appearances  under 
the  microscope  according  to  source,  are  of  equal  value  as  foods,  and 
have  the  same  composition.     Starch  is   insoluble  in  water,  but,  heated 

^  In  this  group  the  kyrines  may  be  included.  For  the  present  we  believe  that  it  will 
be  helpful  to  retain  this  term  as  defined,  reserving  the  expression  peptide  for  the  sim- 
pler compounds  of  definite  structure,  such  as  dipeptides,  etc. 

_  ^  The  peptones  are  undoubtedly  peptides  oi-  mixtures  of  peptides,  the  latter  term 
being  at  present  used  to  designate  those  of  definite  structure. 


COMPOSITION   OF  FOODS.  2'.) 

witli  it  to  72°  C,  tho  oolls  hvvcII  mihI  hiir-t,  imd  pi'.diK-.-  ;i  M.rt  f.f 
iniicilajre,  II(!;ik;(l  vvilli  diliilc;  riiiiKirul  luids,  it  is  convrTt<-fl  into  <\cx- 
trosc;.      Siil)j(!(i((ul  to  the:  luilioii  oC  diustiisc,  it  \h  cojivfrtcd  into  ninllo-c, 

Sturc.li  is  (oiiiid  ulniost  (!xc,liisiv(;ly  in  vc^ctiihlc^  (tells.  It  forms  tin; 
chief  [)iii't  of  tlu!  s(!cds  of  the  (icroiils  iind  of  tlic;  driod  rcsidnc  of  cfrtiiin 
other  VGj2;ctjil)lc  pnxhicts,  8uch  an  potat^Kis.  A  forrji  of  st'irrh  knrjwn 
as  iininuU  starch  or  <>;lycoir'!n  is  found  in  the  liver  ;ind  Minscles,  inifl  al-o 
in  sonu!  of  the  molliiscii.  Dttxlrin  is  an  ;irti(icial  |iro<hi<!l,  formed  from 
stanch  by  tlu;  action  of  fermcuits  or  of  dilute  aeids  anfj  lioat. 

The  Sugars  arc  of  vcjijotable  and  animal  orif^in^  and  iiiehidc  the 
following  : 

1.  Hucros(>,  c.'iiic  sn^rar,  A  disjuiftharid.  From  snjjar  cano,  sorghnm, 
sugar  maple,  sugar  beet,  and  some  other  vegetai^le  stmrccs.  In.sohibjp 
in  strong  nhtohol,  does  not  I'ednee  copper;  not  directly  fcnncntaf)lc. 
Jioilcd  with  dilute  acids,  is  (jonverted  to  invert  sugar,  a  mixture  of 
dextrose  and  Isevulose. 

2.  Dextrose,  glucose,  gra])o  sugar.  A.  monosaccharid.  Fonnd  in 
many  fruits  and  flowers.  Formed  from  cane  sugar,  malto.-e,  starch, 
and  dextrin  by  boiling  with  dilute  acids.  In  the  presence  of  decr»m- 
posing  proteids,  splits  into  two  molecules  of  lacti(r  acid.  Fcrmentwl 
with  yeast,  splits  into  alcohol  and  carbonic  acid. 

3.  Maltose,  malt  sugar.  A  disacc^harid.  (Two  molecules  of  dex- 
trose.)    Formed  from  starch  by  the  action  of  diastase. 

4.  Lsevulose,  fruit  sugar.  A  monosaccharid.  Found  in  honey  and 
various  fruits.  Rotates  the  ray  of  polarized  light  to  the  left.  Does 
not  form  crystals.      Isomeric  with  dextrose. 

5.  Lactose,  milk  sugar.  A  disaecharid.  (Dextrose  and  galactose.) 
Found  only  in  milk.      Behaves  like  dextrose. 

6.  Galactose.  A  monosaccharid.  Formed  from  lactose  by  boiling 
with  dilute  mineral  acids. 

7.  Inosite,  muscle  sugar,  phaseomannite.  Found  in  certain  animal 
tissues,  as  the  heart's  muscle,  and  in  certain  plants,  as  peas,  beans,  and 
grapes.  Has  no  rotatory  power,  does  not  reduce  copper,  and  is  not  fer- 
mentable. It  contains  the  benzene  ring,  and  hence  is  not  a  true  sugar. 
In  the  presence  of  decomposing  j^roteids,  it  is  converted  into  lactic  and 
butyric  acids. 

Cellulose. — Cellulose,  while  of  value  as  a  food  for  hcrbivora,  has  no 
nutritive  value  for  man.  It  is  converted  to  dextrose  bv  boiling^  with 
dilute  sulphuric  acid. 

Pectin. — Pectin  is  a  substance  not  uncommonly  classified  as  a  car- 
bohydrate. It  is  composed  of  carbon,  hydrogen,  and  oxygen,  but  its 
precise  composition  is  unknown.  It  is  found  in  various  fleshy  fruits 
and  in  roots,  and  is  believed  to  be  formed  from  pectose  by  the  action 
of  vegetable  acids.      It  is  known  also  as  vegetable  jelly. 

Pectose. — Pectose  is  an  insoluble  substance  found  in  unripe  fruits 
and  roots  :  an  eai'lier  stage  of  pectin. 

The  carbohydrates  play  an  iiuportant  part  in  the  maintenance  of 
heat  and  the  production  of  force.  They  lessen  the  need  of  fat  and 
form   fatty  tissue.      Excessive  ingestion  interferes  with  the  metamor- 


24  FOODS. 

pilosis  of  nitroo-enous  tissue,  causes  depositiou  of  fat  in  excess,  and  is 
likely  to  ])nKluco  diucstivc  disturbances.  Deprivation  for  a  time  can  be 
borne,  provided  the  system  receives  sufficient  fatty  food,  but  not  otherwise. 

Organic  Acids. — The  organic  acids  exist  in  foods  cither  in  the  free 
state  or  in  Cf^nbination  as  salts.  In  the  system  they  are  converted  to 
carbonates,  which  exercise  a  most  imjiortant  influence  in  controlling 
the  alkalinity  of  the  blood  and  other  fluids.  Dejirivation  leads  to  a 
peculiar  disturbance  of  the  system  resulting  in  scurvy.  They  include 
malic,  acetic,  lactic,  oxalic,  citric,  and  tartaric  acids.  INIalic  acid  is  a 
constituent  of  apples,  pears,  and  some  other  fruits.  Acetic  acid  is  the 
essential  element  of  vinegar.  Oxalic  acid  is  found  in  considerable 
amounts  in  spinach,  tomatoes,  strawberries,  sorrel,  and  rhubarb.  Lactic 
acid  is  present  in  fresh  meats  and  in  milk.  The  twc^  most  important 
acids  are  citric  and  tartaric.  The  former  is  found  in  oranges,  lemons, 
limes,  and  otlier  fruits ;  the  latter  largely  in  grapes. 

Not  all  vegetables  contain  these  acids,  and,  therefore,  not  all  have 
antiscorbutic  properties.  Potatoes,  cabbage,  and  roots  are  very  effici- 
ent in  this  respect,  while  peas  and  beans  are  notable  examples  to  the 
contrary. 

Inorganic  Salts. — The  important  inorganic  salts  taken  into  the 
system  with  food  include  sodium  and  potassium  chlorides,  sodium, 
potassium,  magnesium  and  calcium  phosphates,  and  compounds  of  iron. 
The  sulphates  are  of  minor  importance  and  are  ingested  in  only  small 
amounts.  The  sulphur  essential  to  growth  is  taken  into  the  system  in 
combination  in  the  proteids.  The  chlorides  keep  the  globulins  of  the 
blood  and  other  fluids  of  the  body  in  solution,  and  are  the  source  of  the 
hydrochloric  acid  of  the  gastric  juice.  The  phosphates  are  very  essential 
to  the  gro^^i:h  of  bone  and  to  the  nervous  system,  and  iron  is  needed  for 
the  haemoglobin  of  the  blood.  Deficiency  of  calcium  and  magnesium 
salts  leads  to  rickets  and  other  abnormal  conditions. 


Section  2.     ANIMAL   FOODS:   MEATS,   FISH,   EGGS, 
AND  MEAT   PRODUCTS. 

The  foods  of  animal  origin  used  by  man  include  the  flesh  and  various 
organs  of  the  herbivora  and  swine,  domestic  and  wild  fowl,  eggs,  fish 
and  shellfish,  milk  and  milk  products.  The  flesh  of  all  carnivorous 
animals  except  fish  is  unpalatable,  and,  therefore,  undesirable  as  food, 
though  under  stress  of  circumstances  it  may  be  borne.  Thus,  during 
the  siege  of  Paris,  about  5,000  cats  and  1,200  dogs  are  said  to  have 
been  eaten  when  the  food  supply  had  become  so  meagre  that  anythuig 
in  the  form  of  flesh  was  acceptable.  In  Germany,  according  to  a  com- 
munication of  Consul-General  Guenther  to  the  State  Department  at 
Washington,  under  date  of  May  26,  1900,  the  statistical  year-book 
shows  that,  on  account  of  the  high  price  of  other  meats,  not  only  horses, 
but  also  dogs  are  much  used  as  food.  At  Breslau,  Chemnitz,  Dresden, 
Leipzig,  Zwickau,  and  other  places,  dogs  are  slaughtered  extensively 
for  this  purpose  and  regularly  inspected. 


ME  A  TF{.  26 

Pirl»  reports  thai  in  S:ix(.iiy  (liiiiiij_r  1H91,  21»r>;  in  18!>r»,  .'JKH;  in 
1  «<)(;,,'{()!)  ;  ;in<l  in  IH!J7,  17  1  do^r.s  were  slniifrlilrTcd  ritul  in-jx-rlcd. 
In  DcMSJin,  l)cl\v(H'n  1  H!);-{  mihI  I  MIlS,  (Ik;  iinnilxT  ;iv(r;i^'-c<l  2-'>l  yr-iirly, 
and  in,sj)('(!ti()n  hIiowcI  (li.ii  nnc  in  202  was  (ricliinons.  Af^'ordinpj 
to  Tcmpci;^  of  2<Si)  killed  ;il  ( 'li<ninif  /  dnrin^  1H!)7,  l..">01  per  fcnt., 
iind  of  I  17  killod  dnrinn  jli,.  first  linjf  f)f  the  year  IHOH,  2.04  pf;r 
cv.ul.  were  (()nn(l  to  l)(!  (rifliiiKins.  'I'lu'  trir-nt  is  caU-n  rliiffly  in  tlie 
roasted  state,  hnt  also,  in  many  j)arls  of  Siixony,  raw,  hut  lii^ldy  sf^- 
soncd.  The  same  animals  arc  eommonly  eaten  by  the  Chinese,  and  the 
(-anada  lynx  and  (lie  sl<nid\  ww.  rated  as  delieaei(!S  hy  the  Xortli  Ameri- 
can Indians. 

MEATS. 

The  value  of  meat  as  food  de|)ends  upon  (lie  presence  of  proteidH, 
fat,  and  mineral  salts.  Tlic  nitro<i;enous  extraedve  niat(ers  (creatin, 
etc.),  sometinu's  called  "meat  hases,"  formed  by  eleavaji-c  of  the  prf>- 
teids,  give  flavor,  but  have  li(tle  value  as  foods.  The  earbohydnites 
play  but  an  insignificant  jnirt,  being  present  chiefly  as  muscle  sugar  and 
to  only  a  very  small  extent.  All  meat,  however  lean,  confciins  fat,  some 
of  which  is  visible  and  some  indistinguishal)le  from  the  musele  fibres  Ijy 
which  it  is  surrounded.  The  visible  fat  varies  widely  in  amount. 
Very  fat  beef  may  contain  considerably  more  than  a  quarter  of  its 
weight  of  visible  fiit,  and  fat  pork  meat  more  than  a  half,  while  chicken 
and  veal  contain  comparatively  little. 

The  content  of  water  varies  veiy  widely  and  in  general  may  be  said 
to  be  governed  by  the  richness  in  fat,  for,  while  the  proteids  are 
fairly  constant  in  amonnt,  the  remainder  is  almost  wholly  water  and 
fat,  and  the  greater  the  amount  of  the  one,  the  less  the  amount  of 
the  other.  The  less  fat  a  meat  contains,  the  less,  therefore,  its  relative 
nutritive  value. 

Digestibility. — ^Miile  the  amount  of  nutriment  contained  in  meats 
chiefly  determines  their  food  value,  the  latter  is  to  no  inconsiderable 
extent  dependent  upon  the  ability  of  the  alimentaiy  tract  to  digest  and 
absorb  them.  Gastric  digestion  is  by  no  means  to  be  accepted  as  a 
measure  of  the  true  digestibility  of  a  food,  and  the  same  is  tnie  of  the 
results  of  artificial  laboratory  experiments  ;  hence  many  of  the  accepted 
statements  bearing  on  this  subject,  based  upon  the  oft-quoted  experi- 
ments on  Alexis  St.  Martin  and  u]ion  test-tube  observations,  may  be 
wholly  disregarded. 

Raw  meat  is  digested  more  easily,  but  less  completely,  than  that 
which  has  undergone  the  process  of  cooking,  and  roastetl  meat  is  more 
completely  digested  than  that  which  has  been  boiled.  Fat  meats,  as 
beef  and  mutton,  and  especially  pork,  require  more  time  for  digestion 
than  those  which,  like  chicken  and  veal,  contain  but  little  fat.  In 
general,  it  may  be  said  that  meats  are  assimilated  more  easily  than  v^e- 
table  foods. 

Flavor. — The  flavor  of  meats  depends  largely  upon  the  nature  and 

1  Zeitsolirift  fiir  Fleisoli-  and  ililclihygieue,  X.,  Xo.  1. 
-  Ibidem,  IX.,  Xo.  1. 


26  FOODS. 

amounts  of  nitroo;enous  extractives  which  they  contain,  and  is  greatly 
modified  by  the  condition  of  the  animal  when  killed,  its  age,  sex,  and 
the  oliaracter  of  its  food.  The  high  flavor  of  birds  and  game  is  due  to 
the  richness  in  extractives,  while  in  the  case  of  meats  deficient  in  these 
substances,  as,  for  example,  mutton  and  ]-)ork,  the  flavor  is  due  largely 
to  their  contained  fats.  Most  meats  are  improved  in  flavor  by  being 
kept  for  a  time,  during  which,  additional  flavors,  due  to  decompo- 
sition products  similar  to  the  extractives,  are  developed.  The  meat 
of  young  animals  is  flavored  less  highly  than  that  of  adults,  and 
that  of  females  than  that  of  males,  though  in  the  case  of  the  goose 
this  condition  is  reversed,  and  in  that  of  swine  no  difl'erence  is  ob- 
servable. 

Asexualization  by  spaying  or  castration  produces  a  fatter,  more 
tender,  and  bc>tter  flavored  meat.  Thus,  the  flesh  of  oxen  is  far  pre- 
ferable to  that  of  bulls  or  cows,  and  that  of  capons  and  poulards  to 
that  of  cocks  and  hens. 

Texture. — Whether  a  given  meat  is  tough  or  tender  depends  upon 
the  character  of  the  walls  of  the  muscle  tubes  and  upon  the  amount  of 
connective  tissue  present.  The  tube  walls  are  thin  and  delicate,  and 
the  connective  tissue  is  small  in  amount  in  the  young  and  well-fed,  but 
as  the  animal  becomes  older  or  is  made  to  work,  the  tubes  thicken  and 
become  hard,  the  connective  tissue  increases  in  amount,  the  fat  may 
diminish,  and  the  result  is  a  coarser  flesh.  Very  young  animals  have 
a  very  watery,  gelatinous,  and  flavorless  flesh. 

The  texture  of  meat  undergoes  very  considerable  change  after 
slaughter.  When  freshly  slaughtered,  it  is  tender  and  juicy,  but  as 
rigor  mortis  supervenes,  it  becomes  hardened  and  tough.  The  stage 
of  rigor  is  succeeded  by  the  first  stage  of  decomposition,  during  which 
lactic  acid  is  formed.  This  acts  upon  the  connective  tissue  and  causes 
softening  and  tenderness,  and  as  the  process  of  decomposition  proceeds 
Avithiu  proper  limits,  increase  of  flavor  is  developed. 

Effects  of  Cooking'. — When  meat  is  cooked,  the  connective  tissue 
is  softened,  the  bundles  of  fibrillse  are  loosened  from  each  other,  the 
albumin  is  coagulated,  flavors  are  improved  and  new  ones  developed, 
parasites  and  micro-organisms  are  destroyed,  and  the  whole  mass  is 
rendered  more  acceptable  to  the  eye  and  palate.  In  the  process  of 
roasting  or  broiling,  considerable  shrinkage  due  to  loss  of  water  occurs. 
The  heat  to  which  the  meat  is  subjected  should  be  sufficiently  intense  to 
produce  speedy  coagulation  of  the  exterior  and  prevent  the  meat  juices 
from  becoming  dried  up.  In  order  that  the  surface  shall  not  be  burned, 
the  meat  must  be  basted  from  time  to  time  with  hot  melted  fat,  which 
forms  a  protective  coating.  The  heat  employed  should  be  less  intense 
with  large  joints  than  with  small  ones,  since  before  the  lieat  can  pene- 
trate well  into  the  interior,  the  outer  parts  will  become  burned. 

In  'boiling,  the  temperature  of  the  water  into  which  the  meat  is  im- 
mersed varies  according  to  the  object  sought.  If  a  rich  broth  is  de- 
sired, the  meat  is  placed  in  cold  water,  which  then  is  heated  gradually. 
During  the  heating  process,  the  soluble  albumins  together  with  a  por- 
tion of  the  salts  and  the  extractives  are  dissolved  out.     When  the  tem- 


MJ'JA  TS.  27 

poratiiro  rcju'licH  1.T4°  1^\,  IIk;  ulhiirMiii  hcfririH  U)  cojij.'iilaff,  ;iri(]  ;ih'>\'<; 
1(50",  IJk!  coniKKil  iv(!  li.MHiK!  Im  (-Ii;! ii|j;c(I  i,(>  ^'clntin  mikI  (liy-olvt-d.  Tin; 
Koliiiioii  of  (tcrl.'iiii  ()(■  I  lie  (UMisI  il  iiciiis  is  jissislcd  hy  flic  small  amountH 
of  Iii(;(.i(!  acid  loriiicd. 

if,  oil  fclio  oth(T  hand,  if,  i.s  (Icsircd  lo  lia.Vf  I  lie  jiiiff-  and  (lavofH  rr- 
tiiiiu^d  williiii  IIk!  mass,  (lie  meat  lioiild  Ix;  iiliiii^n'd  into  boiling-  \va(<T, 
wlii(ili  (|iii('J<ly  c.oai^idalcs  iJic  alhiiiiiiii.s  at  tli(!  siirfacH;  and  caiiscH  tlionhy 
tliu  formal ioii  of  a,  |)r<)((;c,l,iv(!  <;oatin^.  After  tlii.s  is  form(;(J,  tlio  t<;rn- 
poraturo  sliouid  1)0  lowered  to  al)out  180°  F.,  for  otherwise  tlie  nuyithe- 
conuis  tonsil,  even  to  the  center.  The  shrinkaf^e  in  meat  that  lias  been 
|)roj)erly  boiled  amounts  to  from  20  to   10  per  cciil.  of  its  wrtij^ht. 

Iti  frying,  tlic  meat  is  di'oj)|)('d  into  very  hot  fat,  as  lard  or  vegetable 
oil,  which  causes  speedy  coa<z;nlalion  of  the  siirCaci',  sndi  as  is  brought 
about  in  the  proe(Ws  of  boilinjj:;,  whereby  all  the  llavois  and  juices  are 
retained.  Jt  is  essential  that  the  fat  l)e  very  hot,  since  otherwise  it 
will  penetrate  the  tissues  and  (^aiise  the  meat  to  become  greasy  and  un- 
palatable. 

In  stewing,  the  meat  is  cut  into  small  pieces  and  placed  in  cold  water, 
which  then  is  heated  slowly  to  about  180°  F.,  at  which  temperature 
the  whole  is  kept  for  several  hours.  If  heated  abf)ve  180°,  the  nuiat 
becomes  touo;h,  strino;y,  unpalatable,  and  of  diminished  digestibility. 

Characteristics  of  Good  Meat. — Meat  should  have  a  uniform  color, 
neither  abnormally  pale  nor  inclined  to  purplish.  It  should  have  little 
or  no  odor,  and  such  as  it  has  should  give  no  disagreeable  impression 
such  as  the  sickly  cadaveric  smell  characteristic  of  diswiscd  or  decom- 
posing flesh.  It  should  be  iirm  and  elastic,  and  should  not  pit  nor  crackle 
on  pressure.  On  being  handled,  it  should  scarcely  moisten  the  fingers, 
and  with  keeping,  the  exterior  shonld  become  dry  rather  than  wet. 
There  should  be  no  evidence  whatever  of  the  presence  f»f  jiarasites. 

Beef  has  a  bright  red  color  and  a  marbled  appearance,  due  to  the 
presence  of  fat  between  the  bundles  of  muscular  fibers.  This  marbling 
is  much  less  apparent  in  the  flesh  of  animals  that  have  not  been  well 
fed  and  of  old  cows  and  bulls.  Bull  meat  is  darker  than  that  of  oxen 
and  cows,  and  is  coarse,  stringy,  and  of  strong  flavor. 

Veal  is  much  paler  than  beef  and  less  firm  to  the  touch,  and  coming 
from  a  very  young  animal,  "bob-veal,"  it  is  flabby  and  watery,  and  its 
fat  has  a  tallowy  appearance. 

Mutton  should  be  of  a  dull-red  color  and  firm  to  the  touch.  Its  fat 
is  white,  sometimes  yellowish,  and  hard. 

Lamb  is  somewhat  less  firm  to  the  touch  and  has  a  decidedly  lighter 
color  than  mutton. 

Pork  is  much  less  firm  to  the  touch  than  beef  and  mutttMi.  and  its 
fat  is  quite  soft  in  comparison. 

Horse  meat,  the  use  of  which  is  increasing  rapidly  abroad  and  to  a 
much  greater  extent  in  this  country  than  is  commonly  believed,  is 
darker  and  coarser  than  beef  and  possesses  a  very  different  odor.  The 
fat  is  yellow  and  oily  and  has  a  rather  disagreeable  odor. 

The  flesh  of  birds  is  not  marbled  like  that  of  mammals.  That  of  wild 
fowl  that  feed  on  fish  has  a  strong  flavor,  which  is  not  improved  by  keeping. 


28  FOODS. 

Comparative  Dig-estibility  of  Meats. — Beef  is  commonly  and  ccir- 
reetly  reti-arded  as  one  of  tlie  most  tligestible  of  meats,  but  accordiii^-  to 
the  experience  and  testimony  of  many  victims  of  dyspepsia  it  is  inferior 
in  this  respect  to  nuitton.  Pork  is,  without  doubt,  dio-ested  Mith 
greater  difficulty  than  any  other  meat,  on  account  of  its  high  content 
of  fat.  The  evidence  as  to  veal  is  most  conflicting,  some  holding  that 
it  is  digested  very  easily,  while  others  maintain  the  contrary  view. 
Certain  it  is  that  many  persons  bear  it  very  badly.  The  white  meat 
of  chickens,  fowls,  and  turkeys,  is  more  delicate  and  is  digested  more 
easily  than  the  dark  meat,  probably  by  reason  of  its  smaller  amouut 
of  fat.  The  flesh  of  ducks  and  geese  is  harder,  richer,  and  more  difti- 
cult  of  digestion.  Game  birds  are  less  fat  than  poultry  and  are  often 
much  better  borne.  Their  habits  of  life  are  unfavorable  to  the  de])o- 
sitiou  of  much  fat.  Liver,  kidneys,  and  heart  are  generally  regarded 
as  unsuitable  as  foods  for  persons  with  weak  stomachs,  but  tripe  and 
sweetbreads  are  usually  easily  borne. 

"  Red  Meat  "  and  "  White  Meat." — The  prohibition  of  red  meats 
(beef,  mutton,  venison)  to  patients  with  gouty  and  rheumatic  tendencies 
dates  from  the  time  of  Sydenham,  whose  dietetic  rules  allowed  only 
the  white  meats  (veal,  goat,  young  pig,  chicken)  and  flsli  to  such 
persons.  Today,  many  practitioners  extend  this  prohibition  to  those 
with  diseases  of  the  stomach,  intestines,  and  kidneys,  and  various 
neuroses.  The  foundation  of  this  prejudice  against  the  red  meats  is  the 
supposed  presence  in  them  of  a  greater  percentage  of  the  nitrogenous 
extractives  (creatin,  xanthiu,  guaniu,  etc.),  which  are  believed  to  exert 
injurious  action  in  two  ways  :  First,  locally,  by  irritating  the  kidneys 
during  the  process  of  their  elimination  from  the  body  ;  and  second,  in 
cases  of  impaired  functional  activity  of  the  kidneys,  by  causing  systemic 
intoxication.  Unfortunately,  however,  for  the  stability  of  this  belief, 
exact  analysis  has  shown  that  the  very  small  amounts  of  these  sub- 
stances present  are  practically  the  same  in  both  red  and  white  meats, 
with  the  single  exception  of  venison,  which  contains  them  not,  as  would 
be  surmised,  in  highest  percentage,  but,  in  fact,  in  lowest.  Further- 
more, these  extractives  are  not  eliminated  as  such,  but  as  the  normal  ulti- 
mate product  of  metamorphosis,  urea.  It  has  been  supposed,  too,  that 
the  non-nitrogenous  extractives  (lactic,  butyric,  and  acetic  acids,  etc.)  are 
present  to  a  greater  extent  in  red  than  in  white  meats  and  may  cause 
disturbance ;  but  as  a  matter  of  fact,  these  are  present  in  extremely 
small  amounts  in  both  red  and  white  meat,  and  cannot  possibly  be 
regarded  as  harmful,  in  view  of  the  fact  that  appreciable  amounts  exert 
no  influence  on  the  system. 

Composition  of  Meats. — In  the  following  tables,  showing  the  com- 
position of  the  edible  portions  of  meats,  the  figures  given  are  taken, 
unless  otherwise  stated,  from  Bulletin  No.  28  (revised  edition)  of  the 
Office  of  Experiment  Stations  of  the  U.  S.  Department  of  Agriculture  : 
The  Chemical  Composition  of  American  Food  Materials.^ 
^  Government  Priming  Office,  Washington,  1899. 


MJ'JA  TS. 


29 


BEEF. 


Cut. 

22 

'A 

i 
I 

Fat. 

0,9 

0.8 
1,0 
0.9 
0.9 
0.9 
0:9 
1.1 
1.0 
1.0 
0.8 
1.0 

111 

i>riHl<(!l.,  iiu!(liiiiii   ("at 

('Iiiu;l<,  iiicliKliii^  HliDiildur. 

•A 

1 
<2 

4 
4 
2 

54.0 

73.8 
71.3 
68.3 
62.3 
53.2 

15.8 

22.3 
20.2 
19.6 
18.5 
17.2 

28.6 

3.9 
8.2 
11.9 
18.8 
29,0 
15,4 

1495 
580 

IciiM 

720 

865 

flit, 

1135 

very   I'iiL    ....         

1555 

Average 

13 

65.0 

19.2 

1005 

Clmclv  ril),  vory  lean 

loan 

1 

11 

7 
2 

~21 

75.8 
71.3 
62.7 
52.0 

22.2 
19,5 
18,5 
16.6 

1.4 

8.3 

18.0 

31.1 

470 

715 

1105 

fat 

1620 

Average 

66.8 

19.0 

13.4 

920 

Jf'iank,  very  lean 

3 
3 
5 
3 
2 

70.7 
67.8 
60.2 
54.2 
34.7 

25.9 
20,8 
18.9 
17.1 
14.0 

3.3 
11.3 
21,0 
28  4 
51.8 

1.2 
1.0 
0.9 
0.8 
0.7 

620 
865 

niediuni  fat 

lilt 

1240 
1515 

very  fat 

2445 

16 

59.3 

19.6 

21.1 

0.9 

1255 

3 

12 

32 

6 

3 

70.8 
67.0 
60.6 
54.7 
49.7 

24.6 
19.7 
18.5 
17.5 
17.8 

3.7 
12.7 
20.2 
27.6 
32.3 

1.3 
1.0 
1.0 
0.9 
0.9 

615 
900 

medium  fat 

fat                      

1190 
1490 

1695 

Average 

56 

61.3 

19.0 

19.1 

1.0 

1155 

Porterhonse  steak 

7 

21 

1 

6 

60.0 
61.9 
42.2 
59.2 

21.9 
18.9 
13.8 
16.2 

20.4 
18.5 
43,7 
24.4 

1.0 
1.0 

0.8 
0.8 

1270 
1130 

2100 

Tenderloin 

1330 

Ribs,  very  lean 

4 

6 

15 

9 

1 

65.7 
67.9 
55.5 
48.5 
45.9 

21.9 
19.6 
17.5 
15.0 
14.6 

1,1 
12.0 
26.6 
35.6 

38.7 

0.7 
1.0 
0.9 
0.7 
0.6 

4,55 
870 

fat 

1450 
1780 

very  fat 

1905 

Average 

35 
•) 

3 
4 

2 

57.0 

17.8 

24.6 

0.9 

1370 

73.7 
69.0 
63.9 
51.5 

20.8 
20.2 
19.3 
17.2 

5.0 
10.5 
16.7 
31.3 

1.0 
1.0 
0.9 
0.8 

600 
820 

medium  fat 

fat 

1065 
1640 

Average 

11 

64.8 

19.4 

15.5 

0.9 

1015 

Konnd,  very  lean 

6 
31 

18 
5 
2 

73.6 
70.0 
65.5 
60.4 
55.9 

22.6 
21.3 
20.3 
^    19.5 
18.2 

2.8 

7.9 

13.6 

19.5 

26.2 

1.3 
1.1 
1.1 
1.0 

0.8 

540 
730 

medium  fat 

fat          

950 
1185 

very  fat 

1445 

62 

67.8 

20.9 

10.6 

1.1 

835 

Round,  second  cut 

2 

69.8 

20.4 

8.6 

1.1 

740 

Rump,  very  lean 

4 
4 
10 
5 
1 

71.2 
65.7 
5t>.7 
47.1 
40.2 

23.0 
20.9 
17.4 
16.8 
15.0 

5.1 
13.7 
25.5 
35.7 
44.3 

1.2 
1.0 
0.9 
0.8 
0.8 

645 
965 

1400 

fat 

1820 
2150 

24 

57.9 

18.7 

23.1 

0.9 

1325 

30 


FOODS. 


BEEF.— Continued. 


Cut. 


Beef  heart 

Kidney  (carboliydrates  0.4) 
Liver  (carboliydrates  1.5)    . 

Marrow 

Tongue     

Lungs 

Suet      

Roast  beef  (cut  not  specified) 
Sirloin  steak,  baked  .... 
Broiled  tenderloin      .... 

Round  steak 

Canned  corned  beef   .... 

Canned  roast  beef 

Canned  whole  tongue     .    .    . 

Canned  tripe 

Corned  beef  (all  cuts)    .    .    . 

Tongues,  pickled 

Tripe  (carbohydrates  0.2) 


el 

2 
'S 

o 

1 

.a 
< 

>  ^  ^ 

^  t,  OS 

2 

62.6 

16.0 

20.4 

1.0 

1160 

3 

76.7 

16.6 

4.8 

1.2 

520 

6 

71.2 

20.7 

4.5 

1.6 

605 

1 

3.3 

2.2 

92.8 

1.3 

3955 

3 

70.8 

18.9 

9.2 

1.0 

740 

1 

79.7 

16.4 

3.2 

1.0 

440 

9 

13.7 

4.7 

81.8 

0.3 

3540 

7 

48.2 

22.3 

28.6 

1.3 

1620 

1 

63.7 

23.9 

10.2 

1.4 

875 

6 

54.8 

23.5 

20.4 

1.2 

1300 

18 

63.0 

27.6 

7.7 

1.8 

840 

15 

51.8 

26.3 

18.7 

4.0 

1280 

4 

58.9 

25.9 

14.8 

1.3 

1105 

5 

51.3 

19.5 

23.2 

4.0 

1340 

2 

74.6 

16.8 

8.5 

0.5 

670 

10 

53.6 

15.6 

26.2 

4.9 

1395 

2 

62.3 

12.8 

20.5 

4.7 

1105 

4 

86.5 

11.7 

1.2 

0.3 

270 

PORK. 


Cut. 


Ham,  fresh,  lean 

medium  fat 

fat 

vi.sible  fat  largely  removed  . 
Loin  (chops),  lean 

medium  fat 

fat 

Tenderloin 

Shoulder  

Feet      

Head  cheese 

Kidney 

Liver  (carboliydrates  1.4)  .  .  . 
Ham,  smoked,  lean 

medhim  fat 

fat 

smoked,  boiled 

Shoulder,  smoked,  medium  fat    . 

fat 

Salt  pork,  fat 

lean  ends     

Bacon,  smoked,  lean 

medium  fat 


eg 


2' 

10 

5 

3 

1 

19 

4 

11 

19 

8 

3 

2 

1 


3 
14 

4 
2 
3 

2 
7 
4 
2 
17 


60.0 
53.9 

38.7 
64.5 
60.3 
52.0 
41.8 
66.5 
51.2 
50.7 
43.3 
77.8 
71.4 


53.5 
40.3 
27.9 
51.3 
45.0 
26.5 
7.9 
19.9 
31.8 
18.8 


Ph 


25.0 
15.3 
12.4 
19.2 
20.3 
16.6 
14.5 
18.9 
13.3 
8.3 
19.5 
15.5 
21.3 


19.8 

16.3 

14.8 

20.2 

15.9 

15.1 

1.9 

8.4 

15.5 

9.9 


14.4 

28.9 
50.0 
16.2 
19.0 
30.1 
44.4 
13.0 
34.2 
17.4 
33.8 
4.8 
4.5 


20.8 
38.8 
52.3 
22.4 
32.5 
63.6 
86.2 
67.1 
42.6 
67.4 


1.3 
0.8 
0.7 
0.9 
1.0 
1.0 
0.7 
1.0 
0.8 
0.4 
3.3 
1.2 
1.4 


5.5 

4.8 
3.7 
6.1 
6.7 
5.2 
3.9 
5.7 
11.0 
4.4 


1075 

1505 

2345 

1040 

1180 

1580 

2145 

900 

1690 

1090 

1790 

490 

615 


1245 
1940 
2485 
1320 
1665 
2545 
3670 
2985 
2085 
3030 


MI'JA  TS 
VEAL. 


31 


Cut. 

5 

7 

9 

10 

'A 

72.1 

(56.0 

73.r, 

70.0 
70.7 
7;i.3 
69.0 
61.6 
73.2 
75.8 
73.0 

'S 

1 

21.7 
19.6 
21.3 
20.2 
20.3 
20.4 
19.9 
18.7 
16.8 
16.9 
19.0 

i 

JS 

5.fi 

14.0 

4.1 

9.0 

7.7 

5.6 

10.8 

18.9 

9.6 

6.4 

5.3 

1,1 

1.0 
1.2 
1.2 
1.1 
1.2 
1.0 
1.0 
1.0 
1.3 
1.3 

640 

955 

lA'K,    li^a.i   . 

670 
755 

705 

Loin,  Iwui 

iiKMliiiin  (at 

fj,t           

6 
2 

1 
2 
2 

615 

825 

1145 

Heart 

720 
585 

Liver      

575 

MUTTON. 


Cut. 


Hind  leg,  lean      

medium  fat 

fat 

Loin,  medium  fat  without  kidney  and  tallow 

fat  without  kidney  and  tallow    .... 

very  fat  without  kidney  and  tallow  .    . 

Fore  quarter 

Hind  quarter 

Eoast  leg,  cooked 

Kidney  

Liver  (carbohydrates  5.0) 


<.-. 

O  tn 

1 
'53 

s 

i 

< 

'A< 

Ph 

3 

67.4 

19.8 

12.4 

1.1 

11 

62.8 

18.5 

18.0 

1.0 

1 

.55.0 

17.3 

27.1 

0.9 

13 

50.2 

16.0 

33.1 

0.8 

3 

43.3 

14.7 

41.7 

0.8 

1 

30.8 

10.6 

58.7 

0.5 

10 

52.9 

15.6 

30.9 

0.9 

10 

54.8 

16.7 

28.1 

0.8 

2 

50.9 

25.0 

22.6 

1.2 

1 

69.5 

16.9 

12.6 

0.9 

2 

61.2 

23.1 

9.0 

1.7 

a*  t.  s 


890 
1105 
1465 
1695 
2035 
2675 
1595 
1495 
1420 
845 
905 


LAMB. 


Cut. 


o  — — 

t.  a 

•s 

"  =  S 

o 
o 

Pui 

< 

o 

63.9 

19.2 

16.0 

1.1 

1055 

54.6 

18.3 

27.4 

0.9 

1495 

'       1 

51.8 

17.6 

30.1 

0.9 

1595 

53.1 

18.7 

28.3 

1.0 

1540 

55.1 

18.3 

25.8 

1.0 

1430 

60.9 

19.6 

19.1 

1.0 

1170 

47.6 

21.7 

29.9 

1.3 

1665 

67.1 

19.7 

12.7 

0.8 

900 

Hind  leg,  medium  fat     .... 

fiit 

very  fat      

Loin,  without  kidney  and  tallow 

Fore  quarter 

Hind  quarter 

Broiled  chops 

Koast  leg 


32 


FOODS. 


POULTRY. 


Cut. 


Broiler  chickens 

Fowls     .  • 

Young  goose 

Turkey 

Chicken  liver  (carboiiydrates  2.4) 
Goose  liver 


si 


3 

26 
1 
3 
1 
1 


74.8 
63.7 
46.7 
55.5 
Gl).3 
73.8 


21.5 
19.3 
1G.3 
21.1 

22.4 
ly.G 


2.5 
16.3 
36.2 
22.9 

4.2 
5.8 


1.1 
1.0 

0.8 
1.0 
1.7 
1.0 


Jj  tH  aj 


505 

1045 

1830 

1360 

640 

610 


Horse  Meat. — The  nicau  of  twelve  analyses  of  horse  meat  as  given 


Water 74.27 

Proteids       21.71 

Fat 2.55 

Ash 1.01 


The  objection  to  the  use  of  horseflesh  as  food  is  very  largely  senti- 
mental. It  has  not  the  pleasant  flavor  of  beef,  to  which  we  are  accus- 
tomed, but  when  eaten  in  ignorance  of  its  true  character,  it  makes  no 
unpleasant  impression.  Its  use  is  increasing  steadily  in  Eurojie,  and 
is  finding  favor  in  America.  In  Paris,  during  1898,  21,667  horses, 
52  mules,  and  310  donkeys  were  slaughtered  for  food,  and  of  these  but 
734  horses,  1  mule,  and  7  donkeys  were  condemned  as  unsalable.  The 
meat  was  disposed  of  in  193  shops,  where  the  best  cuts  brought  about 
a  franc  (19.3  cents),  and  the  inferior  parts  10  centimes  (2  cents)  per 
pound.  In  1910^  the  annual  amount  of  horse  and  mule  meat  con- 
sumed in  Paris  had  increased  threefold,  reaching  the  sum  of  29,700,000 
pounds  and  representing  about  61,000  animals. 

During  1896,  822  horses  and  mules  were  slaughtered  in  Strass- 
burg,  and  in  1898  the  number  rose  to  1099.  In  Vienna,  where  the 
sale  of  the  meat  was  permitted  first  in  1854,  there  were  slaughtered, 
in  1899,  25,646  horses  and  58  donkeys.  In  the  whole  of  Prussia, 
there  were  slaughtered,  in  1897,  at  367  abattoirs,  58,484  horses,  and 
in  the  following  year  tlie  number  rose  to  63,531.  In  Frankfort,  where, 
in  1847,  the  first  horse-meat  dinner  ever  given  occurred,  about  a  thou- 
sand horses  are  slaughtered  annually,  at  a  special  abattoir.  In  the 
United  States,  during  1899,  3,232  horses  were  slaughtered  and  offi- 
cially inspected  with  other  food  animals. 

It  is  said  that,  unless  the  fat  of  some  other  animal  or  some  starchy 
food  is  eaten  with  it,  horse  meat  may  cause  diarrhoea.  Whatever 
causes  tliis  disturbance  is  soluble  in  water,  and  may  thus  be  removed 
partially  when  the  meat  is  boiled.  From  water  in  which  horse-meat 
had  been  boiled,  E.  Pfliiger^  separated  jecorin,  lecithin,  and  (probably) 
neurin.    He  recommends  the  addition  of  about  25  grams  of  beef  or 

1  Zusammensetzung  der  nienschlichen  Nahrangs-  und  Genussmittel,  Berlin,  1882. 
■■'  U.  S.  Daily  Consiilar  and  Trade  Keports,  Nov.  1,  1910,  p.  420. 
3  Arciiiv  fiir  die  gesanimte  Physiologie,  1900,  Bd,  80,  p.  111. 


MICATS.  33 

mutton  ki(lii((y-f;it  to  cucJi  kilofj^rarn  of  tlio  ni(;;it  when  !i  minw  is  if) 
b(!  iiiiwlc,  iiiid  that,  in  \vliiit(!V(!r  I'orrn  is  i.s  coiisiuncd,  it  Im;  .s(;rvc(l  with 
a  ("at  ^ra,vy. 

Meat  Preparations. — Meat  Extracts. — These  an-  f)r(;}>aratif)nH 
whiiih  arc;  ,sii|)|»os('<l  oCtcn  crroiicoiisly  lo  coiihiin  :ill  ihc  nutritive  partH 
oC  the  iiu^atH  (Voiii  which  <h(!y  are  tiiade,  but  ihey  are  (o  he  repirfJed  a« 
stiimilaiits  rather  than  foods,  since  ihcy  r(;j>resent  thi;  extruefives  and 
not  llie  sul)staii(!es  which  detcrniiiK;  thi;  true  food  value.  In  j)oint  of 
fact,  so  far  as  \\w\r  nntriliv(!  piopertics  arc  concerned,  it  ha.s  bw;n 
shown  thai  animals  will  die  more  (|ui(!kly  of  Btarvation  when  fed  cx- 
chisivc^ly  u])on  these;  slimniatinti;  |>re|)arationH  than  when  entirely  fle- 
privcd  of  food.  They  arc,  however,  of  considerable  value  in  fheir 
proper  place,  paiticularly  in  conditions  of  great  fatigue  and  exhaustion. 

Meat  Powder. — Meat  may  easily  be  treated  so  as  to  retain  all  of  its 
nutriment  and  yet  have  a  very  much  diminished  volume.  The  lean 
])arts  are  cut  into  small  sti'ips,  dipped  for  a  few  mirnites  into  very  hot 
fat  (fried),  drained,  and  tlu^n  slowly  dried  in  an  oven.  When  com- 
pletely dry,  they  are  ground  in  an  ordinary  s])ice  mill  or  coffee  mill  to 
a  fine  powder,  ^vdlich  keeps  well,  has  an  agreeable  tiiste  and  a  ])leasant 
odor,  is  digested  easily,  and  may  be  used  in  a  great  many  different  ways. 

Sausages. — Sausage  is  understood  generally  to  mean  an  article  of 
food  consisting  chiefly  of  finely  chopped  meat,  maiidy  pork  and  beef, 
with  or  without  the  addition  of  a  small  amount  of  meal,  highly  sea- 
soned with  spices,  herbs,  and  other  flavorings,  and  stuffed  into  casings 
made  from  cleaned  and  prepared  intestines.  Their  nutritive  value  is, 
therefore,  about  the  same  as  that  of  average  meat.  As  may  be  suj)posed, 
the  best  cuts  of  meat  are  not  used  in  their  manufacture,  but  only  such 
parts  as  cannot  be  disposed  of  in  pieces  of  fair  size  and  of  attractive 
appearance.  But  there  are  sausages  and  sausages.  There  are  those 
made  from  meat  of  good  quality  and  others  from  materials  which 
would  not  be  salable  in  any  other  form. 

Many  of  the  so-called  Frankforters,  sold  at  very  low  rates,  and  the 
cheap  Bolognas  are  said  to  consist  largely  of  horse  meat,  immature 
veal,  and  the  flesh  of  cows  that  are  no  longer  in  condition  to  produce 
milk.  Certain  it  is  that  a  not  inconsiderable  number  of  persons  g-ain 
a  fair  livelihood  by  going  about  in  the  country  l)uving  up  newly  born 
calves  and  decrepit  cows,  tuberculous  and  othenvise,  and  horses,  and 
that  these  animals  are  not  taken  to  comfortable  stables  and  inviting 
pastures,  but  to  small  slaughtering  establishments,  the  output  of  which 
is  not  very  largely  butchers'  meat.  To  the  cheap  grades  of  sausages 
the  saying  of  Jean  Paul,  "  Only  a  god  can  eat  sausage,  for  only  such 
can  know  of  what  it  is  made,"  applies  very  aptly.  Even  sausages 
made  from  pork,  especially  those  which  have  undergone  a  process  of 
cooking  before  being  stuffed,  are  not  always  beyond  suspicion,  for  the 
triehiuous  pork  condemned  by  government  inspectors  at  public  abat- 
toirs is  neither  destroyed  nor  converted  into  fertilizers,  but  is  allowed 
to  be  sold  after  being  subjected  to  a  heat  sufficient  to  kill  the  parasites ; 
and  cooked  pork  is  not  commonlv  to  be  found  on  sale  as  such. 
3 


34  FOODS. 

Horse  meat  is  said  to  combine  two  advantages  in  the  preparation  of 
sausage  :  it  is  inexpensive,  and  it  lends  a  firmness  which  increases  as 
the  sausage  is  boiled.  A  number  of  chemical  processes  have  been  pro- 
posed for  its  detection,  and  among  them  the  following :  Dr.  Notel  * 
covers  coarsely  chopped  horsemeat  with  a  0.1  per  cent,  solution  of 
sodium  hydroxide,  lets  the  mixture  stand  3  hours  at  37°  C,  and  then 
separates  the  liquid  through  cheese  cloth.  The  liquid  is  injected,  in 
doses  of  8  to  10  cc.,  subeutaneously  into  a  rabbit  at  intervals  of  2  or 
3  days  until  10  or  12  injections  have  been  given.  Six  days  after  the 
last  injection,  the  animal  is  bled  and  its  serum  serves  as  a  reagent. 
The  suspected  food  is  chopjied  finely,  covered  with  0.1  per  cent,  sodium 
hydroxide,  allowed  to  stand  2  hours  in  a  Avarm  room,  and  filtered.  A 
few  drops  of  the  filtrate  are  mixed  in  a  test-tube  with  about  an  equal 
amount  of  the  serum,  and  other  tubes  containing  filtrate  alone  are  used 
as  controls.  The  tubes  are  incubated  at  37°  C,  and  if  the  suspected 
article  contains  horsemeat,  the  tubes  containing  the  serum  will  become 
cloudy  in  from  10  to  40  minutes. 

A  number  of  tests  which  depend  upon  the  reaction  of  iodine  with 
glycogen,  which  is  a  normal  constituent  of  horsemeat,  are  criticised  by 
Niebel  ^  as  uncertain,  on  account  of  the  presence  of  glycogen  in  liver, 
meat  extract,  and  very  young  veal. 

A  recent  and  more  reliable  test  for  horse  meat  has  become  possible 
through  the  studies  of  Ehrlich  and  his  pupils  ^  *  ^  ^  upon  immunity. 
If,  for  example,  a  rabbit  be  inoculated  with  the  blood  serum  of  a 
horse  or  other  alien  animal,  the  serum  of  the  rabbit  acquires,  after  a 
time,  a  property,  by  reason  of  which  a  specific  precipitation  occurs 
when  an  extract  of  horse  meat  is  mixed  with  it.  This  test  method  has 
been  further  developed  by  Wassermann  and  his  pupils,  and  can  be 
applied  with  success  to  other  kinds  of  meat.  The  differentiation  of 
meat  of  closely  allied  species,  however,  such  as  that  of  sheep  and 
goats,  is  said  to  be  at  times  quite  difficult. 

In  the  manufacture  of  all  grades  of  sausage,  scrupulous  care  should 
be  observed  to  secure  cleanliness  of  the  casings,  which  require  more 
thorough  treatment  than  the  mere  passage  of  water  through  them. 
Dr.  Schilling^  reports  the  examination  of  prepared  intestines  which 
yielded  5  grams  of  excrement  per  meter. 

Owing  to  the  occurrence  of  a  gray  color,  which  is  said  by  Meyer*  to 

1  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXXIX.,  p.  373. 

2  Zeitschrift  fur  Fleish-  und  Milchhygiene,  1895,  p.  86.  _ 

3  Schiitze,  A.,  Ueber  weitere  Anwendungen  der  Pracipitine.  (Deutsch.  med.  Woch., 
1902,  No.  45,  p.  804.) 

*  Wassermann,  A.,  u.  Schiitze,  A.,  Ueber  die  Entwickelung  der  biologischen  Methode 
zur  Unterscheidung  von  menschlichem  und  tierschem  Eiweiss  niittels  Pracipitine.    (Ibid., 

1902,  No.  27,  p.  483. ) 

5  Wassermann,  A.,  Ueber  Agglutinine  und  Priicipitine.     (Zeits.  f.  Hyg.,  etc.,  Bd.  42, 

1903,  2,  p.  267. ) 

6  Ulilenhuth,  Die  Unterscheidung  des  Fleisches  verschiedener  Tiere  mit  Hilfe 
spezifische  Sera  und  die  praktische  Anwendung  der  Methode  in  der  Fleischbeschau. 
(Deutsch.  Med.  Woch.,  1901,  No.  45,  p.  780.) 

^  Deutsche  medicinische  Wochenschrift,  1900,  p.  602. 
8  Chemiker  Zeitung,  1900,  p.  3. 


FISH.  35 

JH'  (liK!  U)  tlio  paH.sa^o  of  Halt  by  dilTiiHion  from  \\\c  ronfxaits  to  tho 
(iasiiiff;,  wlii(!li  is  rich  in  watcir  iiiul  poor  in  salt,  llic.  coiiiiiicroial  value 
of  c(!rt,ain  vari(!tics  of  HauHa|ij(!  is  impaired,  ;iii<l  Ikjucc  it  bwjomoH  ncccH- 
sary  to  iip|)ly  artidc^ial  (H)lorH,  or  ,so  to  treat  the.  stiilTiii^;  fliattlio  oliati^e 
ill  color  slinll  not  occur.  The  V(!ry  nid  !ip|)caraiicc  which  so  often  h\\\r- 
gests  the  prcsiiiuu',  of  (toal-tar  products  may  h<r  due  to  the  action  of 
harmless  ])reservatives,  like  niter,  or  the  hicmo^lohin  of  swine  blood. 
In  such  case,  th(!  extract  with  alcohol,  glycerin,  or  amyl  alcohol  will 
not  dye  wool,  and   th(!  (u)I(>r  cannot  Ik;  precij)itatcd  as  a  lake. 

Accordinj^  to  J.  Ilaldane,*  the  red  color  of  cooked  sidted  nncata  is 
due  to  thoi)rcsence  of  N()-h:cmochromogen  produced  l)y  the  decomjiosi- 
tion  of  NO-hficniot2;Iol)in,  which  is  formed  by  the;  action  of  a  nitrit<;  on 
the  N()-hicmoehronioo;(!n  in  tlu;  absence  of  oxygen  and  presence  of  re- 
(lucino;  agcMits.  Tlu;  nitrite  is  formed  by  reduction,  within  the  raw 
meat,  of  the  niter  used  in  salting. 

Certain  of  the  artificial  sausage  colors,  as  "Orange  II.,"  the  sodium 
salt  of  /?-naphtli()laz()benzcne,  arc  extracted  easily  with  acidulated 
water,  and  will  dye  woolen  fibers  immersed  therein. 

FISH. 

In  the  ordinary  sense  of  the  word,  fish  includes,  in  addition  to  the 
varieties  of  fish  in  its  narrow  sense,  mollusks  (clams,  oysters,  mussels, 
etc.)  and  crustaceans  (lobsters,  crabs,  crawfish,  and  shrimps). 

Many  prejudices  have  existed  from  the  earliest  times,  and  to  a  cer- 
tain extent  still  exist,  against  the  use  of  fish  in  the  diet.  The  ancient 
belief  that  a  fish  diet  is  a  common  cause  of  leprosy  still  obtains  to  a 
certain  extent,  even  among  enlightened  people,  in  s})ite  of  all  scientific 
evidence  to  the  contrary.  Thus,  Mr.  Jonathan  Hutchinson^  main- 
tiiins  that  this  disease  is  so  caused,  especially  if  the  fish  is  poorly  cooked 
or  partially  decomposed.  He  asserts  that  the  disease  prevails  near  the 
sea  and  is  disappeariug  before  the  advance  of  agriculture  ;  but  op- 
posed to  this  is  the  fact  that,  in  the  interior  of  India,  the  disease  is  very 
common  among  people  whose  religion  forbids  the  use  of  fish,  and  who 
cannot  obtain  it  even  if  it  w-ere  desired. 

Some  varieties  of  fish  cannot  be  eaten,  because  of  their  inherent 
poisonous  properties.  But  few  of  these  are,  however,  found  north  of 
the  tropics.  Some  of  them  are  always  poisonous,  and  others  only  at 
certain  times  ;  and  in  some  cases,  individuals  of  certain  species  may  be 
and  others  may  not  be  noxious.  Some  varieties  of  fish  are  the  hosts 
of  parasites,  some  of  which  are  injurious  to  man,  but  unless  eaten  in 
the  raw  state  they  are  not  likely  to  produce  harm. 

There  is  a  belief  that  fish  is  particularly  valuable  as  a  brain  fotKl,  on 

account  of  the  supposed  high  percentage  of  phosphorus  that  it  contains. 

The  amount  of  phosphorus  is,  however,  so  far  as  is  known,  no  higher 

in  fish  than  in  meat  and,  moreover,  this  element  is  no  more  essential 

to  the  brain  and  nervous  system  than  any  others  which  are  present. 

1  Journal  of  Hyariene.  1901,  Vol.  I.,  p.  115. 
'  Archives  of  Surgery,  April,  1S99. 


36  FOODS. 

If  there  were  any  truth  in  this  common  belief,  we  should  expect 
naturally  to  find  men  of  commandine;  intellect  among  those  whose 
diet  consists  mainly  of  fish,  but,  as  is  well  known,  such  jicople  are  of  a 
low  order  of  intelligence,  though  not  by  reason  of  their  diet. 

In  spite  of  the  large  amount  of  nutriment  contained,  fish  has  not  the 
same  satisfying  properties  that  belong  to  meats,  but  it  is  an  exceed- 
ingly valuable  food,  and  in  many  parts  of  northern  countries  is  the 
principal  animal  food.  The  flavor  of  fish  is  infiucnced  greatly  by  the 
nature  of  the  food  supply  and  by  the  content  of  fat.  Generally  speak- 
ing, salt-water  fish  from  deep  water,  where  the  current  is  strong,  are 
better  than  those  from  shallow,  warm,  and  quiet  Avater,  and  both  salt- 
water and  fresh-water  fish  taken  from  rocky  and  sandy  bottoms  are 
preferred  to  those  from  muddy  bottoms. 

Condition  is  dependent  upon  a  variety  of  circumstances.  Some  fish 
are  regarded  most  highly  during  their  spawning  season  (shad  and 
smelts),  while  others  are  looked  upon  with  disfavor  at  this  period. 
Fish  caught  by  the  gills  in  gill  nets  die  slowly,  but  decompose  rapidly, 
and  such  are  of  inferior  flavor  and  value.  Fish  taken  from  the  water 
alive  and  killed  at  once  remain  firm  and  retain  their  flavor  longer  than 
those  allowed  to  die  slowly. 

Digestibility. — So  far  as  is  known,  the  digestibility  of  fish  and  meat 
is  about  equal,  but,  as  is  true  of  meats,  diifereut  varieties  of  fish  are 
diflerently  digestible.  Thus,  those  which  contain  the  greatest  per- 
centages of  fat,  as  salmon,  eels,  and  mackerel,  are  the  most  difficult  of 
digestion.  The  processes  of  drying,  smoking,  salting,  and  pickling 
lessen  digestibility,  and  fish  so  treated  are,  in  consequence,  less  suited 
to  the  needs  of  invalids  and  dyspeptics.  The  mollusks  are  regarded 
generally  as  most  digestible,  Avhile  the  crustaceans  are  believed  to  tax 
the  digestive  powers  much  more  than  any  other  animal  food.  Many 
persons  are  unable  to  digest  them  in  any  form,  and  others  who  suifer 
no  inconvenience,  so  far  as  digestion  is  concerned,  are  obliged  to  prac- 
tise self-denial,  because  of  idiosyncrasy,  which  manifests  itself  in  dis- 
tressing eruptive  disorders  of  the  skin,  dizziness,  and  other  nervous 
symptoms.  Lobster  and  crabs  are  much  alike,  but  the  former  is  less 
likelv  to  disagree.  The  claws  of  the  lobster  are  more  tender  and  deli- 
cate  than  the  tail,  which  is  firmer  and  much  closer  grained.  Shrimps 
are  rated  generally  as  more  difficult  of  digestion  than  lobsters  and 
crabs,  but  with  many  they  are  borne  more  easily. 

The  mollusks  are  more  digestible  in  the  raw  state  than  when  cooked. 
The  comparatively  tough  part  of  the  oyster,  the  adductor  muscle,  is 
very  trying  to  some  persons,  and  for  such  it  is  best  removed  and 
rejected. 

Keeping-  Qualities. — Fish  flesh  differs  very  greatly  from  meats  in 
keeping  qualities.  While  the  latter  are  improved  up  to  a  certain  point 
by  hanging,  fish  should  be  eaten  while  fairly  fresh,  since  decomposition 
sets  in  very  quickly.  Some  varieties,  as  halibut,  cod,  haddock,  and 
turbot,  may  be  kept  a  week  or  more  when  properly  cared  for,  while 
others  begin  to  deteriorate  almost  immediately.     So  long  as  the  flesh 


/'7.S7/. 


37 


isfirrn  iiiid  stilT,  all  fisli  Ih  edible,  but,  wlien  it,  is  eriislied  readily  by  ^<'n- 
tle  jtressiire  bcii-vvcten  tlie  (iiifi;ers,  if  is  misoiind  and  .should  be  rejcefed. 
MoIIusUh  and  enislaeeaiis  deeniiipose  very  (|iiiel<ly,  and  tlic  latter  wIkii 
boiled  a  Hliorl,  tiiiu!  ader  natural  deatJi  have  l»iit   little  fla\or. 

'I^Ik!  a,V(!ra^(;  elxitnieal  <;orri|»osit  ion  of  the  cililJc  portions  of  many 
vari(^tJes  of  American  lish  is  jriven  in  the  ibllowinj^  table,  eompiled 
from  IiulletJn  No.  'i'S  (Ifcivised  Ivlition),  U.  8.  J)ej)artm(!nt  of  Agri- 
(jnllure,  ( )nie(!  o("   l<]x|>erlmen(,  Stations: 


Food  Materia i.h. 


Fresh  Fish. 

Bass,  striped 

Blackfisli 

mueiish 

Buiiklo  fish 

iiutter-fish 

Catfisli 

Ciscoe 

Cod,  whole 

(Jod,  sections 

disk 

Eels,  salt  water 

Flounder .    . 

Haddock 

Hake 

Halibut 

Herring 

Kingfish 

Lamprey 

Mackerel 

Mullet 

Muskellunge 

Perch,  white 

Perch,  pike  (wall-eyed  pike)  .    .    . 

Perch,  yellow 

Pickerel,  pike 

Pike,  gray 

Pollock 

Pompano 

Porgy  

Red  grouper  

Red  snapper  

Salmon,   whole 

Salmon,  landlocked,  whole,  spent  . 
Salmon,  California,  anterior  sections 

Shad 

Sheepshead  

Skate,  lobe  of  body 

Smelt ." 

Spanish  mackerel 

Sturgeon,  anterior  sections  .... 

Tomcod 

Trout,  brook 

Trout,  salmon  or  lake 

Turbot 

Weakfish 

Whitefish 


Water, 
Per  ct. 

Protein 

N  X  G.25 

Fat. 

Ash. 

Per  ct. 

Per  ct. 

Per  ct. 

77.7 

18.6 

2.8 

1.2 

70.1 

18.7 

1.3 

1.1 

78.5 

19.4 

1.2 

1.3 

78.() 

18.0 

2.3 

1.2 

70.0 

18.0 

11.0 

1.2 

04. 1 

14.4 

20.6 

.9 

74.0 

18.5 

6.8 

1.1 

82.6 

16.5 

.4 

1.2 

82.5 

16.7 

.3 

.9 

82.0 

17.0 

2 

.9 

71.6 

18.6 

9.1 

1.0 

84.2 

14.2 

.6 

1.3 

81.7 

17.2 

.3 

1.2 

83.1 

15.4 

.7 

1.0 

75.4 

18.6 

5.2 

1.0 

72.5 

10.5 

7.1 

1.5 

79.2 

18.9 

.9 

1.2 

71.1 

15.0 

13.3 

.7 

73.4 

18.7 

7.1 

1.2 

74.9 

19.5 

4.6 

1.2 

76.3 

20.2 

2.5 

1.6 

75.7 

19.3 

4.0 

1.2 

79.7 

18.6 

.5 

1.4 

79.3 

18.7 

.8 

1.2 

79.8 

18.7 

.5 

1.1 

80.8 

17.9 

.8 

1.1 

76.0 

21.6 

.8 

1.5 

72.8 

18.8 

7.5 

1.0 

75.0 

18.6 

5.1 

1.4 

79.5 

19.3 

.6 

1.1 

78.5 

19.7 

1.0 

1.3 

64.6 

22.0 

12.8 

1.4 

77.7 

17.8 

3.3 

1.2 

63.6 

17.8 

17.8 

1.1      1 

70.6 

18.8 

9.5 

1.3 

75.6 

20.1 

3.7 

1.2 

82.2 

18.2 

1.4 

1.1 

79.2 

17.6 

1.8 

1.7 

68.1 

21.5 

9.4 

1.5 

78.7 

18.1 

1.9 

1.4 

81.5 

17.2 

.4 

1.0 

77.8 

19.2 

2.1 

1.2 

70.8 

17.8 

10.3 

1.2 

71.4 

14.8 

14.4 

1.3 

79.0 

17.8 

2.4 

1.2 

69.8 

22.9 

6.5 

1.6 

Fael 

value  per 

pound. 


Calor. 

465 
405 
410 
430 
800 

1135 
630 
325 
325 
190 
730 
290 
335 
315 
565 
660 
390 
840 
645 
555 
480 
530 
365 
380 
370 
365 
435 
665 
560 
385 
410 
950 
470 

1080 
750 
530 
400 
405 
795 
415 
335 
445 
765 
885 
430 
700 


38 


FOODS. 


Food  Materials. 


Fish,  Preserved  and  Canned. 


Cod,  salt 

Cod,  salt,  "boneless" 

Haililock,  smoked 

Halibut,    smoked 

Herring,  smoked 

Lamprey,  canned 

Mackerel,  salt 

Mackerel,  salt,  canned  in  oil  .    . 

Mackerel,  salt,  dressed 

Minogy,  pickled,  canned  .... 

Salmon,  canned 

Sardines,  canned 

Sturgeon,  dried,   Russia  .... 

Trout,  brook 

Tunney,  canned  in  oil,   Russia  . 

Shellfish,  Fi-esh  and  Canned. 

Clams,  long,  in  shell 

Clam.s,  long,  canned 

Clams,  round,  in  shell 

Clams,  round,  canned 

Crabs,  hard  shell 

Crabs,  canned 

Crayfish,  abdomen 

Lobster 

Lobster,  canned 

Mussels,  in  shell 

Oystei-s,  in  shell 

Oysters,  canned 

Shrimp,  canned 

Terrapin 

Turtle,  green 


Water. 

Protein 
N  X  6.25. 

Fat. 

Ash. 

Per  ct. 

Per  ct. 

Per  ct. 

Per  ct. 

53.5 

25.4 

.3 

24.7 

55.0 

27.3 

.3 

19.0 

72.5 

23.3 

.2 

3.6 

49.4 

20.7 

15.0 

15.0 

34.6 

36.9 

15.8 

13.2 

63.3 

16.9 

12.2 

4.0 

42.2 

21.1 

22.6 

13.2 

58.3 

25.4 

14.1 

4.1 

43.4 

17.3 

26.4 

12.9 

56.5 

22.0 

18.6 

3.0 

63.5 

21.8 

12.1 

2.6 

52.3 

23.0 

19.7 

5.6 

50.6 

31.8 

9.6 

7.6 

68.4 

22.3 

6.1 

3.7 

51.3 

23.8 

20.0 

4.3 

85.8 

8.6 

1.0 

2.6 

84.5 

9.0 

1.3 

2.3 

86.2 

6.5 

.4 

2.7 

82.9 

10.5 

.8 

2.8 

77.1 

16.6 

2.0 

3.1 

80.0 

15.8 

L5 

2.0 

8L2 

16.0 

.5 

1.3 

79.2 

16.4 

1.8 

2.2 

77.8 

18.1 

1.1 

2.5 

84.2 

8.7 

1.1 

1.9 

86.9 

6.2 

1.2 

2.0 

83.4 

8.8 

2.4 

1.5 

70.8 

25.4 

1.0 

2.6 

74.5 

21.2 

3.5 

1.0 

79.8 

19.8 

.5 

1.2 

Fuel 

value  per 

pound. 


Calor. 

410 
490 

440 
1020 
1355 

895 
1345 
1065 
1435 
1195 

915 
1260 

995 

670 
1300 


240 
275 
215 
285 
415 
370 
340 
390 
390 
285 
235 
335 
520 
545 
390 


Composition. — In  proteids,  fish  rank  nearly  as  high  as  meats,  but 
they  are  very  much  poorer  in  fat,  only  a  few  varieties  yielding  over  10 
per  cent.  These  include  salmon,  turbot,  lamprey  eels,  eels,  butterfish, 
lake  trout,  and  herring,  and  are  followed  by  shad  and  Spanish  mack- 
erel, with  over  9  per  cent.  The  great  majority  of  species  contain  less 
than  5  per  cent.,  and  many  of  the  commoner  kinds  even  less  than  1 
per  cent.  In  fact,  most  fish  flesh  yields  more  mineral  matter  than  fat. 
Shellfish  are  fairly  rich  in  proteids  and  contain  notable  amounts  of 
carbohydrates,  but  they  are  very  poor  in  fat. 


Meat  and  Fish  and  Parasitic  Disease. 

Man  is  often  the  host  of  parasites  through  ingestion  of  infested  meat 
and  fish.  Of  these,  the  most  common  is  the  tapeworm,  of  which  at 
least  ten  species  are  known,  though  only  three  have  been  demonstrated 
as  having  any  connection  with  food.  These  are  Taenia  saginata  (T. 
mediocanellata)  due  to  measly  beef.  Taenia  solium  to  measly  pork,  and 
Bothriocephalus  latus  to  infested  sturgeon,  pike,  perch,  and  salmon. 


MI<:AT  AND    FISH   AND    rAllASITK!  D/.SJ-JA.SK  .'iO 

Tli(!  hdU'.r  iH  very  run;  in  tlii.s  coiiiifry,  tlioii^li  not  iiru;r)mrnon  .'iKtii^^ 
tli(!  liiiJlJt!.  OCIIm-  Iav'^c  miirilxir  of  worrriH  \vlii<'li  iii(i.~t  fisli,  tins  is  tlir- 
only  on(!  l<novvn  to  he.  (;onv(!y(!(l  lo  iiinii.  1 1  is  kilKd  very  (jni<;l<ly  if 
tli(!  fish  is  (!ool<('(l  properly. 

'^l^lu!  l;irv;il  fornis  of  T.  fia^injitn  ;in(|  T.  solinin  cxisf  in  Ixd'  ;inf| 
pork  r(!Sp('c,livcly  uh  (Jy.sticHircu.s  hovis  .-ind  ( '.  <'clinlosjc.  TIk-  latt<T 
Ih  Cound  r;ir-('Iy  jiIho  in  mutton.  Meats  infesl<;(l  with  thesr;  forms  are 
known  us  "  monsly  "  or  "  mcasled,"  and  tho  animals  from  whif;h  tho 
meats  an;  (lei-ivcd  are  known  as  the  intermediate  hosts,  man  hein^ 
the  final  host.  The  liCe  history  of  the  tapeworm  is  much  more  Kimpic 
than  that  of  many  other  j)arasites.  I'efrinninf:;  with  tlx;  adult  tiip(;- 
worm  in  man,  llu;  cycle!  is  as  follows:  J^'rom  vnr.\\  individual  segment, 
which  is  ])()ssessed  of  a  complete;  reproductive  system,  f^nyif  numherH 
of  eggs  arc  discharged.  The  latter  are  exj)elled  from  the  intestine  with 
the  feces,  and  some  of  them  eventually  may  enter  the  digestive  tract  of 
ciittle  or  swine  through  the  food  or  water.  In  the  intestine,  the  emhryos 
become  liberated  from  the  eggs,  and  they  then  make  their  way  in  large 
numbers  to  the  muscular  tissues,  brain,  liver,  and  other  [)arts,  where 
they  come  to  rest  and  develop  as  bladder  worms.  The  bladders  are 
variable  in  size,  the  smallest  being  about  -^-y^  inch,  and  the  largest  about 
1^  inch  across,  and,  in  the  flesh,  are  embedded  between  the  nniscular 
fibers.  The  living  animal  shows  nothing  in  its  appejirance  to  indi«itc 
the  presence  of  the  parasite,  excepting  when  the  cyst  can  be  seen  in  the 
under  side  of  the  tongue  or  between  the  tongue  and  the  lower  jaw.  If 
now  the  animal  is  slaughtered  and  the  meat  is  eaten  raw  or  imperfectly 
cooked,  the  Cysticercus  is  freed  from  its  enveloping  cajisule  and  ])ro- 
ceeds  to  develop  into  an  adult  ta])cworm,  and  the  cycle  is  complete. 
The  Cysticercus  bo  vis  dies  within  t^vo  or  three  weeks  after  the 
slaughter  of  its  host,  and,  therefore,  raeasled  beef,  kept  for  three  weeks 
in  cold  storage,  becomes  incapable  of  producing  harmful  effects.  It  is 
killed  within  24  hours  by  pickling  solutions  of  common  salt,  Avhen 
brought  into  intimate  contact.  The  Cysticercus  cellulosae  lives  rather 
longer  in  cold  storage  :  probably  a  month  or  more,  Both  of  these 
larvaj  are  killed  by  exposure  to  a  temperature  of  140°  F.  for  5 
minutes,  and  as  this  is  lower  than  the  temperature  in  the  interior  of 
well-cooked  meat,  it  is  necessary  only  to  make  sure  that  the  meat  is 
properly  cooked  to  escape  danger.  Neither  parasite  is  destroyed  by 
ordinaiy  smoking  or  salting,  but  both  are  killed  by  hot  smoking. 

The  sale  of  measled  meat  is  permitted  in  many  countries  of  Europe, 
but  it  must  be  sold  as  such  and  only  in  specially  designated  places.  It 
finds  a  ready  market  at  a  low  price,  and  the  purchasers  are  warned 
that  it  should  be  cooked  thoroughly.  According  to  Virchow,  since  the 
introduction  of  systematic  meat  inspection,  the  proportion  of  tapeworm 
in  the  human  subject  dissected  in  Berlin  has  fallen  from  1  in  31  to  1 
in  280. 

A  parasite  of  far  greater  importance  is  the  TricMna  spiralis,  which 
is  found  almost  exclusively  in  pork  and  only  occasionally  in  the  flesh 
of  other  mammals  and  of  birds  and  frogs.    Trichiuie  are  small,  thread- 


40 


FOODS. 


like  worms  nuich  longer  than  cue  would  suppose  on  passing  examina- 
tion of  flin-ly  thick  niicrosco]M'o  preparations,  since  tliev  are  coiled  with 
several  turns  within  the  minute  cysts  in  ^v]wh  they  "are  lodged.  In 
Plate  I.,  Fig.  1,  IS  shown  one  of  tlie  iiarasites  in  tlie  free  state.  In  the 
pig  the  worm  infests  Ix.th  the  fat  and  the  voluntarv  muscles,  but  chiefly 
the  latter,  and  es])ecially  the  diaphragm,  the  intercostals,  and  the  mus- 
cles of  the  jaw.  When  encapsulated  in  the  flesh,  their  location  may  be 
evident  to  the  naked  eye  as  small  white  specks.  Thin  sections  of 
muscles,  treated  a  few  minutes  in  weak  caustic  potash  solution  (1:10) 
are  soon  made  sulHciently  clear  to  reveal  the  coiled  worm  under  a  lens 
of  low  power.  If  very  much  fat  is  present  or  if  the  capsule  has 
l)ecome  calcareous  and  thick,  it  may  be  necessary  to  emj^loy  ether  or 
acetic  acid  before  api)lying  the  potash.  When  the  parasites  are  very 
numerous,  the  flesh  is  both  speckled  and  ])ale. 

Our  first  knowledge   of  the  serious  effects  which  may  result  from 
eating  infested  pork  dates  back  only  to  1860,  although  the  parasite  had 
been  discovered  in  the  muscles  of  a   human  subject  by  James  Paget  in 
1833  and  named  by  Richard  Owen.     It  long  was  regarded  as  a  harm- 
less parasite   and  curiosity,  and  its  effects  were  mistaken  for  rheuma- 
tism, typhoid  fever,  and  other  diseases  of  common  occurrence      The 
case  which  finally  revealed  its  capacity  for  harm  was  that  of  a  youn^ 
woman  admitted  to  the  hospital   at  Dresden  suffering,  it  was  supposed, 
from  t>jhr,id  fever.     In  a  short  time,  a  train  of  symptoms  quite  unlike 
those  of  that  disease  appeared,  the  most  marked  one  being  very  acute 
pain  involving  the  entire  muscular  system,  and  intensified  on  attempting 
to  naove.     On  account  of  the  agony  induced,  extension  of  the  arms 
and  legs  ^vas  quite  impossible.      Pneumonia  supervened,  and  in  a  few 
days  the  victim  died.     The  autopsy  revealed  the  parasite  in  vast  numl)ers 
in  the  muscles,  and  this   led  to  further  investigation,  which  showed 
that,  four  days  before  the  first  symptoms  of  illness  a])])cared,  she  had 
eaten  freshly  killed  pork.     Some  of  this  was  secured  in  the  form  of  ham 
and  sausage,  and  examination  demonstrated  the  presence  of  the  parasite 
1  lie  first  extensive  outbreak  which  caused  the  disease  to  be  looked 
upon  as  one  of  great  importance  occurred  in  Prussia  in   1863   when 
more  tlian  20  persons  died  within  a  month  after  a  dinner  in  whicli  103 
had  participated,  and  at  which  smoked  sausages  made  from  an  infested 
pi^ghad   been  served.     The  parasites  were   discovered  in  the  muscles 
of    those  who   died  and    in  the    sausages  that  remained.     Since  that 
time.  It  has  been  customary  in  most  large   slaughtering  establishments 
to  examine  pork  for  evidence  of  the  parasite,  before  passing  it  as  fit  for 
food.      Lut  examination  is  not  always   a  safeguard,  even  in  countries 
where  it  is  observed  most  carefully.      In  Germany,  for  instance,  where 
all  meats  are  supposed   to  be   examined  with  scrupulous  care,  particu- 
larly those  from  the  United  States,  the  disease  is  viry  commom 

In  1883,  on  account  of  the  alleged  dangers  which  lurked  in  Ameri- 
can meats,  importation  was  interdicted  for  a  time,  but  in   the  succeed- 
ing 15  years  there  were  in  Prussia  alone  3,003  cases  and  207  deaths 
not  one  of    which  could  be  traced  to  American  meat  either  salted' 


FLA'I  E    I 


ru:     1 


^.«*,  "«i 


Free  Trichina.     :<  38. 


Trichinse  in   Pig  Muscle.      X  75. 


MJ'JAT  AND   FISH  AND  J'ARASJ'J'KJ  DISEASE.  41 

j)ickl<^<l,  canned,  or  ni;i<l(!  into  Hmokcd  HJinHn^cs,  Oxer  40  [x-r  wtnt. 
of  I.Ik!  (',ii,S(\s  w(!r(!  <t;hu!(1  f,o  IOiin)|)('!in  nic-it  wliicli  luid  Ijfcn  [Kissed  hh 
fr('(!  from  <rl<',liina;,  ;i.n(l  \\n\  icst  lo  lOiiropciin  fiic'it  wliieli  |i;id  lieeri 
foiMid  1.0  contiiin  the  puni.sitc!,  hut  had,  nevcitlKtlcHM,  heen  liandh'<l  hy 
the  trade.  During  lHJ)i),  the  ])araHiteH  were  found  hy  the  rnicrow!^>j)iHt« 
of  the  IT.  S.  I)e|)artmcnt  of  A^nicMiHun;  in  U  ,i\r/.)  <,f  tlie  2,227,710 
hogs  examined. 

It  is  j)r()hahle,  as  stjitcd  hy  ('harles  W.  Sliles,'  who  eon<(;t<(l 
ahout  900  re[)orted  eases  wlii<^li  had  occurred  in  tliis  count ry  rhiriii}: 
the  .'^(5  years  ]H()()-l<S9r),  that.  \\n\  disease  is  more  w^minon  in  the 
United  States  than  generally  is  su])j»()S('(l.  T<  is  af^-epfed  commonly 
that  1  or  2  ])er  cent,  of  dissccting-rootn  snhjccts  siiow  evidence  of 
th(^  parasite,  l)ut  it  would  appear  froin  the  investigations  of  11.  U. 
Williams^  that  this  estimate  is  much  too  low,  lor  careful  (examination 
of  505  cadavers  taken  at  random  showed  old  encaj)sulation  and  calcifi- 
cation in  no  less  than  27  instancies,  or  5..'M  per  cent.  The  l)irthplae<!S 
of  the  snhjects  included  all  of  the  most  im])oi"tant  countries  of  Kur(»j)e 
and  North  America,  but  the  number  of  cases  examined  was  tf)0  sniall 
to  admit  of  accurate  ccmclusions  as  to  the  influence  of  nationality  upon 
the  frequency  of  the  disease.  It  is  evident  that  many  cases  of  trichinosis 
escape  detection,  and  that,  as  Williams  jioints  out,  estimates  have  been 
based  on  naked-eye  diagnosis. 

In  spite  of  the  danger  of  eating  trichinous  meat,  there  are  those  who 
are  not  deterred  by  fear  from  eating  it.  In  Germany,  for  instance,  it 
has  happened  a  number  of  times  that  hogs  which  have  been  condemned 
and  ordered  buried  by  the  sanitary  authorities  have  been  dug  w\>  sur- 
reptitiously and  exiteu.^ 

Trichinosis  bears  certain  resemblances  to  typhoid  fever  and  to  acute  tu- 
berculosis, but  in  addition  is  accompanied  by  oedema  and  intense  pain. 
It  arises  from  eating  the  infested  meat  in  a  raw  or  not  well  cooked 
condition.  The  trichinae  are  killed  by  exposure  to  155°  F.,  if  they  are 
not  encapsulated;  otherwise  by  a  temperature  of  158°  to  160°.  They 
are  not  affected  by  intense  cold,  putrefactive  processes,  nor  ordinary 
smoking,  but  are  killed  by  long  pickling. 

The  first  symptoms  appear  in  a  few  days  after  ingestion,  and  indi- 
cate irritation  of  the  alimentary  canal.  These  are  followed  by  feV)rile 
symptoms  and  intense  muscular  pains.  Death  may  occur  within  a 
few  weeks.  In  case  of  recovery,  the  parasites  become  encysted,  and 
then  are  incapable  of  producing  further  injury  to  their  host.  The 
manner  in  which  they  jn'oduce  their  effects  is  as  follows  :  When  the 
infested  meat  reaches  the  stomach,  the  digestive  juices  dissolve  the 
capsules,  and  the  parasites  thus  are  left  in  a  free  state.  In  the  intes- 
tine, they  find  conditions  flivorable  to  growth,  and  in  a  few  days'  time 
they  grow  so  large  that  they  can  be  seen  with  the  naked  eye  and  appear 
like  fine  threads. 

1  Philadelphia  Medical  Journal,  June  1,  1901. 
'  Journal  of  Medical  Research,  July,  1901,  p.  64. 

3  For  an  account  of  such  a  case  consult  Zeitschrift  fiir  Fleisch-  und  MilchliTgiene, 
1897,  VU.,  p.  104. 


42  FOODS. 

The  female  parasites  when  fully  mature  begin  to  produce  young, 
each  to  the  extent  of  upward  of  500.  These  begin  at  once  a  migra- 
tion through  the  walls  of  the  intestine  and  find  their  way  to  all  parts 
of  the  body,  and  it  is  during  this  stage  that  the  fever  and  intense  pain 
are  caused. 

W.  G.  Thompson,^  as  a  result  of  observation  upon  52  cases  in  his 
personal  practice,  believes  that  the  diif'erential  diagnosis  can  easily  be 
made  if  the  following  points  are  observed  : 

1.  Acute  onset  usually  with  vomiting  and  abdominal  cramps. 

2.  A  high  grade  of  eosinophilia  invariably  present ;  usually  above 
30  per  cent,  and  frequently  much  higher — even  above  80  per  cent. 

3.  A  high  grade  of  temperature,  often  reaching  104°  F.  or  more, 
and  lasting,  in  lessening  degree,  for  two  to  six  weeks. 

4.  Puffiuess  of  the  eyelids  and  face,  with  pains  in  the  eyes  occurring 
in  one-fourth  of  the  cases. 

5.  Dyspnoea  and  diaphragmatic  breathing  occurring  without  cyanosis 
in  about  one-fourth  of  the  cases. 

6.  The  generalized  muscle  pains,  cramps,  soreness,  and  prostration, 
causing  sometmes  deceptive  apparent  immobility. 

7.  The  sudden  occurrence  of  symmetrical  circumscribed  corneal 
hemorrhages  in  a  patient  whose  bloodvessels  are  not  degenerated 
should  give  rise  to  a  suspicion  of  trichinosis. 

The  examination  of  the  blood  for  an  increased  number  of  eosino- 
philes  is  of  the  greatest  importance.  Furthermore,  if  a  small  piece  of 
muscle  be  excised  under  local  anesthesia,  the  parasites  can  be  fre- 
quently discerned  under  low  powers  of  the  microscope.  It  is  not, 
however,  always  possible  to  secure  the  consent  of  the  patient  to  this 
minor  operation.  For  this  reason  an  observation,  made  recently  by 
Herrick  and  Janeway,^  is  of  great  interest.  These  investigators,  fol- 
lowing a  method  devised  by  Stiiubli,^  in  which  method  a  small  amount 
of  blood  is  laked  with  3  per  cent,  acetic  acid,  were  able  to  detect  the 
parasite  in  the  circulating  blood. 

Cross^  also  was  able  to  demonstrate  the  trichinella  in  the  blood  taken 
from  an  ordinary  ear  puncture.  The  patient  was  taken  sick  on  August 
17,  1909.  On  August  24th  the  diagnosis  of  trichinosis  was  made, 
largely  because  of  a  differential  count,  showing  that  20  per  cent,  of  the 
white  corpuscles  were  eosinophiles.  Excision  of  a  piece  of  muscle 
could  not  be  done,  and  on  August  25th  a  blood  examination  was  made. 
One  cubic  centimeter  of  blood  was  squeezed  from  the  ear  and  laked 
with  12  cubic  centimeters  of  3  per  cent,  acetic  acid.  The  sediment 
obtained  by  centrifuge  was  examined  under  low  powers  of  the  micro- 
scope. One  trichinella  was  easily  found  and  two  others  were  seen 
with  less  distinctness. 

1  American  Journal  of  Medical  Sciences,  August,  1910. 

^  Archives  of  Internal  Medicine,  1909,  April,  p.  263. 

3  Stiiubli,  Klin,  und  exper.  Untei-sucb.  iiber  Trichinosis.  Verhandlung.  des  Kon- 
gre.ss  f.  Klin.  Med.  Wiesbaden,  1905,  354.  Beitrag  zum  Nachweis  von  Parasiten  in 
Blut.  Miinch.  Med.  Woch.,  1908,  Iv.,  2601. 

^  Archives  of  Internal  Medicine,  Sept.,  1910. 


HLA'i'h    II 


Trichinae  in  Huinan   Muscle,  showing  Thickened 
Capsule.      X  78. 


Triehinag  iu  Human  Muscle,     x  75. 


MI'JAT  AND    FISH   AND    I'AJIASITK!   DISIIASE.  43 

In  rki(!  I.,  V\\!^.  "A,  .'111(1  I'hiff!  II.,  V'lii;.  1,  uro  ko(;ii  fliiri  Hections  of 
mu8olo  from  a  linrMiUi  subject,  KJiowing  the  worm  coiled  up  and  the 
thickoiio'l  <!a,i»siilo  foriruid  al)Out  it.  in  I'lutc;  II.,  I'^i^r.  2,  it  may  ho 
s(!(Mi  within  the  iniisch;  oC  an  in((;.st(!d  pif^. 

The  sheep  disease  wiiich  is  known  as  rot,  whieh  term,  i(  mii.-t  ]><• 
said,  is  used  to  inchid(!  a  large  number  of  abnc^rmal  ecmdition.s,  but 
which,  in  its  strict  apj)lication,  means  a  parasitic  disea-se  of  the  liver,  \h 
believed  by  many  to  be  of  sufTicient  im|)ortance  to  warrant  the  con- 
denmation  ofllie  fh^sh  of  the  animal,  but  the  scientific  evi<lence  on  thi.s 
point  is  to  the  effect  that  no  j)()ssible  harm  can  come  tx)  tlu;  efH)Humer, 
even  thouj^h  the  liver  itself  be  eaten.  The  parasite  infests  not  alone 
sheep,  but  cattle  as  well,  and  is  known  as  the  "fluke."  Of  the  many 
varieties  of  flukes,  (hen!  are  but  two  known  in  the  Unit(.-d  States  ;  the«e 
are  the  common  liver  Ihdvc  (leberwurm,  leberegel,  schafegel,  douve 
h6patique)  and  the  large  American  fluke.  The  former  infests  cjittle 
and  sheep  ;  the  latter,  only  cattle. 

The  life  history  of  the  worm  is  exceedingly  complicated,  and  is  as 
follows  :  The  adult  or  hernunphroditic  worm  fertilizers  itself  in  the 
biliary  passages  of  the  liver,  and  produces  an  ex(;eedingly  large  num- 
ber of  eggs,  which  pass  to  the  intestine  of  the  host  with  the  bile,  and 
are  expelled  in  the  feces.  Such  of  the  eggs  as  eventually  reach  water 
give  rise  after  a  longer  or  shorter  period,  according  to  temperature,  to 
a  ciliated  embryo,  which  on  its  escape  from  the  egg  becomes  a  free 
swimming  ciliated  miracidium,  and  enters  the  body  of  certain  species 
of  snails,  where  it  comes  to  rest.  Here  the  organism  grows,  and,  after 
a  time,  certain  germ  cells  in  its  posterior  portion  develop  a  still  differ- 
ent form  of  life,  the  ridi?e.  These  wander  to  the  host's  liver  and  in- 
crease in  size,  and  in  turn  develop  from  their  germ  cells  the  next  gen- 
eration, which  are  called  cercarise.  These  leave  the  body  of  the  snail 
and  swim  about  in  the  water,  and  some  become  attached  to  blades  of 
grass,  where  they  form  enveloping  cysts  and  undergo  anatomical  changes. 
For  their  next  stage  it  is  necessary  that  they  be  received  into  the  stomach 
of  some  herbivorous  animal  by  being  swallowed  with  the  grass  to  which 
they  are  attached.  On  reaching  the  stomach,  the  cysts  are  destroyed  and 
the  parasites  migrate  to  the  liver  and  become  adult  hermaphrodites,  thus 
completing  the  cycle.  Occasionally  they  wander  to  the  lungs  and  other 
parts  of  the  body.  In  the  liver,  the  parasites  attach  themselves  to  the 
walls  of  the  bile  ducts,  which  may  become  completely  blocked,  and  they 
cause  the  breaking-down  of  the  surrounding  tissues  and  general  symptoms 
due  to  structural  changes.  The  parasite  cannot  be  transmitted  directly 
from  animal  to  man,  since  it  requires  an  intermediate  host,  and  in  the 
stage  preceding  its  final  development  it  is  not  attached  to  material  con- 
stituting human  food.  There  ai-e,  to  be  sure,  some  instances  of  the  dis- 
ease in  man,  though  not  by  direct  transmission  from  meat.  The  con- 
dition caused  by  flukes  is  known  variously  as  rot,  liver  rot,  fluke  dis- 
ease, and  distomatosis. 


44  FOODS. 

TRANSMISSION  OF  DISEASE  BY  MEAT,  FISH,  AND  VEGE- 
TABLES. 

Living  pathogenic  bacteria  in  diseased  meat  and  fish  may  gain  access 
to  the  stomach  in  limited  numbers  and  beget  no  disease.  If  they  are 
not  destroyed  by  tlie  gastric  juice,  they  have  to  contend  with  myriads 
of  organisms  normal  to  the  intestines,  and  it  is  only  when  the  condi- 
tions are  such  as  to  favor  extensive  nudtiplication  that  they  are  likely 
to  produce  harmful  eli'ects.  In  meat  that  is  cooked  thoroughly,  they 
are  killed  by  the  heat  to  which  they  are  subjected. 

It  is  well  known  that  the  stomach  has  great  ju-otcctive  ]iower  in 
its  natural  functions,  since  certain  violent  organic  poisons  may  be 
taken  into  that  organ  without  injury,  while  if  the  same  are  intro- 
duced iuto  the  circulation,  the  results  are  fatal ;  thus  the  venom  of  poi- 
sonous serpents  is  digested  and  made  harmless  by  the  stomach  juices. 
An  instance  of  the  immunity  conferred  by  cooking  or  by  the  process 
of  digestion,  or  by  both  together,  and  of  the  fatal  result  of  the  admis- 
sion of  the  harmful  element  of  the  same  meat  to  the  system  through 
cuts  and  abrasions,  is  given  by  Lardier.^     The  case  is  as  follows  : 

A  cow  died  suddenly  of  anthrax  and  was  dressed  for  food.  The 
meat  was  eaten  by  a  large  number  of  people,  none  of  whom  suffered 
the  slightest  inconvenience  or  injury.  A  number  of  cats,  however, 
which  ate  some  of  the  waste  matters  and  licked  uj)  the  blood,  died  with 
some  suddenness.  A  woman  who  bought  the  head  and  wounded  her- 
self m  the  process  of  cutting  it  up  had  a  charbon  at  the  place  of  injury 
and  died.  Two  men  who  helped  skin  the  cow  had  charbon,  but  re- 
covered. A  calf  belonging  to  one  of  these  two  died  of  anthrax,  and 
another  man,  removing  the  skin,  cut  himself  and  died.  The  skin  of 
the  original  animal  was  sold  and  the  purchaser  put  it  in  a  shed  on  his 
farm.  Some  time  later,  one  of  his  cows  died  suddenly,  and  the  man 
who  dressed  the  carcass  wouuded  himself  during  the  process,  acquired 
a  charbon,  and  died.  How  much  farther  this  series  of  fatalities  might 
have  extended  cannot  be  Imown,  since  the  authorities  took  steps  in  the 
matter  and  prevented  further  fatalities. 

Many  instances  are  known  in  which  the  flesh  of  cattle  dead  of  in- 
fectious disease  has  been  eaten  with  impunity.  During  the  siege 
of  Paris,  for  example,  when  the  food  supply  was  exceedingly  limited 
in  amount,  no  one  paid  the  slightest  attention  to  the  condition  of  meat 
in  respect  to  disease,  even  glandered  horses  finding  a  ready  market, 
and,  so  far  as  is  known,  no  ill  effects  resulted. 

Many  years  ago,  when  the  rinderpest  was  very  prevalent  in  Bohemia, 
the  diseased  cattle  were  killed  and  buried  by  order  of  the  government ; 
but  the  poorer  class  dug  up  the  carcasses  and  cooked  and  ate  them 
without  suffering  any  evil  consequences  whatsoever. 

During  the  prevalence  'of  the  same  disease  in  England  in  the  early 
sixties,  the  meat  from  the  diseased  animals  in  all  stages  of  the  distem- 
per was  sent  in  enormous  quantities  to  market,  and  sold  and  eaten 

1  Kevue  d'Hygiene,  1898,  No.  5,  p.  431. 


TIlANSMISHION   Oh'   DISK  ASK    11  Y    MKA'I',    I'ISII,     VKd  KTA  I'.LKS.    V> 

willioiit  evil  (id'dcls.  A  siinilar  iiiitniinily  li:is  often  Iccn  noticed  ulU.T 
the  c()iiHiiinj)tJoii  of"  \\h'.  (•;i,rejisH(!S  of  :inlin;ils  <l}in^'-  fVoni  ;iciitx;  jdeiiro- 
'jyiwi(,m()id((,.  In  ordinary  cases  oC  tliis  disease,  which  i^  jtecnliarto  \){:v{' 
catil<!,  iJic,  elT'ects  a,r(!  localized  in  (he  hiii<rs.  Sometimes,  in  very  pro- 
noinuHid  cases,  the  llesli  is  altered  in  a|)]»e;ir;nie(,  hecomin^  dark  and 
discolored,  aiK  I  it.  is  als<>  moist  ;ind  llahhy.  It  i-  liilie\cd  ihnt  the  nnsit 
Is  cdil)l(!,  if  it^  poSHCHKCS  a  norinal  a|)|»ear;Miee.  The  nuiil  in  rinderpest 
iindcrj^oes  no  niai'ked  (tliannc  in  appearance,  cxc(;|)liii^  in  advanced 
cas(\s,  when    it,   is   dark   in   color  and    llahhy  and  of"  disa^reeal)l(!  txior. 

Jn  or<linai'y  cases  of  /"oo/  (iiul  iinnil/i.  (I,m',(w,  it  appwirs  that  the  car- 
<!a,ss  is  edible,  hnt  in  exceplioiiai  cases,  wIkmi  tlu;  animal  has  snd'jjrcd  for 
a  lonj^  time,  tlu;  llcsli  may  be  so  dctcriorat(!d  as  to  be  nndesirabh;.  As 
a  rnle,  ahli(»n<i:;h  the  disease  is  very  infections,  its  cours(!  is  niihl  and 
intcrf(M'es  oidy  slightly,  if  at  all,  with  llu;  (H)ndilion  of  the  in(yit,  whicii 
generally  cannot  be  distinguished  from  tliat  of  h«dthy  animals. 

Although  many  instauees  are  known  that  sliow  that  the  meat  of 
{inimals  sulfering  with  (inthrax  may  be  eaten  without  injury,  it  is  the 
unanimous  opinion  of  those  who  have  given  the  matter  attentioi;,  that, 
no  matter  how  good  the  meat  may  appear,  it  should  be  condenuied  and 
destroycHl.  If  the  meat  is  well  cooked,  accidents  are  rare,  but  many 
cases  of  fatal  injury,  involving  a  lai'ge  number  of  victims,  have  been 
traced  to  the  use  of  such  meat,  presumably  not  thoroughly  cooked. 
In  spite  of  the  protection  conferred  by  cooking,  there  is  such  ati  ele- 
ment of  danger,  even  in  the  handling  of  the  meat,  that  its  use  should 
be  discouraged  and  forbidden.  In  Scotland,  it  is  a  common  practice 
with  farm  laborers  and  other  poor  to  eat  the  meat  of  sheep  which 
have  died  of  acute  inflammatory  diseases,  even  of  antJirax.  The  car- 
cass of  an  animal  dying  of  diseiise  is  the  perquisite  of  the  herdsman 
and  ahuost  invariably  is  eaten  after  being  salted.  No  precaution  is 
taken,  except  to  cut  away  the  darker  portions  of  the  meat  which 
show  stagnation  of  the  blood.  Occasionally,  serious  consequences, 
due  either  to  imperfect  cooking  or  to  insufficient  salting,  result  from  its 
consumption. 

It  is  held,  furthermore,  that  the  flesh  of  animals  that  have  died  from 
the  following  diseases  is  unfit  for  human  food  :  ^ 

Blackleg,  hemorrhagic  septicemia,  pyemia  or  septicemia,  vaccine 
animals,  rabies,  tetanus,  malignant  epizootic  catarrh  (generalized  in- 
flammation of  the  mucous  membranes),  hog  cholera  or  swine  plague 
(generalized),  actinomycosis  (generalized),  extensive  caseous  lymphad- 
enitis with  or  without  pleuritic  adhesions,  generalized  tuberculosis, 
Texas  fever,  jiarasitic  ictero-hematuria,  advanced  mange  or  scab,  car- 
casses aifected  with  tapeworm  cysts,  known  as  Cysticercus  bovis  and 
Cysticercus  cellulosoe.  Meat  infested  with  Cceuurus  cerebralis,  Multi- 
ceps  socialis,  and  echinococcus  may  be  used  after  the  infected  part  or 
organ  has  been  condemned. 

1  Regulations  Governing  the  Meat  Inspection  of  the  United  States  Department  of 

Agriculture,  Bureau  of  Animal  Industry,  Order  150.  as  Amended.     Effective  Mav  1, 
1908.  ' 


46  FOODS. 

Moreover,  meat  or  meat  food  products  from  animals  which  have 
suffered  from — 

(rt)  Acute  inflammation  of  the  lungs,  pleura,  pericardium,  perito- 
neum, or  meninges. 

(6)  Septicemia  or  pyemia,  whether  puerperal,  traumatic,  or  without 
any  evident  cause. 

(c)  Severe  hemorrhagic  or  gangrenous  enteritis  or  gastritis. 

(d)  Acute  diffuse  metritis  or  mammitis. 
(c)  Polyarthritis. 

(/)  Phlebitis  of  the  umbilical  veins. 

[g)  Traumatic  pericarditis, 

(A)  Any  other  inflammation,  abscess,  or  suppurating  sore  if  associ- 
ated with  acute  nephritis,  fatty  and  degenerated  liver,  swollen  soft 
spleen,  marked  pulmonary  hyperemia,  general  swelling  of  lymphatic 
glands,  and  diffuse  redness  of  the  skin,  either  singly  or  in  combination, 
must  be  condemned  as  likely  to  produce  meat  poisoning. 

Tuberculosis. — The  cattle  disease  most  commonly  known  in  this 
country,  if  not  elsewhere,  is  tuberculosis,  and  concerning  the  advisability 
of  using  the  flesh  of  its  victims,  there  is  much  difference  of  opinion, 
here  and  abroad.  The  disease  is  more  common  in  cows,  especially  those 
kept  in  confinement,  than  in  steers  and  oxen.  It  is  almost  an  unknown 
disease  in  the  great  herds  roaming  the  western  plains.  In  Berlin,  in 
1892—93,  15.1  per  cent,  of  all  cattle,  1.55  per  cent,  of  swine,  0.11  per 
cent,  of  calves,  and  0.004  per  cent,  of  sheep  slaughtered  showed  some 
evidence  of  the  existence  of  the  disease.  In  Copenhagen,  in  the  years 
1890-93,  the  figures  were  somewhat  higher  than  those  of  Berlin,  ex- 
cepting in  the  case  of  sheep.  They  were  as  follows  :  17.7  per  cent,  of 
cattle,  15.3  per  cent,  of  swine,  0.2  per  cent,  of  calves,  and  only  one 
sheep  out  of  337,014.  At  the  abattoirs  of  Leipzig,  in  1897,  nearly 
half  of  the  cows  and  about  20  per  cent,  of  the  other  cattle  were  found 
to  be  tuberculous;  2.78  per  cent,  of  swine,  0.2  per  cent,  of  calves,  and 
8  sheep  out  of  49,559. 

Out  of  over  8,000  beeves  of  American  origin  lauded,  slaughtered, 
and  examined  at  Hamburg,  4  were  found  to  be  tuberculous,  while  of 
the  same  number  of  native  animals,  640,  or  160  times  as  many,  were 
found  to  be  afflicted  with  the  disease.  At  that  time  the  German  press 
had  been  carrying  on  one  of  its  periodical  agitations  against  the  impor- 
tation of  American  beef  cattle  on  account  of  the  dangers  to  which 
native  breeds  were  thereby  subjected. 

In  Great  Britain,  30  per  cent,  of  the  cows  are  estimated  by  Mac- 
Faydean  to  be  tuberculous.  In  Belgium,  of  20,850  animals  tested 
with  tuberculin  in  1896,  48.88  per  cent,  reacted.  In  Denmark,  of 
67,263  thus  tested,  32.80  per  cent,  reacted.  In  Mexico,  about  a  third 
of  the  beeves  slaughtered  are  tuberculous. 

In  this  country,  while  the  percentage  of  affected  animals  is  low,  it  is 
believed  to  be  on  the  increase,  both  with  cattle  and  swine.  In  the 
State  of  New  York,  it  is  said  by  veterinarians  that,  in  some  districts  in 
which  the  herds  are  mainly  of  the  hardy  grades  of  the  Ayrshire,  Hoi- 


TRANSMISSION   O/''   DISKASK    IIY   MKA'I\    FISH,     VFJlFTAIiLES.     47 


Htdn,  !ui<l  Sliori-liorii  fhiiiilics,  uhout  1  per  cent,  of  tli<;  cowk,  ;ui«1  in 
<)tli(!i'M  wli(!ro  .I('rs(;yK  und  ( jiicnisciyH  arc  more,  common,  ubont  2  to  .'> 
per  cent.  iU'(!  tnbercnlons.  In  Mn.ssuclniHCittH,  tlio.se  in  .'i  yK).sition  to  Ix; 
best  informed  Kliite  that,  ;unon^  covvh,  the  (lise;is(!  in  mnr-h  mon;  frecpjcnt 
th:in  in  New  York,  but  tluit  it  is  rarely  to  be  CoiuhI  in  <;i1v(jh,  Ht(M;rH, 
and  ox(!n.  In  Peimsylvainn,  tlu!  Slat(!  velerinarian  believes  that  not 
ovi'Y  2  per  cent,  of  all  cattle  an;  tnbercnlons.  At  the  larp-  abaltx»irs  of 
this  country,  ubont  1  in  2,000  cattle  is  f(»nnd  to  be  tnbercnlons.  Dnr- 
\w\r  the  two  years  (nided.Innc  oO,  1801),  «,H;}|,027  cattle  were  inspected 
by  tlu;  Federal  atithoriti('s,  and  7,015,  or  1  in  1,259,  were  condemned 
on  account  of  tuberculosis.  During  1000,  of  4,801,100  inspected, 
5,27!),  or  1  in  021,  were  condemiuid.  Of  2.'>,'>.')0,)S84  hogs  insj)ectcd, 
5,440,  or  1  in  4,200  were  sufficiently  affected  to  warrant  wndemnaticm 
of  at  least  a  part  of  the  carcass. 

Some  Rksui.ts  of  Tuiieucumn  Tksts  of  Cattle  hy  State  and  Fedekai-  f )fkker« 

WITH    TlUiEKCULlN    FuErAUED    IJY   THE    lit  KFAU    OF    AnIMAL    LvjUSTItY, 

1898,  TO  July  31,  1908,  Inclusive.^ 


states. 


California  .  . 
Connecticut  . 
Illinois  .  .  . 
Indiana  •  .  . 
Iowa     .... 

Maine  .... 
Massachusetts 
Michigan .  .  . 
Minnesota  .  . 
Missouri  .    .    . 

New  Jersey  . 
New  York  .  . 
North  Carolina 
Ohio     .... 

Oregon     .    .  . 

Vermont .    .  . 

Washington  . 

Wisconsin   .  • 


Number 
of  cattle 
tested. 


9,618 
6,080 
7,120 
2,935 
4,020 

3,264 
86,223 

2,155 
60,733 

1,680 

3,293 
4,034 
1,207 
2,933 

1,466 

162,570 

2,779 

32,297 


Number 
reacting. 


1,112 
852 
790 
246 

778 

149 

11,853 

351 

3,031 

133 

828 
565 
208 
425 

351 

10,628 

455 

3,477 


Percentage 
reacting. 


11.56 
14.01 
11.09 
8.38 
193.5 

4.56 

13.75 

16.29 

4.99 

7.92 

2.5.14 
14.00 
17.23 
14.49 

23.94 

6.54 

16.37 

10.77 


The  organs  iuvolved  most  frequently  in  tuberculosis  of  animals  are 
the  liver,\mgs,  kidneys,  bram,  and  udder.  The  muscles  are  aflected 
very  rarely,  although  the  bacilli  have  been  found  in  the  expressed  juice. 

At  what  stage  of  the  disease  meat  becomes  unfit  for  food,  is  a  ques- 
tion over  which  there  is  much  cimtroversy.  Extremists  on  the  one 
side  believe  in  condemning  the  entire  carcass  on  the  slightest  evidence 
of  disease  in  any  part  thereof,  while  those  on  the  other  side  maintain 
that  the  entire  animal  may  be  used  as  food  without  injur}-.     In  Eng- 

1  Circular  No.  8,  June,  1910,  INIichigan  Agricultural  College  Experiment  Station, 
Division  of  Bacteriology  and  Hygiene,  page  61. 


48  FOODS. 

land,  the  practice  is  to  condemn  any  carcass  in  which  the  disease 
has  made  such  extensive  progress  that  the  flesh  has  become  dete- 
riorated. The  Royal  Commission  on  Tuberculosis^  concluded  that 
meat  from  tuberculous  animals  may  be  consumed  with  hnpuuity,  if 
sufficient  discriuiiuation  aud  care  are  exercised  in  slaughtcrinji:  and 
dressino^.  Every  part  containing  tubercles  should  be  removed  and 
destroyed, "  and  '  the  whole  carcass  itself  in  advanced  or  general 
tuberculosis. 

The  Frcuch  law  excludes  carcasses  with  generalized  tuberculosis  and 
those  in  which  local  lesions  have  involved  the  greater  i)art  of  an  organ. 
The  same  is  true  in  Austria,  In  Prussia,  the  meat  is  held  to  be  unfit 
for  food  if  the  animal  has  begun  to  show  emaciation,  but  is  passed  as 
fit  for  human  consumption  if  the  disease  occurs  in  only  one  organ,  and 
in  general,  if  the  animal  is  well  nourished.  In  Belgium,  the  law  of 
September  30,  1895,  permits  the  sale  of  meat  of  tuberculous  animals 
after  sterilization. 

In  the  United  States  the  following  rules  are  given  by  the  Bureau  of 
Animal  Industry,  in  reference  to  carcasses  affected  with  tuberculosis  :  ^ 

Section  13. — Paragraph  1. — The  following  principles  are  declared 
for  guidance  in  passing  on  carcasses  affected  Avith  tuberculosis  : 

Principle  A. — The  fundamental  thought  is  that  meat  should  not  be 
used  for  food  if  it  contains  tubercle  bacilli,  if  there  is  a  reasonable 
possibility  that  it  may  contain  tubercle  bacilli,  or  if  it  is  impregnated 
with  toxic  substances  of  tuberculosis  or  associated  septic  infections. 

Principle  B. — On  the  other  hand,  if  the  lesions  are  localized  and  not 
numerous,  if  there  is  no  evidence  of  distribution  of  tubercle  bacilli 
through  the  blood,  or  by  other  means,  to  the  muscles  or  to  parts  that 
may  be  eaten  with  the  muscles,  aud  if  the  animal  is  well  nourished 
and  in  good  condition,  there  is  no  proof,  or  even  reason  to  suspect, 
that  the  flesh  is  unwholesome. 

Principle  C. — Evidences  of  generalized  tuberculosis  are  to  be  sought 
in  such  distribution  and  number  of  tuberculous  lesions  as  can  be 
explained  only  upon  the  supposition  of  the  entrance  of  tubercle  bacilli 
in  considerable  number  into  the  systemic  circulation.  Significant  of 
such  generalization  are  the  presence  of  numerous  uniformly  distributed 
tubercles  throughout  both  lungs,  also  tubercles  in  the  spleen,  kidneys, 
bones,  joints,  and  sexual  glands,  and  in  the  lymphatic  glands  con- 
nected with  these  organs  and  parts,  or  in  the  splenic,  renal,  prescap- 
ular,  popliteal,  and  inguinal  glands,  when  several  of  these  organs  and 
parts  are  coincidentally  affected. 

Principle  D. — By  localized  tuberculosis  is  understood  tuberculosis  lim- 
ited to  a  single  or  several  parts  of  organs  of  the  body  without  evidence 
of  recent  invasion  of  numerous  bacilli  into  the  systemic  circulation. 

Paragraph  2. — The  following  rules  shall  govern  the  disposal  of 
tuberculous  meat : 

1  The  Veterinary  Journal  and  Annals  of  Comparative  Pathology,  June,  1895. 

"^  Regulations  Governing  The  Meat  Inspection  of  the  United  States  Department  of 
Agriculture,  Bureau  of  Animal  Industry,  Order  150,  as  Amended,  Effective  Mav  1, 
1908. 


TRANSMISSION    Oh'   DISHASh:   llV   Mh'A'l',    FISH,     V I'.d ETA  IiLI-:s.     V.) 

Rule  A, — TIh-  ciilin!  cun^uHS  sliull  \n-  coinlciniKid  — 

(a)  WIkmi  it,  wiis  ()l)S(!rv<'<l  liclorc  llic  ;iiiiiii:il  waH  killcl  that  it  wjih 
suffcriiifij  with  {'v.wv. 

(b)  Wlicii  there,  \h  a  (tilicrciilons  or  oilier  cachexia,  as  hhowii  by 
anaMiiIa  and  eiiiaclatioii. 

(<;)  When  (h(;  h'sioiis  ol"  (iibetciilosis  are  j^rcncrali/ed,  as  H}if)\vn  hy 
their  j)re,seiu!(!  not  only  at  (he  usual  seals  oC  primary  inleetir)n,  but  also 
in  parts  of  the  carcass  or  the  orj^ans  that  n)ay  \h'.  reached  hy  th<;  bacilli 
of  tuheninlosis  only  wluiii  they  are  carried  in  the  Hystcrnic  circulatiorj, 
'I'nherciilons  lesions  in  any  two  of  the  rollowinj2;-rnentioned  r»r^ans  are 
to  be  accH'pted  as  e\idenc(!  ol"  {^((iKd'ali/aiioii  when  tluy  o(!Ciir  in  addi- 
tion to  local  tuberculous  lesions  in  the  difrestive  or  rcsj>iratory  tracts, 
in(^lu(lin<>;  the  lymphatic  ji;lands  connect(;d  therewith  :  Sj)leen,  kidney, 
uterus,  udder,  ovary,  testicle,  adrenal  fi;lan(l,  brain,  oi'  .sj)inal  cord  or 
their  nuMubranes.  Numei'ous  uniforridy  distributed  tubercles  through- 
out both  lungs  also  ailbrd  evidence  o("  generalization. 

(r/)  When  the  lesions  of  tuberculosis  are  found  in  the  riuiscles  or 
intermuscular  tissue  or  bones  or  joints,  or  in  the  l)ody  lymphatic  glands 
as  a  result  of  draining  the  muscles,  bones,  or  joints. 

(e)  When  the  U'sions  are  extensive  in  one  or  both  body  cavities. 

(/)  When  the  lesions  are  multiple,  acute,  and  actively  j)rogressive. 
(Evidence  of  active  progress  consists  in  signs  of  acute  inflammation 
about  the  lesions,  or  liquefaction  necrosis,  or  the  presence  of  young 
tubercles.) 

Rule  B. — An  organ  or  a  j)art  of  a  carcass  shall  be  condemned — 

(rt)   When  it  contains  lesions  of  tuberculosis. 

(6)  When  the  lesion  is  immediately  adjacent  to  the  flesh,  as  in  the 
case  of  tuberculosis  of  the  parietal  pleura  or  peritoneum,  not  only  tlie 
membrane  or  part  affected  but  also  the  adjacent  thoracic  or  alxlominal 
wall  is  to  be  condemned. 

(c)  When  it  has  been  contaminated  by  tuberculous  material,  through 
contact  with  the  floor,  a  soiled  knife,  or  otherwise. 

(d)  All  heads  showing  lesions  of  tuberculosis  shall  be  condemned. 

(e)  An  organ  shall  be  condemned  when  the  corresponding  lymphatic 
gland  is  tuberculous. 

Rule  C. — The  carcass,  if  the  tuberculous  lesions  are  limited  to  a 
single  or  several  parts  or  organs  of  the  body  (except  as  noted  in  Rule 
A),  without  evidence  of  recent  invasion  of  tubercle  bacilli  into  the  sys- 
temic circulation,  shall  be  passed  after  the  parts  containing  the  local- 
ized lesions  are  removed  and  condemned  in  accordance  with  Rule  B. 

Rule  D. — Carcasses  which  revei\l  lesions  more  numerous  than  those 
described  for  carcasses  to  be  passed  (Rule  C),  but  not  so  severe  as  the 
lesions  described  for  carcasses  to  be  condemned  (Rule  A),  may  be  ren- 
dered into  lard  or  tallow  if  the  distribution  of  the  lesions  is  such  that 
all  parts  containing  tuberculous  lesions  can  be  removed.  Such  car- 
casses shall  be  cooked  by  steam  at  a  temperature  not  lower  than  220° 
F.  for  not  less  than  four  hours. 

Meat  from  tuberculous  cattle  is  infective  to  other  animals  in  very 


50  FOODS. 

variable  dos^rees.  As  a  rule,  the  more  advanced  the  disease,  the  more 
likely  is  tiie  meat  to  be  infeetive.  Experiment  has  demonstrated  that 
inteetion  depends  to  a  not  ineonsiderable  extent  upon  contamination  of 
the  meat,  in  the  process  of  dressing;,  by  the  hands,  knives,  or  cloths, 
which  have  been  in  contact  with  tuberculons  matter. 

Although  lesions  in  the  muscular  tissue  itself  are  not  at  all  common, 
positive  results  liave  repeatedly  been  obtained  in  exi)eriments  in  which 
the  expressed  juice  of  the  meat  has  been  injected  into  susceptible 
animals.  Thus,  Kastner  obtained  9  positive  results  in  11  injections  of 
the  juice  of  the  meat  of  7  tuberculous  animals,  and  Steinheil  transmitted 
the  disease  to  guinea-pigs  by  means  of  juice  from  meat  apparently 
sound.  Arloing  inoculated  the  muscle  juice  of  10  tuberculous  cows  into 
guiuea-pigs  and  demonstrated  that  that  from  2  of  the  animals  w^as  infec- 
tive. Nocard  produced  the  disease  with  the  muscle  juice  of  but  1  of 
21  tuberculous  cows  with  w^hicli  he  experimented.  All  of  these  cows 
had  been  condemned  at  the  abattoir  on  account  of  extensive  lesions. 
Woodhead,  Galtier,  Humbert,  and  others  have  met  with  varying  degrees 
of  success  in  similar  experiments. 

That  tuberculosis  can  be  transmitted  to  animals  by  feeding  them  on 
tuberculous  material  has  been  abundantly  proved,  but  the  lesions  pro- 
duced almost  never  invoh'e  the  muscular  apparatus,  and  many  of  the 
subjects  escape  infection  altogether.  It  was  reported,  for  example,  by 
Thomassen,  at  the  Tuberculosis  Congress  at  Paris,  that  of  10  young 
pigs,  each  of  which  was  made  to  eat  4.5  kilos  of  meat  from  animals 
with  advanced  general  tuberculosis,  but  2  were  affected,  and  their  por- 
tions had  contained  a  quantity  of  splintered  bone.  Ravenel '  has  held 
for  a  long  time  that  food  tuberculosis  may  appear  first  in  the  lungs  and 
cervical  glands,  and  cites  the  case  of  2  cows  which,  fed  on  tuberculous 
material,  developed  extensive  disease  of  the  lungs  and  lesions  nowhere 
else.  As  stated  by  Dr.  D.  E.  Salmon,^  Woodhead,  St.  Clair  Thomp- 
son, and  Lord  Lister  have  shown  "  that  infection  through  the  medium 
of  the  food  may  not  necessarily  be  accompanied  by  disease  of  the  in- 
testines. The  organs  first  attacked  after  feeding  on  tubercular  material 
may  be  the  mesenteric  glands  and  liver,  or  even  the  bronchial  and 
mediastinal  glands  and  the  lungs.'' 

Relation  between  Human  and  Bovine  Tuberculosis. — The  ques- 
tion of  the  identity  of  the  bacilli  of  human  and  bovine  tuberculosis, 
raised  in  1901  by  Koch's  assertion  of  the  impossibility  of  transference 
of  the  disease  from  man  to  cattle  and  from  cattle  to  man,  has  led  to 
much  experimentation  and  study.  That  the  human  and  the  bovine 
types  of  B.  tuberculosis  are  distinct,  differing  in  virulence,  morphology, 
and  cultural  peculiarities,  was  demonstrated  by  Theobald  Smith  five 
years  before  Koch  asserted  that  the  difference  is  so  marked  that  bovine 
tuberculosis  is  a  negligible  factor  in  the  human  disease.  In  1902 
Ravenel  ^  stated  that  the  bovine  bacillus  shows  persistent  peculiarities 

1  Philadelphia  Medical  .Journal,  August  14,  1901,  p.  284. 

^  Bulletin  No.  33,  Bureau  of  Animal  Industry,  Washington,  1901. 

3  Journal  of  Comparative  Medicine  and  Veterinary  Archives,  1902,  pp.  65,  139. 


TRANSMISSION   OF   DISEASE   I'.Y   MEAT,    EISII,    VEO  ETA  I'.LES.    51 

of  ^rowili  aiid  iiiorpholoj^y,  wliicli  ciiiihlf;  it  to  Ik;  (lidiTcntiHt*'*]  from 
tlie  liiiman  variety,  and  tliat  it  is  j>:i(lio^ciiif',  not  only  for  nearly  all 
of  the  species  of  oxporiniontal  aninmls,  hut  for  man  also.  He  sayH,' 
inoniovor,  that  human  hacilli  vvitli  a  lii^li  decree  of  virulence  for  experi- 
nuiutal  animals  are  rarely  foinid,  and  that  cultures  liijrlijy  j)atho^enic 
for  cattle  an;  still  mon;  rare.  rjX))(;rimen(s  conducted  hy  Nocard, 
Cij)ollina,  and  others  indicate;  that  the  bovine  bacillus  is  the  more 
infective.  Nocard ^  observed  liiai  monkeys  fed  with  material  a^ntain- 
inj^  bovine  bacilli  became  iiilec^ted  much  sooner  than  did  thos(j  whos^; 
food  C()ntain(!d  the  human  variety;  and  (/ij)ollina  '  produced  genctral 
tubenudosis  in  a  healthy  a|)(!  with  milk  containing  bovine  bacilli,  while 
a  calf  resisted  infection  with  the  human  variety. 

The  experiments  of  V.  Dungern  and  Schmidt  *  gave  results  indicating 
a  selectiv(!  inf(>ctivity.  Human  and  boviiu;  bacilli  were  fed  to  anthro- 
poid apes;  the  former  ])roduced  tuberculosis  of  the  lungs,  the  latter  of 
the  alimentary  tract  and  mesenteric  glands.  In  Ravenel's  experiments 
guinea-pigs  infected  with  human  bacilli  lived  more  than  twice  as  long 
as  those  inoculated  with  the  bovine  variety,  and  rabbits  were  much  less 
extensively  infected  and,  indeed,  gained  in  weight. 

That  human  bacilli  from  different  lesions  are  differently  virulent 
has  been  observed  repeatedly.  Those  from  the  lungs  almost  invariably 
fail  to  infect  calves,  but  Delepiue^  produced  lesions  in  the  alimentary 
tract  of  a  calf  to  which  was  given  50  c.c.  of  mixed  sputum  with  its 
food.  The  animal  died  at  the  end  of  28  days.  Bacilli  from  other 
than  pulmonary  lesions  prove  to  be  far  more  virulent.  Fibiger  and 
Jensen  *'  found  that  bacilli  from  3  cases  of  chronic  intestinal  tubercu- 
losis were  exceedingly  virulent,  and  Wolffs  produced  general  tubercu- 
losis in  a  calf  which  he  inoculated  with  material  from  a  similar  source. 
In  1904  the  Bureau  of  Animal  Industry  experimented  with  9  cultures 
of  human  origin,  and  found  that  whereas  none  of  the  5  derived  from 
adults  was  infective  for  calves,  2  of  4  obtained  from  children  with  gen- 
eralized tuberculosis  caused  general  infection  of  calves,  with  lesions 
which  were  quite  as  severe  as  those  produced  bv  a  fresh  culture  of 
bovine  bacilli.  Ravenei*  found  two  cultures  from  the  mesenteric 
glands  of  milk-fed  children,  one  quite  as  virulent  as  bovine  bacilli  and 
the  other  more  virulent  than  the  usual  human  culture.  Races  of  human 
tubercle  bacilli  have  been  found  that  are  capable  of  producing  general 
tuberculosis  in  calves  and  swine  very  quickly.  Thus  Dammann,* 
experimenting  with  bacilli  from  a  human  case  of  peritoneal  tubercu- 
losis, produced  striking  cases  of  pulmonary  tuberculosis  in  hogs  inocu- 
lated subcutaneously,  Avith  fatal  results  within  28  to  42  days. 

1  Journal  of  the  American  Medical  Association,  June  3,  1903. 

^  Journal  of  the  Sanitary  Institute,  Januarv.  1903,  p.  571. 

3  Berliner  klinische  Wochcnschrift,  February  23,  1903.  p.  163. 

^  Arbeiten  aus  dem  Kaiserlichen  Gesundheitsaiute,  XXIII.,  1906,  p.  570. 

5  British  Medical  Journal,  October  26,  1901. 

®  Berliner  klinische  Wochcnschrift,  September  22,  1902. 

^  Ibid.,  November  17,  1902. 

^  Journal  of  the  American  Medical  Association,  June  3,  1903. 

^  Deutsche  Tieriirztliche  Wochcnschrift,  XII.,  1904,  p.  541. 


52  FOODS. 

Orth  1  has  convinced  himself  by  experiment  that  human  and  bovine 
tubercidosis  are  reciprocally  transmissible,  and  he  believes  that  virulence 
can  be  increased  materially  by  passage  through  a  series  of  animals. 
Behring-  increased  the  virulence  of  the  human  bacillus  by  passage 
through  rabbits  and  goats,  until  it  became  as  virulent  for  cattle  as  any 
strain  of  bovine  bacilli ;  and,  according  to  Salmon,^  Mohler  did  the 
same  by  passage  through  five  cats.  Hamilton  and  Young*  noted  an 
enormous  increase  in  virulence  on  reinoculation  from  one  calf  to 
another  and  great  variation  in  morphological  character.  Arloing  re- 
ports positive  results  from  inoculation  of  cattle,  asses,  sheep,  and  hogs 
with  human  bacilli  from  five  sources,  and  Theobald  Smith  has  found  a 
human  culture  directly  virulent  for  cattle.  Eber  '^  inoculated  a  bovine 
animal  with  material  from  tuberculous  human  mesenteric  glands,  and 
from  this  one  he  reinoculated  another,  which  succumbed  to  acute  mil- 
iary tuberculosis  within  a  week.  By  passing  the  material  through  a 
guinea-pig  first  and  then  inoculating  a  bovine  animal,  a  fatal  tuberculosis 
was  produced,  death  occurring  in  51  days. 

The  German  Tuberculosis  Commission,  appointed  on  Koch's  sug- 
gestion, found  that  different  bovine  cultures  varied  much  in  virulence, 
some  failing  to  transmit  the  disease  to  other  cattle.  They  tested  56 
cultures  of  human  origin  and  found  6  that  caused  marked  lesions  in 
cattle,  all  but  one  from  children  under  7  years  of  age.  The  fact  that 
the  bacilli  were  from  children  and  mainly  from  lesions  of  the  intestines 
and  mesenteric  glands  led  Kossel  ^  to  conclude  that  the  children  must 
have  been  infected  with  bovine  bacilli.  His  experiments  show  that 
the  bovines,  in  a  certain  small  proportion  of  cases,  may  yield  to  human 
bacilli,  and  in  endeavoring  to  explain  the  fact  he  admits  that  the 
reverse  is  also  true.  Orth,^  having  succeeded  in  producing  general 
tuberculosis  in  2  out  of  5  calves  inoculated  with  human  bacilli,  asks 
Koch  to  reconcile  his  own  negative  results  with  the  positive  results  of 
others. 

The  British  Royal  Commission  on  Tuberculosis  examined  a  large 
number  of  strains  of  human  tuberculosis  material  from  sputum,  lungs, 
glands,  and  joints,  and  found  a  number  which  were  capable  of  causing 
remarkably  severe  tuberculosis  in  cattle,  with  lesions  in  various  organs 
(lungs,  spleen,  liver,  lymphatic  glands,  etc.).  Several  of  the  less  viru- 
lent strains  were  found  to  gain  greatly  on  reinoculation  from  one  bovine 
into  another  or  into  a  guinea-pig.  The  Commission  concluded  that  in  a 
certain  proportion  of  cases,  especially  in  children,  human  tuberculosis 
is  the  direct  result  of  the  introduction,  mainly  in  milk,  of  the  bovine 
bacillus.  Of  60  cases  investigated,  the  clinical  histories  of  28  indicated 
the  entrance  of  the  exciting  cause  through  the  alimentary  canal. 

1  Berliner  klinjsche  Wochensehrift,  July  20,  1903. 
'  Beitriisje  ziir  Exper.  Therapie,  No.  2. 

3  .Journal  of  the  American  Medical  Association,  March  12,  1904. 

4  Public  Health,  September,  1903,  p.  689. 

5  Zeitschrift  fiir  Fleisch-  und  Milchhygiene,  XVI.,  1906,  p.  218. 
«  Berliner  klinische  Wochenschrift,  July  20,  1903. 

7  Ibid. 


TRANSMISSION   OF   hlSEASF.    l:Y    Ml!. IT,    llSIt,     V IJHyrM: I.ES.     tA 

(JoiKicniintr;  i\n\  possiltilit  v  <>'  <lii'<'''l  I  i:in-riiissii)ii  oC  t  iilicrciilo.-is  from 
siniiiiiiJ  (.o  in:ui  by  inociihil 'khi,  com- iilii;il)lc  csiilfiicc  i-,  rtH'cn;*!,  Iiiil  in 
inost  ciiHCiS  llic  iiil(;(;ti()n  is  lociil  :iihI  i.->  <liic  to  wound.-.  r(!C<'iv<^l  in  mak- 
ing :iiito|)si(!S  on  (lis(;iis(!(l  (!;itllo.  ITcilVcr'  records  an  accident  of  tliiH 
sort  wliicli  was  followed  in  IS  montiis  by  dculli  from  |)litliisis,  and  tlic 
originally  infected  joint,  was  I'ound  to  Im^  extensively  tnlH-rcnlar. 
Spronck  and  Hoefnagiil  -  record  a  similar  (;ase.  A  man  aged  <;.'{ 
years  ont  his  linger  while  skinning  a  vcsry  tiihercnlous  cow,  and,  thongli 
the  wound  healed  (jiiicikly,  the  glands  at  tlu;  elhow  hecame  enlarged 
and,  after  nine  months,  they  were  excrised  and  fonnd  to  he  infective 
for  guinea-pigs.  The  disease  was  conveyed  from  one  of  these  to  a 
healtiiy  heifer,  which  showed  general  infection  after  two  montli-.  'Die 
man  developed  a  catarrh  of  the  right  apex  20  months  lat(;r.  J>assar^ 
saw  in  ten  years  .'M  eases  of  undoiii)tcd  inoculation  tuberculosis,  chiefly 
in  veterinarians,  butchers,  and  others  wiio  handle  meats.  Cases  of 
similar  infection  through  milk  are  exceedingly  rare.  SaluKai  ••  cites  but 
3  cases  in  all ;  one,  from  the  a])plication  of  cream  to  a  leg  supposedly 
poisoned  by  ivy;  a  second,  from  milking  with  a  womid  in  r)ne  finger; 
and  a  third,  from  attempt(>d  removal  of  tattoo-marks  by  the  introduction 
of  milk  through  needle-punctures. 

Raw,  who  in  1904  ''  was  led  to  conclude  from  a  study  of  more  than 
3000  cases  of  pulmonary  tuberculosis  that  man  is  subject  to  two  kinds 
of  tuberculosis — the  pulmonary  form,  rare  in  children  under  twelve 
and  due  to  human  bacilli,  and  other  forms,  as  tubercular  joints,  tuber- 
culous meningitis,  and  abdominal  tuberculosis,  rare  in  adults  and 
due  to  bovine  bacilli — is  still  further  convinced  by  the  study  ^  of  a 
total  of  4000  cases,  including  700  which  came  to  autopsy,  that  bovine 
tuberculosis  affects  young  people,  attacking  the  tonsils,  the  alimentary 
tract,  the  glands,  and  through  the  blood,  the  meninges,  bones,  joints, 
and  other  parts,  and  that  the  human  variety  affects  adults  by  way  of 
the  lungs.  He  asserts  that  the  human  type  of  bacillus  causes  phthisis 
pulmonalis,  secondary  ulceration  of  the  intestines,  and  tuberculous 
laryngitis,  and  that  the  bovine  type  causes  acute  miliary  tuberculosis, 
primary  intestinal  and  mesenteric  disease  (including  tabes  mesenterica, 
tuberculous  peritonitis,  and  tuberculosis  of  the  pelvic  organs),  tubercu- 
lous glands,  joints  and  bones,  tuberculous  meningitis,  ulceration  of  the 
cornea,  and  lupus.  Of  nearly  300  cases  of  tabes  mesenterica  observed 
in  a  period  of  twelve  years,  not  one  of  the  subjects  was  a  breast-fed 
child.  McCaw,^  of  Belfast,  relates  that,  during  the  year  1906,  more 
than  200  of  827  children  treated  in  hos]iital  were  tuberculous,  and  lays 
special  emphasis  upon  cows'  milk  as  the  cause  of  forms  other  than  pul- 
monary.    Vou  Hausemann  '^  gives  particulars  of  25  cases  of  intestinal 

1  Zeitschrift  fiir  Hygiene,  HI.,  p.  209. 

'  La  Seniaine  Medicale,  October  15.  1902,  p.  341. 

^  Deutsclie  uiedicinisolie  Wochensohrift,  October  2,  1901. 

*  Bureau  of  Animal  Industrv,  Bulletin  33,  1901. 

5  British  Medical  Journal,  October  8.  1904. 

6  The  Lancet.  August  5,  190."\  and  March  2,  1907. 
^  British  iSledical  Journal,  December  21,  1907. 

^  Berliner  klinische  Wochenschrift,  1903,  Nos.  7  and  8. 


54  FOODS. 

tuberculosis  due  apparently  to  bovine  bacilli.  Fibiger  and  Yenseu  * 
report  2  cases  of  intestinal  tuberculosis  in  infants  of  four  and  eight 
months  respectively,  deemed  by  them  to  be  due  undoubtedly  to  milk 
of  tuberculous  cows.  One  had  had  milk  from  a  very  unsanitary  dairy 
in  which  a  case  of  tuberculous  udder  had  been  notorious.  Their  con- 
tention that  abdominal  tuberculosis  in  infancy  is  more  frequent  than  is 
commonly  supposed  is  borne  out  l)y  the  experience  of  Briining-  of  the 
Leipzig  Children's  Hospital,  who  found  evidences  of  tuberculous 
lesions  in  44  cases  which  came  to  autopsy  ;  in  25  the  liver  and  mesen- 
teric glands  were  diseased,  in  20  the  small  intestine,  in  10  the  large 
intestine.  General  miliary  tuberculosis  was  found  in  25.  In  8  cases 
there  was  evidence  of  tuberculous  infection  of  the  intestines  and  mesen- 
teric glands  alone,  and  these  must  be  considered  as  primary  infections. 
In  not  one  of  these  cases  had  tuberculosis  been  diagnosed  during  life, 
and  all  of  the  victims  had  died  of  some  acute  infectious  disease. 

Von  Hansemann  ^  believes  that  infection  can  take  place  through  the 
healthy  mucous  membrane,  and  von  Behring*  is  of  like  mind.  He 
believes  that  the  chief  source  of  tuberculosis  is  infected  milk,  and  that 
infection  of  infants  is  due  to  lack  of  continuity  of  the  epithelial  lining 
of  the  alimentary  tract,  which  permits  the  passage  of  bacteria. 

Evidence  that  infection  of  the  lungs  can  occur  through  food  without 
local  lesions  of  the  digestive  tract  is  offered  by  several.  Thus,  Nicolas 
and  Descas  ^  fed  fatty  broth  containing  large  numbers  of  tubercle  bacilli 
to  healthy  dogs,  some  of  which,  after  three  hours,  yielded  chyle  con- 
taining bacilli  in  such  abundance  that  they  could  be  demonstrated 
microscopically;  and  Ravenel^  introduced  a  quantity  of  bovine  bacilli 
in  melted  butter  into  the  stomachs  of  8  healthy  fasting  dogs,  and  found 
that  the  chyle  and  mesenteric  glands,  removed  about  four  hours  later, 
were  infective  for  guinea-pigs,  and  that  not  the  slightest  evidence  of 
abnormality  of  the  intestinal  mucosa  could  be  seen.  MacFadyen '' 
obtained  like  results  with  monkeys  fed  with  tuberculous  material  from 
cattle.  General  tuberculosis  was  produced,  but  no  lesions  of  the  intes- 
tines were  observed.  Calmette  and  Guerin  ^  have  proved  that  adult 
cows,  as  well  as  calves,  can  become  infected  with  tuberculosis  through 
the  alimentary  tract  without  anything  in  the  walls  of  the  intestine  to 
show  where  the  bacilli  may  have  passed  through,  and  they  believe  that 
pulmonary  lesions  in  the  adult  are  in  the  majority  of  instances  of  ali- 
mentary origin.  In  all  of  their  experiments  on  animals,  in  which  the 
infective  material  was  introduced  by  the  mouth  with  careful  avoidance 
of  inhalation,  the  peribronchial  lymph-nodes  became  affected  in  30 
to  45  days,  the  lesions  being  the  more  marked  the  greater  the  num- 
ber of  infected  meals. 

1  Berliner  klinische  Wochenschrift,  February  4, 1907. 

^  Hygienische  Rundschau,  November  15,  1906,  p.  1257. 

3  Loc.  cit. 

*  Deutsche  medizinische  Wochenschrift,  1903,  No.  39. 

5  Centralblatt  fiir  Bakteriologie,  etc.,  1902,  XXXIL,  p.  306. 

®  Journal  of  Medical  Research,  December,  1903,  p.  460. 

'  The  Lancet,  September  12,  1903. 

^  Annales  de  I'lnstitut  Pasteur,  XX.,  August,  1906. 


TRANSMISSION   OF  I)ISI<:ASI<:  IlY  M/'JAT,    h'ISII,    VF/lKTMlLHS.    oo 

Tho  l)(;licl"  licid  by  (iiaiiy  lli:it,  sill  liihcniilo.-is  Dri^^inatiiif^  in  tlu; 
intoHtiiial  tract  i.s  of"  boviiu!  origin  i>  not  .shared  by  TlicohaM  Srnilli,' 
wlio  i.s  of  opinion  tiiat  man  lias  only  a  limited  Hn.seeplihilily  to  bovine 
tuberculosi.s,  depending  on  e(!rtuin  .still  unknown  fuctor.s.  In  ii  cx^rtniri 
number  of  selecited  ca.ses  of  alimentary  tnlxrreiilo.sis  l\\v.  bovine  baeiiliiH 
has  been  found,  and,  Ik;  ways,  all  tlu;  rcj.st  i.s  uneertiiin  and  sjK'enJative. 
ri(i  l)(>liev(!s-  thai  ih(>  ratio  of  (!as(!.s  of  inteslinal  tiiberenlrK-is  aH.s<K;iaU'd 
with  bovin(!  biuMlli  may  be  rone;hly  estimated  at  20  to  K)  per  cent, 
L.  Rabinowitseh  ■'  has  summed  up  her  observations  on  hnm.-in  and 
bovine  tuberculosis,  and  concludes  that  wiiik;  the  bovine  baf;illiiH  does 
cau.se  tubercular  lesions  in  man,  the  proportion  of  ca.ses  due  theret/) 
cannot  be  di^termined.  Ac(V)rdinf^  to  Weber,'  infection  f)f  the;  human 
subject  with  bovine  bacilli  is  of  far  le.ss  importance  than  that  due  to 
those  of  human  origin,  since  the  former  produces  only  intestinal  and 
mesenteric  l(\sions,  and  these  forms  of  the  di.sease  are  mu(;h  le.ss  likely 
to  be  transmitted  from  on(>  victim  to  another.  Tliey  are,  moreover, 
found  almost  ex(;lusively  among  children,  and  possess  a  marked  tend- 
ency to  .s])ontaneous  cure.  Nevertheless,  since  bovine  infection  of  the 
human  subject  is  a  real  danger,  although  insignificant  in  compariwrn 
with  that  of  the  human  type,  proper  ]>recautions  should  be  taken  to 
prevent  its  occurrence  at  all  through  food  and,  notably,  milk. 

The  question  was  again  discussed  in  great  detail  at  the  Sixth  Inter- 
national Congress  on  Tuberculosis,  held  in  Washington  in  1908.  It 
was  agreed  that  two  types  of  organisms  exist,  differentiated,  first,  by 
the  manner  and  rapidity  of  growth  ;  second,  by  differences  of  reactions 
in  cultures  of  appropriate  age,  as  pointed  out  by  Theobald  Smith  ;  and 
third,  by  very  marked  differences  in  virulence  as  shown  by  their  action 
upon  certain  experimental  animals.  There  was  an  attempt,  further- 
more, to  come  to  some  general  conclusion  as  to  the  importance  of 
bovine  tuberculosis  in  its  relation  to  man,  but  no  agreement  on  this 
point  could  be  reached. 

Koch,  although  he  did  not  deny  the  occasional  transfer  of  bovine 
tuberculosis  from  animals  to  man,  insisted  that  such  transfer  was  rare, 
and,  as  supporting  Koch,  a  series  of  observations  reported  l\v  Kossel  * 
is  of  great  interest  in  this  connection.  From  1905  to  1909  113  cases 
of  tuberculosis  of  the  udder  were  reported,  and  628  persons  had  par- 
taken of  milk  from  these  tuberculous  cows.  In  44  of  the  113  cases 
the  milk  was  said  to  have  been  cooked.  In  the  other  69  cases  it  was 
taken  raw  by  360  individuals  (151  children,  200  adults,  and  9  of 
unknown  age).  Of  these  360  individuals,  only  2  became  surely 
infected.  These  2  were  children,  one  a  year  and  ten  months  old  and 
the  other  a  year  and  three  months  old.     Both  showed  disease  of  the 

^  Boston  Medical  and  Surgical  Journal,  January  IS,  1906. 

'•'  American  Journal  of  Public  Hygiene,  XIV.,  190(3,  p.  516. 

3  Berliner  klinische  Wochenschrift,  1906,  Xo.  24,  p.  784. 

■*  Deutsche  medizinisclie  Wochenschrift,  December  6,  1906. 

'  Die  Sammelforechung  des  Kaiserlichen  CTesundheits;\mtes  iiber  Milchgenuss  und 
Tuberkulose.  Deutsche  med.  "Wochensclir.,  Leipzig  u.  Berlin,  1910,  XXXVI.,  pp.  349- 
351. 


56 


FOODS. 


cervical  glands.  An  examination  of  these  glands  showed  tubercle 
bacilli  of  the  bovine  type.  In  12  instances  conditions  developed 
which  led  to  the  suspicion  only  of  tuberculosis.  In  346  people,  how- 
ever, and  among  these  136  children,  no  trouble  ensued. 

Others,  such  as  Eavenel,  Arloing,  and  Fibiger,  insisted  that  bovine 
tuberculosis,  although  it  but  infrequently  caused  disease  of  human 
beings,  was  a  distinct  menace  to  health  and  should  be  given  extended 
consideration.  The  best  and  most  recent  figures  are  those  of  Park 
and  Ivrumwiede.^ 

Park  and  Krurawiede  investigated  material  from  606  cases  of  tuber- 
culosis, in  order  to  determine  in  what  percentage  tubercle  bacilli  of  the 
human  and  bovine  types  occurred  in  different  varieties  of  the  disease. 
The  following  table  shows  the  results  obtained  : 

Total  Summary  of  Tabulated  Cases. 


Diagnosis  of  Cases  Examined. 

Adults 
16  Years  and  Over. 

Children 
5  to  16  Years. 

Children 
Under  5  Years. 

Human. 

Bovine. 

Human. 

Bovine. 

Human. 

Bovine. 

Pulmonary  tuberculosis 

Tuberculous  adenitis.     Axillary  .   . 
Tuberculous  adenitis.     Cervical  .   . 

Abdominal  tuberculosis 

Generalized  tuberculosis.    Alimen- 
tary origin 

290 

1 

13 
14 

6 
26 

4 

'  17  ' 

8 
1 

1 

1? 

1 
3 

1 
1 
1 

1 
3 

1 

3 

4 
6 

1 

i 

6 

1 

1 

3 

1 

'3 

1 

1 

3 

12 
14 

2 
1 

7 
2 
9 
3 

2 
3 

7 
5 

1 

1 

6 

9 

1 

8 
4 

Generalized  tuberculosis 

Generalized  tuberculosis  including 

meninges.     Alimentary  origin  .   . 
Generalized  tuberculosis  including 

meninges 

Tubercular  meningitis 

Tuberculosis  of  bones  and  joints  .   . 
Genito-urinary  tuberculosis    .... 
Tuberculosis  of  skin 

Miscellaneous  cases : 

Tuberculosis  of  tonsils 

Tuberculosis      of      mouth      and 

cervical  nodes 

Tuberculous  sinus  or  abscesses  .  . 
Sepsis.     Latent  bacilli 

8 
1 

Totals  .... 

381 

8 

54 

24 

99 

37 

Mixed  or  double  infections,  3  cases : 

Generalized  tuberculosis :  alimentary  origin.     30  years.     Human  and  bovine  type 

in  mesenteric  node.     Human  type  in  bronchial  node. 
Generalized  tuberculosis :  alimentary  origin.     5^  years.     Human  type  in  spleen. 

Bovine  type  in  mesenteric  node. 
Generalized    tuberculosis    including    meninges:    alimentary    origin.      4    years. 

Human  type  in  meninges  and   bronchial  nodes.     Bovine  type  in  mesenteric 

nodes.     Total  cases,  606. 

Finally,  these  authors  combined  the  cases  observed  by  them  with 
those  reported  by  thirty-two  other  reliable  observers.^     This  combined 

1  Park  and  Krumwiede.  The  relative  importance  of  the  bovine  and  human  types 
of  tubercle  bacilli  in  the  different  forms  of  human  tuberculosis,  Journal  of  Medical 
Kesearch,  October,  1910,  p.  205. 

2  Smith,  >Smitli  and  Brown,  Lewis,  Ravenel,  deSchweinitz,  Dorset  and  Schroeder, 
Mohler  and  Washburn,  Kossel,  Weber  and  Heuss,  W^eber  and  Taute,  Oehlecker  and 
Dieterlen,  Weber,  Hoelzinger ,  De  .Tong-Stuurmann,  Dammann  and  Miissemaier, 
Henschen,  Jundell  and  Svenson,  Rabinowitsch,  Beitzke,  Royal  Commission,  Watt, 
Kitasato,  Hess,  Gorter,  Fibiger  and  Jensen,  and  Burckhardt. 


TRANSMISSION   OF  hiSEASE   llY   MHAT,    FISH,    VFaF/l'AI'.LFS.     :>1 

liil)I(!  sliows  llif  coiiiiinr.'iiixf  <li.-l  ril)ii(  ion  nC  tlir;  two  tyjM'H  of  Wnfilli  in 
I  ()-12  OMSCH  iiii<l  i'('|»i'<'.sciits  (lie  iiiu'-l  r(li;il)li'  inrortiintioii  dii  flii>-  yul)- 
jcct  ill  tlic  |)r((S(!iil  lime. 

CoMitiNMi)  Taiiiilaiion,  Cahes  Reportkd  and  Own  Skiiikh  ok  Cahiw 


DiuynoHifc). 


Pulmonary  tuberculosis 

TulxTcnlous  luk'uitis.     Axillary  or 

iiiKiiiiuil 

'rulKTcnldiis  lulciiitis.    Cervical  .   . 

Aliiliimiiuil  UilxTculdHiM 

(iciicrali/eil  Uibiirculosis.  Alimen- 
tary orif^in 

(ienenili/eii  tuberculosis 

(ieneralized  tuliereulosis  including 
nioninfres.    Alimentiiry  ori|,'in  .   . 

(Tcneralized  tulx'rculosis  including 
meninges 

'I'uhcreular  uieniuKitis 

Tuberculosis  of  bones  and  joints  .    . 

(ienito-urinary  tuberculosis    .   .   .   . 

Tuberculosis  of  skin 

Miscellaneous  cases: 

Tuberculosis  of  tonsils 

Tuberculosis      of      mouth      and 

cervical  nodes 

Tuberculous  sinus  or  abscesses     . 
Sepsis.    Latent  bacilli 

Totals  .   .   .   . 


Adults 
lf>  Years  and  Over. 

Hi  11(1 

r.  to  If, 

Human, 

Hovliie. 

Human.  | 

r)68 

1? 

11 

2'J 

1 

4 
7 

f. 

1 

1 

7        ! 

■1 

_ 

i« 
11 

1 

1 
1 

'Jf> 
1 

1 

?. 

1 

- 

— 

677 

9 

99 

f;hllrlr«'n 
Under .',  Vfiim. 


12 


Mixed  or  double  infoclions,  4  cases ;  total  cases,  1042. 


It  is  apparent  from  these  tables  that  bovine  tuberculosis  decreases 
in  importance  with  the  increasing  age  of  the  individual.  It  is  further- 
more manifest  that  the  bovine  type  of  the  disease  falls  far  below  the 
human  type  in  its  im]>ortance  to  the  human  race. 

That  young  children  are  subject  to  bovine  tuberculosis  to  a  consid- 
erable extent,  although  the  amount  of  this  infection  is  far  less  than  was 
at  one  time  thought  to  be  the  case,  and  the  great  probability  that  this 
infection  of  children  is  due  in  the  majority  of  instances  to  the  drinking 
of  milk  of  diseased  cattle,  makes  it  very  evident  that  all  etfort  should 
be  made  to  restrict  bovine  tuberculosis,  not  only  in  the  commercial  in- 
terest of  the  farmer,  but  also  from  the  point  of  view  of  human  health. 
As  regards  the  cultures  isolated  by  them,  Park  and  Krumwiede  state 
that  9S  per  cent,  of  all  tuberculosis  cultures  fall  into  two  groups  so 
distinctive  as  to  be  surely  diagnostic.  The  other  2  per  cent.,  spoken 
of  by  diiferent  authors  as  atypical  or  irregidar,  they  }>refer  to  speak  of 
as  viruses  showing  variant  characters. 

Concerning  the  possibility  of  transmission  of  tuberculosis  l>v  eating 
the  meat  of  diseased  animals,  there  is  practically  no  evidence  of  value, 
but  whatever  danger  there  is,  if  any  at  all,  is  disposed  of  by  thorough 


58  FOODS. 

cookiug,  since  thereby  the  bacillus  is  quickly  killed.  Since  raw  meat 
is  frequently  used  as  food,  particularly  in  some  diseased  conditions,  it 
is  best,  in  order  to  be  on  the  safe  side,  to  see  that  meat  so  used  shall 
be  free  from  infective  properties. 

Typhoid  Fever  and  Cholera. — Foods  of  all  kind  may  be  made  the 
bearers  of  infection  to  man,  though  themselves  in  good  condition.  Par- 
ticularly is  this  noticeable  with  regard  to  oysters,  which  have  many 
times  conveyed  the  specific  organisms  of  typhoid  fever  and  cholera. 

In  1880,  Sir  Charles  Cameron  ^  brought  it  to  the  attention  of  the  pro- 
fession, that  oysters,  transplanted  from  the  coast  of  the  County  of  Wex- 
ford to  the  northern  shore  of  Dublin  Bay,  had  for  some  years  been 
much  subject  to  disease  and  had  died  in  large  numbers.  Specimens 
which  were  examined  were  found  to  contain  sewage  matters,  and  inves- 
tigation showed  that  the  beds  "  were  literally  bathed  in  sewage."  He 
otfered  the  suggestion  that  raw  oysters,  taken  from  the  shore  close  to 
sewer  outlets,  were,  perhaps,  as  likely  to  act  as  the  vehicle  of  typhoid 
fever  and  other  diseases  as  contaminated  water  or  milk,  and  advised 
that  "  oyster  beds  should  not  be  laid  down  at  any  point  on  or  close 
to  the  mouth  of  a  sewer."  But  the  warning  appears  to  have  excited 
no  more  than  a  languid  mterest  until  1893,  when  the  late  Sir  R. 
Thorne-Thorne,  in  a  report  to  the  Local  Government  Board,  stated 
his  belief  that  the  sporadic  cases  of  cholera  which  had  occurred  at 
various  inland  places  in  England  in  that  year  were  due  to  oysters  and 
other  shellfish  from  sewage-contaminated  water  at  Grimsby,  where  there 
had  been  a  small  outbreak  of  the  disease. 

In  the  following  year  occurred  the  well-known  outbreak  of  typhoid 
fever  at  AVesleyan  University,  which  was  so  ably  and  conclusively 
traced  by  Professor  Conn  ^  of  that  institution  to  polluted  oysters.  On 
October  20,  1894,  several  of  the  students  were  reported  as  slightly 
ill,  with  a  moderate  degree  of  fever.  The  number  of  cases  grew 
from  day  to  day,  and  shortly  included  several  of  undoubted  typhoid 
fever.  By  November  1st,  there  Avere  20  cases  of  the  disease,  which 
number  was  shortly  further  increased  to  23.  All  of  the  victims  were 
men  ;  there  was  no  illness  among  the  58  women  students.  Investi- 
gation completely  absolved  the  water  supply,  the  general  and  par- 
ticular food  supplies  of  the  various  boarding  places,  and  the  local 
conditions  of  the  dormitories  and  outside  lodgings  of  all  suspicion  of 
blame.  It  appeared  that  nearly  all  of  the  victims  were  members  of 
three  of  the  seven  college  fraternities.  The  combined  membership  of 
the  three  was  about  one  hundred.  On  October  1 2th,  eight  days  before 
the  development  of  the  first  symptoms,  all  seven  fraternities  had  had 
their  initiation  ceremonies  and  had  celebrated  in  the  usual  way  with  a 
supper.  Investigation  of  the  origin  of  the  components  of  the  suppers 
showed  that  there  was  but  one  dish  from  a  common  source,  and  that 
was  oysters.     The  three  a,fflicted  societies  and  one  other  had  obtained 

1  British  Medical  Journal,  September  18,  1880,  p.  471. 
=»  Medical  Record,  Dec.  15,  1894,  p.  743. 


TliANSMfSS/ON   OF  IHSF.ASI'I   /,')'   MEAT,    FISH,    VKd FTAIi[.FS.    59 

tluiir  oysic^rs  from  ;i  locnl  denier;  of  tlu;  rcMiniiiiiij.'-  fliree,  (\vf)  liiul  li;ul 
no  oysl(;rs,  ;uhI  (lie  (Jiird  liiid  li;i<l  some  from  ;i  de.-der  in  Ihirll'oi-d.  Of 
[\n\  four  sn|)|»lied  I)}'  ilie  loe;il  dciilir,  one  li;i(|  citcii  I  lie  oyKt^Ji'H  cookwi, 
:ind  ils  m(!ml)(!rslii|)  vv;is  iiol,  iii\;i(|cd.  'riiii-  tlic  iroiil)l(!  waH  Hiftird 
down  jo  the  niw  oy.stci's  from  llie  locnl  At-.Aiv.  I'.ut  then;  waw  one 
\  iciim  who  wmh  ii  non-so(;ie(y  man,  ;ind,  clearly,  his  ease  eoiild  ii'tt  he 
liaecul  to  tlu!  inilialion  snpjx^r.  Invesli^al  ion  of  his  dieletie  history 
estali)Hsh(!(l  the  f^uill  <if  IIh'  local  oyster  snj)|)ly  even  more  Hocurely,  for 
it  was  shown  that  \\v.  had  eaten  raw  oystiirs  from  the  sam(!  lot  at  tlic 
shop  of  th(^  dealer.  It  was  h-ariKsd,  loo,  that  5  men  from  Vale  had 
attended  the  exercises  of  the  societies  in  which  tlu!  onli)reaI<  occiirn^fl, 
and  in(|niry  develo|)ed  the  information  thai  2  of  tiie  0  were  seized  with 
typhoid  fever  some  weeks  after  their  id  urn  to  New  Haven.  Further 
investi<2;atioii  revealed  the  fact  that  (Ik;  incriminated  oysters  liad  heen 
l)r()n<;'ht  Ironi  a  bed  in  rjoiiu:;  Island  Sound,  and,  on  Otrtoher  lOtli,  two 
days  before  use,  had  been  stored  in  a  be<l  at  the  mouth  of  the  C^nin- 
ni|)iae  River,  a  short  distance  (oOO  feet)  from  the  outlet  of  a  private 
drain  from,  a  dwelling,  in  which  2  persons  lay  ill  with  typhoid  fever. 

Dr.  Arthur  Newsholme,'  M.  O.  H.  for  Brisj^hton,  England,  rejtoi-ted 
that  of  5']  eases  of  typhoid  fever  occurring  within  his  district  during 
1894,  no  fewer  than  15  were  due  to  infected  oysters,  and  6  to  other 
contaminated  shellfish  (clams,  cockles,  and  mussels).  In  a  later  com- 
munication,'^ after  a  thorough  examination  of  the  cases  that  had  occurred 
within  four  years,  he  reported  the  percentages  of  infection  due  i()  oys- 
ters and  nmssels  as  follows  :  In  1894,  38.2  ;  1895,  33.9  ;  1896,  31.'8  ; 
1897,  30.7. 

Dr.  J.  T.  C.  Nash,'^  M.  O.  H.  for  Southend-on-Sea,  says  that  prior 
to  1900  attacks  of  typhoid  fever  within  his  district  were  ascribed  to 
the  commonly  accepted  causes  and  occasionally  to  shellfish.  In  1900, 
investigation  showed  that  in  a  majority  of  the  reported  cases  there  was 
a  history  of  consumption  of  shellfish  within  2  or  3  weeks  of  the  onset. 
In  a  majority  of  the  cases  reported  during  the  last  5  months  of  1901 
there  was  a  similar  history.  During  June  and  July,  1902,  in  a  major- 
ity of  the  39  cases  reported  there  was  a  history  of  eating,  within  a 
month  of  the  onset,  cockles  from  a  sewage-polluted  creek  in  another 
district,  where,  during  June,  9  cases  of  typhoid  fever  had  existed. 
Cockles  obtained  from  these  layings  were  examined  and  the  presence 
of  sewage  bacteria  was  demonstrated.  In  a  later  communication  *  he 
states  that  in  82  of  the  102  cases  of  typhoid  fever  reported  during 
1902  there  was  a  shellfish  history.  Diminished  consumption  of  shell- 
fish, the  adoption  of  better  methods  of  storage,  and  the  exercise  of 
greater  care  in  obtaining  supplies  from  clean  lavings  were  followed  by 
a  very  decided  diminution  in  the  incidence  of  typhoid  fever.  By  care- 
ful inquiry  he  determined  that  somewhat  less  than  5  per  cent,  of  the 

1  British  IMedical  Joumal,  June  8,  1905,  p.  1285. 
^Public  Healtli,  SSoptemher.  1898. 

'Journal  of  tho  Sanitary  Institute,  January,  1903,  p.  369. 
*  Journal  of  State  Medicine,  December,  1903,  p.  710. 


60  FOODS. 

entire  population  of  the  district  were  eaters  of  sliellfish,  and  during 
1902  the  attack-rate  of  typhoid  fever  per  1000  among  this  section  \vas 
51.25  against  3.28  lor  the  whole  population,  and  0.75  for  the  non- 
eaters  of  shellfish.  The  attack-rate  among  the  dealers  and  their  em- 
ployees was  no  less  than  1()0  per  1000. 

Dr.  J.  F.  Allen/  M.  O.  H.  for  AVestminster,  secured  specimens  of 
cockles  which  were  from  the  same  bed  as  some  which  w^ere  supposed  to 
have  caused  a  number  of  cases  of  typhoid  fever,  and  had  them  ex- 
amined, at  the  Jenner  Institute,  for  sewage  bacteria.  The  results  were 
positive,  and  the  typhoiil  bacillus  itself  was  found  to  be  })resent.  Hew- 
lett -  records  that  cockles  purchased  at  the  fishmarket  of  Billingsgate 
and  examined  by  Klein  yielded  the  usual  sewage  bacteria  and  the 
typhoid  organisms  as  well.  Four  cases  of  ty]>hoid  fever  attributed  to 
cockles  from  the  same  source  were  the  cause  of  the  inquiry.  Sewage 
contamination  was  demonstrated  by  the  same  authority  in  11  of  18 
lots  of  oysters  from  five  different  localities. 

Chantemesse  ^  relates  the  following  case :  There  had  been  no  case 
of  typhoid  fever  in  the  village  of  I'Herault  Saint  Andr6  de  San- 
gonis  for  about  a  year,  when,  on  February  15th,  a  shopkeeper  received 
a  consignment  of  oysters  from  Cette.  The  entire  lot  was  consumed  by 
14  persons,  all  of  whom  were  made  sick.  In  the  6  dwellings  in 
which  the  victims  lived,  no  other  inmates  were  sick  in  any  way.  Eight 
of  the  number  were  made  only  slightly  ill,  the  symptoms,  which  in- 
cluded abdominal  pain,  vomiting,  diarrhoea,  borborygmus,  anorexia, 
and  general  malaise,  lasting  but  2  or  3  days.  The  4  youngest,  who 
ate  but  a  few,  were  very  sick  for  a  much  longer  time  (15  to  25  days), 
but  recovered.  The  stools  were  very  offensive,  were  passed  with  pain, 
and  were  dysenteric  in  appearance ;  there  was  tympanites  with  tender- 
ness and  gurgling.  All  4  were  greatly  prostrated.  The  remaining  2, 
a  woman  of  twenty  and  a  man  of  twenty-one,  developed  very  severe 
cases  of  typhoid  fever.      The  woman  died. 

INIosny,'*  to  whom  the  French  authorities  referred  the  whole  subject 
of  mollusk  poisoning  for  investigation,  has  reported  that  5  members  of 
a  family  of  7,  living  in  a  village  in  a  suburb  of  Paris,  in  which  there 
had  been  no  case  of  typhoid  fever  in  4  years,  were  made  sick  after 
eating  oysters  sent  to  them  from  Cette.  Four  were  seized  in  the 
evening  of  the  following  day  with  gastro-intestinal  disturbance,  which 
lasted  24  hours.  On  the  eighteenth  day,  a  youth  of  17  years  devel- 
oped unmistakable  symptoms  of  typhoid  fever,  of  which,  9  days  later, 
he  died.  In  March,  1897,  Chatin^  reported  the  case  of  a  family,  of 
which  several  members  were  stricken  with  typhoid  fever  after  eating 
oysters  from  a  bed  which  was  contaminated  by  sewage. 

Klein  and  Boyce  have  shown  that  oysters  contaminated  by  typhoid 

^  .Tom-nal  of  the  Sanitary  Institute,  .January,  1903. 
2  .Journal  of  State  Medicine,  March,  190.'^,  p.  163. 
^  Bulletin  de  I'Academie  de  Medecine,  1896,  35-36,  p.  588. 

*  Revue  d'Hyj^iene,  .January,  February,  and  March,  1900. 

*  LaSemaine  Medicale,  1897,  p.  9. 


TIlANSMISSION   OF    DISHASI':    i:Y    MI'.A'I',    I'ISII,     VEd  F/I'A  I'.IJ-IS.     (\\ 

bacilli  (;:ui  nttaiii  llnir  inrcctivi-  |)ro|)(it  irs  (or  '1  or  '.)  w»'<'ks,  ;ui(]  it  in 
shown  tliul,  lliftsc  iVoiii  scwaf^c-coiitiifiiiiiiii'ii  lnil-  iii;ty  not  lif  c'lti n 
with  entire,  widely  until  (luiy  have  lain  lor  nWoiit  2  weeks  in  iin|)ollNt<(l 
water.  It  a|)[)ears,  liowevc^r,  thai  in  (cockles  the  (yplioid  orj^ani.-rn 
thrives,  and  that  this  kind  of  shclKish  is  not  free*!  of  its  infective 
j)r()|)(!rties  hy  st()ra<^(!  in  clean  \v;iter.  Altliou;,di  rockles  are  not 
eaten  raw,  tlu;  cookinj:;  to  which  they  :ire  snhjected  is  hy  no  means 
thoi'on<:;h,  (or  hoilini;-  ("or  :uiy  con-^idefiihie  time  make.-,  fhem  toii|.;!i  ;ind 
iHKuitable. 

It  was  shown  hy  Foote,'  after  the  ontWreak  at  Wesleyan  Univer-ity, 
that  typiioicl  cultures,  introduced  witiiin  the  cells  of  oysters  from  the 
bed  from  which  the  incriminated  oysters  were  derived,  were  virulent  at 
the  end  of  4S  hours,  whi(^h  was  the  period  which  elaj)sed  between  tlie 
gatheriiiii;  and  consumption  of  those  which  caused  th<;  outbreak.  Fur- 
thermore, it  was  demonstrated  that,  if  the  specimens  were  kept  at 
57°  F.,  the  ortranisms  were  active  as  lonj^  as  a  month  later. 

The  influence  of  the  sewage  of  a  large  city  is  shown  by  C.  A.  Fuller,' 
who  collected  sain])les  of  water  and  shelKish  from  various  plac<'S  in 
Narragansctt  Bay,  into  which  about  1 4,0()(>,(  100  gallons  (jf  sewage  from 
Providence,  llhode  Island,  are  discharged  daily.  Water,  oysters,  clams, 
and  mussels,  taken  at  a  distance  of  a  quarter  of  a  mile  from  the  sewer 
outlet,  yielded  BarUbin  coll  eoinnmnis,  Bdc'dlns  c/oaccc,  and  JUictcrium 
(((cfis  f/.(TOf/('/(t'.s.  The  water  and  oysters  from  a  bed  two  miles  distant 
yielded  the  same  organisms.  Barilln.'i  (•oil  communis  was  fcnind  in  30 
per  cent,  of  the  oysters,  and  in  60  per  cent,  of  the  samples  of  \\ater 
from  a  bed  situated  in  the  line  of  a  strong  tidal  current,  five  miles 
away ;  and  in  40  per  cent,  of  the  oysters  and  70  per  cent,  of  the  water 
samples  from  another  in  sluggish  water  more  than  five  miles  away. 
One  bed  six  miles  distant  was  found  to  be  contaminated,  but  those 
farther  down  than  six  and  one-half  miles  were  unpolluted. 

These  findings  are  in  accord  with  the  statement  of  Dr.  E.  Klein,' 
that  the  nearer  to  sewer  outlets  oysters  and  cockles  are  planted,  the 
greater  the  percentage  of  specimens  yielding  evidence  of  pollution. 
In  the  examination  of  oysters  he  holds  that  the  presence  of  Bacillus 
enterlildls  sporogcnes  alone  is  not  sufficient  proof  of  recent  sewage  pol- 
lution, but  that  when  the  spores  of  this  organism  are  found  together 
with  streptococci  and  Bacillus  coll  communis  they  constitute  strong 
evidence  of  recent  contamination. 

Dr.  Hibbert  W.  Hill  ^  has  recorded  interesting  results  of  examination 
of  clams  from  flats  in  the  immediate  vicinity  of  the  sewer  outlets  of  a 
number  of  private  dwellings.  Attention  was  devoted  solely  to  the 
bodies  of  the  clams  and  not  to  the  water  contained  between  the  shells, 
which  was  practiciilly  the  same  as  that  which  surrounded  them.  The 
technique  followed  was  such  as  to  insure  absolutely  against  contamiua- 

^  Medical  News,  March  "Jo,  1895. 

'  Science,  1902,  No.  875.  p.  o63. 

^  British  Medical  Journal,  February  21,  1903. 

*  Report  of  the  Board  of  Health  of  Boston,  Massachusetts,  for  1901. 


62  FOODS. 

tion  by  bacteria  on  the  surface,  and  the  portion  of  the  body  selected  as 
most  likely  to  show  infection  was  the  intestines.  The  following  were 
isolated  and  identitied  :  Bacillus  coll  comvmnis,  Bacillns  enter itidis 
sporofjcncs,  and  Bacillus  acrogcnes  capsulatus  (Welch),  all  three  of 
which  are  found  commonly  in  sewage.  The  typhoid  bacillus  was  not 
found  nor  was  it  expected,  since  there  was  but  1  case  in  the  neighbor- 
hood and  the  excreta  were  disinfected.  Dr.  Hill  adds  that  the  search 
for  typhoid  bacilli  in  sewage  known  to  contain  them  is,  in  most  cases, 
practically  hopeless,  since  even  in  severe  epidemics  the  number  of 
typhoid  patients  contributing  to  the  sewage  is  almost  always  small  in 
comparis(ni  with  the  total  contributing  persons,  and  only  a  small  pro- 
portion of  the  bacteria  present  in  a  typhoid  stool  are  typhoid  bacilli ; 
and  to  hope  to  find,  by  examining  a  few  cubic  centimeters  from  a  large 
mass  of  w'ater,  a  bacillus  which  is  present  in  the  proportion  of  one 
to  every  ten  or  hundred  gallons  of  water,  is  almost,  if  not  quite, 
useless. 

From  a  series  of  experiments  undertaken  to  determine  the  question 
of  viability  of  the  typhoid  organism  in  sea  water  and  within  the  oyster, 
Bordoni-UlFreduzzi  and  Zernoni^  concluded  that  it  will  live  over  2 
weeks  in  sea  water  and  from  3  to  4  days  in  oysters,  without 
lessening  of  virulence.  Oysters  from  Spezia,  Venice,  and  elsewhere, 
were  exammed  to  determine  the  presence  of  the  typhoid  organism  in 
the  water  contained  between  the  shells  or  in  the  tissues.  The  results 
were  negative  on  this  point,  but  the  colon  bacillus  was  isolated  from 
oysters  from  3  different  sources.  Oysters  immersed  in  sterilized  sea 
water,  which  later  was  infected  with  cultures  of  the  typhoid  organism, 
yielded  virulent  bacilli  from  the  water  between  their  shells  up  to  the 
ninth  day  of  examination,  but  never  from  the  tissues  themselves. 

Stokes^  examined  87  specimens  of  oysters  from  various  sources  and 
found  the  colon  bacillus  in  33  or  37.9  per  cent. ;  2  out  of  33  clams 
showed  the  presence  of  the  colon  bacillus  (6  per  cent.).  Altogether 
120  shellfish  were  examined,  of  which  35  or  29.1  per  cent,  showed  the 
presence  of  the  colon  bacillus.  The  number  of  bacteria  per  cubic  cen- 
timeter of  the  juice  of  the  oysters  varied  from  0  to  14,400.  For  the 
clams  the  counts  varied  from  0  to  3600. 

Furthermore,  Stokes  was  able  to  isolate  two  organisms  from  market 
oysters  which  corresponded  to  the  typhoid  bacillus  in  morphology,  mo- 
tility, staining  characteristics,  and  all  cultural  properties.  They  were, 
furthermore,  pathogenic  for  guinea-pigs. 

Agglutination  tests  gave  results  which  were  suggestive,  but  not  abso- 
lutely characteristic  of  the  typhoid  bacillus. 

Johnstone  ^  examined  oysters  taken  from  deep  sea  beds  and  found 
them  practically  free  from  bacteria.  He  succeeded  only  once  in  iso- 
lating the  typhoid  bacillus  from  shellfish.  This  positive  result  was 
obtained  in  a  mussel  taken  from  a  bed  near  a  sewer  outlet. 

^  Giornale  della  Reale  Societa  Italiana  d'igiene,  1899,  p.  500. 
^  Annual  report,  Health  Department,  City  of  Baltimore,  1909. 
3  Jour.  Hyg.,  Cambridge,  1909,  p.  412. 


TRANSMISSION   OF   IHSKASI':   liV   M KAT,    FISH,    VK<1  F'l'A  liLFS.     03 

()(>Ii(!r  ()l),sorvcrH  li;iv(!  foiiiid  Ui«  Wactcriu  of  flioiini  uikI  l.yplioi*!  f«;v<;r, 
II.  coll  coianiMiiis,  />'.  jn-oiciiH  vidf/ariM,  aii(J  otlicr  or^raiii.srriH,  in  oynUifH 
(M)iil,;i,riiiii:il.c<l  by  scvvafrf,  aixl  all  unite  in  IIk;  opiniiHi  that  the  pnwcncc* 
ol"  />'.  coil  coviiniiiil.s  sliDiild  ar<)n.s(!  sn.s|)icioM  and  indn«;e  iniprovcrncntii 
in  the  managcnKMii  and  snixTvision  of  oyster  Ix-dH. 

Tn  the  investi!i;alion  of  onthreaUs  of  typhoid  icver  HUpposjjdly  duf;  io 
oystofs,  hac,t(M-i()lo^ie,al  j)roof  of  H|)e(!i(ic  infe(!tion  of  thoHf;  eaten  or  of 
othens  from  the  sani<!  lot  always  has  heen  and  always  will  l»e  wantinj:, 
since,  lonj^  hefon;  the  apj)earane(!  of  the  first  symptom  of  the  disease, 
the  raatcM-ial  is  no  lontj^er  availal)l(!  for  investij^ation.  But,  in  view  of 
t\u)  fact  that  ])athot2;(Mii(!  hat^tcria  Jiave  l)een  fonnd  in  the  water  between 
the  shcills  of  oyst(!rs  from  ])ollnted  beds;  that  tlxy  have  In-en  known 
to  live  for  days  in  the  tissues  and  rf^tained  water  ;  and  that,  in  the 
cases  iuvesti<i;ated,  the  beds  have  been  found  to  be  exposed  to  the  influ- 
ence of  sewage,  we  may,  therefore,  properly  conclude  that  a  causal  rela- 
tion is  very  possible. 

The  danger  of  infection  rises  wholly  from  the  presence  of  sewage 
in  the  water  where  the  oysters  are  j)lanted  or  stored.  The  remedy  lies 
either  in  transferring  the  beds  to  cleaner  situations  or  in  storing  the  con- 
taminated oysters  in  clean  sea  water  until  the  bacteria  either  have  per- 
ished or  have  been  washed  away.  What  constitutes  a  sufficient  length 
of  time  to  insure  purification  is  a  matter  of  some  disagreement.  Many 
believe  that  a  week  is  enough;  others,  that  16  days  should  be  allowed. 
Oysters  should  not  be  stored  where  sewage  matters  can  reach  them 
through  long  distances  by  currents  along  the  shore,  nor  where  prevailing 
winds  can  exert  a  harmful  influence  to  the  same  end. 

It  is  ditiicult  to  make  a  rule  as  to  the  conditions  under  which  con- 
taminated shellfish  shall  be  excluded  from  the  market.  Gage,  of  the 
Lawrence  Experiment  Station,  has  given  as  a  criterion  for  the  harm- 
lessness  of  shellfish  the  absence  of  colon  bacilli  from  80  per  cent,  of 
the  shellfish  examined.  Beds  which  produce  shellfish  more  than  50 
per  cent,  of  which  are  contaminated  with  colon  bacilli  are  to  be  con- 
demned. It  is  manifest,  however,  that  the  kind  of  pollution  is  of 
greater  importance  than  its  amount. 

Houston  1  makes  the  following  statement : 

"  A  pollution,  trivial  in  amount  but  specific  in  character,  is  much 
more  dangerous  than  a  contamination  gross  in  amount  but  not  specific 
in  nature.  It  is  also  probable  that  a  pollution,  trivial  in  amount  but 
specific  in  character  and  of  recent  sort,  is  more  dangerous  than  a  pol- 
lution gross  in  amount,  specific  in  character,  but  of  remote  kind." 

Pease,"  after  an  extended  investigation  of  the  shellfish  industry  for 
the  New  York  State  Board  of  Health,  sums  up  as  follows : 

"  Human  discharges  and  refuse  from  collecting  boats  should  not  be 
dumped  into  waters  over  oyster  beds,  for  typhoid  carriers  are  as  likely 
to  exist  among  oystermeu  as  among  milk  producers.     Oyster  houses 

^  Fourth  Report  of  the  British  Roval  Sewage  Commission,  Vol.  I.,  p.  36,  quoted  bv 
?ease,  Long  Island  Medical  Journal,  Sept.,  1910. 
'  Loc.  cit. 


64  FOODS. 

aloiiii;  shore  should  have  efficient  methods  for  the  disposal  of  the  dis- 
charges aud  refuse  from  their  emjiloyes  and  themselves  in  the  vicinity. 
Drinking-  beds  for  oysters  should  be  chosen  lor  purity  of  water  rather 
than  convenience.  Oysters  should  not  be  transported  in  sunken,  open- 
framed  scows  through  polluted  water.  Finally,  oyster  growers  should 
investigate  the  problem  of  removing  ])olluting  bacteria  by  transplanting 
tlu!  shelliish  to  clean  water.  It  is  undoubtedly  true  that  oysters  grow 
better  in  water  pc»lluted  by  sewage.  Cannot  this  fact  be  utilized  and 
its  disadvantage  eliminated  by  thoroughly  cleaning  the  oysters  in  un- 
polluted water  ?  " 

That  the  United  States  authorities  have  taken  cognizance  of  the 
shellfish  situation  is  apparent  from  Food  Inspection  Decisi<:)n  110  of 
the  U.  S.  Department  of  Agriculture,  issued  October  15,  1909,  which 
provides  in  part  that,  "  It  is  unlawful  to  ship  or  sell  in  inter-state 
commerce  oysters  or  other  shellfish  taken  from  unsanitary  or  polluted 
beds." 

Crawfish  and  Typhoid  Fever. — Chapin  ^  mentions  an  outbreak  of 
typlioid  fever  which  was  observed  by  Dr.  Bissell,  of  Buffalo,  and 
which  was  in  all  probability  due  to  the  eating,  by  boys,  of  partially 
cooked  crawfish  taken  from  a  lake  grossly  polluted  with  sewage. 

Water  Cress  and  Typhoid  Fever. — Chapin  also  quotes  Hamer  (special 
representative  to  the  Medical  Office  of  Health,  London,  1900)  as 
having  traced  an  outbreak  of  typhoid  fever  to  water  cress  which  had 
been  grown  in  sewage  polluted  water.  Of  110  cases  55.3  per  cent, 
ate  of  the  suspected  water  cress,  and  the  incidence  of  the  disease  among 
the  water-cress  eaters  was  three  times  as  great  as  among  those  who  did 
not  eat  it. 

Celery  and  Typhoid  Fever. — Morse  ^  reports  an  outbreak  of  49  cases 
in  an  insane  asylum  which  was  due,  in  all  probability,  to  the  eating  of 
celery  which  had  been  fertilized  with  material  taken  from  a  filter  bed, 
upon  which  had  been  placed  the  undisinfected  stools  of  a  typhoid  fever 
patient. 

Poisoning  by  Meat  and  Fish. 

Animal  foods  are  tlie  frequent  cause  of  most  distressing  disorders 
which  not  rarely  have  a  fatal  termination.  Some  of  these  are  due  to 
poisonous  properties  inherent  in  the  living  auimal,  some  to  bacterial 
poisons  formed  in  meats  showing  no  evidence  of  unwholesomeness, 
and  some  to  decomposition  products  developed  during  storage  or  putre- 
faction. 

1.  Poisoning  Due  to  Substances  Normally  Present  in  the  Living 
Organism. — As  lias  been  stated,  certain  species  of  fish  are  always  poi- 
sonous and  others  only  at  times,  and  in  some  cases  only  individual 
members  are  so  constituted.  Certain  species  are  so  well  known  to  be 
poisonous  in  perfectly  fresh  condition  that  they  never  are  eaten  by  the 

1  Sources  and  Modes  of  Infection,  1910,  p.  318, 

2  Mass.  State  Board  of  Health,  1899. 


I'OISONINd    II  y    MEAT  AM)    FISH.  (',', 

natives  of  ilio  pliuxiH  vvlicn;  tlicy  :irf  ('<.iniil,  (■■-.cr^ti  for  piirpowiH  of  Hui- 
cido.  Soirui  liiivci  |)()is()ii<)iiH  j^ImikIh  ((imimcNiI  wiili  lluir  (iiiH,  Homo  have 
noisoiioiis  ovarids,  iitid  ollicrs  iirc.  |)ois<»ii<>iis  tliioii^'-lioiiL  S<)rii<;  an; 
poisonous  only  in  iJu-  raw  sfiilc,  iiiid  others  wlicflicr  cook-cd  «»r  nof, 
TIh!  svin|)l(»ins  prodiKM'd  v.iry  widely,  soinelinie-  indienf injr  ^urivo- 
(Mitcrilis,  sometimes  iiivolvfiinent  of  IIk;  eentrai  nervous  Hysfem. 

'I'lie  IMUSS(.'1  is  rei^arded  not  un(H)mMioidy  as  an  intrinsir'ally  poisonoiiH 
slielllisli,  hut  tlu!  weij^lit  o("  cvidenee  indicates  lli:it  innssel-poi-onin^'-  is 
diK!  to  conditions  o("  disease  or  iidecrtion  ;irisin<i;  from  residence  in  pol- 
llltc<l  water.  Its  poisonous  properties  li;iv('  lon^'  I)ecn  rocof^nized,  and 
have  hveu  the,  subject  of  a  nuinlxir  of  (liss('rt:itions  by  early  writers; 
thus  Hchrcns,  Pc  (i(j'('Hio)iil)i(,H  a  coiihcslis  wi/hi/is,  IIannov(!r,  1  7.'5o,  and 
Mcx^iirint:;,  JlIi/lii/orKni  (/uoniiKl/mi  voirimvi  d  ah  co  ikiI/ik  j/dpii/n.s  mll- 
cakircj^  Kj>if<l(>/<i,  Nnvcuihwi!;,  17  11.  Fn  I*^ ranee,  when;  jrreat  quantities 
of  mussels  iiw,  oaten,  cases  ol"  |)ois(»uinL''  fhereCorm  are  rare,  owing 
doubtless  to  the  fact  that  those  taken  I'roni  polluted  harbors  arc  kept 
for  a  week  or  more  in  (^leau  w.'iter  elsewliere. 

2.  Poisoning-  Due  to  Bacterial  Products  in  Meats  and  Fish. — 
What  is  known  coiumonly  as  nieat-|ioisonin^,  fisli-poisonin<r,  and 
sausage-poisouuig  is  due  to  the  products  of  a  number  of  micro-orgiuiisms 
having  no  connection  with  the  usual  diseases  of  man.  These  toxic 
produ(tts  cause  an  extremely  wide  variety  of  symptoms,  which,  as  may 
be  observed  on  examination  of  the  collection  of  reported  outbreaks 
given  below,  iudicate  the  possible  derangement  of  function  of  })racti- 
cally  every  part  of  the  system.  There  are  two  groups  of  sym])toms, 
liowever,  which  are  fairly  constant,  either  one  of  which  may  pre- 
dominate over  all  the  rest.  These  are  (1)  the  manifestations  of  pro- 
found disturbance  of  the  gastro-intestinal  canal,  and  (2)  those  indi- 
cating more  or  less  intense  jioisoning  of  the  central  nervous  system. 
Prominent  among  these  latter  are  impaired  vision  (dilated  pupils, 
ptosis,  amphodiplopia,  etc.)  and  glosso-pharyngeal  paralysis ;  and 
when  those  are  present,  the  case  is  said  to  be  one  of  "  botulism." 
This  term,  which  came  into  existence  by  reason  of  the  fact  that  many 
of  the  earlier  observed  cases  of  food-poisoning  were  traced  to  sausages 
[hotiUus,  a  sausage),  is,  in  the  light  of  our  present  knowledge,  unfortu- 
nate and  misleading,  for  the  condition  may  be  caused  not  only  by 
sausage,  but  by  any  form  of  meat  and  fish  or  other  food  product  which 
may  happen  to  be  contaminated  by  the  micro-organisms  which  produce 
the  peculiar  toxin  (or  toxins)  by  which  the  manifestations  are  caused. 
And  it  is  not  true,  as  is  supposed  by  some,  that  botulism  is  caused  by 
the  proteid  bacterial  poisons  alone  (commonly  known  as  toxins),  but 
by  certain  of  the  basic  crystalline  jiroducts  of  decomposition,  known 
as  ptomains,  as,  for  example,  mytilotoxin,  a  ptomaiu  isolated  by 
Salkow'ski  and  Brieger  from  contaminated  mussels. 

Not  uncommonly,  ptomains  are  regarded  as  necessarily  poisonous 
substances.  This,  however,  is  far  from  being  the  truth.  They  are 
products  of  decomposition  brought  about  by  micro-cvganisms  which 
break  up  the  complex  orgtmic  matters  into  less  complex  compounds, 


66  FOODS. 

which  in  turn  are  split  up  into  ])ro(hicts  of  diniinisliing-  complexity, 
until  the  tinal  products  are  water,  hydrogen,  carbonic  acid,  sulphur- 
etted hydrogen,  ammonia,  nitrogen,  and  salts.  During  this  process 
of  decomposition,  at  different  stages,  the  ptomains,  which  are  organic 
bases,  are  formed.  Some  are  poisonous,  but  the  great  majority  of 
those  thus  far  isolated  are  wholly  inert.  All  contain  nitrogen,  hut 
not  all  contain  oxygen,  thus  resembling  the  vegetable  alkaloids.  The 
variety  of  ptomains  formed  depends  upon  the  kinds  of  micro-organisms 
at  work,  the  nature  of  the  substance  undergoing  decom]30sition,  and  the 
conditions  of  temperature,  access  of  air,  and  other  attendant  circum- 
stances. One  s])ecies  of  bacteria  may  produce  no  j)tomains  from  one 
kind  of  material,  and  poisonous  or  inert  ones  from  another.  At  one 
stage  of  decomposition  no  ptomains  may  be  formed,  at  another  several 
may  be  present,  and  later  these  may  have  disappeared  completely, 
for  they  are  but  intermediate  products. 

Brieger  has  isolated  a  number  of  varieties  of  ptomains  from  decom- 
posing meats  and  fish,  including  neurine,  choline,  and  one  which  appears 
to  be  identical  with  muscarine  (all  three  of  these  are  antagonized  in  their 
poisonous  action  by  atropine),  and  neuridine,  putrescine,  cadaverine, 
another  which  produces  effects  similar  to  those  of  curare,  and  others. 
Vaughan  discovered  the  very  important  ptomain,  tyrotoxicon,  in  milk 
and  cheese. 

Many  of  the  poisonous  compounds  formed  during  putrefaction  retain 
their  active  character  long  after  the  organisms  through  whose  agency 
they  have  been  produced  have  perished.  This  was  noted  as  early  as 
1856  by  Panum,  who  found  that  the  poison  of  certain  putrid  meat 
retained  its  activity  even  after  it  had  been  boiled  11  hours,  and  his 
observation  has  repeatedly  been  confirmed  by  others.  Naturally,  no 
amount  of  cooking  will  suffice  to  render  such  meat  harmless. 

The  physiological  action  of  these  poisons  is  widely  different.  Some 
cause  intense  gastro-intestinal  irritation,  some  act  directly  on  the  heart, 
some  on  the  central  nervous  system,  and  some  on  particular  centers. 
Very  different  effects  are  produced  in  different  people,  owing  perhaps  to 
varying  degrees  of  susceptibility  and  also  to  unequal  distribution  of  the 
poison  through  the  mass  of  meat. 

The  extent  to  which  the  putrefactive  process  has  advanced  is  by  no 
means  of  such  importance  in  the  determination  of  the  question  of  pos- 
sible ill  effects,  as  the  nature  of  the  engaged  bacteria  and  of  their 
products,  for  meat  may  be  extremely  putrid  and  yet  not  be  poisonous, 
and,  on  the  other  hand,  may  be  apparently  normal  and  yet  deadly  in 
its  effects.  Many  savage  peoples  prefer  putrid  fish  and  meat,  and  the 
more  rotten  it  is,  the  greater  their  enjoyment  in  its  consumption.  In 
less  degree,  the  same  is  true  of  many  of  the  most  enlightened  people, 
who  prefer  game  when  decomposition  is  fairly  well  advanced.  On  the 
other  hand,  the  severest  outbreaks  of  food-poisoning  have  followed  the 
eating  of  meat  apparently  not  undergoing  decomposition.  Indeed,  the 
majority  of  persons  will  reject  meat  which  has  the  slightest  taste  or 
odor  indicating  beginning  putrefaction^,  since  even  this  makes  it  repug- 


P()IS()NIN(J   J'.Y   MKAT  AND  FISH.  67 

nant  to  tii(>  s('.n,s(!H,  Tn  many  oaw'H,  tlio  j)oiHononH  principN  s  uf»j)car  U) 
b(!  (l(!V(!l()|)<!«l  a(l(!r  (Ik;  iiicaL  lias  l)(!(!ii  (iatcii,  (liroii^li  (;li;ui^(«  (XMiurrinjr 
witliiii  lJi(!  iiildsl  iii(;,M. 

The  l)a(!L(M'i;i,  vvhirJi  ji;i\'(!  (Iius  (;ir  I)C(mi  shown  lo  have,  hcfii  tlu;  c^iUHO 
of  outbreaks  of  iiicii-  mikI  (isli-poisoiiin^  inelude  ceilaiii  npore-bwiring 
anaerob(\s  isolalx^d  \)y  \nn  Ki-iii(;ii^(!tn  {li.  hohUiniiM),  and  Klein  ( li. 
enterlUdin  Kjioiuxjnicn),  a  miniber  of  defivativ(!S  of  H.  coll  iwdaJed  by 
GaertiK!!*  (/>.  ciilcrilidi.s),  l>as((iiaii  (/>.  Aow/.v  'iiiorh'ijicdiiK),  Kaensf-lir;  {II, 
Mo7'iiceLcimH  and  Ji.  J}rc,sfavicnsiii),(ji'diVky  and  Vank  (li.  J'ricdcherr/en- 
sis),  Abel,  Giinther,  and  others,  besides  Ji.  proteus  vulgaris,  B.  protetia 
mirdhilin,  jt^laplii/foc.occiiN  jyi/or/oics  Jlavus,  and  others.  The  first  men- 
tioned (/>.  I)()tntlnat^)  ])ro(hi(!es  an  extraordinarily  virnlcnt  toxin,  which 
has  been  the  snljjccit  of  (^arelid  investij^ation,  wliieli  li:is  proved  that  it 
is  related  closely  to  the  toxins  of  diphtheria  and  tetanus. 

Study  of  a  bacillus  which  Trautraaun  '  isolated  as  the  cause  of  an 
outbreak  of  poisoning  at  Diisseldorf,  and  eomj)arison  thereof  with  cul- 
tures of  B.  Fricdchcn/ensis,  B.  enter iLldiH,  Jl.  Morsrelensis,  B.  hovis 
morbifiGanx,  B.  Brefilavicnsis,  and  of  the  organisms  isolated  by  Fischer, 
Abel,  and  Giinther,  and  also  of  the  various  strains  of  paratyphoid 
bacilli,  led  him  to  the  conclusion  that,  while  these  several  kinds  present 
slight  differences  in  morphology  and  cultural  peculiarities,  they  show 
no  fundamental  ditference  and  are  merely  varieties  of  one  and  the  same 
organism.  Others  have  called  attention  to  the  similarity  of  symptoms 
in  meat-poisoning  (not  botulism)  and  paratyjihoid,  and  the  belief  is 
growing  that  the  differences  in  the  nature  and  severity  of  symptoms 
and  in  the  order  of  their  appearance  are  dependent  upon  the  slight 
racial  difterences  in  the  bacteria  and  upon  the  degree  of  virulence  and 
individual  susceptibility.  Many  outbreaks  of  meat-poisoning  have 
been  indistinguishable  from  paratyjihoid,  and  many  of  severe  form  have 
been  mistaken  for  true  typhoid.  Trautmann  believes  that  the  tyj>ical 
meat-poisoning  is  the  hyperacute,  and  paratyphoid  the  subacute,  mani- 
festation of  au  etiologically  similar  disturbance,  and  he  places  all  of 
the  exciting  causes  under  the  general  head  of  B.  i^aratyphosus. 

It  has  not  been  supposed  that  the  organisms  which  cause  meat-poi- 
soning of  the  more  common  types,  such  as  the  Bacillus  botulinus  and  the 
B.  oiteritidis  of  Gaertner,  are  widely  distributed  in  nature,  but  the  fol- 
lowing statements  will  show^  that  the  danger  of  iufectiou  is  not  to  be 
lightly  disregarded.  Ivlein,^  for  instance,  found  the  B.  enteritidis  of 
Gaertner  in  ten  out  of  thirty-nine  milk  samples  which  had  been  col- 
lected for  examination  for  tuberculosis.  The  number  of  organisms  was 
not  large,  to  be  sure,  but  if  this  milk  had  been  kept  in  suitable  sur- 
roundings of  temperature  it  could  have  become  very  dangerous.  The 
farm  from  which  this  milk  came  was  a  very  dirty  one. 

Conradi  ^  found  paratyphoid  bacilli  in  natural  ice  from  various 
sources,    and    suggests   that   this   may   be   the    origin    of  paratyphoid 

1  Zeitsobrift  fiir  Hvsriene  und  Infectionskrankheiten.  XLV.,  p.  139,  and  XL VI.,  p.  6S. 

-'  Centralb.  f.  Bakt."  Orii-..  Vol.  XXXVIII.,  1905. 

3  Munch,  Med.  Woch,,  May  4,  Vol.  LVI.,  pp.  897  and  952, 


68  FOODS. 

infection  in  certain  cases.  He  fouml,  furthermore,  that  cliopped  ice  is 
mixed  with  the  meat  in  certain  districts  in  the  process  of  making  sau- 
saijes. 

Uhlenhnth  ^  examined  a  number  of  healthy  hogs  killed  at  the  abat- 
toir in  Berlin  ;  G  per  cent,  of  the  cases  showed  bacilli  very  similar  to 
paratyphoid,'  tyjie  B. 

l\impau-  found  twenty-six  persons  who  were  excreting  paraty])hoid 
bacilli,  type  B ;  10  of  these  were  sick  typhoids,  5  were  typhoid  bacil- 
lus carriers,  and  11  were  healthy  individuals.  His  investigation 
brought  out  three  iniportant  points  :  First,  the  frequent  occurrence  of 
these  bacilli  in  the  urine  ;  second,  bacilli  were  present  in  persons  who 
had  been  in  contact  with  those  sick  with  })aratyphoid  B  infection  ; 
third,  the  occurrence  of  this  organism  in  external  nature.  Of  the 
26  cases,  the  germs  were  found  15  times  in  the  nrine  and  stools,  and  9 
times  in  the  urine  alone.  They  may  be  found  in  the  blood  without  caus- 
ing any  symptoms,  and  once  were  found  in  the  blood  of  a  true  tyjihoid. 
He  found  this  bacillus  also  in  the  stools  of  fifty  presumably  healthy 
school  boys.     Rimpau  found  it  also  in  a  perfectly  good  sausage. 

Hiibener^  examined  100  samples  of  sausage  and  found  paratyphoid 
organisms  of  this  type  in  6.  The  sausage  was  apparently  good  and 
caused  no  disagreeable  symptoms. 

Duchan  *  quotes  Ford^  as  having  found  the  B.  cnteriiidis  of  Gaert- 
ner  in  the  large  intestine  of  a  human  subject.  He  quotes  Savage  also 
as  having  found  members  of  the  Gaertner  group  in  the  intestines  of  four 
pigs.     In  one  of  these  they  were  present  in  large  numbers. 

Signs  Pointing  to  an  Epidemic. — Vagedes  ^  gives  three  chief  indi- 
cations for  an  epidemic  of  food  poisoning.  First,  sudden  appearance 
of  poisoning  in  ]5ersons  up  to  that  time  perfectly  well ;  second,  symp- 
toms of  illness  following  the  ingestion  of  a  certain  food  product ;  third, 
sickness  in  several  persons  who  have  eaten  the  same  food  product. 

Onset  and  Course  of  Symptoms. — The  first  symptoms  in  cases  of 
poisoning  by  fish  and  meats  may  occur  within  an  hour  or  two  after  eat- 
ing or  may  be  delayed  a  number  of  days.  In  one  outbreak  cited  (see 
Poisoning  by  Herrings,  page  73),  in  which  5  persons  were  seized,  the 
initial  symptoms  appeared  in  2,  3,  5,  7,  and  9  clays  respectively ; 
ordinarily  they  appear  within  a  few  hours — 3,  6, 12.  When  numbers  of 
persons  are  affected  by  the  same  food,  the  onset  is  by  no  means  uni- 
form. In  the  Ellezelles  case  (see  page  81),  in  which  20  jiersons  were 
seized,  the  time  in  which  the  symptoms  first  were  manifested  ranged 
from  3  to  36  hours,  but  as  a  rule,  it  is  the  appearance  ^vithiu  the  same 
day  of  similar  symptoms  in  a  number  of  persons  which  calls  attention 

1  Deutsch.  Med.  Woch.,  1907,  No.  11. 

^  Zur  Frage  der  Verbreitung  der  B.  ans  der  Paratvphus  Gruppe,  Deutsch.  Med. 
Woch.,  1908,' 124. 

^  Ueher  das  Vorkommen  von  Bakterien  der  paratvphus  Gruppe  in  der  Aussenwelt, 
Deutsch.  Med.  Woch.,  lOOS,  No.  24. 

*  Public  Health,  ,Jnlv,  1908. 

^  Studies  from  the  Rockefeller  Institute,  Vol.  II.,  1904. 

«  Vieileljahrschr.  f.  Gerichtl.  Medizin.,  Vol.  XXIX.,  1905. 


r<>is(>Ni\'(i  r.y  meat  am>  fish.  60 

to  tlio  food   Hiij)j»ly  ;iH  ji  (loiiiiiioM  cniisf!  of  tlio  troiihh;.      I'oiKOiiinj^   l>y 
ptoiiiiiiiis    is  iii;iiiircslc(|  (rciicnilly  wifliin  ;i  few  lioiirs. 

In  (',iiH(W  of  i';i|)iil  onset,  Ihc  prourcss  clllicr  lo  recovery  or  ;i  I'ahil 
i(!rmiii;i(,ioii  is  coiiimoiily  sliorl,,  hut  may  he  soineliincH  a  iiiaU<;r  (»f" 
tiioiil.lis,  and  in  [\\v.m\  (txcrcplional  caHt«  event  mil  rce^ovory  is  prohahK;. 
Tho  shortiist  case  on  re(!ord  is  that,  of  nnissel-poisoninj^  at  Wilhehn.s- 
liavcMi  (hog  |)a<;(!  72),  in  which  1  victim  (Med  in  2,  another  in  '.),  and 
2  others  in  5  hoiu's  after  eatina;. 

A  ])(!cnliaf  t(!ndcn(y  to  rcilapscis  oflxsn  is  obs(!rvcd.  The  patient  hc^in.H 
to  itn])r()ve,  wh(Mi  snddcnly  the  ori<i;inal  symptoms  reappear  with  espial, 
^r(Mit(!r,  or  (Mminished  inlc^nsity.  I  inprovftiniMit  may  he  snc.cecrh'd  a^iiii 
by  a  rehipse,  and  the  aUernation  may  obtain  for  many  months.  The 
toxins  secreted  by  the  orifrinal  inva(hn<:;  l)a(teria  arc  antajronized  by 
antitoxins  ])ro(hi<HMl  by  the  system  aiul  improvement  occurs;  then  diir- 
ino;  this  interval  th(!  spore-bearers  llml  ojjportnnity  to  develop  a  new 
crop  of  bacteria,  which,  a^'ain  prodiieinjj;  toxins,  (;anse  a  recurrence  <»f 
the  orii;inal  symptoms. 

Nature  of  Symptoms. — As  has  bec^n  stated,  the  effects  produce*!  var}' 
very  greatly,  but  tlu^  symptoms  of  abdominal  disturl)anee  and  of  jkji- 
soning  of  the  central  nervous  system  are  the  most  constant  as  well  a.s 
most  predominant.  Fever  may  or  may  not  be  ])resent ;  usually  it  is 
not,  but  in  some  outbreaks  temperatures  exceeding  104°  F.  have  been 
recorded.  In  some  cases,  the  temperature  is  subnormal.  Disturbance 
of  the  circulation  is  more  common  than  fever,  the  pulse  being  small 
and  rapid,  and  sometimes  dicrotic.  In  a  few  instances,  marked  embar- 
rassment of  respiration  has  been  noted.  In  most  of  the  recorded  cases, 
no  mention  is  made  of  involvement  of  the  kidneys,  but  in  some  in- 
stances evidence  of  acute  nephritis  has  been  observed.  Dysuria, 
anuria,  and  paralysis  of  the  bladder  arc  not  uncommon.  In  most  cases, 
extreme  muscular  weakness  is  a  prominent  symptom,  and  not  hifre- 
qucntly  muscular  pains  and  cramps.  While  diarrhoea,  long  continued, 
is  a  most  common  occurrence,  in  many  cases  most  obstinate  constipation, 
sometimes  follo\ving  diarrhrea  and  sometimes  present  from  the  first,  is 
noted.  In  some  cases  abdominal  symptoms  are  by  no  means  prtimineut, 
and  in  others  they  are  practically  the  only  ones  observeil.  The  symp- 
toms of  involvement  of  the  nervous  system  include  those  mentioned 
above,  and  drowsiness  or  insomnia,  headache,  dizziness,  delirium,  dimin- 
ished co-ordination  of  movement,  numbness,  cramps,  convulsions,  and 
paralyses. 

Post-mortem  Appearances. — The  post-mortem  appearances  observed 
in  cases  of  poisoning  are  very  inconstant,  both  as  to  extent  and  kind, 
and  are  by  no  means  proportionate  to  the  severity  of  the  symptoms. 
Even  when  a  number  of  individuals  succumb  to  the  same  iutiuences,  the 
appciirances  may  show  but  little  in  common.  Thus,  in  the  AA'elbeck 
case  (page  79),  one  showed  nothing  more  than  a  few  bright  red  patches 
in  the  stomach  ;  a  second,  congestion  of  the  gastro-intestmal  mucous 
membrane  ;  and  a  third,  severe  parenchymatous  inflammation  with  dis- 
tention and  plugging  of  the  arterioles  and  capillaries  of  the  Malpighian 


70  FOODS. 

corpuscles  by  emboli  of  bacteria.  The  most  exteusive  changes  observed 
are  those  occurring  in  poisoning  by  mussels  and  oysters,  in  -which  cases 
the  extremely  rapid  onset  and  the  veiy  short  course  to  a  fatal  termina- 
tion suggest  the  action  of  poisonous  jitomains.  Indeed,  animal  experi- 
mentation has  demonstrated  that  certain  of  these  compounds  produce 
these  very  changes,  which  include  great  enlargement  of  the  spleen,  punc- 
tiform  ecchymoses  and  hemorrhagic  infarctions,  and  fatty  degenera- 
tion of  the  heart,  liver,  and  kidneys.  In  cases  of  meat-poisoning,  the 
appearances  noted  range  from  a  few  red  patches  in  the  intestines  to 
severe  gastro-enteritis  with  destructive  changes  in  all  the  principal 
viscera. 

Character  of  Meats  which  Cause  Poisoning. — In  general,  outbreaks  of 
poisoning  are  caused  by  the  meat  of  animals  slaughtered  while  suffer- 
ing from  diseases  other  than  those  which  are  best  known  to  the  public 
because  of  the  great  destructioii  wrought  when  raging  in  epidemic  form  ; 
but  they  may  also  be  traced  to  the  flesh  of  perfectly  healthy  animals 
which  has  become  contaminated,  both  in  the  raw  and  cooked  states,  by 
poison-producing  bacteria. 

The  most  dangerous  forms  of  meat-poisoning  are  those  due  to  the 
pyaemias,  septicaemias,  and  j)neumo-enteritis,  and  the  greatest  mtensity 
ojf  action  is  produced  by  preparations  made  from  the  entrails. 

In  a  majority  of  the  reported  outbreaks,  the  meat  has  been  consumed 
either  raw  or  only  imperfectly  cooked,  or  after  being  kept  a  day  or  two 
after  being  cooked.  The  meats  most  commonly  the  cause  are  pork  and 
its  preparations,  and  veal.  Both  yield  a  considerable  amount  of  gelatin, 
and  this  fact  has  been  suggested  as  having  an  important  bearing,  since 
this  material  is  a  medium  which  offers  favorable  opportunities  for  the 
growth  of  bacteria. 

Most  of  the  reported  outbreaks  have  occurred  in  the  countries  of 
Europe,  where  the  meat  supply,  in  consequence  of  being  very  restricted, 
is  utilized  to  its  fullest  extent.  Viscera  which  with  us  are  rejected  as 
refuse,  and  the  flesh  and  viscera  of  animals  slaughtered  in  consequence 
of  sickness,  with  the  consent  and  approval  of  official  veterinarians,  are 
sold  and  eaten.  Another  reason  for  the  frequency  of  the  outbreaks  is  a 
very  common  preference  for  scraped  or  minced  raw  meats  and  for  sau- 
sages of  domestic  manufacture  made  under  most  unsanitary  conditions. 

Veal. — According  to  Vallin,  in  a  communication  to  the  Academy 
of  Medicine  in  1895,  a  large  number  of  outbreaks  of  poisoning  in 
Germany,  Switzerland,  and  elsewhere  are  due  to  the  consumption  of 
veal  from  animals  either  sick  or  too  immature.  Darde  and  Drouineau  ^ 
relate  that  they  have  seen  nearly  the  whole  strength  of  a  military 
company,  135  out  of  147,  poisoned  by  eating  roast  veal.  The  symp- 
toms appear  generally  in  from  6  to  24  hours,  and  include  vomiting, 
purging,  and  great  prostration.  Dilatation  of  the  pupil  is  common, 
but  not  constant.      Occasionally,  skin  eruptions  appear. 

By  Vallin,^  and  by  others  as  well,  it  is  deemed  probable  that  vcal= 

^  Archives  de  Medecine  et  de  Pharmacie  militaires,  1895. 
^  Revue  d'Hygiene,  1895,  XVIJ.,  p.  473. 


POISON  I  N(  J    nV  MEAT  AM)   FISH.  71 

poisoniiif^  i.s  duo  lur^cly  to  tlio  (!xist(!Hf,(!  of  Hfptio  pya;mia  and  wptic 
|)iicuiri()-(!nlcriiis  it)  cnlvcs,  and  V.'iii  Druwu^i-m  hits  sw^t^i-hU-A  that  a 
iiiiinbcr  oCsdplic  disoiiHos  of  IIkwc;  aiiimnis  iVYo.  ^r<>ii|)(:d  coriiinonly  iiiidcT 
t.lic  \wm\  <)(■  dinrrlKca.  II(!  I'cd  IIk;  frcsli  meat,  of  f)ii<;  of  llurs(!  r^ilvcw 
io  mI(U!  and  o;iiinc;i-|)ij:;s,  wliirli  died  williin  a  i'vw  dayH  with  f;iit<;ntw. 
From  th(!  hone  ni;iri-ovv  \n\  isoljitcd  ;in  or}/;anisin  which  apjM-nrs  lo  be  rc- 
hitod  closely  to  (jiiKirtncr'H  /*.  oifcrU.ldis,  and  which  on  inoculation  into 
aniinids  |)r()du(!('S  a,  filial  cntcrilis. 

/;,;,/. —  15(!cf-|)oisonin<;  has  been  notic('d  willi  coiisidcr.iblc  frc(jucn(ry, 
followinfr  the  use  of  meat  from  animals  KJaufrhtcrcd  while  Hick,  and  it 
has  be(Mi  pointcid  out  by  M(!vcral  observers  that  cortidn  scj)tic  di.s^iscs  of 
cattle  are  cspeei;dly  prone  to  render  meat  poisonous.  These  include  the 
.septic  form  of  calf  paralysis,  hemorrhagic  enteritis  of  calv(;s,  .sejitic 
metritis  of  cows,  various  intestinal  disorders,  the  He])ticx)-j)yamiic  dis- 
eases, and  a  numl^cr  of  others.  Gaertner's  B.  enteritidis  was  disc/jvered 
by  him  oriti:;inally  in  the  Hosh  of  a  cow  that  had  been  slautrht^'red  on 
account  of  a  severe  diarrluea,  and  in  tlu;  spleen  of  a  ])crson  who  died  in 
consequence  of  eatin*^  it.  He  showed  that  not  only  the  bacillus,  but 
also  its  boiled  bouillon  cultures,  are  highly  toxic. 

Many  deaths  have  been  recorded  as  a  consequence  of  eating  the  cooked 
meat  of  cows  slaughtered  on  account  of  ])uerperal  fever,  and  it  was  from 
such  an  animal  that  Basenau  isolated  />.  Aoc/.s-  morhificfnis.  This  cow 
showed  such  lesions  of  the  viscera  that  the  director  of  the  Amsterdam 
abattoir  forbade  the  use  of  the  meat. 

Basenau*  has  examined  the  flesh  of  beeves  which  had  succumbed  to 
a  variety  of  diseases,  and  he  has  isolated  a  numl)cr  of  species  of  bac- 
teria bearing  a  close  resemblance  to  i>.  bovis  inorhlf}cf(}i.'<,  all  of  which 
are  fatal  to  mice.  Some  of  them  produce  poisonous  mattei's  which 
withstand  boiling  without  impairment  of  their  properties.  Ordinan*' 
mspcction  being  useless  for  determining  whether  such  meat  is  infected, 
he  recommends  that  bacteriological  and  feechng  ex]X'riments  should  be 
instituted  toii'ether  within  24  h(>urs  after  slaughtering.  If  no  colonies 
are  observed  at  the  end  of  24  hours  and  no  bacteria  are  seen  in  the  tis- 
sues, the  meat  may  be  regarded  as  safe  to  eat.  If  colonies  are  yielded, 
the  acceptance  or  rejection  of  the  meat  must  depend  upon  the  results  of 
the  feeding  experiments.  If  the  mice  fed  on  the  raw  meat  die  and  those 
fed  on  the  cooked  meat  survive,  it  may  be  concluded  that  the  meat  is 
safe,  if  thoroughly  cooked.  If  both  die,  the  meat  should  unhesitatingly 
be  condemned. 

Sausaac. — Sausage  has  loup-  been  recognized  as  a  verv  common 
cause  of  poisoning,  and  has  a  much  larger  record  of  accidents  than  any 
other  meat  or  meat  compound.  This  is  due  in  large  part  to  a  very 
common  practice  of  nialdug  use  of  all  manner  of  uninviting  fragments 
and  scraps  of  meat,  oftal,  and  the  flesh  of  sick  and  ill-conditi<med 
animals  in  preparing  sausage  meat,  and  perhaps  to  a  greater  extent  to 
the  extremely  unsanitary  methods  of  manufacture  which  obtam  in  those 
districts  where  this  form  of  poisoning  is  most  prevalent.  In  many 
^  Arcliiv  fiir  Hygiene,  XXXII.,  p.  219. 


72  FOODS. 

instances  the  symptoms  caused  are  duo  to  the  jM-esence  of  ptoniains,  and 
in  mauy  to  the  contained  bacteria  aud  their  toxius. 

In  most  instances,  it  is  impossible  to  fix  the  blame  upon  any  in- 
dividual constituent,  nor  aside  from  its  scientific  interest  is  this  of 
special  importance.  The  symptoms  present  as  wide  variations  in  char- 
acter as  are  observed  in  any  other  form  of  food-poisoning 

The  process  of  smoking,  to  which  certain  varieties  of  sausages  are 
subjected,  while  not  destructive  to  the  bacteria  of  putrefaction,  is  often 
successful  iu  masking  any  unpleasant  smell  or  taste  due  to  change. 

Cases  Illustrative  of  Poisoning-  by  Fish  and  Meat. 

Poisoning  by  Mussels.  Case  I. — At  Wilhelmshaven,  in  1885, 
several  lougshoremeu  and  their  families,  19  persons  in  all,  were  stricken 
with  veiy  severe  symptoms  shortly  after  eating  a  meal  of  mussels. 
The  symptoms  were  in  general  the  same  in  all,  regardless  of  the  amount 
eaten,  and  included  nausea  and  vomiting  without  abdominal  pain  or 
purging,  trembling,  constriction  of  the  throat,  dizziness,  and  diminished 
coordination  of  movement  similar  to  that  due  to  alcoholic  intoxication. 
There  was  no  fever.  Speech  was  difficult  and  thick,  and  in  a  short 
time  the  legs  were  unable  to  support  the  body.  The  pupils  were  dilated 
and  unresponsive  to  reaction  tests.  The  extremities  were  cold  and 
numb.  Four  deaths  occurred,  one  within  two  hours,  one  in  three  aud 
a-half,  and  the  others  within  five  hours  from  the  time  of  ingestion.  The 
autopsy  in  the  only  case  examined  revealed  enteritis,  enormous  enlarge- 
ment of  the  spleen,  numerous  hsemorrhagic  infarctions,  and  fatty  degen- 
eration of  the  heart,  liver,  and  kidneys. 

In  this  case,  the  sudden  onset  and  rapidly  fatal  termination  indicate 
a  true  poisoning  rather  than  an  mvasion  of  the  system  by  bacteria,  and, 
indeed,  the  poison  was  proved  by  Salkowski  and  Brieger  to  be  a  ptomain, 
to  which  they  gave  the  name  mytilotoxin. 

Case  II. — Dr.  James  S.  Combe,^  of  Edinburgh,  reported,  in  1828, 
an  outbreak  which  involved  a  large  number  of  persons  of  the  lower 
class  ranging  in  age  from  2  to  70  years.  The  first  case  seen  was  a 
man  of  60,  who  complained  of  thirst,  heat  in  the  mouth,  difficulty  in 
swallowing,  tension  about  the  jaws  and  throat.  The  pulse  was  small 
and  weak,  the  respiration  normal,  the  surface  cool.  The  hands  were 
numb  and  the  legs  unable  to  support  the  body.  Recovery  followed 
purgative  treatment.  He  had  supped  the  evening  before  with  a  friend, 
who  died  during  the  night.  They  had  eaten  mussels  boiled  with  salt, 
but  had  noticed  no  peculiarity  of  taste.  The  next  case  seen  was  that 
of  a  man  of  30  who,  on  the  previous  evening,  had  picked  a  few  mussels, 
not  over  five  or  six,  and  had  eaten  them  raw.  No  effects  were  noticed 
until  morning,  excepting  slight  burning  of  the  lips  and  tongue.  On 
attempting  to  get  up  he  found  that  he  could  not  stand,  although  he, 
like  the  first,  could  move  his  legs  about  in  bed. 

Although  hundreds  of  cases,  with  many  deaths,  were  said  to  have 

1  Edinburgh  Medical  and  Surgical  Journal,  1828,  XXIX.,  p.  86. 


CAS/<!S   ILIJJSTllA'riVI':   OF   I'OISOMSC    /!)'    FISH    AM)    MEAT.       !'.'> 

oc(5urr(!(l,  iti  c()nsc(jii<'nc-(!  oC  wliif'li  (lie  niii^istr.ilcs  isHUcd  a  wurnirig 
ajraJiisI,  IJk!  iis(!  of"  miisscls,  \)v.  ('oiiilx'  foiiiid  l»iit,  lliii-(y  cMscn  with  two 
(leaMis.  Ill  :ill,  i\\r  syiiipt.nins  prcscnlcd  ;i  -t  rik  in;/  iini  (onnit  y,  tlioiij^li 
tliey  varied  nmcli  in  s(!V(!i'ily.  Mo.^l  of  I  he  \i<liiii.s  li:ul  caleii  tlif; 
miiHSiils  l)(>ii(Ml  with  snlt  iiinl  pepper,  ami  none  liad  wAiccA  any  urniHiial 
taHte.      Ill  <i;(!ii(U';il  tlw;  svMi|»loms  a|)|)e;ire(l  in  an  lifdir  or  fwf). 

Tlic  miiii  who  (Hed  had  vomited  ;i  1(!W  lioiirs  after  (iitin^.  Iff;  lay 
down,  hiul  occasional  <i;eneral  I  remblinf^,  was  rational  to  tli<!  last,  and 
diod  as  if  by  in<',r<;asini;-  weakness.  On  section  a  few  dark-red  patches 
were  fonn<l  in  the  ilcMini.  Tlu!  stoni;i<^h  was  empty  and  jtresented  no 
abnorin:il  :i,ppearan(!e.  The  otluu*  fatiil  case  w;is  that  of  a  woman  who 
died  in  three;  lionrs  after  eating.  The  autopsy  revealed  a  full  stomach 
eontaininii;  mussels  and  potatoes,  and  beyond  a  few  red  patches  in  the 
iiilcsline  the  viscera  weix;  (piite  normal. 

In  his  report,  Dr.  (-omlx!  referred  to  a  case  relate<I  by  Captain  Van- 
couver/ a  number  of  whose  men  ate  a  breiikfast  of  roasted  mussels. 
Soon,  several  were  seized  with  numbness  about  the  face  and  extremities, 
followed  by  involvement  of  the  whole  body.  One  man,  who  died  in 
five  and  a  half  hours  after  eatiutr,  was  unable  to  swallow,  and  thoufrh 
he  could  row  in  the  boat  while  sick,  he  was  unable  to  stand  on  leaving  it. 

Poisoning  by  Herrings. — A  ease  involving  five  persons,  reporter! 
by  R.  David, ^  '•'^  remarkable  for  the  variety  of  manifesfcitions,  tlie  length 
of  time  that  elapsed  before  the  apjiearance  of  the  symptoms,  and,  in 
two  of  them,  the  severity  and  duration  of  the  illness.  The  afflicted 
persons,  adult  raeuibcrs  of  one  family,  ate  on  March  10,  18f)8,  some 
raw  red  herrings,  which  gave  oif  odor  indicative  of  commencing  putre- 
faction. Each  ate  the  same  amount,  a  whole  fish,  but  whether  each 
fish  was  equally  advanced  in  decomposition  cannot,  of  course,  be  deter- 
mined, and  the  dilferiug  degrees  of  severity  of  effects  may  be  explainetl 
by  unequal  susceptibility.  The  father  and  mother  aged,  respectively, 
65  and  G7  years,  suffered  least ;  the  son,  aged  31,  was  affected  more 
seriously  ;  the  two  daughters  presented  unusually  severe  and  compli- 
cated symptoms. 

The  first  effects  were  manifested  by  the  sou,  who,  on  the  second  day, 
was  seized  with  loss  of  appetite,  disagreeable  eructations,  vomiting, 
diarrhoea,  dryness  of  the  throat,  and  general  weakness.  On  the  fol- 
lowing day,  he  was  better,  but  soon  became  Avorse.  Diarrhoea  was 
followed  by  obstinate  constipation,  which  finally  yielded  to  cathartics. 
Five  days  later,  he  had  dinniess  of  sight,  Avhich  was  followed  after  a 
week  by  double  vision  and  difficult  deglutition.  The  symptoms  gradu- 
ally abated,  and  on  jNIay  27th  there  was  distinct  uuprovement  of  sight. 
On  June  '2d  glasses  were  hardly  needed. 

The  mother  first  showed  symptoms  on  the  fifth  day,  when  nausea, 
constipation,  and  dryness  of  the  throat  appeared.  Several  days  later 
she  had  double  vision  and  difficult  deglutition. 

1  Voyage  of  Discovery,  Vol.  IV.,  p.  45. 

'  Deutsche  niediciiiische  Wocheuschiift,  1899,  Xo.  S. 


74  FOODS. 

The  father's  case  began  on  the  ninth  day  and  presented  similar  symp- 
toms, which  disappeared  iu  six  weeks. 

One  of  the  daughters  was  seized  on  the  third  day  with  bad  taste  in 
the  mouth,  constipation,  and  dryness  of  the  throat,  followed  in  six  days 
by  dimness  of  near  vision,  then  by  donble  vision,  paralysis  of  accom- 
modation, and  dithcult  swallowing.  As  was  the  case  with  the  others, 
the  temperature,  circulation,  and  uriue  remained  normal.  On  May  2d, 
there  was  complete  inability  to  swallow  and  it  was  necessary  to  intro- 
duce food  by  means  of  a  stomach-tube.  There  was  slight  ptosis 
of  the  right  eye,  then  of  both ;  the  voice  was  nasal ;  the  gait  was 
affected  and  the  pulse  became  veiy  small,  though  not  very  rapid.  On 
May  9th,  bladder  symptoms,  which  had  been  gradually  appearing,  cul- 
minated in  paralysis  of  that  organ,  and  after  the  13th,  a  variety  of 
bladder  and  abdominal  sym]itoms  appeared.  In  the  first  part  of 
July,  she  felt  completely  well,  but  a  month  later  she  suffered  a  slight 
relapse,  with  reappearance  of  constipation,  difficult  deglutition,  and 
disturbance  of  vision,  which  persisted  with  varying  intensity  into  Sep- 
tember. Complete  recovery  did  not  occur  until  October,  almost  seven 
months  after  the  initial  symptoms. 

The  other  daughter  first  showed  symptoms  after  the  lapse  of  a 
week.  These  were  in  the  main  like  those  of  her  sister,  but  were  more 
severe  and  extensive.  She  began  to  improve  in  May,  and  then  ensued 
alternate  improvement  and  loss  of  ground,  better  one  day  and  worse 
the  next.  On  the  1 5th,  there  was  pain  in  the  left  hypochondrium  ;  on 
the  17th,  an  eruption  like  that  of  scarlet  fever  over  the  whole  body, 
with  albuminuria,  but  no  casts.  On  the  19th,  severe  pain  in  the  left 
hypochondrium,  less  in  the  right,  and  tenderness  in  the  region  of  the 
kidneys,  with  epistaxis,  disappearance  of  tlie  rash,  slight  desquamation, 
and  improved  vision.  At  the  end  of  May,  the  albuminuria  and  pain 
in  the  region  of  the  kidneys  had  nearly  disappeared,  and  deglutition 
was  perfect.  On  June  2d,  heart  complications  appeared,  which 
persisted  into  November,  when  hypertrophy  was  established.  In 
August,  after  a  general  improvement,  there  was  a  relapse  like  that 
which  occurred  in  the  case  of  her  sister.  Improvement  was  well 
established  in  October,  and  in  November  she  had  almost  wholly 
recovered. 

Unfortunately,  it  was  impossible  to  make  a  bacteriological  and  chem- 
ical examination  of  the  fish,  because  no  material  was  obtainable. 

Poisoning"  by  Salmon. — Professor  Vaughan^  reports  the  following 
case  :  "  K.,  a  very  vigorous  man  of  34  years,  ate  freely  of  canned 
salmon.  Others  at  the  table  with  him  remarked  that  the  taste  of  the 
salmon  was  peculiar,  and  refrained  from  eating  it.  Twelve  hours  later, 
K.  began  to  suffer  from  nausea,  vomiting,  and  a  griping  pain  in  the 
abdomen.  Eighteen  hours  after  he  had  eaten  the  fish,  the  writer  saw 
him.  He  was  vomiting  small  quantities  of  mucus,  colored  with  bile, 
at  frequent  intervals.  The  bowels  had  not  moved  and  the  griping 
pain  continued.     He  was  covered  with  a  scarlatinous  rash  from  head  to 

^  Ptomains,  Leucomains,  Toxins,  and  Antitoxins,  1896,  p.  56. 


GASES  fLHJSrilATIVI<:  OF  I'OISONINd   liY  FISH  AM)   MEAT,    ir, 

foot,  iris  j)iils(!  wuH  140,  t(!iri|)('r;iliin!  102°  F.,  arif]  rcKpinition  slial- 
low  itiid  irrci;iil;ir."  Af'tci'  ;i|»|)i()|)ii.it(',  f I't'iitniciit  Ik;  hcHun  to  iiii|)r«»V(;, 
''Tlic  n((xt  (iiiy  111''  I'lisli  (li.-;i|)|)(';ir('(l,  Unl  tlic  lcMi|)<'r;itiir(!  n-iii:iiii«'(l 
ubovi!  the  normiil  ("or  (our  or  (ivc  (luys,  and  it  wan  not  until  a  \\vx-\i. 
later  that  the;  man  was  ahic  lo  leave  IiIh  housf;."  Vanj^haii  (txaniiiiwl 
the  salmon  and  lonnd  a  microcofHMiH  prcsfint  in  ^n-at  nurnhcrs.  TIiIh 
ori^anism,  ^rown  for  t\V(;nty  days  in  a  st(!rilized  i'\i^\f,  jirodiircd  a  inoHt 
potent  j)ois()n.  Tlic  \vhit(!  heeamc  thin,  watery,  and  markedly  alkaline, 
and  ten  dro])s  sndiecid  to  kill  white  rats. 

Poisoning  by  Pike. — Ulrieh  '  reports  an  epidemic;  of  fish  poisoning 
through  the  eating;  o( "pike  (M(!erhe(;ht).  \\i'  makes  the  j)oint  that  the  fish 
beeame  more  and  more  [)oisonons  aeeordirij^  to  the  time  elapsed  subse- 
quent to  eooking.  In  2  patients  baeillus  paratyplioid  J5  was  isolated 
from  the  blood  and  4  other  j>atients  ^ave  positive  afrghitination  tests 
with  the  same  organism.  Ulrieh  believes  that  fish  should  never  be 
eaten  later  than  twenty-four  hours  after  it  has  been  cooked. 

Abraham^  reports  twenty-eight  cases  of  poisoning  after  eating  ))ikc. 
In  eighteen  hours  there  occurred  severe  colic,  nausea,  and  diarrhoea. 
The  infection  had  some  resemblance  to  typhoid  fever.  A  piece  of  the 
suspected  fish  presented  a  good  aji])earance  and  showed  no  evidence  of 
ptomains  or  metallic  })oisons.  Prof.  Neisscr  found  in  the  fish  bacilli 
of  the  paratyphoid  or  meat-])oisoning  group  (type  Aertryck).  The 
toxin  produced  by  this  organism  was  resistant  to  heat  and  the  blood 
of  the  patient  gave  with  this  organism  positive  agglutination  tests. 
The  specific  bacilli  could  not,  however,  be  found  in  the  stools  of  the 
patients.  It  is,  therefore,  most  probable  that  the  fish  was  infected 
during  life.  It  is  said  that  pike  favor  localities  like  sewer  outlets,  and 
could  easily  become  infected.  There  were  no  deaths  among  the.se 
patients. 

Poisoning  by  Oysters. — Case  I. — The  following  case,  which  ended 
fatally,  is  reported  by  Brosch.^  An  officer  ate  a  number  of  oysters 
toward  midnight,  ami  within  6  hours  was  seized  with  headache,  pain 
in  the  side,  nausea,  dimness  of  sight,  difficult  deglutition,  retention  of 
urine,  and  salivation.  Toward  noon,  right  facial  paralysis,  dilatation 
of  the  right  pupil,  and  thickness  of  speech  appeared,  followed  shortly 
by  cyanosis,  ptosis  of  the  right  eyelid,  great  muscular  relaxation,  and 
paralysis  of  respiration.  Autopsy  reveiiled  punctiform  ecchymoses  in 
various  parts,  enlargement  of  the  spleen,  and  fatty  degeneration  of  the 
liver  and  kidneys. 

Case  IL — Another  fatal  case  is  recorded  by  Casey  *  "  H.  P.,  about 
32  years  of  age,  ate  8  oysters  for  supper,  remarking  at  the  time  that 
one  of  them  was  bad.  Others  of  the  same  lot  appeared  to  be  quite 
fresh  and  were  eateu  by  other  persons  with  impunity.  Symptoms  of 
poisoning  began  about  12—14  h(^urs  later,  with  pain  in  the  back.  s«x>n 
followed  by  violent  paius  m  the  stomach,  frequent  vomitmg,  and  intense 

1  Zeit.  f.  Hyg.,  Vol.  LIIL,  1906. 
^Miinch.  Med.  Woch.,  1906.  No.  50,  p.  2466. 
^  Wiener  klinisclie  Wochensolirift,  1896,  Xo.  13. 
■*  British  Medical  Journal,  March  3,  1894,  p.  463. 


76  FOODS. 

thirst.  The  bowels  did  not  act.  Tliesc  symptoms  continued  until  the 
following  morning,  when  the  pulse,  which  had  been  small  and  quick, 
became  almost  imperceptible,  the  fingers  shrunken,  the  nails  blue.  The 
tongue  was  at  that  time  dark  and  swollen,  and  swallowing  difficult. 
There  were  occasional  spasms  of  the  arms.  A  little  later,  the  ja\v' 
became  set,  and  soon,  after  a  sudden  struggle  for  breath,  he  died,  41 
hours  after  eating  the  oysters.  At  the  post-mortem  examination,  the 
heart  -was  found  to  be  very  soft  and  relaxed  and  contained  fluid  blood. 
The  kidneys  and  spleen  were  also  very  soft  and  congested  ;  the  stomach 
emjitv  and  darklv  congested  ;  the  peritoneum  was  thickly  studded  with 
flecks  of  lymph.'' 

Poisoning'  by  Veal. — Boyer  ^  reports  the  following  case  of  sextuple 
poisoning  by  veal.  The  persons  aifccted  were  members  of  one 
h(»usehold,  and  ranged  widely  in  pouit  of  age,  the  yoimgest  being 
children  of  3  and  (3  years.  The  symptoms  appeared  in  the  night, 
about  6  hours  after  the  food  was  taken,  and  began  with  vomiting  and 
violent  colic.  In  the  morning,  all  had  intense  gastric  irritability,  coated 
t<)ngue,  pain  on  pressure,  especially  in  the  right  iliac  fossa,  rumbling, 
slight  tympanites,  and  scanty  urine.  The  cook  had  markedly  dilated 
pupils,  a  sensation  of  suffocation,  constriction  and  dryness  of  the 
throat,  and  intense  suffusion  of  the  face.  The  child  of  6  had  dilated 
pupils  and  disturbance  of  vision,  and  finally  pain  and  stiffness  of  the 
muscles  of  the  neck.  The  younger  of  the  two  children  and  the  mother 
were  affected  less  than  the  others,  and  made  a  more  rapid  recovery. 
The  chambermaid  had  at  first  a  certain  degree  of  aggravation  of  symj)- 
toms,  with  a  tendency  to  syncope  and  great  muscular  weakness,  which 
latter  effects  were  maiked  also  in  the  case  of  the  cook,  who  continued 
for  some  time  to  be  troubled  by  dilatation  of  the  pupils  and  disturbed 
vision.  At  the  end  of  nine  days,  there  was  no  evidence  of  danger,  and 
the  two  most  severely  affected  were  well  on  the  way  to  recovery. 

Unfortunately,  no  bacteriological  examination  was  made  either  of  the 
meat  or  the  discharges,  but  the  nature  of  the  symptoms  leaves  no  room 
for  doubt  as  to  their  cause. 

Case  IT. — Drs.  Wilkinson,^  Ashton,  and  Durham  have  recorded  an 
extensive  outbreak  of  poisoning  due  to  imperfectly  cooked  veal  pies. 
All  the  cases,  over  fifty  in  number,  presented  very  similar  symj)- 
toms,  the  chief  of  which  were  severe  and  uncontrollable  vomiting  and 
diarrhoea,  accompanied  at  first  by  shivering,  and  followed  by  collajjse. 
In  some  there  were  violent  abdominal  pains,  and  in  several  the  abdo- 
men was  swollen  and  tender.  Many  had  severe  pains  in  the  back.  The 
symptoms  began  in  from  5  to  14  hours  after  eating,  and,  as  a  rule, 
were  severe  from  the  start.  The  motions  were  first  grass-green,  then 
dark  green,  and  highly  offensive.  The  severity  of  the  diarrhoea  in- 
creased on  the  second  day  ;  one  patient  was  purged  40  or  more  times 
in  a  single  day.  In  very  fe^v  cases,  the  dejecta  contained  a  little 
blood. 

'  Lyon  medical,  May  14,  1899. 

^  Public  Health,  Januaiy,  1899,  and  British  Medical  Journal,  December  17,  1898. 


CASES  njjis'rn.\'rivi<:  <>i''  roisosisc  r.v  iisii  asd  mi:.\t.   11 

III  \hv  worsi,  <':isc.s,  (he  |i;iliiiils  Iicciuik;  Hciiii-coniutoHc,  rcstlc.'-H,  :iinl 
delirious  in  llic  cdiirH'  oC  ;i  liw  Ikmii-,-;.  Occasionally,  tlKfn;  were  jIIh- 
iiirhMiK^cs  i)['  vision,  which  lasted  iinlil  liic  f<'iii|)('ralnrc,  wliic^li  raiijr<'d 
ironi  100'^  in  Ihc  niildcsl  to  101. 5''  V.  in  the  scvcrrsi  cmscs,  hfcjiriu-  n<*r- 
nuil.  The  j)uls((  was  wvy  r'lipid,  wc'ik,  ;iiid  <h'ci-oti<-.  M;iMy  of  the  j)a- 
tlcnls  were  ninrkcdK'  <'y;in(ilif  ;iiiil  h;id  mimic  m-  |c-s  dillicidly  in  hrcjith- 
in^'.  Sonic  h;id  ciMnips,  ;ind  iii;irl\'  ;ill  hiid  niii-cnl;ir  |>;iin  ;ind  stilViKtHH, 
Til  very  many  cas<^s,  herpes  ;i|)|)e;ircd  ;d)ont  the  lips  on  ihc  third  to 
the  sixth  day,  and  sonic;  had  a  lash  rollf)Wc(j  hy  dcs((n:ini;ition.  C'on- 
valos(!oncc  in  the  scvei'c;  cases  was  ])rolon<rcd  ;  some  wen;  still  weak 
after  thrc*;  and  a  half  months.  PV)iir  cases  terniinaled  fatally,  and  in 
two  of  those,  autopsies  were  sccMired.  'VUv  iirain  siM'fac(!  sliowcfl  sli^^ht 
conf!;estion  ;  tlu^  small  intcslincs  showed  con<;-este<l  p;itchcs,  which  Ix;- 
camc  lar>:,"ei"  and  iiioih;  iiiimiM'oiis  lower  down,  and  did  not  correspond 
with  Peyer's  j)atches.  The  whole  lower  third  was  hij^hly  con^eKtcd, 
and  contained  yellow  diarrh<eic  llnid.  Otherwise  the  organs  of  the 
body  were  in  a  fairly   healthy  eondition. 

Investigation  of  the  cause  of  the  onl break  yicMed  the  following; 
facts:  On  Jnly  2Gth,  an  apparently  healthy  calf  was  slanghtored, 
and  two  days  later  the  fore  qjiarter  and  breast  were  delivered  to  a 
baker,  who  made  the  meat  into  the  jiics  which  were  shown  to  have  been 
the  cause  of  the  outbreak.  Other  portions  of  the  animal  were  sold  to 
others,  who  made  pies  which  caused  no  trouble.  A  ])oi*tion  of  a  knuckle 
end,  which  was  in  the  possession  of  the  butcher  when  the  mvestigation 
was  begun,  was  to  all  appearances  perfectly  good. 

The  baker  to  whom  the  trouble  was  traced  made,  on  the  day  he 
received  the  meat,  IGO  veal  pies  and  108  jiork  pies.  The  pastiy  was 
the  same  for  the  entire  lot,  and  both  kinds  were  treated  to  the  same 
lot  of  jelly,  which  was  made  by  boiling  the  veal  bones  with  two  pigs'- 
feet  in  4  quarts  of  water.  Inasmuch  as  the  pork  pies  caused  no 
disturbance  of  any  kind,  no  responsibility  could  be  attached  to  the 
pastry  or  to  the  jelly.  The  veal  pies  were  baked  in  not  less  than  3 
nor  more  than  5  batches,  hence  the  batches  would  have  included  about 
32,  42,  or  53  pies.  The  time  occupied  in  baking  each  batch  was  said 
to  have  been  about  20  minutes.  The  number  of  persons  aiiected  was 
over  50  and  as  in  some  cases  single  pies  were  shared  by  2,  3,  and  4 
persons,  it  is  obvious  that  less  than  50  pies  caused  all  the  trouble. 
Since  no  other  parts  of  the  animal  caused  any  sickness,  there  can  be 
no  doubt  that  the  contamination  of  the  meat  occurred  after  the  sale  and 
delivery. 

According  to  the  findings  of  Dr.  Durham,  based  on  a  study  of  the 
blood  of  a  number  of  the  patients  as  to  the  behavior  of  the  serum 
when  tested  for  clumping  properties  with  various  micro-org-anisms, 
with  controls  of  seinim  from  normal  persons,  the  outbreak  was  due  to 
B.  entcvitkUs.  This  limitation  of  the  inquiry  was  necessitated  by  the 
fact  that  it  was  impossible  to  secure  either  one  of  the  pies,  or  part 
of  one,  or  any  of  the  first  vomitings.  The  conclusion  arrived  at, 
strengthened  by  the  fact  that  all  4  tatal  cases  were  from  pies  which 


78  FOODS. 

were  2  or  more  days  old  when  eaten,  whieh  period  allowed  enormous 
mnltiplieation,  makes  most  probable  the  further  eonelu.sion  that  one 
whole  bateh  was  cooked  so  insutiieiently  as  to  jn-eclnde  the  killing  of 
the  organisms,  which,  according  to  Basenan,  cannot  survive  exposure 
for  1  minute  to  a  temperature  of  70°  C. 

Case  III. — Brekle  ^  reports  an  epidemic  of  poisoning  due  to  the 
eating  of  meat  coming  from  a  calf  which  had  been  subjected  to  emer- 
gency slaughter  because  of  sickness.  There  were  13  cases  and  2 
deaths.  Symptoms  came  on  in  about  eighteen  hours,  characterized  by 
vomiting,  giddiness,  chills  and  fever,  colic,  and  diarrhoea.  Some  of  the 
cases  were  quite  protracted,  lasting  as  much  as  four  weeks.  There  was 
no  especial  taste  to  the  meat  which  was  at  fault.  The  same  organism 
was  isolated  from  the  infected  meat,  from  the  organs  of  those  who  died, 
and  from  the  stools  of  the  sick.  This  organism  gave  reactions  Avhich 
identified  it  very  closely  with  the  B.  enferitidis  of  Gaertner.  The  toxin 
produced  by  this  organism  was,  furthermore,  resistant  to  heat,  and 
therein  agreed  in  character  with  the  bacillus  of  Gaertner. 

Poisoning  by  Pork. — Case  I. — Meredith  Youngz  records  a  case 
of  pork-poisoning  in  which  5  persons  were  affected.  The  oflPeuding 
meat  was  three-quarters  of  a  pound  of  "  pig's  cheek,"  which  was 
eaten  at  half-past  four  in  the  afternoon,  between  which  time  and  the 
onset  of  symptoms  nothmg  else  was  eaten.  On  the  following  morning, 
INIr.  A.  was  seized  suddenly  with  vomiting,  purging,  and  severe 
abdominal  pain,  and  shortly  afterward  became  very  feverish  and  weak, 
and  suffered  from  severe  frontal  headache.  His  wife  had  severe 
abdominal  pain,  and  toward  noon  was  strongly  purged.  She  suffered 
nausea,  retched,  but  could  not  vomit,  had  fever  and  severe  headache, 
and  was  much  more  prostrated  and  took  more  time  to  recover  than 
her  husband.  She  was  unable  to  ingest  food  for  3  days.  The  daughter 
was  taken  sick  at  the  same  time  and  with  the  same  symptoms,  though 
less  severely.  Her  chief  symptom  was  an  overpowering  tendency  to 
sleep.  A  fourth  person,  who  ate  but  little  as  compared  with  the  amounts 
ingested  by  the  others,  was  purged  slightly,  but  suffering  nothing  more. 
The  remaining  member  showed  no  effects  until  during  the  second  night. 
On  the  following  morning,  she  was  feverish,  had  severe  headache  and 
abdominal  pain,  and  retched  unsuccessfully.  Purging  did  not  occur 
until  the  afternoon.  As  was  the  case  with  the  daughter,  the  most 
prominent  symptom  after  the  onset  was  somnolence.  Recovery  fol- 
lowed in  every  case.  Investigation  showed  that  the  cheeks  had  been 
cooked  2  days  before,  and  had  been  placed  together  to  cool  and  "  set." 
It  was  estimated  that  between  50  and  60  persons  had  purchased  of 
them,  but  all  but  a  small  proportion  were  unknown  to  the  seller,  and 
so  no  systematic  inquiry  could  be  made.  Only  4  could  be  followed 
up,  and  2  of  these  reported  no  trouble  ;  a  third  was  made  severely 
sick  and  lost  2  days'  work,  and  the  fourth,  after  eating,  drank  so 
much  beer  that  he  was  made  sick  and  lost  it  all  by  vomiting,  and  yet 

1  Miinch.  Med.  Woch.,  June  7,  1910,  p.  1227. 

2  Public  Health,  June,  1899. 


OAsi<:s  njjis'rnA'r/vh'  or  i'oihoninci  i:y  iisii  and  meat.   79 

WUH  alleck'cJ  Iil<<;  iJi*'.  olJicrs,  hul,  not  so  uclivcly.  It  \va.s  iuipo.sbibh;  to 
procure  any  ol'  the  nicil  or  \(»niil(<l  ni;ill(r  or  (Icjcc-tiofiH  for  bacttjrio- 
lof2;i<'.<iI  ('Xiuniii;i(ion. 

('ASM  II. — At  (lie  ScN'cnili  Iiilcrn.'ilioiKil  .Mc(lic;il  ( 'isu^rc'ri^,  licid  iti 
Ivondon,  ill  IHSI,  I'>;ill;ir<l  '  rend  licCorc  llic  section  on  St;itc.  Mc<li- 
cin(!  ;in  nccoMnI  of  :i  \(i\'  serious  oiill)re;d\,  now  generally  known  a.s 
the  "  Wdllx'ck  c'lse."  Tliis  in\'ol\ed  72  |)(!rHonH,  wlio  attended  a  kjiIo 
ofiinilxM-  ;ind  iniicliinery  on  (lie  csfnlc.  of'tlic  Dnkc  of"  Porlliind  ;it  W(;l- 
bcck,  vvliicli  k'isicd  Iroin  TiicsckMy,  .Inno  1  o,  I  MHO,  liironffli  the  wccjk. 
Jicfreslnnenls  \v(^rc  served  l)V  IIk'  kee|)er  oC  ;i  |)iil)lie  house,  ;iud  ;Muon^ 
tlio  urtielos  f'unn'slied  wc^re  seven  lianis,  to  wliieh  the  entire  trouhle 
was  tra(H'd.  VVliilc!  many  eompkiints  were  ni;ide  th;it  the  h;ini  was  not 
suilieienlly  cooked,  that  the;  fat  was  yellowish  or  greenish,  that  it  was 
too  salt,  that  it  "tasted  (pieer,"  and  that  it  had  no  true  flavor  of  ham, 
many  made  no  complaint,  and  no  one  said  that  it  was  tainted.  <  )f"  the  I'l 
persons  seized,    I  died.      The  history  of  .'>  of  these  follows  : 

1.  VV.  W.,  a<^ed  ()4,  ate  luim  on  Wednesday  and  Friday,  and 
was  seized  on  I^'riday  ni<i;lit,  when  lie  com|)laine(l  of  feclin;,''  cold.  On 
Saturday  mornino'^  he  ate  but  little  and  said  he  ached  all  over.  In  the 
course  of  the  day,  he  suffered  from  vomiting  and  diarrha3a,  with  severe 
pain  and  cramps  in  the  legs.  The  evacuations  were  exceedingly  offen- 
sive and  were  i)assed  involuntarily.  The  pidsewasl28;  temj)erature 
not  taken.  On  Monday,  he  began  to  colla})se,  and  on  Friday,  he  died. 
The  post-mortem  examination  revealed  little  that  was  noteworthy,  but 
microscopic  examination  of  the  kidneys  showed  parenchymatous  inflam- 
mation, and  distention  and  plugging  of  the  afferent  arterioles  and  capil- 
laries of  the  Malpigliian  corpuscles  by  emboli  of  bacilli. 

2.  Mrs.  L.,  aged  62,  ate  some  scraps  of  the  ham  on  Wednes- 
day, and  was  seized  on  Friday  with  faintnass,  cliarrlicca,  vomiting,  and 
abdominal  pain.  On  the  following  day  she  fell  into  a  state  of  collapse, 
and  on  the  following  Tuesday  she  died.  The  mucous  membrane  of  the 
stomach  and  intestines  was  highly  congested ;  otherwise  the  autopsy 
revealed  nothing  abnormal. 

3.  Mr.  S.,  aged  37,  ate  four  sandwiches  on  Thursday.  In  the 
evening  he  vomited,  and  diarrhoea  began.  In  the  morning  of  the 
foUoAving  day,  he  complained  of  burning  pain  in  the  lower  part  of  the 
abdomen.  The  vomiting  and  purging  continued.  Though  cold  and 
clammy  to  the  touch,  he  complained  that  he  was  "  all  on  fire."  He  had 
cramps  in  the  legs  and  Avas  very  restless.  His  mind  was  clear  to  the 
last.  The  dischai-ges  were,  at  first,  watery  and  oii^lnisive,  and  later  were 
dark  green  in  color.  He  was  very  thirsty  and  drank  freely  of  water. 
He  died  on  the  following  Friday.  Only  a  partial  autopsy  was  made. 
This  revealed  bright-red  patches  on  the  mucosa  of  the  stomach. 

The  period  of  incubation  W'as  accurately  determined  in  51  cases  ;  in 
5  it  was  12  hours  or  less,  iii  34  it  was  between  36  and  48,  and  in  4 
it  exceeded  48  hours.  In  many  cases  the  onset  was  sudden,  and  in 
others  it  was  preceded  by  greater  or  less  indisposition.     The  most  cou- 

»  Supplement  tu  10th  Annual  Report  of  the  Local  Government  Board,  1881,  p.  36. 


80  FOODS. 

stant  symptom  was  diarrhoea.  "  In  about  a  third  of  the  cases  the  first 
definite  .symptom  was  a  sense  of  cliilliness,  usually  with  rio-ors  or  tremb- 
ling:, ill  <^iit'  case  accompanied  by  dyspncea  ;  in  a  few  cases  it  was  gid- 
diness with  faintness,  sometimes  accomiianied  by  a  cold  sweat  and 
tottering  ;  in  others  the  first  symptom  was  hejidache  or  pain  somewhere 
in  the  trunk  of  tlie  body,  c.  r/.,  in  the  chest,  back,  betAvccn  the  shoulders, 
or  in  the  abdomen,  to  which  part  the  pain,  wherever  it  might  have  com- 
menced, subsequently  extended. 

"  In  one  case  the  first  symptom  noticed  ^^^as  a  difficult}^  in  swalloAV- 
ing.  In  tM'o  cases  it  was  intense  thirst.  But,  however  the  attack  may 
have  commenced,  it  was  usually  not  long  before  jxiin  in  the  abdomen, 
diarrhcea,  and  vomiting  came  on,  diarrha?a  being  of  more  certain  occur- 
rence than  vomiting.  The  pain  in  several  cases  commenced  in  the  chest 
or  between  the  shoulders,  and  extended  first  to  the  upper  and  then  to 
the  lower  part  of  the  abdomen.  It  was  usually  very  severe  indeed, 
quickly  producing  prostration  or  faintness  with  cold  sweats.  It  was 
variously  described  as  'crampy,'  'burning,'  'tearing,'  etc. 

"  The  diarrheal  discharges  were  in  some  cases  quite  unrestrainable, 
and  (where  a  description  of  them  could  be  obtained)  were  said  to  have 
been  exceedingly  oifensive,  and  usually  of  a  dark  color.  Muscular 
weakness  was  an  early  and  very  remarkable  symptom  in  nearly  all 
cases,  and  in  many  it  was  so  great  that  the  patient  could  only  stand  by 
holding  on  to  something.  Headache,  sometimes  severe,  was  a  common 
and  early  symptom  ;  in  most  cases  there  was  thirst,  often  intense  and 
most  distressing.  The  tongue,  when  observed,  was  described  usually  as 
thickly  coated  with  a  brown  velvety  fur,  but  red  at  the  tip  and  edges. 

"  In  the  early  stage,  the  skin  was  often  cold  to  the  touch,  but  after- 
ward some  fever  set  in,  the  temperature  arising  in  some  cases  to  101°, 
103°,  and  104°  F,  In  a  few  severe  cases  where  the  skin  was  actually 
cold,  the  patient  complained  of  heat,  insisted  on  throwing  off  the  bed- 
clothes, and  was  very  restless.  The  pulse  in  the  height  of  the  illness 
became  quick,  countuag  in  some  cases  100  to  128. 

"The  above  were  the  symptoms  most  frequently  noted.  Other 
symptoms  occurred,  hoM'ever,  some  in  a  few  cases,  and  some  in  only 
solitary  cases.  These  I  now  proceed  to  enumerate.  Excessive  sweat- 
ing, cramps  in  the  legs,  or  in  both  legs  and  arms ;  convulsive  flexion  of 
the  hands  ;  aching  pain  in  the  shoulders,  joints,  or  extremities  ;  a  sense 
of  stiifness  of  the  joints  ;  prickling  or  tingling  or  numbness  of  the  hands, 
lasting  far  into  convalescence  in  some  cases ;  a  sense  of  general  com- 
pression of  the  skin,  drowsiness,  hallucinations,  imperfection  of  vision, 
and  intolerance  of  light. 

"  In  three  cases  (one  that  of  a  medical  man)  there  was  observed 
yellowness  of  the  skin,  either  general  or  confined  to  the  face  and  eyes. 
In  one  case,  at  a  late  stage  of  the  illness,  there  was  some  pulmonary 
congestion,  and  an  attack  of  what  was  regarded  as  gout.  In  the  fatal 
cases  death  was  preceded  by  collapse  like  that  of  cholera,  coldness  of 
the  surface,  pinched  features  and  bluencss  of  the  fingers  and  toes,  and 


(JASh'S   ILUIS'I'UATIVI':   OF   I'OlSOSISd    IIY    FfSll    A.\/>    M/:A7'.    H\ 

around  llic  simkcii  tycs.  'I'lic  (lcl)ilit,y  oi'  (;(jMval(;.s(;(:ii(;c  \v:i-  in  iicirly 
all  ciiKcs  |)n»(r;ic(('(l  l<»  scvcr.-il  W(!('I<h. 

"TIk!  inildcsl  cuscs  \V(!i'(!  cliMnicU-i-i/cd  usually  hy  little  n'liiark.'iMc 
l)(!y(>n(l  ilic  (ullowin^'  syniploms,  viz.,  altdominal  |»ains,  vomit iii^r,  <liar- 
\uxy,\,  tliirHt,  lieadaclic,  ami  iiiiis<'iilar  w  takiicss,  any  one  ov  two  of  wliicli 
niiji;lit  bo  absent." 

Invostif^'ation  ol  llie  liains  showed  ai)scnce  ol'  tricliina-  and  tlie  pres- 
en(!C  of  a  baciilliis,  wliieli  on  inoeulatinn  inio  animal-  \\a>  foinid  in  most 
cas(>,s  to  ])rodnee  a  ])nennionia. 

'riie  period  of  inciibal  ion  indicates  llial  in  these  eases  there  waH  a 
triu^  bai'terial  infection. 

Casio  III. — Another  epidemic  investigated  by  Uallard  '  involved 
a  far  <2;reMter  nnmbei"  of  persons  and  had  an  imnsnal  atfendaht 
mortality,  nearly  AOO  persons  ont  of  a  jnipnlation  of  abont  'l(U),()()() 
(Middlc^sbron^'h)  dvini;'  dnrin^^  the  \i-,w  of  a  ]»cenliar  form  of  |)lenro- 
pneumonia. 

The  caiiso  of  this  I'emarkable  e])ideinie  was  ])roved  to  be  the  c-on- 
sunij)tioii  of  what  was  known  as  "Aiiieriean  baeon,"  a  food  ])i-oduct 
prepared  from  imported  salt  pork  at  a  number  of  loeal  cstablislnnents 
conducted  under  most  unsanitary  conditions.  Twenty  samples  of 
bacon,  some  obtained  at  shops  and  some  at  the  homes  of  victim.s, 
were  examined,  and  fourteen  were  found  to  be  distinctly  poisonous  to 
animals.  The  lesions  discovered  in  the  dead  animals  were  of  the  same 
nature  and  extent  of  those  in  the  organs  of  the  persons  who  had  died. 
These  included  destructive  changes  in  all  the  principal  viscera,  and 
more  particularly  in  the  lungs.  Dr.  Klein  discovered  in  the  lung  a 
short  bacillus  which  had  never  before  been  described.  Inoculati(»n 
exjKn'iments  on  animals  produced  results  identical  with  those  following 
feeding  experiments  with  the  so-called  bacon. 

Case  IV. — A  remarkable  outbreak  due  to  raw  pickled  ham  has 
been  recorded  by  Van  Ermengem^  and  carefully  investigated  by  him- 
self and  others.  More  thau  twenty  members  of  a  musical  society  at 
Ellezelles,  in  Belgium,  were  seized  with  serious  illness  after  eating  the 
greater  part  of  a  raw  pickled  ham  ;  three  died  withm  a  week,  and  ten 
lay  in  a  critical  condition.  Other  parts  of  the  animal  from  the  same 
pickling  tub  were  eaten  in  a  raw  state  Avithout  ill  effects,  and  pieces  of 
the  particular  ham  had  been  consumed  a  short  time  before,  also  without 
.  ill  effects.  Only  those  persons  who  ate  of  the  ham  were  seized  -with  the 
very  peculiar  train  of  symptoms  recorded.  Most  of  them  were  seized 
in  from  20  to  24  hours,  3  in  less  than  that  time,  and  a  few  as  late  as 
86  hours  after  eating. 

The  iirst  symptoms  were  gastric  pain,  nausea,  and  vomitiug  of  mi- 
digested  food  and  gelatinous  blackish  matters.  lusteiid  of  diarrhoea, 
which  one  would  expect,  there  was  obstinate  constipation  in  all  but 
2  cases,  and  the  tirst  dejections,  with  or  without  cathartics,  were  black 
and  viscid.  In  every  case,  in  from  oG  to  48  Ikhu's,  there  were  pro- 
found disturbances  of  vision — amphodiplopia,  markai  dilatation  of  the 

>  Supplement  to  18th  Annual  Eeport  of  the  Local  Government  Board,  1S89,  p.  163. 
^  Zeitschrift  fiir  Hygiene  und  Infoctionskrankheiten,  XXVI.,  p.  1. 


82  FOODS. 

pupils,  with  absence  of  reaction  to  light,  ptosis  of  both  lids,  and  a 
peculiar  fixed  stare.  There  was  burnino-  thirst  with  a  stranglino;  sensa- 
tion in  the  throat.  Swallowino-,  even  of  H(|uids,  was  difficult  or  impos- 
sible, and  every  attempt  was  accompanied  by  choking. 

In  some  instances,  the  saliva  was  suppressed  and  the  mucous  mem- 
brane dry  and  glossy.  The  voice  was  weak,  and  with  some  there  was 
total  aphonia.  Dysuria  and  anuria  were  common.  Tiiere  was  but 
little  disturbance  of  respiration  and  circulation  ;  tlie  pulse  never  reached 
over  90,  respiration  was  quiet,  temperature  normal.  Consciousness  and 
geueml  sensibility  remained  unimpaired  throughout,  except  in  the  fatal 
cases,  in  Avhich  alone,  several  hours  before  death,  there  occurred  collapse, 
dyspnoea,  small  irregular  pulse,  light  delirium,  and  coma. 

There  was  obstinate  insomnia  in  many,  during  the  first  period.  The 
extremities  and  trunk  muscles  showed  neither  complete  paralysis  nor 
atrophy,  but  there  was  great  general  muscular  weakness,  and  slight 
movements  caused  extreme  fatigue.  After  two  or  three  weeks,  the  eye 
symjitoms  began  to  improve.  The  dilated  pupils  contracted,  the  cloudi- 
ness disappeared,  and  the  half-paralyzed  eyelids  regained  their  power. 
Diplopia  disappeared  only  when  both  eyes  were  fixed  laterally.  Par- 
alysis of  accommodation  lasted  a  long  time  after  the  disappearance  of  all 
the  other  symptoms,  and  normal  vision  did  not  return  until  after  six 
to  eight  months. 

Autopsy  in  two  cases  showed  no  characteristic  changes  in  the  organs, 
only  extensive  hypersemia  of  the  kidneys,  liver,  and  meninges,  and 
softening  and  unusual  friability  of  the  stomach  Avails.  In  one,  the  liver 
showed  marked  degeneration,  and  the  brain  punctiform  hemorrhages. 
Neither  the  liver  nor  kidneys  showed  anything  unusual  on  bacteriologi- 
cal examination,  but  the  s^^leen  yielded  an  anaerobic  bacillus,  which 
proved  later  to  be  capable  of  causing  botulism. 

The  pig  from  which  the  ham  came  was  killed  some  months  pre- 
viously, and  what  was  not  eaten  at  once  was  pickled  in  the  usual  way. 
During  the  time  that  elapsed  between  the  pickling  and  the  supper, 
the  greater  part  of  the  animal  had  been  consumed  without  causing  any 
sickness,  but  the  ham  which  was  nearly  intact  was  the  last  to  be  eaten, 
lay  on  the  bottom  of  the  tub,  and  was  the  only  part  that  was  immersed 
completely  in  the  weak  brine.  What  was  left  of  it  gave  no  odor  of 
putridity,  but  had  a  distinct  odor  like  that  of  rancid  butter.  That  the 
ham  had  a  bad  taste,  was  agreed  by  nearly  all  who  ate  of  it.  It  appeared 
normal  to  the  eye,  but  was  pale,  like  any  meat  that  has  been  soaked 
some  time  in  water.  There  was  no  evidence  of  decomposition,  and 
no  ptomains  were  detected. 

Bacteriological  examination  proved  in  different  parts  the  presence  of 
a  hitherto  unknown  spore-bearing  bacillus  in  great  abundance,  the 
same  organism  as  that  isolated  from  the  spleen  of  one  of  the  victims. 
It  produced  an  extraordinarily  virulent  toxin,  which  was  isolated  by 
Brieger  from  cultures  supplied  by  the  discoverer,  by  whom  the  organ- 
ism was  named  Bacillus  botidinus.  The  toxin  is  rendered  inert  by  a 
temperature  of  60°  to  70°  C,  therein  agreeing  with  other  bacterial 
toxins  thus  far  isolated. 


CASKS'  /LLdS'rnA'nvh'  or  roisoNisc  i;y  iisii  AM)  Mi:Ar.   K) 

Ali.(!iti|»(s  to  (lis('()V(!r  IIk!  or^iuiiMin  in  llic  Icccs  of  varioiiH  aiiitn:ilH 
jiikI  ill  (illii  of  v.'irioiis  kinds,  jhkI  in  spccinicns  Croin  wlicrc  llu-  jii^'  wjih 
raised  were  nc^iilivc  in  rcsiills. 

Fc(;diii,i!;-('X|"'riiii('ii(s,  condiu'tc*!  on  \';irion-  kind-  itf  ;niini;d.-  ullli  iIk; 
meat  itself  :ind  willi  ;i(|neons  I  riliii';il  ions  of  il  ;id(k'd  lo  oilier  food-,  pn)- 
dneed,ns  a  rule,  filial  resiilfs  with  llie  same  tniin  of  syniptonis  ;is  ;d)ov«! 
nieii(ioiie(k  SiibentniXMHis  iiijeetions  of  f lie  walcrv  exlrael  |»rodiieed  tlio 
H:uiie  results  as  feediiit:;-ex|)eriinen(s.  TIk"  ;i(|iieoiis  extr;iet  kept  in  tlie 
dark  in  ;i  scMJed  (iiiie  rel;iiii<'<|  i(s  properl  ies  unimpaired  for  1 0  inotitliK, 
and  sninll  pieces  of  I  lie  iiie.if  kcpl  in  eollon-stoiyix-red  tiihes  witlioilt 
SjH'cial  preeniilioiis  relaiiie(l  t  lieir  viriilenee  cN'en  lon^'cr.  Tlie  poison 
resists  tlu^  elfeels  of  piitreliietion,  iiiid  |)roved  fo  lie  e(pi:illy  jioisoiioiiH 
after  4  diivs'  slandiiii;-  in  ,i  inixluie  willi  feces,  decoinposiiijr  Mood  ami 
urine,  and  fill  i-ntioii  lliroiinli  porcelnin.  >\  fresli  (iltnite,  to  wliicli  wore 
added  //.  prodii/iosiis,  II.  jh-oIchx  liijiicfdi-'inis^  /I.  fiioreHceriH  jndrhleH, 
and  B.  coil,  was  found  at  l)ic  end  ol"  a  week  to  he  as  active  a.s  ever. 

Mayer  ^  reports  an  epidemic  in  which  several  pei'sons  were  infected 
with  para-typhoid  bacillus  throu<i;h  the  eating  of  pork  chops  which  had 
become  infected  by  uncleanly  butchers.  The  para-typhoid  germs  were 
found  in  the  stools  of  these  meat  venders.  An  extraordinary  finding 
was  noted  in  a  man  who  ate  of  the  same  chops,  was  not  sick,  but  in 
whose  blood  j)ara-typhoid  germs  were  found  in  large  numbers.  Fur- 
thermore, they  persisted  in  the  blood  for  two  weeks.  At  this  time  no 
para-typhoid  germs  could  be  found  in  the  stools  or  in  the  urine,  but 
as  soon  as  they  disappeared  from  the  blood  they  were  found  in  the 
stools  and  urine. 

Buchan  -  reports  an  outbreak  of  food  poisoning  due  to  eating  pork 
brawn.  Eighty  cases  occurred  and  the  symptoms  came  on  from  one 
and  one- half  to  four  hours  after  eating.  The  brawn  was  made  by 
boiling  for  tweuty-four  hours  boucs,  skin,  and  other  portions  of  the 
pig.  The  bones  were  then  removed  and  the  liquid  placed  in  dishes 
and  allowed  to  cool.  The  same  article  of  food  had  been  made  many 
times  in  the  same  manner  by  the  same  butcher  without  deleterious 
eifects.  lu  this  instance,  however,  eating  of  the  said  brawn  was  fol- 
lowed in  a  short  time  by  rigors,  abdominal  pain,  vomiting,  and  diar- 
rhea. There  was  then  a  longer  period  of  great  prostration,  lasting 
sometimes  as  much  as  two  weeks.  There  were  no  symptoms  referable 
to  the  nervous  system. 

42  people  ate  this  brawn  2  davs  after  it  was  made  and  13  became  ill. 
71  "  "  8      ■    "  "  "  65 

4  "  "  4  "  «  u  4  « 

The  braw'u,  therefore,  increased  rapidly  in  virulence  with  the  laj>se  of 
time.  It  is  supposed  to  have  acquired  the  invading  Itacterium  from  a 
slaughterhouse  in  close  proximity  to  the  spot  upon  which  it  was  cooled. 
The  organisms  isolated  proved  to  be  of  the  type  of  the  Bacillus  enferi- 
tidis  of  Gaertner,  as  proved  by  cultural  characteristics  and  aggluti- 
nation tests  with   the  patients'  serum. 

1  Cent.  f.  Bakt.,  3  910,  Bd.  53.  •      ^  The  Lancet,  Dec.  7,  1907. 


84  FOODS. 

Poisoning"  by  Beef. — Case  I. — In  December,  1841,  more  than  40 
cases  of  poisoning  occurred  in  New  York  City  from  eating  smoketl 
beef.  As  a  rule  the  symptoms  began  several  hours  after  eating,  with 
pain  and  discomfort  in  the  epigastrium,  extending  to  the  back  and  loins. 
Vomiting  and  purging  were  followed  by  great  thirst  and  burning  pain 
at  tlie  pit  of  the  stomach,  which  became  so  irrital)k'  that  it  could  tolerate 
neither  food  nor  drugs.  Extreme  prostration  followed,  the  functions 
of  the  nervous  and  muscular  system  being  greatly  affected.  One  victim 
died,  and  with  the  others  convalescence  was  extremely  slow.  Autopsy 
revealed  nothing  beyond  inflammation  of  the  ileum. 

Case  II. — In  May,  1888,  at  Fraukenhausen,  58  persons  were  made 
sick  by  eating  the  meat  of  a  cow  killed  while  ill  with  diarrhoea  and 
passed  as  edible  by  a  veterinary.  The  symptoms  were,  in  general, 
nausea,  vomiting,  diarrhoea,  fever,  drowsiness,  dizziness,  and  great  de- 
pression. Those  who  ate  the  meat  in  the  raw  state  were  seized  without 
exception,  and  the  severity  of  the  seizure  was  directly  proportionate 
to  the  amount  eaten.  One  victim  who  ate  a  pound  and  a  half  died 
within  35  hours,  while  those  who  ate  least  suffered  least.  Those  who 
ate  the  cooked  meat  fared  differently.  Not  all  were  attacked,  nor  did 
the  severity  of  the  symptoms  bear  any  relation  to  the  amount  taken. 
Thus,  some  who  ate  freely  suffered  but  little,  while  very  severe  effects 
were  caused  by  slight  amounts  of  the  meat,  and  even  by  small  por- 
tions of  the  broth.  Thirty-six  who  ate  the  cooked  meat  escaped 
altogether.  From  a  portion  of  the  meat,  and  from  the  spleen  of  tlie 
person  who  died,  Gaertner'  isolated  B.  enteritldis,  M^hich,  since  then, 
has  been  shown  to  have  been  the  cause  of  numerous  other  outbreaks. 

Case  III. — In  June,  1889,  137  persons,  including  50  children,  in 
and  about  Cotta,  in  Saxony,^  were  made  ill  by  eating  the  meat  of  a 
cow  slaughtered  on  June  17th,  because  of  an  inflammatory  condition 
of  the  udder.  On  the  11th,  she  had  suddenly  stopped  giving  milk 
and  had  refused  food  and  drink.  The  meat  appeared  to  be  normal  in 
every  way  and  was  sold  on  the  day  after  slaughter.  The  first  cases 
appeared  during  the  night  of  the  day  of  sale.  The  majority  of  the 
victims  had  eaten  the  minced  meat  in  the  raw  state,  others  only  after 
it  had  been  cooked,  and  some  had  eaten  only  broth.  The  butcher  who 
sold  the  meat  tasted  as  much  as  would  cover  a  knife-blade,  and  suffered 
from  diarrhoea,  headache,  and  abdominal  pain  for  three  days.  His  as- 
sistant did  the  same,  and  fared  even  worse.  In  one  case,  the  symptoms 
began  with  a  chill;  in  another,  with  difficult  deglutition,  double  vision, 
and  anxiety;  in  the  rest,  with  nausea,  vomiting,  diarrhoea,  headache, 
abdominal  pain,  dizziness,  great  lassitude,  restlessness,  lethargy,  and 
unquenchal;)le  thirst.  In  many  cases,  the  eyes  were  glassy,  and  the 
pupils  much  dilated.  The  tongue  was  commonly  dry  and  coated.  The 
children  affected  were  extraordinarily  weak,  and  some  had  fever  as  high 
as  104.7°  F.  A  bacillus  isolated  from  the  meat  by  Johne  was  found 
by  Gaertner  to  differ  in  some  respects  from  B.  enteritldis. 

'  Correspondenz-Blatter  des  allgemeinen  iirztlichen  Vereins  von  Thiiringen, 
No.  V). 

■^  XXI.  Jahresbericht  ueber  das  Medicinalwesen  im  Konigreich  Sachsen,  p.  104, 


CAHKs  iIjUis'I'iiativI':  or  I'oisoi^isa  itv  fish  ASh  meat.   80 

C/AHK  IV. — l*()is(iiiiii(i;  liy  (iiKUHMl  corned  hccf  ;il  Slir'lTi(|(|,  i-cportcd 
by  W.  N.  l':irl<('i'.'  On  Oclolx-r  I  I,  I «!»!»,  ii  .HX-|)onn<l  tin  ..f  r..iii.<| 
becii"  was  opened,  ;in<l  iilxml  Iwolhirds  were  :-old,  eliiefly  in  <|nar- 
ter  ponnds.  HcNond  llie  liiet  tlnl  the  nie.-it  .'-eerne(|  ics.-;  solid  lliaii 
usual  and  llie  i<II\'  rallier  oily,  notliin;;-  nnnsnal  wa.s  noticed.  If  had 
no  odoi-,  ils  taste  was  normal,  thon^h  (piitc  salt,  and  ImiI  one  en.-tonier 
found  its  flavor  disa^i'eeahle.  So  Car  as  is  known,  none  who  ate  escaped  ; 
24  persons  raiiL!,ini;-  in  auc  IVoni  2  to  MO  years  wore  aHcctcd.  Tlie  f'ol- 
lowinji;  s(!rv('S  as  an  example,  ihouuli  each  case  presented  one  or  more 
symptoms  jxHudiar  to  itself. 

A  woman  of  IJT)  al(^  '1  ounces  of  the  meat  at  12.30,  aufl  in  2 
hours  was  seized  with  faintuess,  di/ziness,  and  drowsiness,  followed 
by  nausea,  and  great  museular  weakness,  especially  oC  the  le^r...  per- 
sistent vomitinn;  with  frequent  retelling  soon  occurred,  accompanied 
by  intense  i'rontal  headache,  and  followed  by  colic  which  was  not  re- 
lieved bv  purging.  One  hour  aClcr  seizure,  she  was  taken  to  the  Ikj.s- 
j)ital,  where  she  lay  on  a  couch  in  a  state  of"  colla])se  with  her  knees 
drawn  uj).  Her  face  was  pale,  with  livi<l  patches  around  the  eyes,  and 
bathed  in  perspiration.  The  skin  was  cold  and  clammy,  the  pulse 
small  and  rapid,  the  respiration  shallow,  the  temperatiu'e  subnormal, 
and  the  pu])ils  dilated.  Her  stomach  was  washed  out,  and  in  a  short 
time  the  pain  and  retching  ceased,  the  character  of  the  pulse  improved, 
drowsiness  was  diminished,  and  only  the  headache  and  purging 
remained.  Within  an  hour,  the  condition  of  collapse  and  other  symp- 
toms reappeared,  but  with  less  severity.  The  stomach  was  again  washed 
out,  and  this  time  the  good  effects  were  permanent.  On  the  following 
morning  all  that  was  complained  of  was  slight  frontal  headache. 

The  a]>proximate  latent  period  varied  between  one  and  three  and  a 
half  hours,  but  in  only  2  cases  was  it  more  than  two  and  a  lialf  hours. 
Frontal  headache  was  present  in  all  but  4,  vomiting  in  all  but  1,  pain 
in  only  12,  marked  collapse  in  12,  profuse  discharges  in  all  but  6. 
The  initial  symptoms  were  the  same  in  all;  that  is,  drowsiness  or 
giddiness,  or  both. 

Only  one  case  resulted  fatally,  that  of  a  boy  7  years  old,  who  ate 
2  ounces.  His  symptoms  were  especially  severe  ;  collapse  was  very 
marked  and  he  required  constant  stimulation.  About  10  hours 
after  the  onset,  he  had  a  series  of  clonic  contractions  of  the  flexor 
muscles  of  the  neck,  arms,  and  legs.  The  movements  were  violent, 
rapid,  and  almost  rhythmical,  commencing  first  in  the  neck  and  arms, 
but  soon  affecting  the  legs.  The  eyes  were  fixed  and  staring,  and  the 
pupils  widely  dilated.  After  lasting  an  honr  and  a  half,  the  convul- 
sions ceased.  They  reappeared  in  half  an  hour,  affecting  first  the 
right  arm  and  right  side  of  the  face,  but  soon  became  general. 
The  collapse  gradually  deepened,  and  the  boy  died  15  hours  after 
seizure.  Autopsy  showed  nothing  more  than  a  general  hypen^mia 
of  the  stomach  and  intestines,  with  a  few  hemorrhagic  erosions  in  the 
gastric  mucous  membrane.  A  microscopic  examination  of  the  kidney 
showed  cloudy  swelling  of  the  cortex,  with  a  few  scattered  hemorrhages. 
»  British  Medical  Journal,  Xovember  11,  1899. 


86  •  FOODS. 

All  the  other  victims  convnloseed  ra}>icny  and  wove  diH;ehar(i;ed  from 
the  hosjHtal  Avithiii  48  hours.  Stimulants,  ehietly  in  the  form  of  stryeh- 
nine  and  brandy,  were  administered  freely.  The  meat  was  examined 
bacteriologically  about  1 1  hours  after  the  tin  was  said  to  have  been 
opened.  In  the  outer  parts  of  the  meat,  many  species  of  organisms 
wore  found.  "  The  only  organism  ])reseut  both  in  cultures  from  the 
centre  of  the  meat  and  in  those  from  the  surface  was  the  bacillus  of 
Gaertner. 

Case  V. — An  outbreak  at  Mansfield,  in  which  65  persons  became 
ill  after  eating  the  flesh  of  a  cow  slaughtered  in  consequence  of  trau- 
matic pericarditis,  has  been  reported  l)y  Wesenberg.^  Only  those 
who  ate  of  the  minced  meat  in  a  raw  state  or  of  the  partly  cooked 
liver  were  affected ;  those  who  ate  of  the  well-cooked  meat  escaped 
without  exception.  The  symptoms  were  vomiting  and  diarrhoea, 
violent  headache  and  abdominal  pain,  general  muscular  weakness, 
dizziness  and  lassitude.  The  discharges  were  sometimes  greenish, 
sometimes  brownish,  and  always  extremely  offensive.  With  few  excep- 
tions, the  symptoms  abated  in  from  3  to  5  days,  and  all  recovered 
except  one,  and  that  a  doubtful  case  of  a  child  who  was  not  known 
■with  certainty  to  have  partaken,  and  whose  symptoms  might  have 
been  due  to  other  causes. 

The  unconsumed  meat  when  received  for  examination  was  already 
fairly  ^vell  advanced  in  decomposition  and  partly  maggoty.  All  except 
one  piece,  which  was  faintly  acid  to  litmus  papers,  was  alkaline  in 
reaction.  Cultures  on  agar  and  in  bouillon  were  made  from  a  piece 
taken  from  a  part  which  was  apparently  not  yet  in  process  of  decom- 
position. Inoculation  of  the  bouillon  cultures  and  of  small  bits  of  the 
meat  into  white  mice  produced  fatal  results,  in  some  cases  within  from 
1<S  to  28  hours  and  in  others  within  3  days.  A  guinea-pig  which 
received  a  subcutaneous  injection  of  the  bouillon  culture  of  the 
crushed  meat  died  in  48  hours,  having  shown  marked  lassitude  and 
profuse  diarrhoea.  In  all  cases,  section  showed  enlargement  of  the 
spleen,  which  was  bluish-red  in  color,  strong  injection  of  the  small 
intestine,  and  marked  redness  of  the  medullary  substance  of  the  kid- 
neys. Cover-glass  ])reparations  from  the  spleen  showed  fairly  long  and 
broad  bacilli,  and  the  same  were  developed  on  agar  from  the  meat  itself 

Case  VI. — G.  A.  Brown  ^  reports  an  outbreak  of  poisoning  due  to 
eating  canned  beef.  Symptoms  came  on  in  two  or  three  hours  and 
were  of  the  gastro-intestinal  type.  The  patient's  blood  gave  positive 
tests  with  the  Bacillus  euteritidis  of  Gaertner. 

Poisoning  by  Horse  Meat. — Gaffky  and  Paak^  investigated  an 
outbreak  in  the  district  of  Luwenberg,  which  was  known  to  involve  at 
least  30  and  probably  more  individuals.  The  offending  materials 
were  horse  meat,  horse  liver,  and  horse  sausage.  The  patients  com- 
plained very  soon  after  eating,  in  one  case  within  a  half  hour,  of 
nausea,  headache,   abdominal  pain,   borborygmus,  diarrhoea,  dizziness, 

1  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXVIII.,  p.  484. 

2  The  Lancet,  1907,'  41,  p.  1029. 

3  Arbeiten  aus  dem  kaiserlichen  Gesundheitsamte,  VI.,  p.  159. 


CAsi':s  ujjisrnATivi':  o/-'  roisosisa  nv  risii  a.\i>  mi: at.   87 

tr(!rnl)lin^,  iind  ^^icmI.  (Iiirs',.  Tlic  (ciiipcrjiiiin!  roHc  to  lOJ''  F.  ()\u- 
cuse  tdrniiiiaicd  (iitully.  IJiictcriolojrlc.iil  <'x;iiiiiii;ili(ni  i(v«'al(;(i  a,  hacil- 
luH  wliicli  (lidorwl  in  some  rcHpccts  I'loni  tli;if  uT  ( inert  ii<r. 

Poisoning'  by  Sausages. — (.'ask  I. — 'IVipc'  i(|)<iit<'(l  in  Xovcni- 
ber,  I.S7!),  an  onlhicak  wliicli  iiidlialcd  <>  I  (lut.  ol"  (iO  pcrsonH  who  had 
oat(Mi  <)("  a,  single  hatch  oC  sansaf:;('s.  Tlic  onset  waH  churactiTizi-d  hy 
vomitinfj^,  pnri^in^-,  and  (li//in{!ss,  which  came  f»ii  art<'i'  int<'rvals  of 
varyiiifjj  kinfjjlJi.  There  was  cxtnMiie  weakness,  and  many  had  seven! 
(',i"arn|)s  in  the  h'^^s  and  pains  in  th(!  ah(h)inen.  In  (he  inajorify  of 
eases  the  vonii(-in<i;  and  pnr^inj^  histed  from  .'{(i  to  hS  lionrs,  Tln! 
diseharji^es  were  \(iy  olleiisive,  and  h)ol<ed  like  dirty  wash-watj-r. 
Tliero  was  marked  eerehral  distnrhance,  and  a  sen-ation  of  acridity 
in  the  throat  was  common.  One  ol"  the  victims  died,  l)n(  the  antopHy 
revealed  nothini;'  nnnsnal  Ixyond  a  mnnher  of  red  patelies  in  tlie 
intestine.  The  remainiiiij;  sausages  were  found  to  have  a  tainted  and 
putrid  odor. 

Case  II. — The  "Ijimmetshauscn  case."  The;  liver  of  a  lu^dthy 
pig  was  made  into  sausages,  which  Avere  then  smoked  for  a  niiinher  of 
days  and  hung  up.  On  the  eighth  day,  they  were  eaten  hy  a  family 
and  a  number  of  invited  guests,  one  of  whom,  objecting  to  their  peculiar 
taste,  refrained  from  eating  and  escaped  the  trouble  that  came  to  all  the 
rest.  Tlic  symptoms,  which  a]>]3eared  within  a  short  time,  were  the 
same  in  kind  in  all,  but  ditlered  in  severity.  Tluy  included  abdonn'nal 
pain,  vomiting,  dizziness,  dryness  of  the  mouth  and  throat,  an<l  diffi- 
cult deglutition.  The  ])U])ils  became  dilated,  and  vision  was  much  im- 
paired and  finally  lost.  The  muscular  and  nervous  systems  were  very 
nuich  affected;  the  jndse  was  rapid  and  weak;  resjiiration  ])eeame  em- 
barrassed, swallowing  and  speaking  impossible.  Death  ensued  in  3 
cases,  preceded  by  great  lividity  of  the  face  and  spasms  of  the 
extremities. 

Case  III. — Van  Ermengcm^  relates  an  instance  in  which  the  remain- 
ing sausages  of  a  lot  which  had  caused  illness  in  several  persons  were 
apparently  so  wholesome  and  looked  so  inviting  that  the  exjx-rt  and 
his  assistants  to  whom  they  were  sent  ate  them  and  themselves  became 
ill.  The  expert  died  on  the  sixth  day,  and  autopsy  showed  gastro- 
enteritis, acute  nephritis,  and  fatty  degeneration  of  the  liver.  Gaert- 
ner's  B.  cntcritidl^  was  found  both  in  the  organs  and  in  the  sausages. 
The  latter  were  made  of  horse  meat. 

Case  IV. — Carl  Giinther^  reports  that,  in  several  places  in  Posen,  a 
lai'ge  number  of  persons  were  made  sick  after  eating  pork  sausages  and 
blood,  all  of  which  had  been  sup]ilied  by  one  butcher.  The  most  im- 
portant symptonis  were  abdominal  pain,  vomiting,  ]iurging,  great 
weakness,  and  lassitude.  One  man  of  47  years  died  after  hardly  a 
day's  sickness.  Giinther  examined  portions  of  the  deceased  and  also 
samples  of  meat  and  blood  found  in  the  house,  and  Siiusage  and  meat 

'  jNIedioal  Times  and  Gazette,  Nov.  29,  1879. 

■•'Kevue  d"Hvc:iene,  189li,  p.  7(il. 

3  Archiv  fur'Hygiene,  XXVIII.,  p.  1-16. 


88  FOODS. 

from  the  shop  of  the  butcher.  From  the  victim's  splecD  and  liver  he 
isolated  £.  enteritidi.'^,  but  while  a  number  of  species  were  found  in  the 
foods,  this  bacterium  was  not  detected,  perhaps  having  perished 
through  the  iuHuenee  of  the  other  species  i)resent. 

Case  Y. — This  interesting  case  of  poisoning  by  sausage  composed 
of    pork   aiid    beef  is    related    by  Silberschmidt/  and    serves   as  an 
illustration  of  the  methods  commonly  employed  in  the  manufacture  of 
sausao;es.     Nearly  fifty  people  were  poisoned  by  eating  a  kind  of  sau- 
sage known  in  Switzerland  as  "Landjager."     It  is  made  of  beef,  often, 
also,  horse    meat  with    pig    fat.     The  materials  are   chopped   rather 
coarselv,  spiced,  put  into  casmgs,  pressed  flat  for  a  day,  smoked  two 
davs,  dried  in   the  air   several  days  more  and   then  eaten  in  the  raw 
state.     The  sausages  in  this  instance  were  made  of  cow  beef  from  ani- 
mals that  had  been  certified  as  sound  by  a  veterinarian,  and  pork  that 
had  been  bought  about  two  weeks  previously  and  kept  with  preserva- 
tive  salt,  and    had   appeared   fresh    and   unchanged   when   used.      In 
the  morning  of  the  first  day  that  the  sausages  were  on  sale,  a  man  and 
his  wife  ate  one  of  them  together,  and  both  were  made  so  sick  toward 
evening  and  during  the  night  that  a  physician   was   called.     In  the 
afternoon  of  the  same  day,  19  fishermen  ate  of  them,  and  on  the  fol- 
lowing day  it  was  reported  that  all  of  them  had  been  made  sick.     In 
the  evening,  another  man  ate  one,  and  it  pleased  him  so  much  that  he 
took  one  home  to  his  wife   and  children.     On  the  next  day,  he  had 
abdominal   pains,   headache,   vomiting,   diarrhoea,   thirst,  and   a   chill. 
In  the  afternoon,  his  wife  and  two  children  who  had  eaten  were   simi- 
larly seized.     A    l^oatman   who   ate  two  whole    sausages    suffered    no 
inconvenience    beyond  a  little   pain  on  the  following  day.     Another, 
who  was  sick  eighteen  days  and  then  returned  to  his  work,  was  seized 
again  ten  days  later  with  the  same  train  of  symptoms.      One  man, 
aged  eighteen  years,  entered  the  hospital  in  the  morning  of  the  second 
day,  and  died  during  the  night,  two  days  and  a  half  after  ingestion 
of  the  sausage.     At  the  time  of  entrance,    the   abdomen  was  sensitive 
and  he  was  passing  grayish  watery  stools;   in  the  afternoon,  he  was 
delirious,  and  his  pulse  was  very  small,  irregular,  and  rapid.     Dur- 
ing  the   night   he   collapsed    and    died.      Section   after   twelve   hours 
showed  a  spleen  of  normal  size,  swollen  mesenteric  glands,  and  hyper- 
gemia  of  the  stomach  and  intestines.      The  follicles  were  much  swollen, 
and  in  the  ileum  were  several  areas  from  4  to  6  cm.  in  length  by  1  cm. 
in   breadth,  where  the   mucous   membrane  was  discolored  and  eroded. 
Other  organs  were  normal.     Six  others  of  those  affected  Avere  discharged 
from  the  hospital   after  from  seven  to  fifteen  days'  treatment.     In  an 
adjoining  town,  where  sausages  of  the  same  lot  were  sold,  there  were  16 
other  cases,  all  with  the  same  symptoms.       Taking  all  the  cases  to- 
gether, the   symptoms   of  prominence  were  as  follows:    Very  severe, 
partially  crampy,  abdominal  pains;  very  profuse  diarrhoea,  the  stools 
numbering  from  eight  to  twelve  per  day,  and  in  color  varying  between 
gray,  greenish,  and  yellow ;  usually  vomiting,  the  rejected  matters  being 
1  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXX.,  p.  328. 


MJ'JA'I'  INSPECTION  ANI>  SI.AIK; llTElLlNfl.  80 

wat(Ty  iuid  hr-ovvnisli ;  siinkcMi  (lycs,  \\\\y\\  ("ever,  f.';rciif,  l.-isHitiidc,  t<Ti<l<'r- 
ncsH  ovf^r  iihdoiiicii,  crniiips  in  |Ii<m!;i1v<!H,  [rrcjit  tliirsl,  iiiid,  orTa-iomilly, 
moteorisiii.  In  inosi  of  the  (tjiscs,  tlic  .symptonj.s  Jippcnrcd  <>n  tlicday 
;i,fV(M'  <!<ilin^'.  'I'lic  duration  <»("  tlic  illness  ranged  between  (»ne  and 
tJiir(y  days,  I  he  ^I'eater  ninnher  reeoverinii;  in  two  weeks,  and  lieeornin;^ 
(i(,  for  Wdi'lv  in  three. 

vVs  is  (lonnnoidv  the  case  in  these  uiil  hn  al<-,  t  he  alliiilion  u\'  tju; 
JUltliorities  was  not- drawn  to  fhe  niall<r  in  cilhci-  town  inilil  -onie  days 
had  ela|)sed.  Cheinieal  analyses  ol"  innised  sansa^n's  were  made  at  hotli 
phw^es.  ( )ne  analyst  re|)orled  ne<;a(ive  resnits  ;  the  otiier  rej)orted  tlu; 
})roHcncc  oi"  ptoniains,  hnt  did  not  Inrlher  |»arlienlarize.  ]Jaeten<»loj.'ieiil 
investifjjation  revealed  tlu;  presence  of  u  variety  ol"  firf^anisnis,  as  was 
to  have  been  aiiticiputed,  and  among  them,  especially  marked,  J'rotcius 

Poisoning  by  Kid  Meat. — Ilensncn'  has  reported  the  ensc  fjf  a 
whole  familv  stricken  after  eatinj;  the  meat  of  a  kid  wliicli  was  kille<l 
when  bnt  a  few  days  old.  A  twelve  year  old  girl  was  seized  in  eleven 
hours  with  a  chill,  followed  by  fever,  dizziness,  vomiting,  and  violent 
diarrlxxMi.  The  temperatuiv  rose  to  10.'>.()°  F.  She  was  confined  to 
her  bed  I'or  five  days.  The  fathei',  forty-nine  years  old,  was  .seized 
with  the  same  symptoms  in  twelve  to  thirteen  hours,  and  had  also 
headache,  pain  in  the  joints,  thirst,  and  inability  to  walk.  The  tongue 
was  dry,  the  pulse  rapid  and  small,  and  the  pupils  reacted  slowly.  He 
was  sick  eight  days.  The  mother,  who  ate  but  little,  was  seized  sud- 
denly in  the  night  with  vomiting,  and  such  great  dizziness  that  she  was 
unable  to  walk  without  holding  on  to  the  furniture.  A  boy,  under  two 
years  of  age,  was  seized  in  the  night  A\ith  vomiting  and  violent  diar- 
rhoea, which  soon  became  bloody.  The  stools  Mere  unusually  offensive, 
and  persisted  so  for  several  days.  He  Mas  sick  nine  days.  Three 
other  children,  M'ho  ate  but  very  little.  Mere  sick  tMO  days  Muth  slight 
abdominal  pain  and  diarrhoea.  No  material  M'as  obtainable  for  exami- 
nation. The  butcher  said  that  the  kid  Mas  apparently  healthy,  but  the 
mother  declared  that  the  meat  around  the  joints  of  the  hind  legs  M-as 
verv  soft  and  M-atery,  and  the  joints  themselves  enlarged  (septic  poly- 
arthritis ?). 

Meat  Inspection  and  Slaughtering-. 

The  value  and  advisability  of  thorough  inspection  of  meats  before 
they  are  placed  on  sale  are  universally  conceded.  In  this  country, 
under  the  inspection  laM'  of  March  3,  1891,  all  meat  intended  for  ex- 
port is  required  to  pass  a  very  strict  system  of  inspection.  The  ani- 
mals are  inspected  before  being  slaughtered,  and  their  carcasses  are 
examined  microscopically  by  officials  of  the  Bureau  of  Animal  Indus- 
try before  being  packed.  The  inspection  of  meat  for  local  consump- 
tion is  M'holly  a  matter  of  local  authority  ;  some  States  have  inspection 
laws  and  others  have  none  ;  many  cities  have  special  regulations  Mhich 
are  enforced  by  officials  M'ho  may  or  may  not  be  competent  through 
^  Zeitscbrift  fiiv  Fleisch-  nnd  Milehbrgiene,  VIII.,  p.  ISl. 


90 


FOODS. 


proper  trainiug.  In  Germany,  the  system  of  inspection  is  very  rigid, 
particularly  iu  the  Ciise  of  meats  from  foreign  countries.  This  is  due 
very  largely  to  the  activity  of  the  agricultural  interests  in  jirotecting 
themselves  from  outside  eompetitiou  ;  and  under  the  benevolent  ])lea 
of  protectiug  the  health  of  meat  consumers,  much  care  and  attention 
are  given  to  hunting  for  excuses  for  excluding  American  meiits  which 
have  already  been  uispected. 

The  Federal  meat  inspection  service  is,  according  to  Salmon,' 
a  sanitarv  rather  than  a  commercial  inspection,  apjilied  not  alone  to 
meats  for  export,  but  also  to  those  intended  for  inter-state  commerce. 
Curiously,  however,  the  very  important  inspection  for  trichinae  is  pri- 
marily a  commercial  matter,  being  applied  only  to  pork  intended  for 
shipment  to  certain  foreign  countries  which  require  it. 

The  United  States  inspectors  are  instructed  to  condemn  all  female 
animals  in  an  advanced  stage  of  gestation,  and  to  prevent  their  slaughter 
for  food,  Salmon  ruling  that,  though  "  the  animal  is,  strictly  speaking, 
iu  a  physiologic  condition,  it  is  not  in  its  usual  physiologic  condition, 
nor  is  the  change  one  which  is  calculated  to  improve  the  quality  of  the 
meat."  Females  in  which  parturition  has  recently  occurred  are  like- 
wise condemned  as  nnfit  for  food.  Many  animals  are  condemned  on 
account  of  bruises  and  injuries  received  on  their  way  to  market ;  during 
1900,  there  were  condemned  for  this  cause,  in  round  numbers,  carcasses 
or  parts  of  carcasses  of  4500  cattle,  1,000  sheep,  and  12,300  hogs. 
In  some  of  these,  the  injuries  were  extensive,  sometimes  complicated 
with  abscesses,  septic  infection,  and  gangrene. 

At  the  end  of  1908^  it  was  estimated  that  Federal  meat  inspection 
covered  slightly  more  than  one-half  of  the  entire  number  of  animals 
slauo^htered  for  food  in  the  United  States.  The  followinsj:  table  shows 
the  diseases  and  conditions  for  which  condemnations  were  made  on 
post-mortem  inspection  for  the  fiscal  year  1909.^ 


CatUe 

Calves. 

Swine. 

Sheep. 

Go.als. 

Cause  of  coaderauation. 

Car- 
casses. 

Parts. 

Car- 
casses. 

Parts. 

Car- 

Parts. 

Car- 
casses. 

Parts. 

Cnr- 

Parts. 

Tuberculosis 

Actinomycosis 

24,525 
589 

40,148 
44,440 

177 

151 
69 

45,113 

20,789 
7,173 

6,329 
1,623 

791,735 

21 

676 

1,479 
862 

1,023 
102 

107 
763 

5,714 

1 

7 
37 

129 

5 

3 

8 
18 

8 

4 
41 

1 

Sep)tieemia,  pyemia,  and  uremia 

Pneumonia,  pleurisy,  enteritis, 

hepatitis,  nephritis,  metritis, 

etc 

Icterus      

845 

1,418 

60 

427 

523 

295 
45 

775 

Texas  fever 

Caseous  lymphadenitis    .... 

Tumors  and  abscesses 

Pregnancy  and    recent  partu- 
rition   

Injuries,  bruises, etc 

Immaturity 

107 

254 
2,261 

5,989 
'l,'941 

28 

34i 
4,376 

43 
132 

1,178 

89 
372 

1,031 
3.215 

1,609 
3,842 
2,114 

1 

Sexual  odor 

Miscellaneous 

4,617 

7,221 

1,653 

14 

Total 

35,103 

99.739 

8,213 

409 

86,912 

799,300 

10,714 

170 

82 

1 

^  Jouraal  of  the  American  Medical  Association,  Dec.  28,  1901,  p.  1715. 

''  Report  of  the  Chief  of  the  Bureau  of  Animal  Industry,  1908,  p.  5.     3  ibid.,  1909,  p.  20. 


In  inspcc^liiifr  mcnis,  s|)(H;ijil  ;il(ciilioii  .sli(»iil(l  he  paid  to  flic  fonncclivc 
tlHHiK^  iiiid  ;;l;iii<liil;ir  organs.  'I'lic  (tdor  of  a  carcass  slioiild  l>c  sweet, 
uiid  llic  tii(';ii  slioidd  cdiiiiiiiiiiicilc  no  iiii|ilc;isant  stiicll  to  a  wrxtdcii 
Hkovvcr  lliriisl  inlo  il,  aixl  wil  lidiviw  n.  The  iriii>clc  slioidd  Itc  firm  and 
eluHtic!,  Will  not  loMt;li.  Any  \aii;ilion  I'loni  lli<-  n;itni':d  color  slionld  !)•; 
rejj;iir(lcd  wilJi  siis|)ici(>ii,  wry  dark  (lolor  siif^^;cstinjj;  lcl»rilc  condilioii, 
or  llial,  (lie  animal  was  wot  slanj^litered,  or  was  sian^-lilcrcd  in  a  dvinj; 
condition,  Sncli  meal  iMidci'ijocs  dcconipo.-iiioii  nmcji  moi'c  rajtidiv 
than  noi'inal  inc^ai.  Animals  llial  lias'c  \n-r\\  drowned  or  liavc  heen 
killcul  by  acicidenit  withont  heinj^  hied  yield  a  dark  and  discolr»re«i  meat 
that,  is  likely  to  decompose  more;  rapidly  than  that  of  animals  that  have 
rej^idarly  heen  slannhtcred,  hnt  an  animal  that  has  Ix-cn  injnrcd,  hnt, 
not  killed,  may  he  slaMt;'litercd,  propei'K  hied  and  dres.-ed,  and  its  meal, 
i,s  then  |)er(eetly  L!,'ood. 

7\nimals  should  he  kept  without  food  lor  at  least  twelve  hours  before 
sla.iif>'hter,  and  tlu!  (carcasses  should  he  hiuiu'  (in-  a  nundier  <»f'  lionr.s  to 
cool.  Many  diseases  are  indicated  more  clearl}-  alter  the  body  luw 
cooled. 

The  Jewish  method  of  slaiisi^hterinu;  is  rcg'arded  by  many  as  far 
superior  to  any  other.  Aeeordino-  to  Dendx),'  it  is  the  most  nitional 
from  a  hygienic  stand])oint,  since  the  animal  is  hied  rapidlv  and  com- 
pletely, and  the  convulsive  movements  cause  the  meat  to  be  more 
tender  and  of  more  attractive  appearance.  I^actic  acid  is  develo])cd, 
and  through  its  chemical  action  on  ])otassium  jihosphate,  ])otassimn 
lactiite  and  acid  ]>hosphate  of  potassium  are  formed.  'J'he  latter 
hinders  the  development  of  micro-organisms,  delays  tlie  formation 
of  ptomains  and  other  poisonous  matters,  and  improves  the  taste, 
lligor  mortis  comes  on  more  quickly,  and  the  meat  is,  therefore,  more 
quickly  available  for  use,  and  also  will  keep  several  days  longer  than 
ordinarily. 

A  process  of  slaughtering  originating  in  Denmark  appears  to 
have  borne  the  test  of  a  hard  tlu'ee-months'  trial  in  a  very  satisfactory 
manner,  and  recommends  itself  for  adoption  in  the  tro])ics,  where 
meats  decompose  with  exceeding  rapidity.  The  animal  is  shot  in 
the  forehead  and  killed  or  stunned,  and  as  it  falls,  an  incision  is  made 
over  the  heart  and  the  ventricle  is  opened  for  two  juii'poses  :  to  allow 
the  blood  to  esca]>e,  and  to  admit  of  the  injection  of  a  solution  of  salt 
through  the  bloodvessels  by  the  aid  of  a  poAverful  syringe.  The  process 
requires  but  a  few  minutes,  and  the  carcass  may  be  cut  up  at  once. 

EGGS. 

Eggs  form  a  valuable  substitute  for  meats,  being  fairly  rich  in  fats 
and  proteids,  and  are  well  adapted  to  the  stomach  of  the  invalid  and 
convalescent  when  meats  cannot  be  borne.  The  nutritive  part  of  the 
white  is  practically  limited  to  proteids,  which  amount  to  about  12  per 
cent. ;  the  yolk  is  richer  in  proteids,  and  contains  in  addition  about  33 
^Deutsche  Vierteljabi-schnft  fiir  ol^t?ntliobe  Gesundheitspflefre,  XXVI.,  p.  688. 


92 


FOODS. 


per  cent,  of  fat.  The  albumiu  of  the  white  is  in  a  condition  of  sohi- 
tion  in  cells  with  very  thin  walls.  The  fatty  matters  of  the  yolk  are 
in  a  condition  of  emulsion,  being  held  in  suspension  by  the  vitellin. 
The  entire  yolk  is  held  together  by  an  enveloping  membrane  and  is  sus- 
pended in  the  white,  being  hold  in  position  by  an  albuminous  band  at 
either  end  : 

The  following  table  by  Langworthy  ^  shows  the  average  composition 
of  eggs  of  different  sorts  : 


Hen: 

Whole  egg  as  purchased    .... 

Whole  egg,  edible  portion    .   .   . 

White 

Yolk 

Whole  egg  boiled,  edible  portion 

White-shelled  eggs  as  purchased 

Brown-shelled  eggs  as  purchased 
Duck: 

Whole  egg  as  purchased    .... 

Whole  egg,  edible  portion       .   . 

White 

Yolk 

Goose : 

Whole  egg  as  purchased    .... 

Whole  egg,  edible  portion 

White 

Yolk 

Turkey : 

Whole  egg  as  purchased    .... 

Whole  egg,  edible  portion    .   .   . 

White 

Yolk 

Guinea  fowl : 

Whole  egg  as  purchased    .... 

Whole  egg,  edible  portion 

White 

Y'olk     

Plover: 

Whole  egg  as  purchased    .... 

Whole  egg,  edible  portion  .  .  . 
Evaporated  hens'  eggs 


Refuse. 


Per  cent. 
11.2 


10.7 
10.9 


13.7 


14.2 


9.6 


Water. 


Per  cent. 
65.5 
73.7 
86.2 
49.5 
73.3 
65.6 
64.8 

60.8 
70.5 
87.0 
45.8 

59.7 
69.5 
86.3 
44.1 

63.5 
73.7 
86.7 
48.3 

60.5 
72.8 
86.6 
49.7 

67.3 
74.4 
6.4 


Protein. 


Per  cent. 
11.9 
13.4 
12,3 
15.7 
13.2 
11.8 
11.9 

12.1 
13.3 
11.1 

16.8 

12.9 
13.8 
11.6 
17.3 

12.2 
13.4 
11,5 

17.4 

11.9 
13.5 
11.6 
16.7 

9.7 
10.7 
46.9 


Per  cent. 
9.3 
10.5 
2 
33^3 
12.0 
10.8 
11.2 

12.5 
14.5 

.03 
36.2 

12.3 

14.4 

.02 
36.2 

9.7 
11.2 
.03 
32.9 

9.9 
12.0 
.03 
31.8 

10.6 
11.7 
36.0 


Per  cent. 
0.9 
10 

.6 
1.1 

.8 

.6 

.7 


1.0 

.8 

1.2 


.9 

1.0 


.9 

.8 

1.2 

.9 
1.0 
3.6 


Fuel 

value  per 

pound. 


Calories. 
635 
720 
250 
1,705 
765 
675 
695 

750 

860 

210 

1,840 

760 

865 

215 

1,850 

635 

720 

215 

1,710 

640 

755 

215 

1,655 

625 
695 
2525 


The  proteids  of  eggs  have  been  studied  by  Osborne  and  Campbell,^ 
who  found  that  the  yolk  contains  a  large  amount  of  protein  which 
resembles  a  globulin,  but  is  believed  to  be  a  mixture  of  compounds  of 
protein  matter  with  lecithin.  The  proteids  of  the  white  were  found  to 
include  ovalbumin,  ovomucin,  ovomucoid,  and  conalbumin. 

Eggs  contain  a  certain  amount  of  sulphur,  to  which  the  staining  of 
silver  spoons  and  the  odor  of  rotten  eggs  (hydrogen  sulphide)  are  due. 
The  rotting  of  eggs  is  supposed  to  be  due  to  the  admission  of  fermenta- 
tive micro-organisms  through  the  pores  of  the  shell,  or  to  those  already 
present  before  the  shell  is  formed. 

It  is  a  commonly  accepted  idea  in  some  parts  of  the  country  that 
eggs  with  brown  shells  are  of  greater  richness  than  others,  and  that  the 
degree  of  richness  is  directly  proportionate  to  the  depth  of  color.  In 
some  markets,  on  the  other  hand,  the  white  egg  is  held  in  higher  esteem. 

^U.  S.  Department  of  Agriculture,  Farmer.s'  Bulletin,  No.  128  (1901). 
*  Report  of  Connecticut  Experiment  Station,  1899,  p.  339. 


EddH. 


93 


According  to  \\\i\  rc^siill.s  ofjiii  (!xfx!H.siv(!  sfiidy  of  I  Ik;  clicrnicjil  roiiipoHi- 
tion  of  ((}j^f^,s  curried  on  iii  (Ik;  (/nliloniiii  10x|)(;rim(iil  SImiIod  miiinlv  for 
tli(^  jmrposc  ()(■  ddrcniiiiiiii^  wliiii  didri'ciiccs,  if"  any,  exist  betwc'eii  (licrn, 
tliere  is  no  luisis  ol"  (act  (or  IIk;  |)(»|»ular  Ix-lief".  Jn  fact,  (lie  very  hiiglit 
difforcnecM  noted  were  in  (';i\(»r  of  the  ulille  c^^s,  hiii  tli<'  average  dif- 
ferences Ix'tween  llie  two  kinds  wen;  less  than  tlie  fliict nat ions  hetweon 
individual  specimens  of  the  same  ^ronp.  'I  !)<•  (ij/nrcs  fthtained  arc 
])i'es(Uit('.d  in  the  (oliowin^-  table  taken  IVdhi   i'ainuM^'  I5ulletin  No.  87  :' 


ANALYSIS  OF  BKOWN  Sil  KIJ,i;i)    AM)    W  F[ITJ!>flHELLP:i)  EGGS. 


Brown-shelled  eggs : 

Yolk 

White 

I'^utire  egg 

W hilc-shdU.d  eggs  : 

Yolk ."    .    . 

White 

Entire  egg 


Water. 


Per  ct 
49.59 
86.60 
65.57 


49.81 
86.37 
64.79 


Protein. 

Per  ct. 

15.58 
11.99 
11.84 


15.49 
12.14 
11.92 


Fat. 

Per  ct. 

33.52 

.21 

10.77 

33.34 

.35 

11.22 


A8h. 


Per  ct. 

1.04 

.54 

.64 

1.05 
.56 
.67 


Shell. 


Perct. 


10.70 


ToUl, 


Perct 
99.73 
99.34 
99.52 


99.69 
99.42 
10.92  I  99.52 


The  question  of  influence  of  breed  on  composition  has  been  investi- 
gated at  the  Michigan  Experiment  Station.  The  results  .showed  that 
the  variations  in  composition  are  too  slight  to  be  of  practiad  value, 
and,  as  with  the  brown  and  tlie  Avhite  eggs,  so  slight  as  to  be  le.S'^  than 
the  variations  between  individual  specimens  from  the  same  l)ree<l.  The 
influence  of  the  nature  of  the  feed  Avas  investigated  also,  and  was  found 
to  be  of  little  or  no  importance. 

The  flavor  of  eggs  varies  according  to  age,  those  wliich  are  jxt- 
fectly  fresh  having  the  finest  flavor.  It  is  dependent  also,  to  some 
extent,  upon  the  nature  of  the  food  consumed  by  the  fowl,  the  best 
coming  from  a  purely  grain  feed.  A  ver}-  nitrogenous  feed  causes  a 
more  or  less  disagreeable  flavor  and  odor.  The  influence  of  highly 
flavored  feed  lias  been  studied  by  Emery,"  who  fed  hens  with  a  ration 
containing  wild  onion  tops  and  bulbs.  After  fifteen  days,  the  eggs 
having  no  unusual  taste,  each  hen  received  daily  one  ounce  of  tliis 
addition  instead  of  a  half  ounce  as  before,  and  in  three  days  the  eggs 
Avere  flavored  so  strongly  as  to  be  repugnant  to  the  taste. 

The  iron  content  of  the  yolk  of  eggs  is  said  by  Schmidt^  to  be  in- 
creased materially  by  feeding  saccharate  of  iron  to  hens.  He  asserts, 
also,  that  the  iron  so  incorporated  is  more  assimilable  than  most  iron 
preparations  given  in  the  antemic  condition.  Aufsberg*  asserts  that 
by  feeding  certaiii  iron  compounds,  the  iron  content  can  be  increased 
eight  times. 

The  digestibilitv  of  eggs  has  been  studied  at  the  ^Minnesota  Experi- 

HTOvernment  Printing  Office,  "Washington.  18',19,  p.  24. 
'  Bulletin  167,  North  Carolina  Experiment  Station. 
'  Zeitschrift  fiir  angewandte  Cheiuie,  1900,  p.  705. 
*  Pharmaceutische  Zeitung,  1900,  p.  366. 


94  FOODS. 

ment  Station.^  It  was  shown  tliat,  while  the  method  of  cooking  has 
some  etiect  on  the  rate  of  digestion,  the  total  digestibility  is  not  atfected. 
Eggs  boiled  three,  hve,  and  twenty  minntes,  and  digested  for  five  hours 
with  pepsin  solution,  showed  at  the  expiration  of  that  time  respectively 
8.3,  3.9,  and  4.1  per  cent,  of  undigested  proteids.  Cooked  tor  five  and 
ten  minutes  in  water  at  180°  F.  and  similarly  treated,  they  left  no  un- 
digested residuum. 

LARD. 

Lard  is  the  semi-solid  fat  of  the  slaughtered  hog,  separated  from  the 
tissues  by  the  aid  of  heat.  According  to  the  parts  from  which  it  is  de- 
rived, it  is  classified  as  follows  :  (1)  Neutral  lard.  This  is  derived 
from  the  fresh  leaf,  which  is  reduced  to  a  pulp  after  being  cooled,  and 
then  rendered  in  the  kettle.  A  part  of  the  fat  is  separated  at  from 
105°  to  120°  F.,  and  the  residue  is  sent  to  the  rendering  tanks  ibr 
further  treatment.  The  lard  obtained  is  washed,  while  hot,  with  water 
containing  a  trace  of  sodium  carbonate,  common  salt,  or  dilute  acid. 
(2)  Leaf  lard.  This  is  obtained  from  the  residue  above  mentioned, 
which  is  subjected  to  steam  heat  under  pressure.  (3)  Choice  kettle 
rendered  lard.  This  is  obtained  from  the  remaining  portions  of  the 
leaf  together  with  the  fat  from  the  backs.  Both  the  leaf  and  baclv  fat 
are  passed  first  through  a  pulping  machine.  (4)  Prime  steam  lard. 
This  is  made  from  the  head,  the  fat  of  the  small  intestine,  trimmings, 
and  other  fatty  parts. 

The  spleen,  pancreas,  trachea,  and  all  other  refuse  parts  and  trim- 
mings, with  the  exception  of  the  small  intestine,  the  liver,  lungs,  and 
part  of  the  heart,  go  into  the  rendering-kettle  for  what  fat  there  may 
be  in  them,  and  the  product  is  variously,  but  not  graphically,  desig- 
nated. 

"  Refined  lard  "  is  a  term  used  to  designate  a  lard  composed  chiefly 
of  cotton  oil  and  stearin.  It  is  known  more  often  as  "lard  com- 
pound." 

United  States  Standards. — Standard  lard  and  standard  leaf  lard 
are  lard  and  leaf  lard  respectively,  free  from  rancidity,  containing  not 
more  than  1  per  cent,  of  substances  other  than  fatty  acids,  not  fat, 
necessarily  incorporated  therein  in  the  process  of  rendering,  and  stand- 
ard leaf  lard  has  an  iodine  number  not  greater  than  60. 

Physical  and  Chemical  Properties  of  Lard. — At  40°  F.,  the 
specific  gravity  is  0.890;  at  100°,  about  0.860  ;  it  differs  not  very 
materially  from  that  of  the  substances  used  as  adulterants,  excepting 
cotton-seed  oil,  which  is  notably  heavier.  The  melting-point  ranges 
from  39.1°  to  44.9°  C.  (102.4°  to  112.8°  F.),  according  to  the  part 
of  the  carcass  from  which  the  fat  is  derived,  and  hence  it  cannot  be 
taken  as  a  safe  guide  in  the  determination  of  purity. 

Pure  lard,  melted,  and  mixed  with  strong  sulphuric  or  nitric  acid, 
will  give  only  a  slight  color,  which  may  be  yellowish,  pinkish,  or 
inclined  to  light  brownish.      Cotton-seed  oil  and  other  seed  oils,  and 

'  FarraeiV  Bulletin,  No.  87,  Government  Printing  Office,  Washington,  1899,  p.  25. 


fjARD.  95 

inixtiiniH  (;()iil,;iiiiiti<;'  I  liciii,  siniilnily  lr<;if<'l,  yi'l'l  :iny  folor  l)ct\Vf<ii 
ycllowi.sli  hr'owii  luid  very  Itrowiiisli  Muck  or  cvcii  l)l;i(|<.  'I'lic  rc- 
rnu!tiv(!  index  of  [tiirc  lunl  is  iii;if<r'i:illy  lower  tliaii  lliiit  of  eoffori- 
S{!C<1  oil. 

I*ur(!  liinl  coiiiuiiis  only  traecs  o("  volnlile  lady  arridH,  5  {rratns  yield- 
ing an  amonnt  wliicJi  i.s  neutralized  l)y  I  or  '^  of  a  ee.  of  dceinorrnal 
Kodiuni  hydrate  solntion.  'I'lu;  non-volatih;  fiitty  aeid.s  are  pn^Hent  to 
tlu!  extent  of  ahont  !)5  per  (icnt.  Tlx^  iodine  aI)sor|)lion  rnimher  varicH 
aeeording  to  the  j)art  of  th(?  (!ar<;ass  from  which  the  fat  is  deriv(;d,  but 
avenigeH  about  (JO.  The  iodine  ninnber  of  cotton-seed  oil  is  about  ]<)'.}, 
and  that  of  stearin  is  approximately  20.  Thus,  these  substaneeH  used 
as  adulterants  may  be  mixed  in  such  proportion  as  to  yield  the  normal 
iodine  number  of  lard. 

With  nitrate  of  silver  solution,  j»ure  lard  causes  no  inon;  than  the 
very  slightest  anioimt  of  redu(!tion,  and  generally  none  at  all  ;  but  eotton- 
seed  oil  causes  a  very  marked  reduction  of  the  salt  to  the  metallic  state, 
with  the  result  that  the  mixture  has  a  l)rovvnisli  or  black  appearance 
from  the  minut(!  black  ])articl(>s  formed. 

A  small  amount  of  lard,  dissolved  in  a  mixture  of  ecjual  j)arts  of 
alcohol  and  strong  ether  in  a  test-tube  and  allowed  to  .stand  in  a  cw)! 
place,  will,  when  the  solvent  in  large  part  is  evaporated,  show  masses 
of  crystals,  which,  on  examination  under  the  microscope,  are  seen  to  be 
rhombic  and  extremely  varialile  in  size.  Beef  stearin,  sinn'larly  treated, 
shows  fan-shaped  and  dumbbell-shaped  clusters  of  needle  cr}'stals. 
Mixtures  of  pure  lard  and  beef  stearin  will  show  both  forms  of  crys- 
tals. Sometimes,  when  crystallization  ])roeecds  rapidly,  the  crj'stals 
from  pure  lard  an^  extremely  small,  and  are  clustered  in  such  a  way  as 
to  be  distinguished  from  beef  stearin  crystids  only  with  great  difficulty. 
It  is  essential  that  the  crystallizing  process  shall  proceed  slowly,  and 
that  the  amount  of  lard  dissolved  in  half  a  test-tube  of  the  solvent 
shall  be  quite  small — not  larger  than  a  large  pea.  The  mouth  of  the 
test-tube  should  be  stopped  with  cotton. 

Section  3.     MILK   AND   MILK   PRODUCTS. 
MILK. 

United  States  Standard. — Standard  milk  is  the  fresh,  clean,  lac- 
teal secretion  obtained  by  the  complete  milking  of  one  or  more  per- 
fectly healthy  cows  properly  fed  and  kept,  excluding  that  obtained 
within  lifteen  days  before  and  ten  days  after  calving,  and  contains  not 
less  than  8.5  per  cent,  of  solids  (not  fat)  nor  less  than  3.25  per  cent,  of 
milk  fat. 

ISIilk  is  a  solution  of  sugar,  mineral  matter,  and  proteids,  with  other 
proteids  and  fat  in  suspension.  Its  composition  is  very  variable,  not 
alone  as  between  difterent  species  of  mammalia  by  which  it  is  produced, 
but  as  between  different  individuals  of  the  same  species.  Of  the 
domestic  animals,  the  ass  and  mare  produce  milk  which  most  closely 
approximates  that  of  woman  in  composition,  but  our  chief  interest  in 


96  FOODS. 

milk  as  au  article  of  food  in  general  nsc  lies  in  that  produced  by  cows 
and,  to  a  certain  extent,  in  that  of  g-oats,  which  is  very  similar  in  com- 
position. AA'hilc  the  comjiosition  of  milk  of  other  animals  than  those 
already  mentioned  can  have  for  most  of  us  merely  a  scientific  interest, 
it  may  be  of  some  practical  utility  in  the  management  of  breast-milk 
to  bear  iii  mind  that  the  milk  of  animals  whose  diet  is  largelv  or  chiefly 
mejit  is  richest  in  tliose  elements,  the  proteids,  that  are  most  conmionly 
at  the  bottom  of  digestive  disturbances  in  breast-fed  children. 

Composition  of  Milk. — The  composition  of  cows'  milk  of  average 
good  quality  may  be  expressed  fairly  in  round  numbers  as  follows : 

Fat 4.00 

Sugar 5.00 

Proteids 3.30 

Mineral  matter 0.70 

Total  solids 13.00 

Water 87.00 

100.00 

According  to  Vieth,  the  average  composition  of  more  than  120,000 
samples  analyzed  in  England  was  : 

Fat 4.10 

Solids  not  fat 8.80 

Total  solids 12.90 

Water 87.10 

100.00 

The  average  of  a  large  number  of  analyses  made  in  this  country 
showed  :  ^ 

Fat '. 4.00 

Sugar 4.95 

Proteids 3.30 

Mineral  matter 0.75 

Total  solids 13.00 

Water 87.00 

100.00 

According  to  Van  Slyke/  the  average  composition  of  about  5500 
s})ecimens,  examined  chiefly  at  State  Experiment  Stations,  was  approx- 
imately as  follows  : 

Fat 3.90 

Sugar 5.10 

Proteids 3.20 

Mineral  matter 0.70 

Total  solids 12.90 

Water      87.10 

100.00 

The  milk  yielded  by  426  cows  from  private  farms  in  Massachusetts, 
and  by   175  more  belonging  to  public  institutions,  was  analyzed   by 

1  Experiment  Station  Record,  V.,  No.  10. 
»  Medical  Record,  May  25,  1907,  p.  878. 


MILK. 


97 


tli(!    .'iiilJior    ;iii(l     lii.s    ;iss()c.iiil(;s,    :iii<l     foiind    to    ^iv<!     tlif    following 
nisulLs  : ' 

420  v.oWH  (Vi)iii  private!  fiiriiis,  total  Holids |.''...'><j 

175  cowH  rimii  |Hil)li(-  iiiHtitiitii)iiK,  tutiil  wilidH l.'i.OO 

001  COWH  (liddi  clasHcH),  total  solidn 1.'>.20 

At  ilic  Piiris  Miiiiici|)al  I>;il)<>r;ilory  -  tlic  following  sl;iii(|;inlK  arc 
rccogiii/tMl  : 

Kj,t 4.00 

KiiKiir       •'"'•00 

I'rotoids •'^•fiO 

Mineral  niiittcr 0,70 

TotJil  .solida 13.30 

Water '    •    •_86.70 

ioo;bb 

The  following  compilation  1)V  Lwicli,^  from  Kocnif^'s  C^licniic;  dcr 
mens.  Nalir.  u.  (Jcnnss.,  ^ives  tlio  composition  of  human  milk  ami  that 
of  a  number  of  ditlercnt  animals  : 


Number 

(if 
analyses. 


800 


200 


32 


47 


Kind  of  milk. 


Cow's  milk : 
Minimum 
Maximum 
Mean  .   .   . 

Human  milk 
Minimum 
Maximum 
Mean  .    .   . 

Goat's  milk: 
Minimum 
Maximum 
Mean  .    .   . 

Ewe's  milk : 
Minimum 
Maximum 
Mean  .   .   . 

Mare's  milk : 
Mean .   .   . 

Ass's  milk : 
Mean  .   .  . 


Specific 
gravity. 

Water. 

Casein. 

Albu- 
min. 

1.0264 
l.()o7(l 
l.OSlo 

80.32 
90.32 
87.27 

1.79 
6.29 
3.02 

0.25 
1.44 
0.53 

1.027 
1.032 

81.09 
91.40 
87.41 

0.18 
1.96 
1.03 

0.32 
2.36 
1.26 

1.0280 
1.0360 
1.0305 

82.02 
90.16 
85.71 

2.44 
3.94 
3.20 

0.78 
2.01 
1.09 

1.0298 
1.0385 
1.0311 

74.47 
87.02 
80.82 

3.59 
5.69 
4.97 

0.83 
1.77 
1.55 

1.0347 

90.78 

1.24 

0.75 

1.036 

89.64 

0.67 

1.55 

Total 
pro- 
teids. 


2.07 
6.40 
3.55 

0.69 
4.70 
2.29 


4.29 

6.52 
1.99 
2.22 


Fat. 


1.67 
6.47 
3.64 

1.43 
6.83 
3.78 

3.10 
7.55 
4.78 

2.81 
9.80 
6.86 

1.21 

1.64 


Milk- 
sugar. 


Ash. 


2.11 
6.12 
4.88 

3.88 
8.34 
6.21 

3.26 
5.77 
4.46 

2.76 

4.91 

5.67 


0.35 
1.21 
0.71 

0.12 
1.90 
0.31 

0.39 
1.06 
0.76 

0.13 
1.72 
0.89 

0.35 

0.51 


Constituents  and  Chemical  and  Physical  Characteristics  of 
Milk. — Fat. — The  fat  of  milk  exists  in  very  minute  globules  which 
vary  widely  in  size,  the  largest  being  between  six  and  seven  times 
larger  than  the  smallest,  but  the  latter  are  most  abundant.  Their 
average  diameter  is  about  -5-Q-V0  J"ch,  Whether  or  not  they  have  an 
albuminous  envelope  is  a  matter  of  doubt,  the  evidence  for  and  against 
being  about  equal  and  of  no  great  imjiortancc. 

It  consists  of  glycerides  of  ten  diiferent  fatty  acids,  five  of  which 
belong  to  the  non-volatile  and  five  to  the  volatile  class.  The  glycerides 
of  the  former  group  constitute  by  far  the  greater  part.      They  are 

^  The  detailed  analyses,  with  data  as  to  breed,  nature,  and  amount  of  feed,  etc-,  can 
be  found  in  the  pamphlet  issued  by  the  State  Board  of  Health  :  Eesult.<  of  Inquiries 
Relative  to  the  Quality  of  Milk  as  Produced  in  Massachusetts.     Boston,  February,  1SS7, 

-  Hygiene  Generale,  1907,  p.  303. 

3  Food  Inspection  and  Analysis,  1909. 

7 


98  FOODS. 

steariu,  palmitin,  olein,  myristiii,  and  butin  ;  the  two  last  are  present 
in  very  uiinute  amounts.  Those  of  the  latter  group  give  the  charaeter- 
istic  butter  tlavor.  They  are  butyrin,  caproin,  caprylin,  caprin,  and 
laurin  ;  the  first  two  are  the  important  ones,  and  together  amount  to 
over  7  per  cent,  of  the  whole  fat ;  the  three  others  are  present  in  but 
insignificant  traces. 

The  fat,  being  the  lightest  part  of  milk,  tends  to  rise  to  the  surface 
when  the  milk  is  allowed  to  stand,  and  then  forms  a  layer  which  we 
know  as  cream.  This  contains  not  fat  alone,  but  all  of  the  constituents 
of  the  milk,  and  is,  therefore,  simply  milk « containing  an  excessive 
amount  of  fat. 

It  is  a  common  error  to  regard  the  depth  of  the  cream  layer  which 
forms  on  standing  a  given  length  of-  time  as  an  infallible  measure  of 
the  richness  of  the  milk  by  which  it  is  yielded  ;  but  cream  does  not 
always  rise  well  in  rich  milk,  even  after  standing  more  than  twenty- 
four  hours.  The  author  repeatedly  has  found  the  percentage  of  cream 
thrown  up  by  a  specimen  of  milk  in  a  100  cc.  graduate  in  twenty -four 
hours,  as  measured  by  the  lines  of  graduation,  to  be  less  than  the  actual 
percentage  of  fat  as  shown  by  analysis.  The  rapidity  with  which  the  fat 
finds  its  way  to  the  surface  depends  largely  upon  the  size  of  the  fat 
globules.  The  largest  rise  first,  and  the  very  smallest  may  not  rise  at 
all.  Again,  a  watered  milk  throws  up  its  fat  more  quickly  than  a 
normal  specimen,  although  it  does  not  contain  as  much.  Furthermore? 
according  to  Rosenau,^  heating  of  milk  for  one-half  hour  at  150°  F. 
(65°  C.)  prevents  entirely  the  rising  of  cream,  or  very  materially 
delays  it.  It  appears,  therefore,  that  a  milk  of  inferior  grade  may 
under  some  circumstances  show  a  deeper  cream  layer  than  a  milk  of 
unusual  richness.  Generally  speaking,  however,  a  rich  milk  will 
usually  show  its  quality  on  standing. 

The  first  part  of  a  milking  is  always  poor  in  fat,  the  middle  portion 
contains  about  the  average  amount  of  the  whole,  and  the  last  portion  is 
always  the  richest.  The  first  portion  is  known  as  "  fore-milk,"  the  last 
as  "  strippings."  A  specimen  of  "  strippmgs,"  analyzed  by  the  author, 
gave  the  following  results  : 

Fat 9.82 

Sugar 4.00 

Proteids 4.21 

Ash _0^ 

Total  solids 18-82 

Water 81.18 

100.00 

Milk-sugar. — Lactose  or  sugar  of  milk,  is  peculiar  to  milk.  It  is 
much  less  soluble  in  water  than  dextrose  and  sucrose.  Heated  to 
100°-131°  C,  it  becomes  changed  in  color  to  brownish,  and  at  higher 
temperatures  loses  water  of  crystallization  and  undergoes  further  change. 
At  175°  C,  lactocaramel  is  formed.    When  heated  in  solution,  in  milk 

1  Hygienic  Bull.,  No.  41,  1908. 


MILK.  y.i 

itn(;ir,  for  <!xarn|)I(!,  if,  Ixi^IiiH  to  imdcrjro  (K'cornpositioii  v\v.u\\rvH  at  70'^ 
C.  Jind  above.  Tliroii^li  llic  iiclion  of"  llic  l;ic(i<'  fcriiicnts,  it- ^^ivcH  r\H(^ 
to  liuil.ic,  ;ic-i<l.       Ill  the  |)oI;ii'i,sc()|)c,  it  i.s  dcxf rorolnry. 

Proteids.^'i'lic  iric-i I cr  piirl  of  Hi*-  ptdtcid.s  of  milk,  about  80  ))cr 
cont.,  is  (casein,  or,  ;is  il  is  ciillcd  sdiiicliiiicH,  caKfino^cn.  Jt  w>nbiiriH 
boll)  siilphtir  Mild  |>lios|)horiis,  .-iiid  is  in  iiif  iiiinic  coinbiii.'ifioti  with  eal- 
(^iiim  plios|)li;ir('.  Il  is  not  coii^iiIjiIccI  b\'  hc;i(,  but  i~  pn'cipit;it<'d  bv 
acids,  by  whicli  tlic  coiiibiii;iti'iii  is  broken  up.  In  llie  prcscne*'  of 
lactic  a.ci(l  in  siiimII  aiiioimts,  dne  (o  llie  bicikinL'  np  of  Inetosc,  coa^i- 
latioM  is  liastoiicd  by  tlu;  ;i|»plie;il  ion  of  ticnlle  lii;it.  'I'lii-  plienomcnon 
Is  observ(!d  very  (commonly  in  tiio  case  of  milk  wbieli  to  tlic  tast<;  Is 
aj)p!ireiitly  swec^t,  but  vvliieb  is  "just  on  tbc  turn." 

The  chief  j)art  of  tiie  reinaind(!r  of  the  proteids  is  laet;ilbuiniii.  This 
is  coa.^uhitcd  by  heatiii}^  to  65°— 7.'>°  C,  but  not  by  dilute  acids.  It 
coutains  sulj)hur,  but  no  phosj)horus.  In  amount  it  ranp^cs  from  0.2 
to  O.S  j)er  cent.  It  is  inneh  more  abundant  in  colostrum.  Tlu;  re- 
maining proteids  an;  lacto^lobulin,  which  is  ('oaguiated  liy  heat;  lact<^)- 
protcin,  coagulablo  by  neither  heat  nor  dilute  acids,  and  filtrin.  lOadi 
exists  in  but  very  small  amounts. 

Mineral  Matter. — The  mineral  matter  contained  in  milk  consists  of 
phosphat(\s  and  chlorides  of  ])otassium,  sodium,  calcium,  and  magnesium, 
and  extremely  minute  traces  of  iron,  (^f  the  bases,  potassium  is  the 
most  abundant,  with  calcium,  sodium,  and  magnesiiun  in  the  order 
given.  The  phosphates  predominate  over  the  chlorides.  Part  of  the 
calcium  exists  in  combination  as  phosphate  with  the  casein,  and  the 
rest,  according  to  Danilcwsky,^  as  mono-  and  tricalcium  phosphate  and 
in  combination  with  citric  acid.  Part  of  the  magnesium,  also,  exists  in 
combination  with  citric  and  other  organic  acids.  In  very  small 
amounts,  these  are  normal  constituents  of  milk  of  various  animals.  In 
human  milk,  citric  acid  is  present  to  the  extent  of  about  0.05  per  cent., 
and  in  cows'  milk,  it  is  about  three  times  as  abundant. 

Specific  Gravity. — The  specific  gravity  of  cows'  milk  of  normal  com- 
position ranges  from  1.029  to  1.034.  It  increases  very  slightly  for 
about  five  hours  after  the  milk  is  drawn,  and  then  becomes  stationary. 
The  increase  is  believed  to  be  due  to  molecular  modification  of  the 
casein,  and  not  to  the  escape  of  gases.  It  is  lowered  by  fat  and  water, 
and  by  tlie  presence  of  bubbles  of  air,  and  is  raised  by  removal  of  cream. 

Reaction. — When  freshly  draAvu,  milk  shows  the  so-called  amphoteric 
reaction  ;  that  is,  it  is  acid  to  litmus  and  alkaline  to  turmeric.  The 
alkaline  reaction  is  intensified  on  warming,  but  the  acid  reaction  is  not 
influenced  thereby.  On  standing,  the  alkaline  reaction  is  overcome 
by  the  lactic  acid  which  is  formed  gradually  from  the  sugar,  and  the 
acid  refiction  is  increased  in  consequence  of  the  same.  The  original 
acid  reaction  is  due  to  the  presence  of  carbonic  acid,  acid  jihosphates, 
and  diealcium  caseinogenate,  the  alkaline  to  alkaline  carbonates. 
Human  milk  is  normally  alkaline,  and  that  of  carnivora  is  acid. 

Appearance. — The  appearance  of  normal  milk  is  too  familiar  to  need 
1  "Wmtsch,  1001,  p.  549. 


100  FOODS. 

description  ;  but  under  certain  rare  abnormal  conditions,  milk  may 
assume  dilierent  colors,  iucluding  blue,  yellow,  violet,  and  red.  These 
changes  of  color  are  due  to  the  action  of  certain  bacteria,  and  are  always 
evidence  of  unsanitary  conditions  to  which  the  milk  is  exposed  at  the 
dairy  or  during  distribution  and  storage. 

Blue  milk  is  due  to  the  action  of  B.  cyanogcnea,  Avhich  produces  a 
blue  color  in  no  other  food  material.  For  its  development  it  rcipiires 
the  presence  of  lactic  ferments,  and,  therefore,  has  no  effect  on  milk 
that  is  sterile.  Another  organism  capable  of  producing  the  same  effect 
is  B.  cyaneofluoresccns. 

A  red  color  may  be  caused  by  B.  prodigiosus,  B.  lactis  crytlirogcnes, 
Sarcina  rosacea,  and  by  blood.  Yellow  milk  is  caused  by  B.  synxan- 
thus  and  a  number  of  other  organisms.  Like  B.  lactis  ei-ythrogenes, 
B.  synxanthus  produces  the  abnormal  coloration  only  after  coagulating 
the  milk  and  dissolving  the  curd.  B.  lactis  erytJirogenes  causes  red 
color  only  when  the  milk  is  kept  in  darkness  ;  in  the  light  it  causes 
a  yellow  color.      A  violet  color  is  produced  by  B.  violaceus. 

All  of  these  milks  of  abnormal  color  are,  aside  from  their  uninviting 
a])pearance,  unfit  for  food,  since  they  are  likely  to  cause  gastro-intes- 
tinal  irritation.  Thus  Eichert  ^  records  a  case  of  severe  diarrhoea,  with 
very  offensive  stools,  in  a  child  of  nine  months,  due  to  red  milk  caused 
by  a  bacillus  (probably  B.  lactis  erythrogenes)  present  in  the  milk- 
ducts  at  the  time  of  milking. 

Taste. — The  flavor  of  milk  is  modified  very  sensibly  by  the  char- 
acter of  the  feed  and  by  the  absorption  of  gases  and  volatile  matters 
of  all  kinds.  It  is  affected  very  readily  by  turnips,  garlic,  wild  onion, 
mouldy  hay  and  grain,  distillery  swill,  and  damaged,  rotten  ensilage. 
A  very  marked  taste,  suggestive  of  turnips,  is  more  commonly  due  to 
B.  fcMidus  lactis  and  related  species  than  to  turnips.  This  organism 
causes  also  other  disagreeable  tastes,  including  sweet,  bitter,  and  putrid. 

Bitterness  of  taste  may  be  due  to  various  weeds,  chiefly  cruciferse,  or 
to  bacteria.  When  due  to  feed,  the  taste  is  bitter  from  the  very  first, 
but  when  caused  by  bacterial  agency  it  develops  some  time  after  milk- 
ing, when  the  organisms  which  produce  it  have  had  opportunity  to 
produce  peptone  from  the  proteids.  It  may  be  due  to  inflammatory 
conditions  of  the  udder,  in  which  case  it  may  or  may  not  be  noticeable 
when  the  milk  is  freshly  drawn.  The  bacteria  concerned  in  producing 
bitterness  may  exist  in  ducts  of  the  teats,  or  may  come  from  stable 
filth.  Among  them  may  be  mentioned  Micrococcfiis  C'omi,  Micrococcus 
casei  amari  (Freudenreich),  B.  liquefaciens  lactis  amari  (Freudenreich), 
B.  Fli'igge,  and,  in  addition,  various  yeasts. 

A  soapy  taste,  sometimes  also  sweetish,  may  be  caused  by  various 
bacteria,  including  a  bacillus  found  in  hay  and  straw,  discovered  by 
Weigman,  capable  of  producing  its  effects  within  24  hours ;  another, 
isolated  by  Eichholz,  which  causes  first  a  sweetish  soapy  taste  and  then 
one  suggestive  of  cow  manure,  and  grows  well  at  a  temperature  below  50° 
F.,  at  which  the  lactic  acid  bacteria  are  inhibited  ;  and  B.  saponacei. 
1  Zeitschrift  fiir  Fleisch-  und  Milchhjgiene,  VIII.,  No.  5, 


MILK.  101 

A  |niiri(l  taste  i.s  cauHcd  Uy  /!.J'"/iihn^  hit-tin  and  a,  niiinhcr  of  ot!i(;r 
.s|)(!(;i('.s.  A  HiiUy  tasto  may  Ix;  note*!  in  tiiilU  coiitjiiiiii)^  j»iih  ;  HoriK,- 
tiiiics  it  is  (I<H;i(l(!(lly  acrid.  OfJicr  di>a)i;rc(al)lo  tastes,  as  nily,  fisliy, 
aii<l  hiii'iit,  arc  sonuitiiiKis  observed,  and  all  an-  i\\u\  lo  various  specicH 
of  l)a,e(cria. 

Odois  arc  easily  ahsorlxid  by  milk,  with  (;ons('(|iicnt  imj)airmciit  of 
flavor,  and  some  are  retained,  even  after  tlie  milk  is  boiled,  tlion^h 
others  are  driv(!n  off.  Hence  stronf^-sineliing  disinfectiints  may  not  Ix; 
us(\d  with  entire  saf(!ty  in  dairi(!S.  This  absor|)tive  eapaf^ity  is  so  \V(;11 
recoj^ni/.ed  that  milk  is  stored  commonly  in  se|)arate  compartments  of 
refrit!;erat()i's,  away  from  foods  which  evolve  distinct  odors. 

l)istillery  swill  not  only  canscs  a  decidedly  bad  flavor,  but  may,  in 
addition,  and  contrary  to  a  generally  accepted  idea,  cause  an  alcoholic 
milk.  Thus,  accordin<r  to  il.  W.  Weller,'  a  sample  of  milk  derived 
from  cows  fed  on  distillery  refuse  containing  o.OO  per  C(,'nt.  of  alcohol 
yielded,  in  addition  to  a  high  proportion  of  milk  solids,  O.iiG  per  cent, 
by  weight  of  alcjohol.  The  milk  was  complained  of  on  account  of  an 
un])lcasant  after-taste.  Teic^hert^  records  a  case  in  which  calves  and 
lambs  failed  to  thrive,  and  many  dial  from  a  form  of  diarrluea.  The 
mothers  were  fed  on  distillery  waste,  and  yielded  milk  containing  alco- 
hol. That  alcohol  or  something  connected  therewith  may  be  eliminated 
in  milk  is  shown  by  numerous  cases,  among  which  are  the  following: 
Vallin^  records  that  a  nursing  infant  was  seized  with  convulsions  with 
great  regularity  on  Mondays  and  Thursdays,  but  was  (piite  well  on 
other  days.  Investigation  showed  that  the  wet-nurse  on  Sundays  and 
Wednesdays,  her  "days  out,"  was  in  the  habit  of  drinking  freely  of 
alcoholics.  The  curtailment  of  the  privilege  was  followed  by  disap- 
pearance of  the  difficulty.  Farez  *  cites  2  cases  which  show  the  bad 
influence  of  alcohol  on  nursing  children.  In  one,  the  wet-nurse  drank 
wine  at  meals,  and  especially  in  the  evening,  and  the  child  never  ceased 
fretting,  crying,  and  screaming  from  9  o'clock  until  11.  The  nurse 
complained  bitterly  of  the  naughtiness  of  the  child,  and  was  grieved  at 
the  suggestion  that  she  was  herself  at  fault  through  drinking  too  much, 
but  she  was  induced  to  abstain  from  alcohol  entirely,  and  from  that 
time  there  was  no  further  trouble.  In  the  other  ease,  the  mother 
drank  tea  at  noon  and  wine  at  dinner,  and  the  child  was  quiet  during 
the  afternoon,  but  screamed  and  fretted  all  the  evening  and  until  mid- 
night. A  change  to  wine  at  noon  and  tea  at  dinner  producecl  a  cor- 
responding change  in  the  behavior  of  the  child,  the  turbulent  period 
occurring  in  the  afternoon.  When  the  mother  eliminated  wine  from 
her  dietary  entirely  the  trouble  ceased. 

Koumiss  and  Kefir. — Alcoholic  fermentation  of  milk,  although  it 
never  occurs  spontaneously,  is  used  by  some  people  for  the  production 
of  certain  milk  beverages.  Among  these  are  those  known  as  koumiss 
and  kefir. 

1  Foi-schun?sbericbte  iiher  Lebensmittel,  etc.,  1897,  p.  206. 

3  Milch  ZeUuntr,  1901,  p.  148.  3  Kevue  d'Hvgiene,  1896,  p.  95.S. 

4  Tribune  M^dicale,  June  '20,  1900,  p.  488. 


102  FOODS. 

According  to  Kastle/  "  Koumiss,  originally  made  by  the  alcoholic 
fermentation  of  mare's  milk,  is  now  made  from  cows'  milk  by  the 
addition  of  cane-sugar  and  yeast.  The  first  action  of  the  ferments  is 
to  hydrolyze  the  polysaccharides  (cane-sugar  and  lactose),  producing  the 
simpler  sugars,  glucose,  levulosc,  and  galactose,  all  of  which  are  fer- 
mentable by  yeast.  Two  changes  then  occur,  the  alcoholic  fermenta- 
tion, resulting  in  the  production  of  alcohol  and  carbon  dioxide,  and 
the  ordinary  lactic  acid  fermentation,  resulting  in  the  production  of 
lactic  acid.  Kelir,  a  similar  beverage,  originating  in  the  Caucasus,  is 
also  made  from  milk  by  an  alcoholic  fermentation.  The  fermentation 
is  carried  out  in  leather  bottles,  and  is  started  by  means  of  'kefir 
grains,'  concerning  whose  origin  but  little  is  known.  During  the  fer- 
mentation thus  induced  a  considerable  quantity  of  the  ferment  is  pro- 
duced, which  is  removed  and  dried  in  the  sun,  and  thus  new  supplies 
of  the  kefir  grains  obtained." 

Colostnim. — The  milk  secreted  before  and  in  the  early  stage  of 
lactation  is  known  as  colostrum.  It  is  a  yellow,  somewhat  viscid  fluid, 
of  strong  odor  and  acid  reaction.  In  composition  it  differs  very  mate- 
rially from  milk,  particularly  in  its  percentage  of  proteids.  It  contains, 
sometimes,  so  large  a  percentage  of  lactalbumin  and  lactoglobulin  that 
it  is  coagulated  by  boiling.  Its  content  of  casein  is  about  normal,  but 
it  is  not  coagulated  by  rennet,  or  at  most  imperfectly.  In  the  early 
stages  its  sugar  is  dextrose  and  not  lactose.  According  to  Tiemann,^ 
it  ranges  in  specific  gravity  from  1.0299  to  1.0594,  in  fat  from  0.56 
to  9.28,  in  proteids  from  4.66  to  21.78,  in  ash  from  0.82  to  1.25,  and 
in  total  solids  from  12.93  to  32.93.  Under  the  microscope  it  shows 
large  corpuscles,  known  as  colostrum  corpuscles,  which  disappear 
within  two  weeks  at  most  after  the  time  of  calving. 

Consistence  of  Milk. — The  natural  consistence  of  milk,  which  is 
largely  dependent  upon  the  content  of  fat,  is  altered  by  the  action  of  a 
somewhat  large  variety  of  organisms,  which  produce  a  condition  of 
sliminess.  Slimy  or  "  ropy "  milk  throws  up  no  cream,  and  hence 
cannot  be  used  for  the  production  of  butter ;  but  although  it  is  most 
unappetizing,  it  causes  no  digestive  disturbance  if  ingested.  The  most 
common  cause  of  this  condition  is  B.  lactis  viscosus  (Adametz),  which 
multiplies  at  temperatures  as  low  as  46°  F.,  and  acts  somewhat  slowly. 
Its  ability  to  grow  at  temperatures  which  inhibit  other  organisms  may 
enable  it  to  predominate  over  them  in  a  few  hours  in  milk  submerged 
in  ice-water  or  kept  in  a  refrigerator.  Micrococcus  Freudeureichii 
(Guillcbeau)  can  produce  sliminess  in  5  hours,  and  Sti-eptococcus  TIol- 
landicus  can  cause  it  in  ^varm  milk  in  one  day.  B.  laciis  pituitosi  causes 
both  sliminess  and  a  bitter  taste.  Karphococcus  pituitoparus  (Hohl), 
isolated  from  a  bale  of  straw,  was  found  to  be  capable  of  causing  slimi- 
ness in  both  sterilized  and  unsterilized  milk.  Guillebeau's  bacillus 
causes  in  cows  a  mastitis,  a  characteristic  of  which  is  the  exceedingly 
ropy  condition  of  the  milk  when  drawn  from  the  udder.      In  addition 

^  Hygienic  Laboratoiy,  Bulletin  No.  41,  p.  365. 
2  Zeit.  f.  physiolog.,  Chemie,  189S,  p.  363. 


MII.K.  10.'} 

to  the  organismH  abovo  rrKintioiicd,  at  leant  nix  oIIuth  arc  known  wliif-h 
produce  tliiH  clian^f!  in  (lonsisterice. 

Ferments  of  Milk. — Milk  is  not  ■ah  indill'rnnt  inert  lliiid  ;  it  ii:i>j 
eertain  actual  hiolojj^ie,  propctrties,  wliic^li  are  destroyed  Wy  expfwure  to 
liif^li  ternperatJircH,  among  tlieni  heing  tlu;  j)ower  said  to  he  |io.'-HeHHe<l 
by  fresh  milk  to  destroy  certain  kinds  of  bacteria  and  to  inhibit  otJKirH. 
This  batitericidal  proj)er(y  diminishes  mat(!rially  within  a  few  hours  ; 
is  weakeiuid  by  .'{0  minutes'  exposure  to  14!)*^  F.  or  by  2  minutes'  ex- 
posure; to  1S5"  F.  ;  and  is  destroyed  at  onee  by  boihng.  The  lower 
the  temperature  at  which  the  milk  is  kept  the  longer  the  |)roj)erty  jter- 
sists.  Thus,  at  (i8°  F.,  according  to  Coplans/  new  milk  is  slighly 
bactericidal  and  absolutely  inhibitory  for  0  liours,  and  })artially  inhibit- 
ory for  18  hours  longer;  at  incubator  temperatun;  these  j)eriods  are 
reduced  resj)ectively  to  1  and  G  hours;  and  when  raised  to  room  tera- 
j)erature,  after  24  hours'  storage  at  32°  F.,  it  is  absolutely  inhil>iLory 
and  bacteritiidal  for  3  hours,  and  partially  inhibit^jry  for  9  hours  more. 
The  existence  of  this  bactericidal  |)roperty  has,  howfiver,  been  repeatedly 
denied.  Acciording  to  Klimmer,"  neither  human  nor  asses'  nor  cows' 
milk  possesses  bactericidal  j)ower  against  saprophytes,  B.  coli  and  B. 
typJio.siis.  According  to  Stocking^  the  ascribed  jjroperty  may  be  ex- 
plained by  the  fact  that  certain  species  of  bacteria  which  find  in  milk 
no  suitable  food  material  die  out  more  or  less  rapidly.  Kolle  and 
others  ^  found  an  absence  of  bactericidal  power  against  B.  cod,  B.  tj/- 
phosus,  B.  paratjiphoi^m,  and  some  other  sj^ecies ;  but  B.  dyHcnteruB 
was  inhibited  and  cholera  sj)irillfe  were  partly  killed.  Koning,*  how- 
ever, states  that  the  bactericidal  property  ajjpears  soon  after  the  milk 
is  draAvn,  and  exists  in  esjiecially  marked  degree  in  colostrum.  B. 
coll,  B.  fiuorescens  liq.,  B.  ackli  facfiei,  and  other  species  are  destroyed  ; 
and  colostrum  acts  with  especial  vigor  against  B.  coli.  Hippius,*  t<x), 
found  that  cows'  milk  exerted  a  strong  bactericidal  action  on  B.  coli 
and  B.  prodigiosus,  which  was  most  marked  during  the  first  3  or  4 
hours  and  then  gradually  waned,  and  after  6  or  7  hours  disapjieared. 
It  was  weakened  by  30  minutes'  exposure  to  149°  F.  and  by  2  min- 
utes' exposure  to  185°  F.,  and  was  killed  by  boiling. 

More  convincing  are  the  results, of  the  experiments  of  Evre,^  who 
inoculated  fresh  clean  milk  with  cultures  of  B.  fj/phosiis,  and  saw  the 
number  of  bacilli  per  cubic  centimeter  fall  from  78  to  42  at  the  end 
of  4  and  6  hours,  and  then  increase  to  46  at  8  hours,  460  at  12  hours, 
and  6000  at  24  hours.  Thus  it  appears  that  the  property  was  lost  in 
4  to  6  hours  and  was  succeeded  by  first  a  very  slow  and  later  a  verv 
rapid  multiplication  of  the  bacteria. 

The  very  careful  experiments  of  Rosenau  and  McCoy  ^  led  them  to 

1  Tlie  Lancet,  October  10,  1907.  p.  1074. 

»  Centralblatt  fiir  Bakteriologie,  I.  Abt.  190?^  XXXIII..  Kef.,  p.  Si8. 

3  Storr's  Agricultural  Experiment  Station  Report,  1904,  p.  89. 

4  Kliniscbe  Jabrbiiober.  XIII.,  1904. 

5  Apotheker  Zeitung,  XIV.,  1904,  p.  730. 

^  Jabrbucb  fur  Kinderbeilkinide,  etc,  LXI..  1905.  p.  365. 

^  Journal  of  State  Medicine.  XII.,  1904,  p.  72S. 

"^  Hygienic  Laboratory,  Bulletin  No.  41,  Wasbington,  190S,  p.  449. 


104  FOODS. 

conclude  that  the  diminutiou  in  numbers  is  largely  apparent  and  not 
real,  and  is  due,  at  least  iu  part,  to  agglutination.  There  is  a  real  re- 
straiuiug  action  which  persists  for  some  hours,  and  for  a  longer  time  if 
the  milk  is  kept  cool.  Although  some  of  the  polymorphonuclear  leu- 
cocytes seem  to  possess  the  power  of  phagocytosis,  this  plays  no  essen- 
tial part,  for  the  decrease  is  as  marked  in  cell-free  milk  as  in  the 
sedimeut  rich  in  leucocytes.  The  germicidal  actic^n,  whatever  its  nature, 
is  specific,  the  same  sample  restraining  B.  typhosus  and  StapJtylococcus 
pyogenes  aureus,  but  not  JB.  paratyphosus,  A  or  B.  They  found  the 
action  to  be  variable  and  feeble,  but  worthy  of  attention  in  good  dairy 
methods. 

In  1900  Escherich  called  attention  to  the  fact  that  infants  fed  even 
to  a  slight  extent  at  the  breast  could  digest  cows'  milk  perfectly, 
whereas  with  no  breast-milk  such  was  not  the  case.  The  difference 
was  attributed  by  him  to  the  presence  of  ferments,  the  study  of  which 
was  taken  up  at  once  by  Spolverini,^  who  isolated  seven  different  kinds. 
Others  have  since  been  isolated  by  the  same  observer  and  others,  and 
much  study  has  been  devoted  to  their  properties  and  origin.  Not  all 
kinds  of  milk  contain  the  same  kinds  of  ferments.  Thus,  while  all  of 
those  discovered  by  Spolverini  are  present  in  the  milk  of  women  and 
bitches  (carnivora),  certain  of  them  are  lacking  in  that  of  cows  and 
goats  (herbivora).  That  those  not  common  to  both  carnivora  and 
herbivora  can  be  made  to  appear  or  disappear  by  appropriate  diet  has 
been  proved  by  Spolverini,^  who  caused  diastase  and  the  salol-splitting 
ferment  to  appear  in  the  milk  of  a  goat  put  upon  a  mixed  diet,  and 
diastase  to  diminish  markedly  in  the  milk  of  a  bitch  fed  twenty-two 
days  on  a  vegetable  diet.  The  ferments  thus  far  isolated  comprise  the 
following  : 

Trypsin  or  G-alactase. — This  is  found  in  the  milk  of  the  bitch,  cow, 
and  sfoat,  and  to  a  smaller  extent  in  that  of  the  ass  and  woman.  It 
digests  casein.  Exposed  to  168.8°  F.  it  is  destroyed.  According  to 
Neumann-Wender  ^  it  is  not  one,  but  several  enzymes,  and  is  most 
active  at  about  104°  F.,  and  although  it  loses  its  power  to  dissolve 
casein  on  exposure  to  168.8°  F.,  its  power  to  decompose  hydrogen 
peroxide  is  not  impaired  until  the  temperature  reaches  176°  F.,  nor 
entirely  destroyed  under  181.4°  F. 

Pepsin. — This  is  said  by  Spolverini  to  exist  in  human  milk  in  small 
traces.      Its  existence  is  denied  by  Benoit,  but  affirmed  by  Moro.* 

Diastase  or  Amylase. — This  is  present  in  human  milk  and  in  the 
milk  of  the  bitch,  and  to  the  greatest  extent  in  that  of  the  ass.  It  is 
not  normally  present  in  cows'  and  goats'  milk.  This  was  the  first  fer- 
ment to  be  isolated  from  milk.     It  is  destroyed  at  167°  F. 

Lipase. — This  exists  in  the  milk  of  all  the  different  kinds  above 
mentioned,  and  is  most  active  in  human  milk.     According  to  Gillet  s 

1  Archives  de  Medecine  des  Enfants,  December,  1901. 

2  Centralbktt  fiir  Bakteriolopie,  etc.,  I.  Abt.  Kef.,  1902,  XXXII.,  p.  321. 
2  Oesterr.  Chemische  Zeitimg,  1903,  p.  1. 

4  Centralblatt  fiir  Bakteriologie,  etc.,  I  Abt.  Ref.,  1903,  XXXIII.,  p.  10. 

5  .Journal  de  Physiol,  et  Path.  Gen..  1903,  No.  3. 


MII.K.  105 

it  (1()(!M  iiol,  :ili:u;l<  mII  of  llu;  (•()iiKti(u(;ntH  of"  l)iiftcr  fiit,  l)ii(  only  niono- 
butyriii,  iiiid  Ik^iku;  is  not  a  iijKisc,  hut  Jiioiioldilyriiiasc.  It  i.s  dcHtroycd 
at  147"  F. 

Salol-splitting  Ferment. — 'i'lii.s  is  not  foiuKl  iti  the  iiiill<  of  cowk  and 
floats,  hilt  only  in  hinnan  iuid  asses  milk.  Its  fixistence  in  any  milk 
has  h(!on  (hjnicd,  hnt  whattjver  the  mituic  of  tlx;  cause  of  salol-.-jdiif ing 
it  is  kill(Ml  at  11!)°   V\ 

Oxydases. — That  whieii  is  commonly  known  as  oxydu.se  i.s  alwavB 
j)i'('.sent  in  eonsidciMhle  amounts  in  eows'  and  jrouis'  milk,  hut  is  hardly 
notic(!able,  thotit^h  ranily  ahsenl,  in  human  milk.  Aeeordinj^  to  (iillet' 
it  is  always  present  in  human  colostrum,  hein^  united  with  the  poly- 
nuclear  leucocytes.  It  is  killed  at  17G°  F.  S|)olverini2  makes  a  di.s- 
tinction  between  direct  oxydases  which  can  utilize  directly  the  atmo- 
spheric oxyj^en  an<l  indirect  oxydases  which  cannot  do  so,  hut  rcfjuire 
the  presence  of  a  substance  rich  in  oxygen  like  hydr<»gen  peroxide. 
The  ferment  commonly  known  as  oxydase  is  this  anaerobic  indirect 
oxydase,  which  Spolverini  believes  acts  through  two  distinct  enzymes, 
one  of  which  decomposes  hydrogen  peroxide,  the  other  fixing  the  lilj- 
erated  oxygen. 

Seligmann^  divides  the  oxidizing  ferments  into — (1)  su|)eroxy da.se, 
which  decomposes  hydrogen  peroxide  and  is  identical  with  the  catala,se 
of  Loew ;  (2)  direct  oxydase  ;  and  (3)  indirect  oxydase,  which  is  active 
only  in  the  {)rcsence  of  hydrogen  j^eroxide  and  corres]ionds  to  the  per- 
oxydase  of  Linnossier.  Peroxydase,  according  to  Yolles,^  is  always 
present  in  milk,  and  in  human  milk  five  or  six  times  as  abundantly  as 
in  cows'.  It  is  destroyed  at  167°  F.  Superoxydase,  or  catalase,  is 
killed  at  176°  F. 

Reductases. — Fresh  milk  has  a  reducing  action  upon  methylene-blue 
and  other  substances,  which  increases  as  time  elapses,  but  disappears 
on  boiling.  This  property  is  believed  by  some  to  be  due  to  ferments, 
and  by  others  to  be  caused  by  bacterial  action.  That  it  is  due  to  bac- 
teria is  suggested  by  the  fact,  among  others,  that  while  boiled  milk  is 
inactive,  it  may  be  activated  by  inoculation  with  sour  milk.  Accord- 
ing to  Smidt^  fresh  milk  contains  no  preformed  reductase  whatever, 
and  if  methylene-blue  is  decolorized  by  raw  milk  the  action  is  due  to 
bacteria ;  whereas  if  the  reduction  is  accomplished  in  the  j)re,sence  of 
formalin  (Schardinger's  reagent,  2.5  per  cent,  each  of  saturated  alco- 
holic solution  of  methylene-blue  and  formalin  in  distilled  water),  the 
action  is  due  to  a  ferment  which  acts  catalytically  upon  the  formalin. 
This  is  called  by  Jensen^  aldehyde  catalase. 

Bacteria  in  IVIilk. — In  spite  of  all  precautions  taken  to  exclude 
them,  bacteria  of  various  kinds  are  always  present  in  milk  in  consider- 
able numbers.     Although  the  milk  is  sterile  at  the  point  of  secretion 

1  Centralblatt  fiir  Bakteriolosie.  etc.,  I  Abt.  Eef.,  1903,  XXXIII.,  p.  197. 

2  Rev.  Hyg.  et  Med.  Infantile,  III.,  1904,  p.  113. 

3  Zeitschrift  fiir  Hygiene  unci  Infectionskrankheiten,  L.,  1905,  p.  97. 

4  Zeitschrift  fiir  Biologie,  XLV.,  p.  24S. 

5  Archiv  fiir  Hvgiene,  LVIIL,  1906.  p.  313. 

«  Kev.  G^n.  Laif.,  VI.,  1906,  Nos.  2,  3,  and  4. 


106  FOODS. 

and  ill  the  cisterns  of  a  healthy  gland,  it  is  by  no  means  free  from 
bacteria  when  it  is  discharged  frinn  the  niilk-dncts,  for  the  organisms 
gain  entrance  through  the  external  orihces,  and  under  the  favoring  in- 
fluence of  temperature  and  abundance  of  suitable  nutrient  material 
nndtiply  enormously  between  milkings.  They  are  very  largely  ex- 
pelled with  the  first  jets,  but  ordinarily  they  may  be  found  in  some 
numbers  even  in  the  last  strippings,  and  those  which  persist  at  the 
completion  of  the  operation  and  are  left  in  the  ducts  multiply  diu'ing 
the  ensuing  interval.  In  a  study  of  more  than  800  sections  of  35 
teats  of  cows,  goats,  and  sheep,  hardened  in  alcohol  and  appropriately 
stained,  Uhlmann  ^  found  not  one  in  which  bacteria  were  not  present 
in  some  number,  occasionally  as  many  as  a  hundred,  but  generally  only 
a  few.  The  predominating  forms  were  cocci.  Similar  results  were 
obtained  by  von  Freudeureich  ^  on  examining  the  udders  of  15  cows, 
in  13  instances  immediately  after  slaughter. 

The  bacteria  derived  from  the  udder  are  chiefly  pyogenic  cocci ;  and 
when  these  are  present  in  large  numbers  they  are  usually  indicative  of 
inflammatory  conditions.  The  others,  with  which  the  milk  is  commonly 
richly  seeded  when  the  operation  of  milking  is  concluded,  fall  into  the 
pail  with  dust  from  the  air,  with  hairs,  dandruff,  and  other  material 
from  the  animal's  exterior  and  the  person  and  clothing  of  the  milker, 
and  are  also  in  large  part  derived  from  the  pail  itself,  which  under  the 
best  of  conditions  is  never  completely  sterile.  In  the  processes  of 
straining  and  "putting  up,"  still  more  bacteria  are  acquired.  Thus, 
it  will  be  seen,  the  production  of  bacteria-free  milk  is  a  practical  im- 
possibility under  any  circumstances,  and  the  less  the  care  observed  the 
greater  will  be  the  bacterial  content.  Furthermore,  inasmuch  as  milk 
is  an  excellent  culture  medium,  and  since  warmth  is  the  principal  favor- 
ing condition  for  rapid  multiplication,  unless  the  product  is  immediately 
cooled,  the  number  of  bacteria  present  will  soon  be  much  larger. 

With  every  possible  precaution  to  exclude  bacteria  from  external 
sources,  including  tying  the  cow's  tail  to  the  leg  on  the  farther  side, 
washing  the  flank  and  udder  with  boric  acid  solution,  and  wiping  the 
])arts  with  a  sterile  cloth,  treating  the  hands  in  the  same  manner,  milk- 
ing the  cow  half  out,  repeating  the  washing  operation,  and  then  draw- 
ing the  rest  of  the  milk  into  a  sterilized  covered  pail  through  four 
thicknesses  of  sterile  cheese-cloth  and  a  layer  of  sterile  absorbent 
cotton,  Professor  H.  W.  Conn  and  W.  A.  Stocking  ^  succeeded  in 
securing  specimens  which  contained  in  two  series  averages  of  242  and 
267  bacteria  per  cubic  centimeter.  Of  small  samples  drawn  by 
Bergey  *  from  the  udders  of  a  number  of  cows  into  sterile  test-tubes, 
about  one-third  were  sterile  and  about  one-tenth  contained  more  than 
5000  bacteria  per  cubic  centimeter. 

Lactic  Ferments. — Of  the  many  species  of  bacteria  which  commonly 

»  Revue  G^n.  Lait,  1904,  p.  163.     (Abstract  of  Thesis,  Jena,  1903.) 
■■*  Centi-alblatt  fiir  Bakteriologie,  etc.,  II.  Abt.  X.,  1903,  p.  401. 
3  Starr's  Agricultui-al  Experiment  Station  Report,  1903,  p.  52. 
^  Department  of  Agriculture,  Pennsylvania,  Bulletin  125j  1904. 


MILK.  107 

^iiiri  a(!COHK  to  inilk,  ilu;  ^njiilcr  niiinlicr  belong  \n  tli<;  class  kiif>wn  a.s 
liic,ti(!  ((iriiicnts,  vvliifli  convert.  lli<!  iiiilk-,sii^;ir  iiilo  H(;v<:ral  varieties  of 
lactic  ucid  after  it  is  split  inlo  dcxtro.sc  and  ^alacto.m.'.  'i'licy  arc  of 
intestinal  ori^^in,  and  arc  invaiiaMy  prcsc^nt  to  .sonic  extent  tlirou^li  tlic 
nna,voidal)i(!  introdnction  of  particles,  ndinite  or  gross,  of  inannre. 
Tlicy  innltiply  best  at  tcnipcratnrcs  from  70^  V.  to  abrjut  liO'^  I'".,  and 
arc  kilkid  within  20  nnnnics  on  exposiu'c  U)  140°  F. 

The  (ion^innonest  of  the  kuitic  f(!rments  is  Hirc.plfKocA'MH  IwI'icmh  (KruHc), 
which  is  similar  to  or  identical  with  />.  ladU  acidi  (Ivcicibmaiin),  and, 
accordin{>;  to  IFcincMnann/  at^rces  morpholof^ically  and  culturally  with 
Sfrcj>f.()C()cciis  pi/oi/ciics.  indeed,  by  passai^e  thronL;;h  a  scries  of  rabbits, 
lleinemann  succeeded  in  raising  its  virulence  from  praeti(;;dly  nothing 
to  that  of  the  latter  species. 

N(!xt  in  im))ortan(!e  is  B.acldl  ladicl  (TTiiepjic),  which  is  apparently 
identical  with  I>.  /dcfis  (icro<j<'ncs  (Eschericlij,  and  then  I'ollow  Ji.  roti 
and  several  of  lesser  importance  and  certain  saccharomyces. 

Peptonizing  Ferments. — (Jf  greater  importance  than  the  lactic  fer- 
ments from  a  sanitary  standpoint  are  the  grouj)  known  as  jwptonizing 
ferments,  of  which  there  are  many  species.  They  secrete  enzymes 
which  attack  and  dissolve  casein  (hence  known  also  as  casein  ferments) 
and  some  which  may  produce  curdling;.  Some  form  extremely  resist- 
ant spores  which  withstand  long  boiling,  and  hence  they  persist  in 
pasteurized  and  sterilized  milk.  Fliigge^  isolated  from  market  milk 
12  varieties,  8  of  which  were  pathogenic  to  mice,  guinea-pigs,  rabbits, 
and  puppies,  and  he  called  attention,  therefore,  to  the  danger  therefrom 
in  the  use  of  milk  which  has  been  heated  to  such  an  extent  as  to  cause 
the  destruction  of  the  far  less  resistant  souring  bacteria,  which  milk  to 
the  eye  and  in  consistence  appears  to  be  normal,  but  which  may  be  dis- 
tinctly poisonous.  These  forms,  which  include  the  B.  subtilis  group, 
grow  with  great  rapidity  at  77°  F.  and  upward,  but  are  inhibited  in 
uuheated  milk  by  the  lactic  ferments.  They  are  derived  from  stable 
dust  and  filth,  and  are  always  present  in  milk,  no  matter  how  great 
may  be  the  effort  to  exclude  them. 

Butyric  Ferments. — A  third  grou]^  includes  the  so-called  butyric  fer- 
ments, which  are  strictly  anaerobic  spore-bearers.  They  decompose 
milk  rapidly  and  produce  a  strong  acid  reaction  (butyric  acid)  and  gas 
formation,  with  coagulation.  They  are  less  dangerous  than  the  ciiseiu 
ferments,  because  of  causing  coagulation,  and  their  sp<^res  are  ranch 
less  resistant  to  heat,  being  killed  in  less  than  2  hours  by  exposure  to 
the  boiling  temperature.  To  this  class  belong  £.  cnteritidis  sporogcnes 
(Klein),  B.  aerogencs  capsidatus,  and  numerous  others  not  yet  thor- 
oughly studied.  Like  the  casein  ferments,  they  are  inhibited  by  the 
lactic  acid  bacteria. 

Number  of  Bacteria  in  Milk. — The  number  of  bacteria  Mhich  gain 
access  to  milk  while  it  is  beiug  drawn  from  clean  cows  Avith  the  observ- 
ance of  proper  precautions  regarding  cleanly  methods  may  be  materi- 

1  Journal  of  Infections  Diseases,  IV.,  1907,  p.  89. 

-  Zeitschrift  fiir  Hygiene  uud  lufectiouskrauklieiten,  XVII.,  1S94,  p.  272. 


108 


FOODS. 


ally  reiiuced  by  the  use  of  covered  milk  pails,  that  is  to  say/  of  pails 
provided  with  a  cover  iu  wliich  is  an  oriiice  sutliciently  large  to  receive 
the  jets  of  milk  directed  by  an  ordinarily  skilful  milker.  Such  a  pail, 
of  which  there  are  a  number  of  types,  is  shown  in  Fig.  1. 

The  reduction  of  the  opening  of  an  ordinary  pail  to  a  small  propor- 
tion of  its  entire  area  insures  a  corresponding  reduction  in  the  number 
of  bacteria-laden  particles  of  dust,  manure,  and  hairs  which  fall  into  the 
milk  while  it  is  being  drawn.  In  one  series  of  8  milkings  into  an 
ordinary  pail  and  into  one  of  the  type  shown  in  Fig.  1,  Stocking ' 
demonstrated  a  diiference  of  85  per  cent,  in  the  number  of  bacteria  in 
favor  of  the  covered  pail,  and  in  other  series,  the  cows  being  less  clean, 
the  difference  was  even  greater,  the  milk  in  the  covered  pail  yielding 
respectively  one-twentieth  and  one  thirty-third  as  many  as  that  of  the 


Fig.  1. 


StadtmuUer  covered  pail. 

open  pail ;  that  is  to  say,  the  dirtier  the  cow,  the  greater  the  advantage 
of  the  covered  pail. 

Stocking  found  the  covered  pail  to  be  of  great  advantage  in  any 
stable  in  excluding  dirt  and  bacteria  from  milk,  the  relative  advan- 
tage gained  depending  upon  the  sanitary  condition  of  the  stable. 
The  desirability  of  a  strainer  on  the  covered  pail  depends  upon  the 
style  of  the  straining  device,  for  the  dirt  which  falls  into  the  opening 
may  be  driven  through  the  strainer  by  the  succeeding  jets  of  milk, 
unless  absorbent  cotton  in  sufficient  thickness  is  employed  for  the 
purpo.se. 

For  the  purpose  of  excluding  the  bacteria  of  the  air  of  the  stable 
and  the  dirt  from  the  exterior  of  the  cow  and  from  the  hands  and  person 
of  the  milker,  a  number  of  types  of  milking  machines  have  been  de- 

1  Storrs,  Agricultural  Experiment  Station,  Bulletin  48,  May,  1907. 


MILK.  101) 

viw^d  ;  but  on  acconni  of  Ui<^  pnictical  irnpoHsibility  of  k(-(|»iii^  in  a 
fairly  ,stcfil(!  coiidilion  IIk;  InWcs  wliicli  condiici  tli<:  iiiill<  fioin  (Ik-  t<'atH 
to  the  pJiil,  and  because  of  an  nn('X|)l;iinablc  ndn<!lioii  in  the.  yicUl  of 
tJie  (5()w  aft(u-  repeated  a|)pb(!ati(tn,  ibeir  use  appears  U>  posHcs.s  no  par- 
ticular advantatjjc!  iu  dairies  wlicre  cleanly  inetliodH  arc  followwl. 

Tbe  dilferenec  in  the  number  of  biiefcria  \vhi(;h  fall  into  milk  whr^n 
pr()|)(ir  preejuilions  -.wv.  observe(|  and  when  ihcy  arc  ne^deeted  is  ver\' 
considerable.  Thus,  Soxhiel  lunnd  I  hat  the  milk  of  a  cow  with  a  dirty 
udder,  stalled  in  a  dirty  slabh;,  ke|)t  sweet  50  hours  at  ordinary  tem- 
p(!ratin-e,  and  tlint,  when  luir  u(ld(!r  was  washed  and  she  was  milked  in 
the  ojx'n  air,  it  remained  sw(!et  a  day  and  a  half  lon^^.p.  Still  more 
instructive  are  the  results  obtained  by  Freeman,'  who  ex|)osed  j)latex, 
3.5  inches  in  diameter,  for  two  minutes  as  follows  :  one  in  the  ojh'Ii 
air,  one  inside  a,  barn,  and  a  third  in  front  of  the  milk  \)ni\  und<;r  a 
cow  in  the  same  barn  while  bein«r  milked.  The  first  ])lat<!  showed  0, 
the  second  111,  and  the  third  1,.S0()  colonies.  Such  a  number  of  bac- 
teria, fallin<^  upou  so  small  a  surface  Avithin  so  short  a  time,  is  an 
index  of  the  enormous  number  which  may  fall  into  a  jtail  during 
the  time  required  for  a  complete  milkina;. 

The  enormous  number  of  bacteria  Avhich  may  be  commonly  ]ircsent 
in  ordinary  market  milk,  the  great  influence  thereon  f)f  non-^)l)servance 
of  the  strictest  cleanliness,  and  the  extreme  rapidity  of  multiplication 
under  favoring  conditions,  are  shown  in  most  striking  manner  by 
W.  H.  Park,^  who  exposes  the  inexcusable  lack  of  cleanlino^s  in  the 
methods  of  procuring  milk,  and  of  care  in  cooling,  and  in  keeping  it 
during  transportation  to  the  city.  Milk  from  individual  cows,  where 
every  reasonable  means  was  taken  to  insure  cleanliness,  yielded  an  aver- 
age of  6,000  bacteria  per  cc.  when  5  hours  old,  and  kept  at  45°  F.,  to 
which  temperature  it  was  cooled  soon  after  it  was  draw^i.  After  24 
hours,  the  average  number  fell  to  1,933 ;  after  48,  it  increased  to  17,816. 
Milk  taken  in  winter  in  well-ventilated,  iairly  clean,  but  dusty,  barns, 
and  cooled  within  2  hours  to  45°  F.,  the  visible  dirt  having  been 
cleaned  off  the  hair  about  the  udder,  the  milkers'  hands  wijied  off,  but 
not  washed,  the  pails  and  cans  clean,  but  the  straining  cloths  dusty, 
yielded  the  following  average  figures:  At  time  of  milking,  15,500; 
after  24  hours,  21,666  ;  after  48  hours,  76,000.  Milk  taken  from 
cows  kept  in  ordinary  barns,  the  conditions  as  to  cleanliness  of  sur- 
roundings and  method  of  milking  being  about  what  obtain  on  the  aver- 
age farm,  yielded  the  following  average  figures : 

Winter.  Summer. 

Sliortlv  after  milking 16,650  30,366 

After  24  luun-s 31,000  48,000 

After  48  boiii-s 210,000  680,000 

Twenty  samples  of  average  milk  taken  immediately  on  aiTival  in 
the  city,  much  of  it  having  been  transported   more  than  200   miles, 

1  Medical  Eecord,  March  8,  1896. 
Journal  of  Hygiene,  Julv,  1901,  p.  391, 


110  FOODS. 

yielded  from  52,000  to  35,200,000  bacteria  per  cc.  (average  5,(360,- 
850).  The  average  temj)erature  of  the  samjiles  when  taken  from  tlie 
ciius  Avas  45°  F.  Milk  as  sold  in  the  sliops  durin«''  the  moniilm'  honrs 
yielded  the  following  averages : 

From- tenement  districts,  mid-winter  (13  samples)  ....    1,977,692 
From  well-todo         "  "  (10        ")....       327,500 

From  tenement         "         September  (   5        "       \  .    .    .    .  iri,l()3,()00 
From  well-to-do         "  "  (  5        "       )  .    .    .    .    1,061,400 

Of  very  great  importance  in  the  bacterial  contamination  of  milk  are 
the  dust  liberated  into  the  air  of  the  stable  when  hay  and  bedding  are 
thrown  down  and  the  bacteria  in  improperly  cleaned  pails  and  other 
utensils.  During  the  placing  of  bedding,  according  to  Harrison,^  from 
12,000  to  42,000  bacteria  were  deposited  per  minute  into  a  12-inch 
pail,  against  from  400  to  2000  per  minute  an  hour  afterward,  when 
the  dust  had  settled.  He  found  from  215,000  to  806,000  bacteria 
per  cubic  centimeter  in  the  washings  of  poorly  cleaned  cans,  and 
from  15,000  to  93,000  in  those  of  cans  which  had  been  washed  in 
warm  water  and  then  scalded.  Even  from  cans  washed  in  warm  water 
and  steamed  for  5  mmutes  considerable  numbers  of  bacteria  were 
obtainable. 

The  part  played  by  cowdung  in  seeding  milk  with  bacteria  may 
readily  be  understood  from  Wariugton's  estimate  of  165,000,000  bac- 
teria in  1  gram  of  dung  from  a  hay-fed  cow,  and  Wiithrich  and  von 
Freudenreich's  still  higher  estimate  of  375,000,000.  Cowdung  is  said 
not  to  yield  B.  enteritldis  sporogenes  (Klein),  but  horsedung  is  said  to 
contain  it  extensively,  and  this  alone  is  abundant  reason  for  condemn- 
ing the  reprehensible  practice  of  employing  that  material  for  bedding 
cows.  The  amount  of  stable  dirt  in  ordinary  market  milk  is  very 
variable,  in  spite  of  careful  straining.  Straining  removes  only  the 
larger  particles  of  manure,  hairs,  straw,  etc.,  but  does  not  exclude  the 
fine  particles  nor  the  soluble  portions  of  the  dung,  which  pass  through 
with  their  millions  of  bacteria.  It  is  to  this  material  that  dirty  milk 
owes  the  so-called  "  cowy "  taste,  regarded  by  some  as  normal.  The 
insoluble  dirt  has  been  found  by  Renk  to  run  as  high  as  362  milli- 
grams per  liter  in  the  market  milk  of  Halle ;  but  the  average  was 
14.92,  while  that  of  samples  collected  in  Berlin,  Munich,  and  Leipzig 
was  respectively  10.3,  9,  and  3.8.  The  milk  of  Hamburg  has  shown 
an  average  of  13.5.  Ballo  found  that  37  samples  of  the  milk  supply 
of  Budapest,  out  of  502,  were  dirty  to  the  eye,  and  they  yielded  from 
6.9  to  44,  and  one  of  them  as  high  as  110.5  milligrams  per  liter. 

Temperature  is  of  greater  importance  in  the  eventual  bacterial  con- 
tent of  milk  than  the  number  of  bacteria  which  originally  gain  en- 
trance, for  cold  inhibits  the  growth  of  all  of  the  important  species,  and 
during  the  period  of  inhibition  large  numbers  die  off  or  are  destroyed. 
And  the  number  which  may  be  present  after  some  hours  may  be  de- 
termined by  the  species  present  rather  than  by  their  abundance.     Ac- 

»  Bev.  G^n.  Lait.  2,  1903,  Nos.  20-23. 


MILK.  I  1  ] 

cording  (.<»  Ooiiii  and  Ivslcii,'  il  lia|)|)(iis  ('rc(|iicii(  ly  that  milk  coiilain- 
in^  orijj^iiially  hut  ("cw  l)a('tciia,  will  latii'  yidd  roii.sidonihly  lar^'cr 
niiinhcrs  lliaii  Uiosc  in  other  s|Hciiiiciis  wiii(^h  at  the  oiMsci  fntdaiiwd 
iii<»f(!  ihaii  the  (irst,  hoth  samples  l)ciii<i;  kept  under  preeisely  idenlieai 
conditions.  'rii<y  show  that  for  a  ninnlxr  of  hours  after  milk  \h 
drawn  iJiere  is  no  hacterial  tiinltipli(;ation,  l»nt  iVeqiiently  th<;re  in  a 
diminnlion  in  nnmbers.  hi  milk  kept  at  G8"  I'".,  most  Kpecjcs  hc^in 
to  multiply  after  IIk;  first  (I  hours,  some  remain  sfalionary,  and  fttluTH 
(iisaj)p(^ai".  The  most  rapid  mullipliealion  is  that  of  the  eomrnon  la<;tic 
ferm(!nts.  In  milk  kept  at  55"  |<\  there  is  hut  little  growth,  ovon  at 
the  end  of  50  hours,  wIkjii  thc^y  are  usually  no  more  numerous  than 
those  )>resent  after  ]H  hours  in  milk  kept  at  (iH'"  l'\  When  milk  is 
ieed  the  bacteria  orii^dnally  |)rcsent  decrease  in  number  for  a  lonj;  tim<', 
and  since  the  low  temperature  prevents  the  lactic  ferments  from  mul- 
tiplying^ and  gaining  ascendency  over  the  other  species,  the  latter  show 
a  relative  increase  over  their  nundicr  in  milk  which  is  kept  at  higher 
temperaiunvs.  After  the  ])eriods  of  inhibition  and  slow  growth  have 
passed,  the  lactic  acid  bacteria  grow  with  extreme  ra])idity,  and  as  they 
multiply  other  species,  and  finally  practically  all  others,  disapjiear. 
Conn  and  Esteu  state  that  the  lactic  acid  bacteria  sometimes  are  99 
per  cent,  of  all  present.  It  is  on  account  of  the  beneficent  action  of 
these  bacteria  against  those  which  in  their  absence  cause  putrefactive 
changes  that  ordinary  connncrcial  pasteurization  of  public  milk  su])- 
plies  is  objectionable,  for  stale  milk  may  thus  be  kept  a  long  time  with- 
out curdling,  and  meanwhile  deleterious  changes  are  being  caused. 

Many  species  of  milk  bacteria  can  grow  below  40°  F.,  and  they 
grow  more  rapidly  after  several  days'  exposure  has  enabled  them  to 
become  habituated  and  to  adjust  themselves  to  the  unusual  condition. 
Thus  a  milk  which  has  not  been  subjected  to  artificial  heat  may  become 
unwholesome,  although  sweet  and  apparently  wdiolesome.  According 
to  Conn,  it  is  not  unlikely  that  this  may  be  the  explanation  of  some 
of  the  eases  of  ice-cream  poisoning  so  commonly  observed  in  summer, 
the  cream  being  kept  at  a  low  temjierature  for  days,  until  considerable 
is  accumulated  or  demand  arises,  and  then  the  product  when  made  is 
rich  in  bacteria  of  a  sus}>icious  character.  To  a  poisonous  substance 
isolated  by  Professor  Vaughan,  and  shown  to  have  been  the  cause  of 
the  train  of  symptoms  commonly  known  as  ice-cream  poisoning,  milk 
poisoning,  and  cheese  poisoning,  the  name  tyrotoxicon  Avas  given  by 
its  discoverer. 

The  influence  of  different  temperatures  on  the  rapidity  of  bacterial 
multiplication  is  well  shown  by  Park's  results,  obtained  after  allowing 
portions  of  the  same  specimen  to  stand  under  otherwise  similar  con- 
ditions. At  temperatures  below  50°  F.  there  was  at  the  end  of  24 
hours  no  increase — in  fact,  a  decrease — in  the  number  of  bacteria  ;  but 
at  higher  temperatures  the  multiplication  was  enormous.  The  original 
number  per  cc.  was  3000,  and  the  growths  at  the  several  temperatures 
above  55°  F.  were  as  follows  at  the  end  of  24  and  48  hours  : 
1  Starr's  Agricultural  Experiment  Station  Keport,  1901,  p.  13. 


1V2  FOODS. 

Temperature.  24  hours.                                                 48  hours. 

60°  F.,  180,000                                      28,000,000 

68°  R,  450,000                              25,000,000,000 

86°  R,  1,400,000,000 

94°  R,  25,000,000,000 

Milk  of  fair  quality  from  a  shop  was  kept  at  90°  F.  for  8  hours, 
during  M'hich  time  its  contained  bacteria  increased  from  92,000  to 
6,800,000  per  cc. ;  another,  of  poor  quality,  under  the  same  conditions, 
showed  an  increase  from  2,600,000  to  124,000,000. 

As  the  lactic  acid  bacteria  multiply,  they  seize  upon  more  and  more 
of  the  milk-sugar  and  convert  it  to  lactic  acid,  the  amount  of  which  is 
expressed  in  degrees  per  50  cc.  of  milk,  one  degree  representing  the 
amount  neutralized  by  0.5  cubic  centimeter  of  decinormal  sodium 
hytlrate,  which  is  9  milligrams.  When  milk  contains  so  much  lactic 
acid  that  50  cc.  are  neutralized  by  22  cc.  of  the  reagent,  it  begins  to 
taste  sour ;  and  when  42.5  cc.  are  required  it  is  ready  to  curdle. 

That  public  milk  supplies  frequently  show  millions  of  bacteria  to  the 
cubic  centimeter  is  notorious,  and  both  in  this  country  and  in  Europe 
it  is  common  to  find  that  in  some  large  cities  the  sewage  is  less  rich  in 
bacteria  than  the  milk  supply.  Proskauer^  and  others,  for  example, 
found  the  market  milk  of  Berlin  to  average  3,500,000  in  summer  and 
more  than  500,000  in  winter ;  Newman  has  reported  the  following  aver- 
ages for  London  (city),  Westminister,  Halborn,  Islington,  and  Fins- 
bury  :  4,800,000,  1,600,000,  4,800,000,  1,600,000,  2,300,000 ;  Jor- 
dan's averages  for  Chicago  market  milk  during  April,  May,  and  June, 
1904,  give  a  general  average  of  12,785,000. 

The  milk  of  cows  with  garget,  an  inflammatory  condition  of  the  udder, 
the  commonest  of  all  bovine  diseases,  may  have  a  far  more  extensive 
bacterial  flora  than  that  of  ordinary  milk.  The  exciting  cause  of  this 
abnormal  condition  appears  to  be  no  single  organism,  but  various  species, 
among  which  are  Staphylococcus  aureus  and  aJbus,  Staphylococcus  viasti- 
tidis,  Streptococcus  mastitidis,  Galactococcxis  fulvus,  B.  coli,  B.  aerogenes, 
and  B.  pyogenes  hovis.  Several  of  these  species  may  be  present  in  the 
same  udder  at  the  same  time.  In  such  milk  pus  is  always  present  with 
the  bacteria  and  in  such  amounts  as  to  cause  a  salty  taste.  The  disease 
may  be  present  without  any  perceptible  symptoms,  and  attention  may 
be  called  to  it  only  by  the  appearance  of  caseous  masses  or  shreds  on 
the  strainer  ;  hence  the  product  of  the  most  conscientious  dealer  may  be 
extensively  infected  with  the  causative  organisms  and  pus,  in  spite  of 
all  precautions  and  without  his  knoM^edge. 

The  presence  of  streptococci  in  milk  does  not  necessarily  mean  the 
existence  of  garget,  for  they  have  repeatedly  been  found  in  healthy 
udders.  Reed  and  Ward  ^  have  recorded  the  case  of  a  cow,  of  the 
Cornell  University  herd,  apparently  healthy,  whose  milk  yielded  strep- 
tococci at  intervals  extending  over  two  years  and  a  half.  When  she 
was  killed  the  udder  showed  the  organisms  in  abundance. 

1  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  LVII.,  1907  p.  173. 

2  C^ntralblatt  fur  Bakteriologie,  XXIX.,  1901,  p.  496. 


MILK.  llo 

Wlwdlicr  or  ii()(,  f'roin  (lisciiscd  udders,  rimiiy  iiuMi''  milk  Mipplics  will 
yi(!l(l  a  \:\v\rv  |)r<)|)()rl,i()ii  oC  sjimplrs  in  wliidi  strcptMCMc.  i  ;irc  |)rc.'-<'iil  in 
l;i:r^(!  nnmlx-rs.  TIiiim,  l^/i.stcs  '  diseovcrt'd  tliciii  in  KXi  <»("  I  H(i  ,>-;nn|)l«!K 
(•X!Uiiin<'(l  ;  I'x-ck,  ^  in  .'}r>  <»rr)(;  s:nM|.lcs  i.f  (lie  I'x  ilin  ^n|.|.ly  ;  J><-r^cy,'» 
in  20  of  10  Siiniplcs  oC  ni;iri<cl  millv  (  I 'liil;id<i|)lii;i  j  .'Mid  in  '.'>  of  r>9 
sinnplcs  IVoni  (irst-cliiss  diiirics  ;  K;iiscr,'  in  7<i.(i  |kt  ccnl,  u\'  siiinitlcH 
tidscn  in  (ir;i/;  iuul  Smviij^c/'  in  d")  of  (i.S  spcfiincns,  [):irt  of  wliicli 
wore  (lirc'olly  from  the  iiddcr.  Siiviifi;c  disliiiirnislicd  12  <lin'rrciit 
V!iri(!ii('s  of  strcplococc.i,  and  Midler  isolated  from  the  Graz  samjiles 
three  strains  wliieli  pnxhuu'd  liiumolysins. 

,].  linclir"  had  the  followintj:  results:  In  oidy  2  out  of  81  milk  sam- 
j)l(\s  was  it  |)ossil)l(!  to  isolate  the  slreptoeoecMis  pyoj^enes.  One  of  these 
was  traced  to  a  cow  with  a  diseased  udder.  In  (!  I  out  of  HI  samples — 
that  is  to  say,  75  ])er  cent. — he  isolated  an  oi-uaiiism  much  like  Kruse's 
stre])t()coccus  la<'ticiis.  It  seemed  to  him  jirohahle  that  these  strepto- 
cocci f2;ot  into  the  milk  from  the  teees.  JIc  does  not  believe  that  iidant 
troubles  are  caused  by  these  streptococci,  but  it  is  possible  that  these 
germs  may  become  })athogenic  under  favorable  conditions. 

Regarding  the  significance  of  large  numbers  of  leucocytes  in  milk, 
with  or  without  strej)tococci,  there  is  some  difference  of  opinion.  For- 
merly leucocytes  were  regarded  as  pus,  and  streptococci  were  looked 
upon  as  necessarily  pathogenic,  but  it  is  known  now  that  both  can 
occur  in  large  numbers  in  jierfectly  healthy  milk.  Russell  and  Hoff- 
mann ^  examined  many  sam])les  of  milk  from  cow's  with  neither  evi- 
dence of  present  nor  history  of  past  disease  of  the  udder,  and  found 
that  one-third  of  them  gave  counts  higher  than  500,000,  and  some  as 
liigli  as  1,800,000;  and  Savage  **  found  that  more  than  75  per  cent, 
of  such  cows  yielded  counts  averaging  more  than  100,000,  and  some 
as  high  as  4,500,000.  On  the  other  hand,  Rullmanu  and  Tromms- 
dortf "  have  set  an  arbitrary  standard,  and  assert  that  if  mixed  milk 
contains  0.1  per  cent,  of  leucocytes,  mastitis  is  to  be  inferred  ;  and 
Bergey  ^^  is  of  opinion  that  only  when  leucocytes  and  streptococci,  ad- 
mittedly present  to  some  extent  in  practically  all  milk,  are  increased 
to  a  certain  extent,  are  they  indicative  of  pathologic  conditions ;  and 
that  in  practically  all  cases  in  which  the  number  of  leucocytes  is  high 
there  is  a  relative  increase  in  the  number  of  streptococci,  indicating 
the  presence  of  mastitis  in  one  or  more  quarters  of  the  udder,  as  will 
usually  be  revealed  on  expert  pal]>ation  of  the  udder  when  empty. 
Bergey's  statements  are  endorsed  by  Trommsdorff,"  who  found  that 

I  Britisb  Medical  Journal,  Nov.  11,  1899. 

^  Deutsche  Vierteliahisscbrift  fiir  iiffentliche  Gesundheitspflege,  1900,  p.  430. 
3  American  Medicine,  April  20,  1901,  p.  122. 
*  Archiv  fiir  Hygiene,  LYI.,  190(i,  p.  51. 
^  Jotirnal  of  HvCiiene,  VI.,  1906,  p.  12,*^. 
6  Arch.  f.  Ilyg.,"  Miinchen  u.  Berl.,  1910,  Ixxii,  91-158,  1  pi. 
^  Journal  of  Infections  Diseases,  1907,  Suppl.  3,  p.  63. 
8  British  jNIedical  Journal,  1905,  p.  1165. 
'■'  Archiv  fiir  Hygiene,  LIX.,  1906,  p.  224. 
^^^  I'niversity  of  Pennsylvania  Medical  Bulletin,  Sept-,  1907. 

II  Miinchener  medizinische  Wochenschrift,  LIII ,  Xo.  12. 


114  FOODS. 

whenever  leucocytes  were  present  iii  large  numbers  innumerable  strepto- 
cocci were  also  j)resent. 

Miller  ^  comes  to  the  following  conclusions  : 

(1)  Many  leucocytes  and  streptococci  are  present  in  the  normal 
milk  of  a  healthy  cow. 

(2)  Leucocytes  and  stre]>tococei  are,  as  a  rule,  more  numerous  in 
the  milk  of  diseased  than  in^that  of  healthy  cows. 

(3)  As  an  aid  to  veterinary  inspection,  the  number  (^f  leucocytes 
may  furnish  some  information  of  value.  If  a  dairy  milk  shows  an 
unusually  higli  leucocyte  count,  a  special  examination  of  the  herd  for 
garget,  etc.,  should  be  made. 

(4)  No  satisfactory  method  has  been  devised  for  distinguishing  the 
pathogenic  from  the  non-pathogenic  streptococci  in  milk.  Their  sig- 
nificance is,  therefore,  a  matter  for  further  study. 

(5)  In  view  of  the  recent  researches  upon  streptococcus  lacticus,  no 
constant  relationship  may  be  expected  between  the  number  of  strepto- 
cocci and  the  number  of  leucocytes  in  milk. 

Preservation  of  Milk. 

The  keeping  quality  of  milk  is  influenced  by  cold,  which  retards  the 
growth  and  multiplication  of  bacteria  which  bring  about  decomposition  ; 
by  heat,  whicli  destroys  them  ;  and  by  chemicals  (antiseptics),  which 
either  kill  them  or  retard  their  growth. 

Cold. — Preservation  by  cold  is,  in  many  respects,  preferable  to 
either  of  the  other  methods.  The  constituents  are  in  no  way  altered 
in  character,  there  is  no  change  in  digestibility,  and  no  element  is  in- 
troduced into  the  system  with  the  milk  to  exert  any  harmfid  influence 
upon  the  digestive  processes.  In  places  where  ice  is  expensive  or  not 
obtainable,  this  method  is  not  available,  but  where  it  is  cheap  and 
plentiful,  it  is  the  one  in  most  common  use.  In  some  parts  of  Europe 
milk  is  frozen  into  solid  blocks  by  the  ammonia  process,  and  shipped 
in  that  form  to  market,  or  sent  in  large  air-tight  cans,  into  each  of 
which  a  block  of  frozen  milk,  weighing  about  25  pounds^  is  placed,  to 
keep  the  milk  in  which  it  floats  at  a  low  temperature. 

Heat. — Pasteurization  and  Sterilization. — By  pasteurization  is  meant 
raising  the  temperature  of  the  milk  to  such  an  extent  and  for  a  suffi- 
ciently long  period  as  to  ensure  the  destruction  of  the  lactic  acid  bac- 
teria and  pathogenic  organisms  without  afl'ecting  the  enzymes  or  the 
lactalbumin. 

As  regards  the  thermal  death  points  of  various  bacteria,  writers  have 
not  been  in  agreement,  but  the  results  of  Rosenau  ^  are  in  accord  with 
those  of  Yersin,  BonhoflF,  Schroeder,  Theobald  Smith,  Russell  and 
Hastings,  and  Hesse,  and  are  as  follows  : 

The  tubercle  bacillus  in  milk  loses  its  infective  properties  for  guinea- 
pigs  when  heated  to  60°  C.  and  maintained  at  that  temperature  for  20 

^  .Journal  of  Comparative  Pathology  and  Therapeutics,  London,  March,  1909,  p.  34i 
Vol.  XXII,,  Part  1. 

2  Pediatrics,  1908,  p.  549. 


I'lllCHKILVATION   OF   MILK.  115 

rniniltcH,  or  at  (ir)*^  ().  for  "a  \n\\r\\  slioi-tcr  time"  'I'lic  typlioi*!  hufil- 
lus  i,s  killed  iC  Hiihjcftlcd  (o  GO"  (/'.  for  '1  miiinlcs,  'I'lic  <lij)lillM-riii 
bacillus  is  olleii  killed  at  55'^  C,  but  (Kicasioually  survivcH  OO'^  (J.,  jiiid  tluj 
same  is  true  of"  cbokira.  Tlu;  dys(!rit(!ry  bacillus  is  killed  by  00'^  (.'.  for 
10  rninut(!S  ;  00°  C  for  20  rniiuitcs  is  more  than  Huflicnciit  to  kill  the 
bacillus  of  Malta  fever.  Hencte,  as  a  f^ood  working  slaiidnrd,  fJO'^  C. 
for  20  minutes  recommends  itself.  Furtli(;rmore,  tins  lem|)erafure, 
that  is  to  say,  G0°  C.  for  20  minutes,  docs  not  aj>j)reci;d)ly  affect  the 
chemical  ])roj)erties  of  milk. 

In  connnercial  |)iisteurization  a  number  of  dilfcrenl  tyjies  of  ,'i]»j)a- 
nitus  are  (!nj|)loycd  and  different  methods  aic.  followed,  the  teinperatures 
ran<2;ing  from  150°  to  185°  F.,  or  even  higher,  and  the  periods  of  ex- 
posure from  less  than  a  minute  to  as  much  as  an  hour,  with  immediate 
coolint]:;  thereafter,  in  order  to  ])reserve  the  flavoi'  and  to  inhibit  the 
growth  of  the  surviving  bacteria.  Temperatures  higlmr  than  158*^  Y. 
cause  milk  to  ac(piire  a  "cooked"  flavor,  which  to  many  persons  is 
unpleasant. 

By  raising  the  temperature  to  the  ])oiling-point,  milk  is  more  com- 
pletely sterilized  than  by  the  processes  employed  in  j)asteurization  ;  but 
absolute  sterilization  cannot  be  accomplished  cxcej)t  i>y  boiling  on  suc- 
cessive days  or  by  continuous  heating  under  pressure  for  at  least  2 
hours  at  248°  F.,  on  account  of  the  very  resistant  nature  of  the  s])ores 
of  various  species  of  bacteria  commonly  present  in  milk  produced  under 
the  usual  conditions. 

According  to  Rosenau,^  boiling  produces  decomposition  of  ])roteins 
and  other  complex  nitrogenous  derivatives ;  diminution  of  organic 
phosphorus ;  increase  of  inorganic  phosphorus ;  precipitatif)n  of  cal- 
cium and  magnesium  salts  and  the  greater  part  of  the  phosphates  ;  ex- 
pulsion of  the  greater  part  of  the  CO^ ;  caramelization  or  burning  of  a 
certain  portion  of  the  milk-sugar  (lactose),  causing  the  l)rownish  color; 
partial  disarrangement  of  the  normal  emulsion  and  coalescence  of  some 
of  the  fot  globules  ;  and  coagulation  of  the  serum,  which  begins  at 
75°  C.  Casein  is,  furthermore,  rendered  less  easy  of  coagulation  by 
rennin,  and  is  slowly  and  imperfectly  acted  upon  by  pej^sin  and  pan- 
creatin.  A  cooked  taste  is  caused  by  boiling.  Cream  does  not  rise 
well,  if  at  all.  Formation  of  a  scum  begins  at  60°  C.  Heating  kills 
the  ferments  in  milk.  These  can  stand  (30°  to  65°  C.  for  some  time. 
Thev  are  weakened  by  65°  to  70°  C.  They  are  destroyed  at  75°  to 
80°"  C. 

Sterilization  at  higher  temperatures  causes  still  further  changes  in 
the  proteids,  and  converts  part  of  the  lactose  to  caramel. 

Objections  to  Pasteurization  and  Sterilization. — So  flir  as  children  old 
enough  to  receive  a  mixed  diet  and  adults  are  concerned,  there  are  no 
objections  on  the  score  of  develojMuent  and  health  to  the  use  of  pasteur- 
ized and  sterilized  milk,  and,  indeed,  where  it  is  difficult  or  impossible 
to  secure  a  clean  and  wholesome  milk  supply,  pasteurization  is  a  com- 
mendable and  logical  procedure  ;  but,  on  the  other  hand,  against  the 

1  Pediatrics,  1908,  p.  5-47. 


116  FOODS. 

use  of  pasteurized  and  sterilized  tnilk  for  bottle-fed  infiints  and  against 
the  substitution  of  connnercial  pasteurization  for  the  enforcement  of  the 
strictest  dairy  hygiene,  there  are  very  valid  objections.  It  is,  first  of 
all,  to  be  recognized  that  proper  jiasteurization  is,  in  a  sense,  a  labor- 
atory process,  which  requires  considerable  skill  in  bringing  every  part 
of  the  volume  o})erated  upon  to  the  requisite  temperature  and  not  be- 
yond it.  With  insufficient  heating  the  object  of  the  process  is  not 
accomplished;  with  excess  of  temperature  the  biological  properties  of 
the  milk,  residing  in  the  ferments  or  enzymes,  are  destroyed,  and  the 
milk  is  made  an  unfit  food  fov  infants.  Even  with  the  best  of  care, 
untoward  results  of  continued  feeding  of  infants  with  pasteurized  milk 
have  been  so  frequently  observed,  in  both  private  practice  and  insti- 
tutional experience,  as  to  demonstrate  a  real  danger.  Sill  ^  relates  that 
of  about  25,000  infants  that  came  under  his  charge  in  5  years,  those 
that  were  fed  on  pasteurized  or  sterilized  milk  continuously,  or  part  of 
the  time  on  the  one  and  part  on  the  other,  no  less  than  97  per  cent, 
developed  rickets  or  scurvy,  or  a  conibination  of  the  two.  Those  that 
were  fed  partly  at  the  breast  and  5  feedings  per  day  of  heated  milk  had 
the  same  symptoms  in  a  lesser  degree.  Sterilized  milk  was  given  only 
during  the  3  summer  months,  and  pasteurized  milk  at  other  seasons. 
Infants  fed  on  raw  milk  were  attacked  with  symptoms  of  rickets  when 
thev  were  placed  upon  sterilized  or  pasteurized  milk.  Again,  in  an 
English  children's  hospital,^  a  number  of  cases  of  scurvy  which  failed 
to  respond  to  treatment  led  to  an  inquiry,  which  disclosed  the  fact  that 
the  dairy  which  supplied  the  institution  had  been  furnishing  pasteur- 
ized instead  of  raw  milk,  without  informing  the  authorities ;  and  on 
the  substitution  of  fresh  raw  milk  the  children  began  to  improve.  Ex- 
periments with  calves  and  other  young  animals  have  repeatedly  demon- 
strated the  far  greater  and  more  rapid  development  which  occurs  on 
raw  milk.  Jensen  ^  has  shown  that  new-born  calves  fed  ui)on  boiled 
milk  invariably  were  seized  with  a  violent  diarrhoea,  similar  in  all  re- 
spects to  the  disease  known  as  calf  dysentery  (''  Kiilberruhr  "). 

It  is  not,  however,  perfectly  clear  that  pasteurized  milk  is  necessarily 
deleterious  to  the  health  of  infants.  Rosenau  *  states  that  he  has 
"  made  a  careful  compilation  from  the  literature  of  the  results  of  rais- 
ing children  upon  heated  milk,  and  finds  hundreds  of  instances  re- 
corded, especially  by  French  observers,  to  the  effect  that  children 
flourish  well  upon  heated  cows'  milk  (loc.  cit.,  p.  606).  When  all  is 
said  and  done,  the  pasteurization  of  milk  for  infant  feeding  can  neither 
be  recommended  nor  discountenanced  as  a  general  proposition.  The 
saying  that  '  one  man's  meat  is  another  man's  poison,'  applies  with 
special  significance  to  the  artificial  feeding  of  infants." 

Rosenau  ^  also  insists,  as  regards  the  practice  of  pasteurization,  that 
"  we  should  protest  against  a  word  which  means  a  generality  and  insist 

1  New  York  Medical  JonrnMl,  February  8,  1908. 

2  Journal  of  the  Ameriran  Medical  Association,  June  23,  1906. 
^  Quoted  by  Beliring  :  Thenipie  der  Gegenwart,  XLV.,  No.  1. 
■*  Hygienic  Bulletin  41,  p.  607. 

a  Ann.  Med.  Pract.,  Boston,  1910,  237, 


j'lihSh-nvA'rfox  of  milk.  117 

upon  all  ))!is<,('iiri/('(l  niilU  bciiij^  jn'opcrly  lulx-lcd  with  tin-  i\c\rnn'.  of 
li(!;\i,  the  j)<'i'i(t<l  of  iJtiic,  and  alsn  wilh  the  date  on  which  if  was  snl>- 
jeoted  to  the  [d'occss.  It  should,  Curl  hcriiioic,  Ih-  niidc|-  the  iniiiifdi:it<; 
Sllj)ervi.sion  of  tiu!  health  olliee." 

A  very  inij)orlant  ol)je(!lion  to  <'onntiiTci;d  pastcnri/alioii  (,("  pnhlif; 
milk  snpplies  is  that  thronu;h  ihe  dcs( ruction  of"  the  l»nl  slifrhllv  n-si'-t- 
ant  lactic  a(n'd  bacteria,  wlii(th  Prolessor  V.  C  Van^han  has  likened 
to  the  red  lanterns  |)laccd  as  danfrer-si^nals  in  a  hif^hway,  the  ino.«t 
eonspicnoiiH  means  of  iiidieaf int:^  nnfitness  for  use  is  removed.  Stale 
milk  tlins  deprived  of  tlu;  ati;enls  which  |)rf)dnee  sonrin^*-,  l»nt  eoiitaining 
the  very  resistant  casein  ferments  and  other  haeteria  wln'eh  produce 
toxic  snbslances,  remains  fluid  and  aj)parenlly  wholesome  for  a  consid- 
erable time,  and  yet  may  be  a  danjijerons  food.  It  lias  been  demon- 
strated by  Flii,ii',u;e,  who  as  lont:;  ai^o  as  1H94'  called  affenlion  to  the 
danj^(TS  of  imperfectly  ])asfenri/ed  or  sterilized  milk  in  the  feedinj;  of 
infants,  that  these  ])eptonizin^  bacteria  may  develoj)  so  aetiv(!  a  poison 
that  pupj)ies  fed  nj)on  snch  milk  may  be  .seized  with  violent  and  even 
fatal  diarrhceas.  Snch  milk,  without  souring,  gradually  ])utrefies,  but 
without  showing  by  alteration  in  taste  or  appearance  the  damage  which 
it  has  suffered  through  the  raj)id  multiplication  of  bacteria,  winch  in 
raw  milk  are  inhibited  by  the  lactic  acid  ferments.  The  older  the  milk 
before  pasteurization,  the  greater  the  number  of  these  undesirable  or- 
ganisms and  the  less  successful  the  process. 

Another  objection  to  commercial  ])asteurization  and  sterilizatiou  is 
that  these  processes  invite  carelessness  in  the  production  and  handling 
of  milk,  the  acceptation  of  their  necessity  implying  avoidable  dirt  and 
encouraging  carelessness  and  negligence,  the  effects  of  Avhich  can  be 
easily  corrected  by  the  application  of  heat  before  distribution.  Instead 
of  such  encouragement,  there  should  be  a  general  movement  against 
the  existence  of  the  antecedent  conditions  which  make  this  after-treat- 
ment necessary.  In  Massachusetts,  the  sale  of  milk  which  has  been 
heated  higher  than  1()7°  F.  is  contrary  ^  to  law,  unless  the  vessel  in 
which  the  milk  is  sold  is  plainly  marked  "  Heated  Milk." 

Obligatory  pasteurization  of  public  milk  supplies  has,  in  spite  of 
various  valid  objections  thereto,  many  advocates,  and  it  has  with  good 
reason  many  and  more  opponents.  That  coramereially  pasteurized  milk 
is  frequently  excessively  rich  in  bacteria  has  often  been  demoustratt<l. 
Thus,  Pennington  ^  reported  that  samples  obtained  from  difiereut  pas- 
teurizing ]ilants  in  Philadelphia  contained  744,000  and  2,880,000  bac- 
teria per  cubic  centimeter,  and  after  24  hours  respectively  785,000  and 
45,900,000  ;  and  Bergey  *  has  reported  a  sample  which  contained 
148,000,000  bacteria  per  cubic  centimeter,  with  less  than  half  the 
amount  of  acidity  necessary  for  its  condemnation  by  the  acidity  test. 
Impressed  by  the  possibility  of  danger  from  the  use  of  commercially 

*  Zeitsci'ift  fiir  Hve:iene  und  Infectionskrankheiten,  XVII.,  1904,  p.  272. 
^  Acts  of  1908,  Chapter  .i70. 

3  American  Medicine,  March  11.  1905,  p.  381. 

*  Proceedings  of  the  Pathological  Society  of  Philadelphia,  VIII.,  1905,  p.  102. 


118  FOODS. 

pasteurized  milk,  Fliigge  *  has  jiroposed  that  such  milk  should  be  per- 
mitted to  be  sold  only  when  labelled  "  Heated  Milk.  Not  free  from 
germs.  i\Iust  be  kept  undei*  a  temperature  of  18°  C.  or  used  within 
1 2  iiours  "  ;  and  Jensen  '  says  :  "  When  we  compare  the  advantages 
and  disadvantages,  it  will  be  found  that  there  is  serious  doubt  as  to 
whether  it  is  advisable  to  endeavor  to  obtain  general  pasteurization  of 
market  milk,  as  has  been  suggested  by  many.  A  well-organized  and 
well-conducted  large  milk  business  may  be  in  position  to  carry  out 
})asteurization  with  safety  and  to  obtain  all  the  various  advantages  that 
result  from  this  process,  but,  undoubtedly,  it  would  be  necessary  for 
the  great  majority  of  establishments  to  be  kept  under  comprehensive, 
strict,  and  expensive  control  by  the  health  authorities,  which,  even  then, 
could  scarcely  be  effective." 

Chemicals. — Preservation  of  milk  by  the  addition  of  antiseptics  is 
unnecessary,  unjustifiable,  and  possibly  injurious.  If  milk  is  drawn 
properly  from  decently  clean  animals  into  clean  vessels  by  clean  milkers, 
and  stored  in  clean  places,  it  will  keep  sweet  quite  as  long,  under  ordi- 
nary circumstances  and  under  the  usual  conditions  of  frequent  delivery, 
as  is  desired  by  the  consumer.  The  addition  of  antise})tics,  which  only 
retard 'growth  of  bacteria  without  destroying  them,  enables  the  vendor 
to  supply  stale  milk  instead  of  fresh,  and  to  dispense  with  part  of  the 
sanitary  precautions  otherwise  necessary.  The  substances  commonly 
used  are  by  no  means  wholly  innocent  in  their  action  on  the  human 
system,  even  in  very  small  quantities,  and,  moreover,  it  is  impossible 
to  control  the  amount  added  by  a  single  individual  or  to  be  sure  that 
successive  handlers  have  not  contributed  additional  doses.  The  sub- 
stances used  most  commonly  include  boric  acid,  borax,  formaldehyde, 
and  carbonate  of  sodium.  Less  commonly  used  are  salicylic  acid, 
hydrogen  peroxide,  and  chromates. 

Boric  Acid  and  Borax. — These  are  used  generally  in  combination 
with  each  other,  experience  having  shown  that  the  mixture  is  more 
efficient  than  either  alone.  The  minimum  efficient  quantity  of  the 
mixture  is  about  10  grains  to  the  quart,  an  amount  which  even  for  an 
adult  may  well  be  regarded  as  a  fairly  large  medicinal  dose.  In  addi- 
tion to  its  action  on  the  general  system,  it  exerts  a  varying  effect  on 
the  digestion  according  to  the  amount  present. 

Formaldehyde. — This  has  come  into  more  or  less  extensive  use  within 
recent  years.  It  is  a  most  efficient  preservative,  and  not  alone  in- 
hibits growth,  but  kills  many  of  the  contained  bacteria.  According 
to  tests  made  by  Dr.  C.  P.  Worcester,^  1  part  of  commercial  formalin 
in  100,000  of  milk  will  postpone  the  curdling-point  6  hours;  1  in 
50,000,  24  hours;  1  in  20,000,  48  hours;  I'in  10,000,  138  hours; 
1  in  5000,  156  hours.  Although  nothing  is  known  as  to  the  action 
of  small  amounts  of    formaldehyde  on   the  general  system,  it  is  not 

1  Loc.  cit. 

'  Essentials  of  Milk  Hygiene.  Translated  by  L.  Pearson.  Philadelphia:  J.  B. 
Lippincott  Company,  1907,  p.  142. 

3  Twenty-ninth  Annual  Report  of  the  State  Board  of  Health  of  Massachusetts,  1897, 
p.  559. 


PRESERVATION   OF  MIl.K.  IK) 

corroct  to  jishiimx!  (Jiiit,  in  (Ju;  ;il>.s<!ii<',(!  of  iWHU'Mvi'.  to  tin;  contrary,  it  in 
ii(!(!(!,sH;irily  luinnlcss  or  ItciiolicJul.  VVIiilc  tli(!  occ-iiHioiial  inj^cHtion  of  a 
sniiill  iunoniit  of  i'oniialdcliydc  may  prodiicf;  no  vWi-ci,  vv(!  cannot  rcjisf^n 
tliat  its  daily  ms(!  ov<!r  a  lonjr  period  will  he  c(|nally  non-prodncfivc. 
An  occasional  drink  of  water  containing  li^ad  will  do  no  injury,  wliiic 
its  daily  nsc  may  cause  lead  j)aralysis,  and  in  tlie  sarnc!  way  formalde- 
hyde! may  Ix;  the  (5aus(?  of  serious  disturharuieH  attrihutcd  to  homethinj^ 
else.  Jiut  vvheLJier  harndul  or  not,  th(!  use;  of"  this  af.nril  and  of  otlierH 
is  unnecessaiy  and  unjustifiahle.  Aside  from  its  p(»s!-ihly  poisonous 
action,  there  is  the  ol)je(!tion  that  it  alters  the  character  of  the  milk 
proteids  ;  the  casein  becomes  uncoa^ulahUs  hy  rennet,  except  in  thick 
clots,  and  much  less  dij;'estil)Ie,  or  wholly  indip'slihle,  hy  the  jirotco- 
lytic  ferments,  (certain  it  is  that  anything  that  im])oses  additional 
burdens  on  the  di<2,estive  function  of  infants  and  invalids  can  hardly  be 
refj;nTded  as  a  pro})er  substance  for  use  in  food.  Annet,'  after  a  study 
of  formaldehyde  and  boric  acid  as  milk  preservatives,  concludes  that 
they  arc!  injurious,  especially  to  younj:;  infants,  and  su^^^ests  the  ]x>s- 
sibility  of  a  causal  relation  between  their  Wi^ii  and  th(,'  great  infant  nK»r- 
tality  during  the  hot  months.  E.  von  Behring^  asserts  that  the  pres- 
ence of  formalin  to  the  extent  of  1  :  4000  will  not  be  perceptible  to 
the  sense  of  taste,  and  that  nn'lk  containing  as  much  as  1  ])art  in  oOO 
is  absolutely  harmless.  This  assertion  is  denied  by  Schaps,^  who  found 
that  in  still  greater  dilution  (1  :  10,000)  it  causes  an  objectionable  taste, 
which  is  still  perceptible  when  the  dilution  is  1  :  40,000.  He  found, 
moreover,  that  although  the  disinfectant  checks  the  develojiment  of  the 
lactic  ferments,  it  has  much  less  effect  on  staphylococci,  intentionally 
intnxluced,  even  when  the  proportion  is  1  :  5000.  While  a  marked 
inhibitory  influence  is  exerted  u]X)n  milk  bacteria  by  formalin  in  pro- 
portion of  1  :  5000  or  1  :  10,000,  ^vhen  the  milk  is  kept  at  50°  to 
60°  F.,  Sommerfeld*  found  that  it  has  hardly  any  influence  after 
twenty-four  hours  M'hen  the  milk  is  kept  at  68°  F.  At  incubator 
temperature  the  treated  milk  yielded  about  the  same  number  of  bacteria 
as  the  controls.  Typhoid  and  dijihtheria  bacilli  in  sterilized  milk  con- 
taining 1  part  of  formalin  in  5000  resisted  the  disinfectant  when  the 
mixture  was  kept  at  room  temperature  for  24  hours  and  at  incubator 
temperature  for  48  hours. 

According  to  Kolle,''  while  formalin  added  to  milk  to  the  extent  of 
1  :  25,000  or  1  :  40,000  extends  its  commercial  life  after  3  days, 
the  milk  bacteria  multiply  greatly  without  causing  any  change  in  con- 
sistency, because  the  souring  bacteria  are  inhibited  ;  and  although  path- 
ogenic organisms  diminish  in  number  more  rapidly  in  such  milk  than 
in  untreated  milk,  their  pi'esence  may  be  detected  even  after  5  days. 
Moreover,  in  addition  to  the  deleterious  influence  of  continned  inges- 
tion of  small  amounts  of  formalin  one  must  bear  in  mind  the  fact  that 

1  The  Lancet,  Nov.  11.  1899. 

'  Therapio  der  Gesyenwart,  XLV.,  Xo.  1. 

3  Zeitscbiift  fiir  Hvtriene  und  Infectionskrankheiten,  L.,  p.  247. 

4  Ibid.,  p.  153. 

^  Klinische  Jahrbiicher,  1904. 


120  FOODS. 

foi'inalinized  milk  may  become  a  dangerous  food  tlirougli  the  persist- 
ence in  it  of  tlie  more  hardy  peptoui/ing  bacteria.  JJandini  ^  finds  that 
formaldehyde  tends  to  prevent  the  action  of  rennet,  the  influence  being 
greater  the  larger  the  period  of  contact  and  the  larger  the  amount 
added.  Lowenstein  -  asserts  that  the  interference  with  the  action  of 
rennet  is  due  not  to  any  destructive  influence  u])on  the  enzymes,  but 
to  changes  caused  in  the  constitution  of  the  casein. 

Carbonate  of  Sodium. — Carbonate  of  sodium  is  a  weak  agent,  and 
does  not  postpone  decomposition  to  an  extent  sufficient  to  encourage  its 
wide  adoption.  So  far  as  is  known,  there  can  be  no  objection  to  its  use 
on  the  score  of  injury,  except  in  so  far  as  tiie  assertion  that  sodium  lac- 
tate, formed  by  its  decomposition  by  the  free  lactic  acid,  acts  as  a  mild 
cathartic,  is  worthy  of  credence. 

Salicylic  Acid. — The  use  of  salicylic  acid  in  milk  is  not  extensive. 
It  is  a  fairly  efficient  preservative  even  when  used  in  very  small 
amounts. 

Hydrogen  Peroxide. — Hydrogen  peroxide  is  the  least  objectionable, 
and,  on  the  score  of  deleterious  action  upon  the  system,  the  only  unob- 
jectionable chemical  preservative  used  in  milk.  According  to  H. 
Chick,^  who  used  a  3  per  cent,  solution,  0.2  per  cent,  of  the  agent  will 
produce  complete  sterilization  of  milk,  and  0.1  per  cent,  will  keep  it 
sweet  for  a  week  or  more,  regardless  of  whether,  when  added,  the  milk 
is  freshly  drawn  or  has  stood  for  some  time.  The  only  objection  noted 
was  a  disagreeable  stinging  taste,  which  can  be  perceived  when  the 
agent  is  present  in  far  smaller  amounts — even  as  small  as  0.01  per  cent. 
Rosara*  found  that  0.2  per  cent,  would  not  make  milk  sterile,  but 
that  with  0.1  per  cent,  and  heating  to  176°  F.  for  30  to  45  min- 
utes milk  may  be  kept  3  or  4  days  at  almost  incubator  temper- 
ature. He  called  attention  to  the  fact,  however,  that  commercial 
hydrogen  peroxide  is  likely  to  contain  compounds  of  barium  and 
arsenic.  Jablin-Gonnet  ^  suggests  the  use  of  the  "12-volume"  solu- 
tion after  neutralization  with  calcium  carbonate,  and  asserts  that 
1  cc.  will  preserve  a  liter  of  milk  for  2  days,  2  cc.  for  4  days, 
and  6  cc.  for  6  days,  even  if  the  temperature  of  the  milk  is  allowed 
to  be  as  high  as  86°  F.,  and  that  the  taste  is  unimpaired,  Renard** 
found  that  while  the  agent  does  not  sterilize  the  milk,  it  postpones  sour- 
ing considerably.  With  1,  2,  and  3  cc.  of  the  12-volume  solution  the 
souring  point  was  postponed  respectively  24,  26,  and  32  hours  at 
68°  F.,  the  control  souring  in  13  hours.  Nicolle  and  Ducloux  ^  kept 
milk  containing  1  to  2  per  cent,  of  hydrogen  peroxide  at  temperatures 
of  60°,  72°,  and  93°  F.,  and  found  that  the  number  of  bacteria  dimin- 
ished during  the  first  10  hours  and  then  gradually  increased.     No  trace 

1  Centmlbktt  fiir  Bakteriologie,  etc.,  I.  Abt.  Orig.,  XLI.,  1906,  Nos.  2,  3,  and  4. 

2  Zeitschrift  fiir  Hygiene,  XLVIIL,  p.  239. 

3  Centralblatt  fiir  Bakteriologie,  etc.,  II.  Abt.,  1901,  p.  706. 
*  Ibid.,  p.  739. 

^  Zeitschrift  fiir  Untersuchung  der  Nahrnngs-  u.  Gennssmittel,  1902,  p.  169. 
^  Journal  of  the  Society  of  Chemical  Industry,  XXIII.,  1904,  p.  74. 
^  Kevue  d'Hygiene  et  de  Police  Sanitaire,  XXVI.,  1904,  p.  101. 


I'ni'.SI'ULVA'riON    OF  MILK.  121 

of  i\\v  |)(T()xi(l(;  w;is  (IclcctaUlc  iii'tcr  scvctmI  lioiir.s.  With  tlicir  ;i!-.-cr- 
iioii  tliid  |);i(,li');^(wii(!  orj^uiiisiriH  un;  not  ulVcr.lcd,  n:iiitii;i  im  '  iloc-  not 
iljj^rco.  II<!  l)cli(!V<'S  tliMt  vvlicii  j)rc.sciit  to  tlif  cxtcMit  oC  O.oo  j)cr  cent, 
it  has  a  stroiij^  (Instructive  ju-tion  (»ii  ilic  l);i(illi  (»1"  tuherculo.siH,  ty])lioi(l 
fever,  and  (ly.sentcry,  if  (lie  inilk  is  kept  at  I  13°  to  122°  F.  for  2  or 
.'i  lioiH's,  hut  not  ollicrwisc.  (lonijiii-  is  of  opinion  that  in  onler  to 
onsnn;  st(M'iii/ation,  siK^li  an  amount  of  i\\v.  Ji^(!nt  nnist  he  employed  ns 
to  impart  a  taste  so  unjdeasant  as  to  make;  the  milk  unfit  for  use.  All 
observers  a^ree  that  whatever  its  merits  as  a  destroyer  of  baeteriii,  it 
exerts  no  harmful  inflnenee  upon  the  milk  enzymes,  with  the  exe(!f)tion 
of  snperoxydiise  ((^atalase). 

TIk!  "  l>nd(l(i  "  method  of  j)resei-vin!i;  milk  eonsiht-  in  ;i<l<liii}r  a  .'>  j»er 
cent,  solution  of  hydrotj;en  peroxide  to  llie  fic-ii  milk  in  llic  jiroportion 
of  about  12  to  15  ee.  to  eacih  liter,  and  then  iieatin^  to  120'  J'\  for 
three  or  four  hours,  when  more  tlum  5)1)  per  cent,  of  the  bacteria  will 
have  IxHMi  destroyed,  without  (^Imntj^inti'  the  appe:iranee  or  properties  (»f 
the  milk  in  ai\y  way.  Experiments  made  by  different  observers  have 
yielded  widely  different  results,  due,  accordinj^  to  M.  J^ukin,''  to  differ- 
ences in  the  quality  of  the  commercial  jireparations  of  hydrogen  jxr- 
oxide  and  to  the  fact  that  the  amount  necessary  to  success  is  influenced 
by  the  age  and  bacterial  content  of  the  milk.  Hewlett''  tested  the 
efficiency  of  the  process  em])loyin<r  fresh  milk,  to  sam])les  of  which  cul- 
tures of  various  organisms  were  added,  including  B.  tj/pliosuft,  B.  para- 
typho,vi,fi,  B.  diphthcricv,  B.  tuberculosis,  B.  ahthracis  (sporing),  B.  coli, 
B.  (li/senfericr,  B.  suhtilis,  B.  mi/coidcs,  and  Penieillhim  glaucum,  and 
found  that  the  non-sporing  organisms  were  destroyed,  and  the  sjiore- 
bearers  greatly  reduced  in  number.  Hewlett  states  that  milk  jjroperly 
treated  by  this  method  is  unchanged  in  odor,  appearance,  taste,  or 
otherwise,  and  that  it  will  keep  without  ap]iarent  alteration  for  8  to  10 
davs  in  hot  weather,  although  at  the  end  of  the  process  the  whole  of 
the  hydrogen  ]>eroxide  is  decomposed  and  no  trace  of  it  can  be  detected. 
In  ordinary  milk  the  reduction  in  the  number  of  bacteria  amounts  to 
more  than  99.9  per  cent. 

Experiments  with  milk  from  tuberculous  udders  have  given  conflict- 
ing evidence  as  to  the  value  of  this  process.  Thus,  Bergmann  and 
Hullmann  injected  1  cubic  centimeter  of  such  milk,  after  routine  treat- 
ment, into  a  guinea-i)ig,  which,  after  seven  weeks,  showed  a  fairly 
extensive  tubercular  infection.  A  sample  from  an  udder  more  exten- 
sively diseased  was  treated  with  a  larger  amount  of  the  peroxide  and 
warmed  in  the  usual  way  and  injected  into  guinea-pigs,  which  in  4  to 
5  weeks  died  of  general  tuberculosis.  On  the  other  hand,  Svensson 
has  obtained  positive  results  with  similar  material. 

An  improvement  upon  the  Budde  jn-oduct  is  known  as  the  ''  Perhy- 
drase  Milk  "  of  Drs.  Much  and  Ronier,*  who  recommend  placing  the 

'  Miincboner  medizinipche  Wochenschrift,  1905,  No.  23. 

^  Contralblatt  fiir  Bakteriolosrie,  etc.,  II.  Abt..  1904,  p.  716. 

3  Centralblalt  fiir  Eakteiiolosrie,  etc.,  II.  Abt.,  XV..  pp.  '20,  165. 

*  Lancet,  January  '27.  VMM\  p.  209. 

5  Beiti-iige  znr  Ivlinik  der  Tuberculose,  V.,  1906,  No.  3,  p.  349. 


122  FOODS. 

hvdrogen  peroxide  solution  iu  the  milk-pail,  ^vhich  should  be  sterile, 
aud  milking  directly  into  it,  ut^ing-  1  part  of  the  peroxide  (about  30 
ce.  of  the  commercial  3  per  cent,  preparation)  to  the  liter.  After  a 
period  of  6  to  8  hours,  the  milk  is  warmed  to  126°  F.  for  an  hour, 
and  then  a  ferment  derived  from  beef-blood  is  added,  in  the  proportion 
of  0.5  or  1.0  gram  to  the  liter.  After  2  hours'  contact,  with  frequent 
shaking,  the  excess  of  hydrogen  peroxide  is  destroyed,  and  the  milk  is 
ready  for  use.  It  is  normal  in  taste  and  is  free  from  bacteria.  Even 
when  abundantly  seeded  with  tubercle  bacilli  in  the  beginning,  it  fails 
to  infect  guinea-pigs  and  mice  on  inoculation.  The  ferment,  called  by 
Senter  "  hsemase,"  is  a  yellowish  fluid,  containing  0.1  or  0.2  per  cent, 
of  albumin.  In  its  place  defibriuated  beef-blood,  watery  extract  of 
malt^  or  yeast  may  be  used. 

Unless  the  excess  of  hydrogen  peroxide  is  decomposed  by  the  cata- 
lytic agent,  the  milk  has  a  bitter  and  otherwise  disagreeable  taste. 

The  same  authors  ^  noted  that  milk  that  has  been  sterilized  by  hydro- 
gen peroxide  undergoes  changes  in  color,  odor,  and  taste  on  exposure 
to  the  light.  Investigation  showed  that  these  changes  were  produced 
by  the  combined  action  of  light  and  oxygen,  which  affect  mainly  the 
fat,  and  that  the  bottles  containing  the  milk  ought  to  be  kept  in  the 
dark  or  else  wrapped  iu  red  or  green  paper,  since  red  and  green  rays 
are  without  influence,  while  the  ultra-violet,  blue,  and  yellow  rays 
bring  about  the  changes. 

The  assertion  that  no  changes  are  produced  in  the  constituents  of 
milk  treated  by  this  method  is  denied  by  Professor  C  O.  Jensen,  who 
insists  that  anything  which  affects  the  protoplasm  of  the  contained 
bacteria  so  as  to  cause  their  destruction  will  probably  not  fail  to  pro- 
duce changes  in  the  proteid  constituents  of  the  milk ;  and,  as  a  fact, 
coagulation  by  rennet  is  retarded,  and  the  coagulum  is  of  a  different 
character  than  that  of  untreated  milk. 

Chromates. — The  chromates  are  not  extensively  employed,  but  have 
been  found  present  in  preservative  powders  used  in  France.  Deniges  ^ 
found  the  normal  chromate  of  potassium  in  two  of  these  preparations, 
and  the  dichromate  aud  chromate  together  in  a  third.  The  latter  was 
recommended  in  the  proportion  of  2  grains  to  50  liters  of  milk.  Ac- 
cording to  Froidevaux,^  such  an  amount  of  potassium  dichromate  is 
insufficient  to  retard  coagulation  and  imparts  an  abnormal  intense 
yellow  color  to  the  milk. 

The  further  discussion  of  the  subject  of  milk  preservatives  may 
be  looked  for  below,  under  the  general  subject  of  Food  Preserva- 
tives. 

Adulteration  of  Milk. 

This  most  important  article  of  food  is  more  subject  to  adulteration 
than  any  other,  since  it  lends  itself  so  readily  to  fraudulent  manipula- 

1  Berliner  klinische  Wochenschrift,  XLIII.,  1906,  Nos.  30  and  31,  pp.  1004  and 
1041. 

^  Revue  International  des  Falsifications,  IX.,  p.  36. 
3  Journal  de  Pharmacie  et  de  Chemie,  1896,  p.  155. 


ADlJI/rEnATION   OF  MfLh'.  123 

tioii.  Tli(^  ])rlii<;l|>;il  .'tdiilfcnitioDs  :irc  llic  ;i(|(lition  of  w.iU-r,  tlif;  ahsfrac- 
tioii  of  cni.'im,  .'ukI  the  ndinixtiin' of  Hkiiiinicd  milk  to  wliolo  milk.  Tin; 
former  (iimiiiiH,li(!K  tlu;  imtrilivc  v.'iliic,  ;i(i(l,  il"  (Ik;  waUir  used  is  from  an 
unclean  .soure(!,  incii-eascs  the  possibility  of"  disseminatinf^  dinease  ;  the 
latter  robs  the  milk  of  one;  of  its  most  valuable  constituents.  The 
d(;te(!tion  of  these  adnllcraf  ions  by  analysis  is  not  always  j)os>ibIc,  sinr>e 
u  rich  milk  may  be  slit!;li(ly  wati^rcd  or  only  jKirtially  skimmed  and 
still  show  average  (jiiality.  A^ain,  even  thou^di  the  wateriuf^  \h'.  fairly 
considerable,  it  cannot  always  b(!  proved  that  tlu;  milk  was  not  of  low 
^rade  from  natural  (!aus(«,  since  some  cows  give  milk  which,  on  analysis, 
is  far  below  av('ratz;e  o;ood  milk.  l^"'urther,  a  milk  rontaininjr  v<'ry  little 
fat  may  be;  naturally  poor  in  that  (constituent  or  may  Ik;  tlu;  first  j>art 
of  a  milking. 

In  consequence  of  the  didicnity  of  proving  the  addition  of  water  or 
abstra<;ti()n  of  cream,  and  be(;ause  of  the  enormous  importance  of  secur- 
ing a,  |)ublic  su|)ply  of  at  least  average  good  (piality,  most  States  have 
fixed  legal  standards,  to  which  milk  intended  for  sale  must  conform. 
The  standard  for  total  solids  is  commonly  13,  12.5,  or  12  percent.; 
and  for  fat,  3,  3.5,  3.7,  and  4  per  cent.  By  the  ado])tion  of  a  legal 
standard,  all  milk  of  low  grade,  whether  so  l)y  reason  of  fraudulent 
practi(;es  or  be  use  of  ]X)or  l'ov(\  or  individual  peculiarity  of  the  cow, 
must  be  trented  alike.  By  prohibiting  the  sale  of  all  milk  not  of  a 
certain  grade,  it  becomes  unnecessary  to  prove  fraud  or  criminal  knowl- 
edge, the  allegation  of  inferior  quality  being  sustained  by  the  results 
of  tlie  analysis. 

Other  forms  of  adulteration  include  the  addition  of  coloring  matters 
for  the  purpose  of  concealing  watering  or  skimming,  t)r  to  give  a  creamy 
tint  to  a  very  white  milk,  and  the  addition  of  preservatives,  and,  occa- 
sionally, of  other  foreign  substances.  The  coloring  matters  commonly 
used  are,  annatto,  caramel,  and  combinations  of  aniline  dyes.  Their 
detection  is  by  no  means  difficult. 

It  is  a  common  belief,  even  among  people  of  more  than  average 
intelligence,  that  milk  as  found  in  the  market  is  very  largely  a  mixture 
of  chalk  and  water.  Upon  what  this  absurd  tradition  is  based,  it  is 
difficult  to  surmise,  since  even  though  a  person  were  led  to  practise  such 
a  miserable  fraud,  he  would  discover  that  chalk  and  water  will  need 
constant  stirring  to  maintain  even  the  outward  semblance  of  milk,  and 
that  a  few  minutes'  standing  is  sufficient  for  complete  separation  into  a 
deposit  of  chalk  and  a  fairly  clear  supernatant  liquid.  A  less  common, 
but  equally  absurd,  notion  that  calves'  brains  are  a  conmion  adulterant 
of  milk,  arose  about  half  a  century  ago  from  the  report  of  a  microscopi- 
cal examination  of  a  milk  sediment  in  which  certain  particles  were 
detected  which  bore  a  resemblance  to  nerve  tissue.  Calves'  brains  do 
not  lend  themselves  readily  to  the  making  of  emulsions,  the  supply  is 
limited,  and  they  find  a  fairly  good  market  in  their  true  character. 

Cane  sugar  is  said  to  have  been  found  at  rare  intervals,  and  gelatin 
is  used  occasionally  as  a  thickening  for  cream.  Starch  is  believed  by 
many  to  be  a  common  adulterant,  but  it  is  used  verv  rarelv.      In  the 


124  Foods. 

course  of  many  years'  supervision  of  a  large  public  milk  supply,  during 
wiiich  several  hundred  thousand  samples  of  milk  were  examined  for 
adulterants  of  all  sorts,  but  one  instance  of  the  use  of  starch  fell  under 
the  author  s  notice.  This  was  due  to  a  shortage  in  the  normal  sup})ly, 
which  led  a  dealer  to  dispense  a  mixture  of  water  and  condensed  milk, 
which  latter, component  had  been  thickened  with  starch. 

CREAM. 

United  States  Standard. — Standard  cream  is  cream  containing  not 
less  than  18  per  cent,  of  fat. 

Cream,  as  already  stated,  may  be  defined  as  milk  containing  a  large 
excess  of  fit,  and  correspondingly  lacking  in  water.  The  degree  of 
richness  is  dependent  upon  the  method  employed  in  its  separation  from 
the  original  volume  of  milk.  That  obtained  by  the  common  method 
of  skimming  contains  ordinarily  about  16  to  24  per  cent,  of  fat,  while 
that  separated  by  the  centrifugal  machine  contains  from  20  to  upward 
of  50  per  cent.,  according  as  the  machine  is  regulated  for  "  light "  or 
"  heavy  "  cream.  The  latter  is  so  thick  as  to  give  rise  to  a  common 
notion  that  corn  starch  is  used  as  an  adulterant.  This  substance,  how- 
ever, is  used  rarely  if  ever  in  this  way.  Gelatin  is  employed  as  an 
adulterant  to  a  limited  extent.  A  preparation  largely  advertised  to 
the  trade  at  one  time  as  a  "  cream  thickener "  was  analyzed  by  the 
author,  and  found  to  be  a  mixture  of  gelatin,  borax,  and  boric  acid. 

More  recently  sucrate  of  lime,  sometimes  termed  "  viscogen,"  has 
been  added  to  cream  in  order  to  increase  its  thickness.  Lythgoe  ^ 
states  that  60  out  of  1 70  samples  of  cream  examined  by  him  showed 
the  presence  of  calcium  sucrate. 

Furthermore,  a  machine  has  been  put  upon  the  market  which  pro- 
duces an  emulsion  of  fat  globules  of  such  exceeding  fineness  as  to  give 
an  impression  of  thickness  to  cream  100  per  cent,  above  that  actually 
present.  The  common  adulterants  of  cream  are  preservatives  and  color- 
ing agents.  The  former  are  used  mostly  during  the  hot  months  ;  the 
latter  during  tlie  winter,  when,  on  account  of  the  difference  in  feed,  the 
cream  has  not  the  characteristic  yellow  tint  so  highly  prized. 

CONDENSED  MILK. 

United  States  Standard. — Standard  condensed  milk  and  standard 
sweetened  condensed  milk  are  condensed  milk  and  sweetened  condensed 
milk  respectively,  containing  not  less  than  28  per  cent,  of  milk  solids, 
of  wiiich  not  less  than  27.5  per  cent,  is  milk  fat. 

Condensed  milk  is  ])repared  by  evaporating  milk  to  about  a  third  or 
a  fourth  of  its  volume  in  vacimm  pans.  It  is  sold  in  bulk  for  immedi- 
ate use,  and  in  hermetically  sealed  tin  cans  for  use  as  occasion  demands. 
Most  of  that  sold  in  tins  is  made  from  skimmed  milk,  and  is,  therefore, 
very  deficient  in  fat  ;  and  much  of  it  contains  a  large  proportion  of 
cane  sugar,  which  is  added  to  increase  its  keeping  qualities.  Condensed 
^  Annual  Report  of  the  Mass.  State  Board  ot  Health,  1908,  p.  595. 


MILK  AS  A    FACTOIl    IN   Till':  SrUKM)    Oh'   hISHASE.  125 

milk  i.s,  in  in:iiiy  njspccLs  ;iihI  iiikIci-  c  rt;iin  cciHlil  i'ni  ,  ;i  v:ilii:ililc  I'lO'l 
pniparation,  \n\l  iLH  use  in  inliml  (rcdiii!.'  wlicn  oiIki-  milk  i-  ol»l;iiniil*l(j 
is  not  !i  wi.s(!  one,  Hin(H!  it  is  (Icriciciil  in  one  of  llic  IIlo^t.  iiiii«irt:i  iil  *•!'•- 
nx^nts,  unci  (iontains  anollicr  wliidi  is  not  a  normal  f^onsf  it  ii'iit. 

This  point  was  l)ron^lil.  ont,  v<iy  plainly  hy  Jordan  and  Molt,'  wlio 
found,  by  an  examination  o("  II  dincicnt  l)ran<ls  of  condensed  milk, 
that  the  cost  of  a  (jiiart  of  siandnrd  milk  containiiifr  3.35  per  (xjnt.  of 
fat,  when  niaih'  froin  (M)ndenscd  milk,  cost  anywlierf;  from  f)  to  1 2.0 
cents  a  (juart.  l^'nrlliermore,  IIk;  haeterial  (content,  jx-r  enhic  ceiilimeter 
oC  10  brands  of  condensed  milk  varied  anywhere;  from  DOO  to  10,000,- 
000.  The  brands  of  condensed  milk  containing  bacteria  were  mostly 
of  tlie  sweetened  variety,  and  the  reason  for  this  contamination  is  s:ii<l 
to  li<!  in  the  fact  that  sweetened  condensed  milk,  ecmtainin^  •'-"K'"'j  '"""" 
not  be  heated  sntfuuently  without  carameli/-in<i;  the  su^ar. 

Milk  as  a  Factor  in  the  Spread  of  Disease. 

Milk  may  act  as  a  carrier  of  disease  or  cause  of  fnnetional  disturi)- 
ance  through  infectious  or  poisonous  matters  orip;inal]y  present,  or  re- 
ceived or  evolved  durinj^  handlint^  and  distribution.  Thus,  milk  may 
be  ])oisonous  by  reason  of  matters  derived  from  the  feed  or  of  .sub- 
stances formed  after  it  is  drawn  ;  it  may  contain  oriLranisms  of  varioiis 
kinds  connected  with  bovine  diseases  ;  it  may  become  contaminated  in 
various  ways  with  matter  containing  the  exciting  cause  of  various 
human  diseases. 

Poisonous  Milk. — Certain  plants  eaten  by  cows  may  cause  milk  to 
become  unfit  for  drinking  because  of  toxic  properties.  Poison  ivy 
and  white  snakeroot  have  long  been  regarded  as  the  cause  of  the  cattle 
disease  known  as  "  Trembles  "  and  of  the  condition  in  man  known  as 
"  Milk  sickness,"  following  the  drinking  of  milk  or  the  eating  of  meat 
from  cows  having  the  disease,  but  it  has  been  pointed  out  by  Jordan 
and  Harris  2  that  trembles  has  never  been  known  to  exist  in  the  Atlantic 
seaboard  states  and  elsewhere  wdiere  poison  ivy  groM's  in  abundance, 
and  that  white  snakeroot  is  not  known  in  New  Mexico,  where  they 
have  found  a  center  of  the  typical  disease.  Having  had  an  exceptional 
opportunity  to  study  a  somewhat  extensive  outbreak,  they  ap])ear  to 
have  demonstrated  very  conclusively  that  the  cause  is  not  a  poisonous 
vegetable  princi]>le,  but  a  specific  micro-organism  to  which  they  have 
triven  the  name  Bacillus  lacfiinorbi.  Trembles  and  milk  sickness  were 
formerly  of  common  occurrence  in  Ohio,  Indiana,  Illinois,  Kentucky, 
and  Tennessee,  and  occasionally  in  North  Carolina,  but  have  become 
very  rare  of  late  years.  The  condition  caused  in  man  is  very  grave, 
the  cerebral  nervous  system  being  jtrofoundly  involved.  The  symp- 
toms include  great  depression  and  muscular  weakness,  great  thirst, 
labored  respiration,  constant  retching,  paralysis  of  the  intestines,  and 
subnormal  temperature.  Before  death,  which  is  the  rule,  the  entire 
body  becomes  paralyzed.     The  leaves  of  the  common  artichoke  are 

'  American  Journal  of  Public  Hygiene,  May,  1910. 

^  Journal  of  the  American  Medical  Association,  May  23,  1908,  p.  1665. 


126  FOODS. 

siiici  ^  to  impart  to  milk  certain  properties  which  cause  abdominal  pain, 
vomitiiiir,  and  diarrh(ea,  and  Dechorf  -  has  reported  an  outbreak  of  acute 
enteritis  amoni:;  children  that  had  received  sterilized  milk  from  cows 
fed  on  beet  leaves  and  red  cabbage.  A  similar  outbreak  was  observed 
after  the  use  of  milk  of  cows  fed  on  fermented  beet  siluge. 

Under  certain  conditions  normal  milk  may  undergo  peculiar  forms 
of  decomposition  productive  of  intensely  violent  poisonous  substances. 
Fortunately  these  changes  are  uncommon,  but  when  they  do  occur  the 
milk  betrays  to  the  consumer  no  sign  of  its  condition.  The  eUects 
produced  upon  the  consumer  are  various  and  are  well  illustrated  by  the 
following  cases  : 

Case  I.— Reported  by  Dr.  W.  K.  Newton  and  Mr.  S.  A¥allace.» 
On  August  7,  1886,  24  guests  of  one  hotel  at  Long  Branch,  and  19 
of  another  hotel  at  the  same  place,  were  taken  sick  soon  after  suj)per 
Avith  the  same  train  of  symptoms,  which  were  nausea,  vomiting,  cramps, 
and  collapse,  diyness  of  the  throat,  and  burning  sensation  in  the  oesoph- 
agus ;  in  many  cases  there  was  absence  of  diarrhoea,  and  in  several 
there  was  active  diarrhoea  without  vomiting.  Many  had  violent  vom- 
iting followed  by  collapse.  As  a  rule,  the  nausea  and  vomiting  were 
persistent  and  obstinate,  and  accompanied  by  a  tendency  to  exhaustion 
and  collapse.  A  week  later,  30  guests  of  still  another  hotel  were 
seized  in  precisely  the  same  manner.  The  onset  occurred  in  from 
one  to  four  hours  after  eating,  but  in  one  instance  the  symptoms 
appeared  almost  immediately  after  drinking  about  a  quart  of  milk. 
Investigation  showed  that  the  trouble  was  due  wholly  to  milk,  for  only 
the  milk-drinkers  were  seized,  and  those  who  had  had  no  other  food 
were  the  worst  sufferers.  The  three  hotels  were  serN'ed  by  one  dealer, 
who  made  two  deliveries  daily.  The  milk  of  the  second  delivery  was 
the  cause  of  the  mischief  in  each  outbreak.  It  was  drawn  at  noon,  and, 
without  being  cooled  at  all,  was  carted  eight  miles  in  the  heat  of  the 
day.  The  cows  were  healthy  and  well  fed.  In  a  portion  of  the  milk 
that  caused  the  third  group  of  cases,  the  presence  of  tyrotoxicon  Avas 
demonstrated. 

Case  II. — This  was  a  most  extraordinary  outbreak,  limited  to  a 
family  consisting  of  father,  mother,  son,  and  daughter,  of  whom  all 
but  the  first  mentioned  died.  The  family  physician  called  Professor 
V.  C.  Vaughan  in  consultation  after  the  fourth  member  of  the  family 
was  seized,  and  from  his  report  of  the  case  the  following  facts  are 
taken.  The  first  one  seized  was  the  father,  a  man  of  fifty  years.  When 
first  seen,  he  was  vomiting  severely,  his  face  was  flushed,  and  his  tem- 
perature was  subnormal  (96°  F.).  There  was  marked  throbbing  of  the 
abdominal  aorta,  the  tongue  was  heavily  coated,  and  the  breathing  was 
very  labored.  The  pupils  were  dilated,  and  much  of  the  body  was  cov- 
ered with  a  rash.  The  vomiting  continued  some  hours,  the  vomitus  being 
colored  with  bile.     The  bowels  had  not  moved,  but  under  the  influence 

1  Milchzeitung,  1891,  p.  40. 

^  Paris  letter,  Lancet,  February  8,  1908. 

3  Medical  News,  September  25^  1886,  p.  343, 


MILK  AS  A    FACTO n   IN    'nih'  SI'llhlAI)   OF   hISEASK.         127 

ol"  it  cMilKiiiic,  ;i  sl<t(il  (((•(•inrcd  on  llif  ("i)ll(>\\iiij^  (l;iy.  licU-.liiiijr  iitid 
voinitiiif>'  (!(»iil  iiiiicil  (liiilnu  lli;it  <l;i\'  ;iinl  iiij^jit^  .-hkI  fliccc  wuh  |K!rhiKt<'Ht 
Htii|)<)r.  Diiriiit;'  tlic  follow  iii^'  llir(!(;  diiyw,  (lien!  \v;is  hiif  litlK-  r\\:u\\rc, 
'^V\\v\\  iiii|)i'(»\('in(iil  l)f'n;iiij  |)ii(,  rci-ovdi'v  n'(|nir<'(|  ,'i  nioiilli.  Tlic  son,  ;i 
stroiijj^  yoiidi  o("  cialilctiii,  wuh  i\w.  iicxi  to  he,  HcM/cd,  ("our  d;i\-  -.iWi'V  llif 
l)(i}4'i lining'  of  his  liillicr's  sirkiicss.  The  syinptorns  were  .similar,  l)iit 
wcrci  iii<)l'(!  violciil,  .•iiid  I  here  \\:is  no  r:isli.  On  the  (ollowin^  evening, 
i\\(\  rnodicr,  about  loi'ly-liNC,  was  s('i/,<<l  in  I  lie  same  way,  and  on  the 
succeed  in  ji;  cvcnino',  (lie  daniililcr  also.  <  )n  tlicdav  following:;  tlic  IjiHt 
sci/.nrc,  none  of  llic  cases  showed  ini|)ro\cinenl.  The  tenipcnitiircH 
were  snhnornial,  !M"  and  !)">"  l'\  All  c<)in|»lained  o("  a  hnniin^'  con- 
striction in  tlu^  throat  and  didicnlt  swallowin^r,  and  called  f'reiinently 
for  i(;c.  '^J\v<)  days  latci",  tlie  mother  and  son  died  ;  the  daiiffhter  ^rrcw 
worse,  became  nnconscions,  remained  so  three  days,  and  then  (lied. 

Post-niorleni  examination  in  the  case  of  the  daughter  rev«iled  no 
(characteristic  lesions  to  account  for  death.  The  outbrciik  was  most 
carefully  and  thoroujihly  in\('sti<;ated  from  every  standj)oiut,  and  the 
conclusion  reached  was  that  tyrotoxi(!on  was  the  cause.  Tlu;  milk 
had  beeu  kept  iu  a  buttery  which  was  in  a  most  unsanitary  condition. 
During;  three  years,  the  family  had  sull'ered  frequent  attacks  of  like 
character,  l)ut  they  were  much  less  severe.  Fresh  milk,  j)laced  in  the 
buttery  over  niyht,  and  then  examined  ibr  tyrotoxicou,  jrave  unmis- 
takable chemical  and  physiological  e\idence  of  tliat  jioison.  Fresh 
milk  inoculated  with  dirt  from  the  buttery  floor  also  developed  it,  a.s 
did  also  other  portions  treated  with  vomitus,  stomach  contents,  and 
aqueous  extract  of  tlie  intestines,  while  a  fifth  specimen  untreated 
remained  free  from  it.  All  the  evidence  in  this  case  })ointed  to  the 
more  or  less  constant  ])rescnce  of  poison  in  the  milk,  and  the  wide 
variation  in  the  time  of  seizure  in  the  final  outbreak  indicates  that 
all  were  not  affected  by  the  same  day's  supply. 

Milk  from  Diseased  Cows. — The  milk  of  cows  suffering  from  the 
prominent  cattle  plagues  is  more  or  less  altered  in  composition,  and  there 
appears  to  be  evideuce  that  sometimes  it  may  be  actually  dangerous. 

Rinderpest. — In  rinderpest  the  proteids  are  much  increased — iu  fact, 
more  than  doubled  ;  the  mineral  constituents  are  considerably  increased, 
and  the  fat  and  sugar  are  diminished. 

Foot  and  Mouth  Disease. — In  foot  and  mouth  disease  the  total  solids 
are  increased  considerably,  or  diminished  at  different  stages,  and  the 
milk  \vill  sometimes  coagulate  on  boiling  by  reason  of  the  excessive 
amount  of  coagulable  proteids.  There  is  reiison  to  believe  that  this 
disease  may  be  comnumicated  to  other  animals  through  the  milk,  and 
there  is  evidence  that  the  use  of  the  milk  by  man  will  produce  local 
lesions  in  the  mouth  and  throat.  Thus,  Notter  and  Firth^  mention  an 
e})idemic  of  sore  throat  at  Dover  in  1884,  in  which  there  were  205 
cases  of  vesicular  eruption  in  the  throat  or  on  the  lips,  enlarged  tonsils, 
and  iu  most  cases  enlarged  glands  of  the  neck,  all  occurring  within  a 
week  iu  persons  supplied  by  a  single  dairy  where  the  disease  existed. 
^  The  Theory  aud  Practice  of  Hygiene,  London,  1896,  p.  305. 


128  FOODS. 

During  the  epizootic  which  occurred  iu  New  England  in  li)02,  there 
were  reported  a  number  of  oa.scs  of  sore  mouth  antl  throat  with  aphthte 
and  more  or  less  general  disturbance. 

It  is  said  that  iu  mild  cases  of  this  disease  the  milk  is  unchanged, 
but  that  in  severe  cases  it  may  be  very  abnormal  in  appearance  and 
composition  and  may  cause  very  severe  and  even  fatal  sickness  in  man. 

Anthrax. — In  anthrax  the  milk  has  an  abnormal  apj)earance  and 
decomposes  rapidly.  The  specific  organism  has  been  isolated  in  active 
condition  by  Boschetti  ^  from  milk  as  late  as  14  days  after  it  had  been 
drawn. 

Actinomycosis. — In  actinomycosis,  particularly  if  the  udder  is  in- 
volved, the  milk  should  be  avoided,  although  there  appears  to  be  little 
direct  evidence  bearing  upon  transmission  of  the  disease  to  man  by 
this  means.  It  is  certain,  however,  that  the  disease  does  occur  some- 
times in  man,  and  though  in  the  matter  of  transmission  of  disease  from 
animals  to  man  nothing  siiould  be  taken  for  granted,  it  is  commendable 
in  such  cases  of  lack  of  positive  knowledge  to  err  on  the  side  of  safety, 
and  to  avoid  and  prohibit  the  use  of  such  milk,  even  though  it  be  true 
that  the  actinomyces  have  not  as  yet  been  found  in  milk. 

Rabies. — In  rabies  it  has  been  proved  that  the  virus  may  be  secreted 
in  the  milk,  and  Jensen  -  says  that  although  feeding  experiments  have 
yielded  negative  results,  the  possibility  that  infection  may  occur  through 
a  slight  lesion  of  the  mouth  or  pharynx  should  cause  the  milk  of  cows 
bitten  by  rabid  dogs  to  be  regarded  as  most  dangerous. 

Specific  Enteritis. — In  specific  enteritis  due  to  the  hog-cholera  group 
of  bacteria,  the  milk,  which,  perhaps,  is  infected  through  fecal  con- 
tamination, if  not  before  it  leaves  the  cow,  may  be  a  cause  of  sickness. 
Gaffky  ^  has  reported  this  case  :  Three  persons  connected  with  the 
Institute  of  Hygiene  at  Giessen  were  seized,  after  drinking  milk  from 
a  cow  suffering  from  such  a  disease,  with  nausea,  vomiting,  diarrhoea, 
and  mental  confusion.  One  recovered  in  a  few  days,  the  others  in 
about  four  weeks.     The  milk  was  drunk  in  the  raw  state. 

Garget,  Mastitis,  Maramitis. — In  this  commonest  of  bovine  diseases, 
in  which  a  part  of  or  the  whole  udder  may  be  inflamed,  the  milk  is 
often  so  changed  in  character  as  to  be  obviously  unfit  for  use,  but  ordi- 
narily is  of  normal  appearance  on  casual  examinntion.  Even  when 
the  udder  is  only  slightly  involved,  the  milk  frequently  contains  vast 
numbers  of  streptococci.  B.  coll  is  almost  always  present,  and  Staph, 
pyogenes  aureus  and  albus  are  very  commonly  found  in  large  numbers. 
Such  milk  is  believed  by  many  to  be  a  common  cause  of  epidemic  diar- 
rhoea, and  in  a  number  of  instances  the  connection  appears  to  have 
been  conclusively  proved  ;  but  the  most  striking  effects  of  its  use  are 
the  extensive  outbreaks  of  septic  sore  throat,  which  sometimes  have 
passed  for  scarlet  fever,  as,  for  examj^le,  an  outbreak  of  more  than  200 
cases  in  Lincoln,  England.     These  outbreaks  are  often  extremely  se- 

1  Giomale  di  Medicina  Veterinaria,  1891. 

2  Essentials  of  Milk  Hygiene.     Trans,  by  Pearson,  1907,  p.  91. 

3  Deutsche  medizinische  Wochenschrift,  1892,  No.  14. 


MIIJ\'  AS   A    FAdTOn    /;V    Till':  SI'liF.AI)    <il'   DISEAHK.  120 

vcrc,  and  HornctinuiH  iJnty  id'csciil.  ;i  j^rt^nt,  divcoif.y  of"  .sc<'oii<l;iry  (ffloctw, 
aH  may  lu;  ()l)H(!rv(!(l  hctlow. 

OrdiiiMi'ily  (lie  disc-isc  Itc^ins  willi  tlic  inalaisf  and  rliilly  i-ciisaf  ionH 
oliarac.l,(M'isii(i  ol"  (oiisillilis,  with  dianli<r;i,  liijrh  1ciii|)craliir(',  iMMiralgiax, 
and,  not  inrr('(|ii('iilly,  cervical  adciiilis.  In  llic.-c  oiill)i-(rak8,  wliicli  aro 
niislakcn  (or  ,M(;arlct  Icvi;!',  (lie  very  ^oi'c  lIu'oaL  i.s  arcoin|)aiii(;d  hy  an 
apparently  cliarac^tcrislic  orytlicnia;  and  soinctirncw  (lie  crnptioti  n;- 
,s('nil)les  that  oC  nuiash-s. 

As  e\ani|)l(!S  of  such  outbreaks  and  olthc  \ariety  of  the  symptoiiiH 
caused,  the  foUowiuf^  are  presented  : 

(1)  Outbreak  in  Wokinf»;,  in  100.'},  rcporteil  i»y  Pienrc.'  (.'ases  of 
sore  throat  to  tlie  number  of  2r)()  were  tra(;(;d  back  to  a  farmer  to 
whom  complaint  had  been  ina<le  of  the  ropy  character  of  his  ])roduet. 
Four  of  his  20  cows  were  I'ound  to  have  garget,  and  their  milk  r^on- 
tained  much  pus  and  an  abundance  of  streptococci.  He  and  liis  wife 
and  two  daughters  had  had  or  were  then  sulfering  with  sore  throat. 
The  majority  of  the  victims  were  adults.  In  many  instances  whole 
families  were  seized,  and  in  one  house  12  of  the  V-\  inmates  were  vic- 
tims. Many  cases  were  indistinguishable  from  ordinary  follicular  ton- 
sillitis, some  were  suggestive  of  diphtheria,  and  others  developed  into 
quinsy.  There  was  a  marked  tendency  to  involvement  of  the  sub- 
maxillary and  posterior  cervical  glands,  and  in  some  cases  the  pharynx 
and  larynx  were  so  much  involved  that  deglutition  was  exceedingly 
painful  and  difficult.  In  a  number  of  cases  pain  and  tenderness  of  the 
joints  followed  the  throat  symptoms  in  3  to  7  days.  In  5  instances 
very  severe  erysipelas  followed  the  throat  symptoms,  and  one  of  the 
persons  so  afflicted  developed  a  mastoid  abscess  and  died.  Another, 
with  his  nasopharynx  covered  with  a  sloughing  membrane,  was  sent  to 
the  hospital  and  died  of  pyaemia,  with  a  postmortem  temperature  of 
110°  F.     The  total  number  of  deaths  w^as  8. 

(2)  Outbreak  of  sore  throat  with  exudation,  involving  98  families, 
reported  by  Axe.^  There  was  a  common  milk  supply,  and  4  of  the 
cows  were  found  to  yield  pus  and  large  numbers  of  streptococci  in  this 
milk.  The  dairyman's  family  comprised  himself  and  Avife,  two  sons 
and  two  daughters,  and  all  were  affected.  In  addition  to  throat  symp- 
toms, he  and  his  elder  son  had  pains  in  the  joints,  and  the  latter  had 
enlarged  glands. 

(3)  Outbreak  of  140  cases,  reported  by  Savage.^  The  onset  was 
unusually  rapid,  with  considerable  constitutional  disturbance.  In  some 
cases  the  temperature  reached  104°  and  105°  F.  The  throats  were  red 
and  swollen,  and  in  most  cases  the  tonsils  were  enlarged,  with  project- 
ing white  plugs  in  the  follicles.  In  several  cases  distinct  patches  were 
observed  on  the  soft  palate,  and  in  one  case  on  the  uvula  also.  The 
cause  was  traced  to  a  cow  with  garget,  whose  milk  was  very  rich  in 
virulent  streptococci. 

1  Journal  of  State  Medicine,  October,  1904,  p.  595. 

^  Ibid.,  Pecembor,  1904,  p.  708. 

3  Public  Health,  October,  1905,  p.  1. 


130  FOODS. 

(4)  Outbreak  of  548  cases,  and  probably  more,  in  Christiana,  in 
ISIarch,  1908  ;  reported  by  8onime.^  The  picture  of  the  iUness  in- 
ehuled  high  temperature,  104°  F.  and  higher,  with  sore  tlu'oat.  The 
surface  of  the  tonsils,  pharynx,  and  downward  toward  the  hirynx  was 
of  a  glistening  red.  In  some  cases  the  redness  was  confined  to  punc- 
tate areas,  and  in  others  there  was  a  diphtheria-like  membrane,  which 
could  be  easily  removed.  In  the  majority  of  cases  the  throat  was  scar- 
latinal rather  than  diphtheritic.  The  glands  of  the  neck  were  excess- 
ively painful  on  pressure.  Complications  were  extremely  numerous, 
and  included  the  widest  possible  variety  of  streptococcal  infection  of 
the  diifereut  parts  of  the  body.  The  deatiis  numbered  5.  The  cause 
was  traced  to  a  cow  with  a  diseased  udder,  from  which  streptococci 
were  obtained  wliich  were  identical  with  those  taken  from  victims  of 
the  outbreak.  Mice  inoculated  intraperitoneal ly  with  minute  quantities 
of  the  culture  died  in  12  to  24  hours,  and  cultures  could  be  obtained 
from  their  blood. 

Tuberculosis. — There  can  be  no  doubt  that  the  tubercle  bacillus  finds 
its  way  into  milk,  particularly  if  the  udder  is  involved,  but  even  when 
not.  This  was  asserted  so  long  ago  as  1889  by  Ernst,^  who,  after  a 
very  extended  inquiry,  proved  that  the  milk  of  cows  with  tuberculosis 
in  any  part  of  the  body,  and  with  no  local  lesion  of  the  udder  what- 
ever, may  contain  the  bacillus.  This  finding  has  been  confirmed  by  a 
number  of  more  recent  observations.  Rabinowitsch  and  Kempner^ 
obtained  positive  results  from  inoculation  experiments  on  guinea-pigs 
with  the  milk  of  10  out  of  15  cows  that  had  reacted  to  tuberculin. 
Of  these  10  animals,  only  1  showed  clinical  evidence  of  involvement 
of  the  udder,  and  only  1  other  showed  any  sign  of  it  on  microscopical 
examination.  Moussu  *  drew,  under  antiseptic  precautions,  the  milk 
of  a  number  of  cows  showing  no  lesions  of  the  udder,  and  inoculated 
therewith  57  guinea-pigs,  which  yielded  7  positive  results.  Miiller  ^ 
believes  that  it  is  only  when  tuberculosis  has  reached  an  advanced 
stage  without  infecting  the  udder  that  the  bacilli  can  be  found  in  the 
milk,  and  that  infectiousness  of  milk  is  chiefly  referable  to  lesions  of 
the  udder.  A  study  of  mammary  glands  of  tuberculous  cows,  by 
Martel  and  Gu^rin,"  showed  in  some  cases  lesions  which  appeared  to 
be  non-tuberculous  and  in  others  no  lesions  whatever ;  yet,  inoculation 
experiments  proved  that  the  udder  may  be  infectious  at  any  stage  of 
the  disease.  Among  others  who  have  obtained  positive  results  from 
animals  with  normal  udders  may  be  mentioned  Bollinger,  Delepine, 
Bang,  and  Adami. 

In  concluding  from  the  results  of  experiments  with  milk  from  normal 
udders  that  even  in  the  absence  of  tuberculous  lesions  the  bacilli  may 
be  present,  the  fact  should  not  be  lost  sight  of  that  most  milk  as  ordi- 

1  Norsk  Magazin  for  Laegevidenskab,  through  Lancet,  June  13,  1908. 
^  American  Journal  of  Medical  Sciences,  November,  1889. 
3  Zeit.schrift  fiir  Hygiene  und  Infectionskrankheiten,  XXXI.,  p.  137. 
'  Comptes  Kendus  de  la  Societe  de  Biologic,  1904,  No.  13,  p.  617. 
■'  .Journal  of  Comparative  Pathology  and  Therapeutics,  1906,  p.  19. 
6  Rev.  See.  Scient.  d'Hyg.  Aliment.,  II.,  1905,  p.  153. 


MTLK  yl,S'  A    FAdTOIL    IN  Tlll<:  SI'llKAD    OF  DISH  A  SIC.         l.'il 

narily  dniwn  from  :iriini;i,ls  lliiit,  un;  rciisoiiuMy  clciii  c/uitaiiis  parti(;l<;H 
of  niuMiiro  from  the  flunks,  tail,  and  otluir  parts,  and  that  the  fcw;K  of 
a  inh<!rc,iiI()iiH  cow  is  likely  t(»  he  teeiniri}^  with  the  hac^illi. 

That  contamination  of  milk  hy  (In;  mannre  of  tnherciilons  e/)\VK  in- a 
very  sorions  (lan^(!r  is  shown  hy  fh(!  fact  that  Mohh-r,'  "  in  a  rec^'iit 
cxiunination  at  the  Knniaii  of  Animal  Jndnslry  lOxperiment  Station, 
of  th(!  manure  passed  hy  twelve  cows  just  jmrchased  from  dairy  farms 
in  this  city  and  alfectcd  with  tnhcrcnlosis  to  an  extent  only  d(;mon- 
strahlc!  hy  the  tiihc^reulin  test,  tnhercle  hacilli  wer(!  foimd  in  over  41 
per  c(!nt.  of  the  cases,  holh  \)y  microscopic  examination  and  animal 
inoculations." 

The  possibility  that  tin;  ])ositive  n^sidts  reported  by  others  may  have 
been  (hie  to  suc^h  accidental  contamination  was  sii^''^est<!d  by  Osterta^'-,^ 
who  fed  calves  and  pigs  for  months  with  ndlk  from  cows  which  showf-d 
no  evidence  of  tuberculosis  beyond  reacting  to  tuberculin,  and  the 
experimental  animals  remained  healthy.  Stronstron  ^  inoculated  8'> 
animals  with  the  milk  of  50  reacting  cows,  not  one  of  which  showed 
clinical  or  post-mortem  evidence  of  udder  tuberculosis,  and  not  a  single 
one  of  the  animals  acquired  the  disease. 

It  is  asserted  commonly  that  the  use  of  milk  from  tuberculous  cows 
is  a  positive  danger  to  public  health,  and  attention  is  directed  to  the 
persistently  high  rate  of  mortality  from  tuberculosis  in  all  its  forms 
among  very  young  children,  and  to  improvement  in  the  death-rates 
from  other  causes.  It  is  asserted  that  this  condition  can  be  explained 
in  only  one  way  :  that  is,  that  a  very  large  proportion  of  market  milk 
is  derived  from  tuberculous  cows,  and  thus  bottle-fed  children,  if  at  all 
susceptible,  become  infected. 

As  to  the  probable  j)ro]iortion  of  infected  market  milk,  owing  to  the 
wide  diiferences  in  results  obtained  by  various  investigators,  no  definite 
statement  can  be  given.  Rabinowitsch,  for  example,  found  it  to  be  28 
per  cent,  ;  Massone  ^  by  inoculation  experiments  placed  it  at  9  ;  Ott,* 
at  11.6.  Sladen  "  found  that  more  than  half  of  the  samples  tiiken  from 
the  supply  of  the  colleges  at  Cambridge,  England,  conveyed  tubercu- 
losis to  guinea-pigs  on  inoculation.  Del^jnne  found  the  l)acilli  in  17.6 
per  cent,  of  samples  gathered  in  IManchester,  and  Robertson,  in  14  per 
cent,  of  samples  collected  in  Birmingham.  Houston  has  estimated 
that  about  20  per  cent,  of  the  cows  in  the  United  Kingdom  are  tuber- 
culous, and  that  2  per  cent,  have  tuberculosis  of  the  udder.  Ostertag 
believes  that  the  udder  is  involved  in  about  4  per  cent,  of  tuberculous 
cows.  Eastes^  found  the  bacillus  in  but  11  of  186  samples  of  milk 
which  he  examined.  According  to  Newman,^^  in  Liverpool  about  2 
per  cent,  of  the  town-produced  and  9  per  cent,  of  the  country  milk  has 

1  Hygienic  Laboratory  Bulletin,  No.  41,  p.  493. 

2  Zeitschrift  fiir  Hygiene  und  Tnfectionskitinkheiten,  XXXVIII.,  1901,  p.  415. 

3  Zeitschrift  fiir  Tiermedizin,  YI.,  1902,  p.  241. 
*  Annali  d'lgiene  Sperimentale,  1897,  p.  939. 

5  Z.eitschrift'^fiir  Milch-  und  Fleischhygiene,  1898,  No.  8. 

6  The  Lancet,  January  14,  1899. 

''  British  Medical  Journal,  November  11,  1899. 
8  Public  Health,  February,  1904. 


132  FOODS. 

been  foiiiKl  to  be  tuberculous  ;  in  Hackney,  on  one  occasion,  22  ])er 
cent.;  in  Woolwich,  in  1902,  10  per  cent.;  in  Caniberwell,  in  1902, 
11  per  cent. ;  in  Croydon,  in  1901,  G  per  cent.  ;  in  London,  as  a  whole, 
7  per  cent. 

Anderson^  found  that  15  out  of  223  samples  of  market  milk,  that 
is  to  say,  6.72  per  cent.,  caused  tuberculosis  in  inoculated  animals. 
The  milk,  furthermore,  of  11  out  of  102  dairies  contained  tubercle 
bacilli.  Moreover,  the  milk  from  one  out  of  nine  charitable  institu- 
tions caused  tuberculosis  in  both  guinea-pio;s  into  which  it  was  inocu- 
lated. 

Hesse  -found  virulent  tubercle  bacilli  in  17  among  107  specimens, 
that  is,  in  16  per  cent,  of  the  milk  retailed  from  cans  in  New  York 
City. 

Tonney^  found  that  8.9  per  cent,  of  112  samples  showed  tubercu- 
losis. Of  95  raw  samples,  10.5  per  cent,  showed  tuberculosis.  Of  17 
pasteurized  samples,  0  per  cent,  showed  tuberculosis. 

Doubtless  the  differences  are  due  to  variations  in  local  conditions,  to 
differences  in  technic,  and  to  accidents  always  attending  haphazard 
securing  of  any  article  of  food  in  open  market. 

Taking  the  mean  of  the  figures  given,  and  accepting  that  as  a  fair 
approximation  of  the  extent  to  which  public  supplies  are  infected,  it 
must  be  agreed  that,  if  infection  through  milk  is  possible,  the  amount 
of  disease  so  caused  is  quite  small  in  proportion  to  the  number  of  the 
population  who  are  exposed  daily  to  the  danger.  There  are  but  fcAV 
reported  cases  in  which  the  influence  of  other  possible  conditions  can  be 
excluded  so  thoroughly  as  to  leave  no  reasonable  doubt  of  the  causal 
relation  of  milk.  Single  instances  are  necessarily  of  less  value  than 
groups  of  cases,  and  the  latter  are  much  less  conmion  than  generally 
is  supposed.  From  the  number  available  the  following  are  selected  as 
illustrations : 

Brouardel*  records  the  death  of  7  children  with  no  hereditary  taint, 
inmates  of  a  convent,  from  tuberculosis  supposedly  induced  by  the  use 
of  milk  from  a  cow  with  tuberculosis  of  the  udder.  Another  case 
reported  by  him,  and  quoted  by  Freudenreich,*  is  one  in  which  5  of  14 
girls  in  a  boarding-school  became  infected  and  died.  The  milk  which 
they  had  used  daily  came  from  a  tuberculous  coav. 

Demme"  reported  as  the  only  instance  in  his  experience  in  which  all 
other  causes  could  satisfactorily  be  excluded,  a  group  of  4  infants  of 
healthy  parentage  fed  upon  uncooked  milk  of  tuberculous  cows.  They 
all  died  of  tuberculosis  of  the  intestine,  and  the  diagnosis  was  confirmed 
by  autopsy.  Later,  he  reported^  still  another  death  from  the  same 
cause  at  four  months.      In  this  case  also  there  was  absolutely  no  family 

1  Hygienic  Laboratoiy  Bulletin,  No.  41,  p.  191. 
^  .Jour.  Am.  Med.  Assoc,  Mar.  27,  1909. 
3  Ibid.,  Oct.  8,  1910. 

■1  Annales  d' Hygiene  publique,  XXIV.,  p.  65. 

5  Les  Microbes  et  leur  des  Kole  dans  la  Laiterie,  Paris,  1894,  p.  45. 
^  .Jahresbericht  iiber  die  Tliiitigkeit  des  Jenner'sclien  Kinderspitals  •  in  Bern,  1882, 
p.  48. 

7  Ibid.,  1886,  p.  20. 


MILK  AS  A    FAdTOn    IN   Till':  sriil'.M)    OF   hISEASIC.  103 

liiKtory  ol"  tiilxsrculosis.  Al'lcr  llic  '•(.ii(Irrii;iti<)ii  of  llic  (Jiagnohih  by 
autopsy,  the  cow  wan  Hluii^litcrod  iiixl  round  to  Lc  inlx  iciiIoiih. 

Mull(!t'  foiiii<l  ji  iititiiluT  of  (lascs  ol"  iiii(loiil»t((l  cDiiiicclioii  ill  fanji- 
]i(!S  of  milk  jirodiic.cr.s  :  thus,  a  f^irl  oi"  I)  years,  acfiisloiDf*!  to  dijnk 
milk  directly  as  it  was  drawn  from  a  li(;rd  of  21,  I !»  of  wliicli  were 
tub(;rciiloiJH,  died  ol' abdominal  tiiberciiloHis  ;  a  fi;irl  oi"  7  years  wifli  llie 
habit  of  drinkiiifif  lar^e  amounts  of  warm  milk  fntm  a  herd  of  10  tiiber- 
(Miloiis  cows,  died  of  (iibercMilar  peritonitis  ;  \)  similar  cases,  all  of  death 
from  tuberculosis  other  than  the  pulmonary  form,  in  eonserjucncc!  of 
the  use  of  raw  milk  from  tuberculous  cows  owned  by  the  resfjective 
families. 

Some  of  these  eases,  if  not  all,  may  be  accepted  as  very  strong  evi- 
dence that  tuberculosis  may  be  sjiread  through  the  af:<-ncy  of  milk. 
But  ii"  it  is  true  that  so  lar<r(!  a  ])roportioii  of  the  milk  suj)ply  is  frc)m 
diseased  cows,  and  that  the  disease  is  communicable  in  this  way,  it 
follows  that  with  the  vast  majority  of  drinkers  of  mw  milk  the  liaeilli 
perish  or  are  dischart>;ed  without  (rainin*^  entrance  to  th(;  tissues. 

Graiitinti;  that  iiiueii  of  the  public  milk  supply  is  derived  from  tuber- 
culous cows,  and  that  it  is  consumed  very  lar<:;ely  in  unsterilized  r-oudi- 
tiou  by  very  younji;  children,  one  would  naturally  expect,  if  the  bovine 
bacillus  is  markedly  infective  to  man,  to  find  a  very  high  death-rate 
from  alxlominal  tuberculosis  among  the  very  young.  It  is  asserted  that 
this  is  the  case,  and  elaborate  arguments  in  favor  of  the  statement  that 
tuberculous  milk  is  responsible  lor  a  great  part  of  the  constantly  high 
infantile  death-rate  have  been  based  on  figures  given  by  the  late  Sir  R. 
Thorne-Th(M-ne,  in  his  Harben  lectures,  in  November,  18!)8,  showing  that, 
whereas  in  England  and  Wales  the  returns  for  1891—1895,  comjiared 
with  those  for  1851—1860,  indicate  a  reduction  in  mortality  from 
phthisis  at  all  ages  of  45.4  per  cent.,  and  from  all  forms  of  tuberculosis 
of  39.1  per  cent.,  the  decrease  in  tabes  meseuterica  was  for  all  ages  only 
8.5,  and  for  children  under  five  only  3  per  cent.  ;  and  that,  moreover, 
for  children  under  one  year  there  was  not  only  no  reduction,  but  an 
actual  increase  of  27.7  per  cent.  Such  figures,  emanating  from  so  high 
an  authority,  would  seem  to  admit  of  but  one  explanation,  namely, 
that  infected  milk  is  a  danger  hardly  to  be  overrated.  But  these  figures 
are  directly  opposed  to  clinical  experience  elsewhere  and,  as  Avill  appear, 
are  incorrect.  Dr.  D.  Bovaird^  points  out  that  it  is  only  in  England 
that  reports  indicate  any  considerable  number  of  cases  of  primaiy  intes- 
tinal tuberculosis,  and  asserts  that  it  is  very  rare  in  and  about  Xew 
York  City,  and  that  the  evidence  connecting  tuberculosis  in  children 
with  infected  milk  is  very  meagre.  Koch  has  called  attention  to  the 
great  infrequencv  of  primary  tuberculosis  of  the  intestine  among  children 
in  institutions  in  Berlin  ;  and  Biedert,^  too,  asserts  that  the  amount  of 
tubercular  infection  through  the  alimentary  canal  is  veiy  small.    Adami  * 

^  Quoted  in  L'Eobo  medical  dii  Noixi,  April  2,  1903. 
-  Archives  of  Pediatrics,  December,  1901. 
3  Berliner  klinische  Wochenschrilt,  November  25,  1901. 
*  Philadelphia  Medical  Journal,  February  22,  1902. 


134  FOODS. 

is  of  the  opinion  that  tuberculosis  of  young  children,  and  especially  peri- 
toneal and  intestinal  tuberculosis,  is  remarkably  rare  in  the  great  cities 
of  North  America ;  but  Jacobi,*  while  admitting  that  primary  tubercu- 
lar ulcerations  of  the  intestine  and  primary  tuberculosis  of  the  mesen- 
teric glands  are  rare,  holds  that  peritoneal  tuberculosis  is  very  common. 
Adami  cites  the  mortality  returns  for  INIontreal  for  the  year  ended 
June,  1900,  showing  that  of  935  deaths  from  tuberculosis,  but  4  were 
of  children  under  fourteen,  and  3  of  these  were  from  abdominal  tuber- 
culosis in  children  under  five  years.  Crookshank^  dissents  from  the 
opinion  that  abdominal  tuberculosis  of  children  is  connected  with  in- 
fected milk,  but  believes  that  not  sufficient  consideration  is  given  to  the 
possibility  of  infection  from  lunnan  sources. 

The  fallacy  of  Thorne-Thorne's  figures  has  been  pointed  out  by  Carr, 
Guthrie,  Donkin,  and  others,  and  all  arguments  based  thereon  must  fall 
to  the  ground.  In  December,  1898,  Carr^  showed  that  the  vast  ma- 
jority of  cases  returned  as  tabes  mesenterjca  Avere  probably  of  maras- 
mus, due  to  gastro-intestinal  catarrh.  Guthrie*  coucluded  from  the 
results  of  77  autopsies  performed  by  him  on  tuberculous  children  that 
the  disease  begins  far  more  commonly  in  the  chest  than  in  the  abdomen, 
and  that  tabes  mesenterica  as  a  cause  of  death  in  young  children  is 
practically  unknown  or  extremely  rare.  Donkin,  who  contends  that 
the  original  significance  of  the  term  "tabes  mesenterica"  no  longer 
holds,  says  :  ^  "  We  all  know  that  all  kinds  of  intestinal  and  other  dis- 
orders are  constantly  styled  '  tabes  mesenterica  ^  by  those  who  fail  to 
cure  them."  It  has  been  pointed  out  that  whereas  in  England  about 
10  per  cent,  of  all  tuberculosis  and  about  30  per  cent,  of  tuberculosis 
of  children  is  classed  as  tabes  mesenterica,  the  respective  figures  for 
Berlin  in  1898  were  1.8  and  2.8,  for  Paris,  in  1897,-1.33  and  1.65, 
and  for  New  York,  in  1899,  0.47  and  2.86. 

Stowell,^  who  has  had  an  unusual  opportunity  to  study  the  influence 
of  milk  of  tuberculous  cows  at  the  New  York  City  Children's  Hos- 
pitals on  Randall's  Island,  relates  that  during  two  years  the  milk 
supply  consisted  of  market  milk  which  was  pasteurized  at  155°  to 
165°  F.  and  milk  produced  on  the  island.  The  latter  was  reserved 
for  use  in  the  raw  state  by  the  very  young  and  the  acutely  sick.  In 
October,  1907,  the  herd  of  28  cows  and  2  bulls  was  tested  with  tuber- 
culin, and  all  but  3  reacted.  All  the  animals  were  slaughtered  and 
examined.  The  non-reacting  animals  proved  to  be  free  from  tubercu- 
losis, but  all  the  others  were  diseased.  Of  the  entire  number,  but  1 
had  udder  tuberculosis.  Stowell's  experience  led  him  to  conclude  that 
since,  during  the  use  of  this  milk,  there  was  no  evidence  of  any  more 
development  of  tuberculosis  among  those  who  received  it  than  among 
those  who  had  pasteurized  milk,  the  danger  of  tubercular  infection  from 
milk  must  be  very  slight. 

'  New  York  Medical  .Journal,  .January  25,  1902. 

2  The  Lancet,  November  2,  1901. 

3  Ibid.,  1898,  II.,  p.  1662.  *  Ibid.,  1899, 1.,  p.  286. 
■'  British  Medical  Journal,  October  14,  1899,  p.  1046. 

«  Medical  Record,  June  20,  1908,  p.  1023. 


MILK  AS  A    FAdTOIl   IN   Till':  .SJ'R/'JA/}   OF  DISKASK.         13.0 

Notwithst'indiiif^  tlic  |):iiic,ily  of  cMHfH  wliicli  oH'cr  ntron^  cvidciu^;  <»f" 
a  cauKal  relation  l)('tw<'(!M  inrcctcd  milk  mikI  tlu-  occurrence;  of  tiibcrcu- 
lo.sis,  ;ni(l  in  spile  of  flu;  now  rccuij^tii/cd  dilll  ivnccs  hctwccn  \\h-  hovliu; 
and  linnian  hiic.illi,  IIm;  possihilily  of"  dimmer  in  individual  c;i.s(!.s  cannot 
li^Iiily  l)c  l)nislic(l  aside.  yVccordinir  to  'I'lurohald  Srnilli/  it  Ih  fpiitc 
possiliie  that  HouKitliin^  intcrfer(^s  vvitli  the  al)Hor|»fion  of  bovine  Inicilli, 
while  allowing  tli(!  liunian  bacilli  to  pass  ;  and  while  racial  di(!"er(!n(MJ8 
probably  pn^vent  the  absorption  of  bovine  ba(;illi  under  ordinary  circum- 
stances, and  a  few  bacilli  are  harmless,  there  is  danj^cr  if  the  di^e.-tive 
tract  is  flooded  with  bacilli  from  tubentulouH  luhhtrs.  Ostertaf^  advo- 
cates tlio  cullinji;  out  of  all  cows  showing  clinical  evidence  of  tubercu- 
losis (beyond  rea(;tinp^),  and  especially  of  all  with  lesions  within  the 
udder. 

Tjcblaiic^  is  of  tlu;  opinion  (hat  the  milk  of  tuberculous  cows  is 
danf>;erous,  not  on  account  of  the  bacilli,  but  on  account  of  the  t^^xins 
that  it  contains,  for  it  has  been  ])roved  to  liave  toxic  properties. 
Michellaz/i  has  shown  that  such  milk  injected  into  tuberculous  ani- 
mals causes  a  reaction,  and  that  the  milk  of  a  tuberculous  mother  will 
in  time  prove  toxic  to  her  child. 

However  great  or  small  may  be  the  danger  from  the  use  of  tubercu- 
lous milk,  it  may  be  entirely  avoided  by  using  the  milk  of  goats  in- 
stead of  that  of  cows.  Wright^  has  called  attention  to  the  ifact  that 
the  goat  is  a  clean  animal  as  compared  with  the  cow,  that  its  feces  are 
solid  and  rolled  in  balls  and  hence  not  likely  to  become  attached  to  the 
flanks  and  udder,  and  that  it  is  practically  immune  to  tuberculosis, 
Nocard  having  failed  to  find  a  single  case  of  tubercular  lesions  among 
130,000  slaughtered  goats  and  kids.  To  the  common  objection  that 
goats'  milk  is  offensive  in  odor.  Burr*  answers  that,  drawn  in  a  clean 
stable,  the  air  of  which  is  not  made  offensive  by  the  presence  of  the 
male  animal,  goats'  milk  is  as  free  from  distinctive  odor  as  cows'  milk. 
Goats'  milk  appears  to  be  quite  as  digestible  as  cows'  milk,  if  not  more 
so,  especially  if  it  is  taken,  as  in  some  European  countries,  warm  from 
the  animals.  Wood  ^  advises  very  strongly  the  use  of  goats'  milk  for 
bottle-fed  infants,  stating  that  not  one  of  a  number  under  his  care  so 
fed  during  the  whole  summer  had  any  diarrhoea  whatever. 

Curiously  enough,  however,  in  its  relation  to  another  disease  goats' 
milk  has  been  proved  to  be  very  dangerous.  For  a  number  of  years 
epidemics  of  an  irregular  fever  on  the  Island  of  jSIalta  remained  unex- 
plained, although  the  specific  organism  of  the  disease  (the  Micrococcus 
mclitcnsis)  was  discovered  by  Bruce  in  1887.  Although  the  disease 
may  be  spread  by  other  means,  it  has  been  found  that  the  ingestion  of 
the  milk  of  infected  goats  constitutes  the  main  channel  of  transmission. 
As  soon  as  this  fact  became  known  and  the  milk  excluded  as  an  article 
of  diet,  the  occurrence  of  Malta  fever  was  to  a  large  extent  eliminated. 

1  Medical  News,  February  22,  1902. 

•'  Lyon  Medical,  April  14,  1901,  p.  561. 

3  The  Lancet,  November  3,  1906. 

*  Milchzeitung,  1907,  Nos.  19-21. 

^  Intercolonial  Medical  Journal  of  Australasia,  Mar,  1907. 


136  FOODS. 

Milk  Contaminated  from  Without  with  Organisms  Related  to 
Human  Diseases. — Milk  may  become  contaminated  with  infective 
matter  in  various  ways.  It  may  receive  it  from  the  liands,  person,  and 
clothing-  of  the  milkers  and  others  by  whom  it  is  handled,  whether  they 
are  themselves  sick  or  convalescent  or  acting-  in  the  capacity  of  nurse 
or  attendant  for  others ;  it  may  acquire  it  from  unclean  vessels  rinsed 
in  polluted  water,  or  from  water  with  which  it  has  fraudulently  been 
mixed. 

The  first  to  demonstrate  that  human  diseases  may  be  spread  by  cows* 
milk  was  Dr.  Michael  Taylor,  who  was  led  to  the  idea  by  the  occur- 
rence of  13  cases  of  typhoid  fever  in  7  of  14  families  supplied  with 
milk  from  the  same  farm,  the  prior  introduction  of  the  disease  into  the 
farmer's  flimily  by  an  infected  domestic,  and  seizure  of  two  of  his  chil- 
dren. This  outbreak  was  reported  by  him,^  but  the  publication  excited 
no  special  interest,  and,  indeed,  it  fell  to  him  to  report  also  the  second 
milk-borne  outbreak  discovered  10  years  later,  this  one  of  15  cases  of 
scarlet  fever  in  6  of  14  families  supplied  by  a  farmer  whose  wife  milked 
the  4  cows  and  nursed  at  the  same  time  a  child  fatally  ill  with  the  dis- 
ease. A  few  years  later  the  matter  of  milk-borne  infection  began  to 
receive  attention,  and  now  the  reports  of  such  outbreaks  number  many 
hundreds. 

On  account  of  the  danger  of  specific  contamination  of  milk,  no  per- 
son sick  with  or  convalescent  from  infectious  disease,  and  no  person 
having  to  do  with  the  care  of  the  sick,  or  with  the  disposal  of  their 
excreta,  or  with  the  washing  of  their  linen,  should  be  allowed  to  handle 
milk  intended  for  the  use  of  others.  Public  authorities  are  rapidly 
becoming  awakened  to  the  importance  of  restrictive  measures  in  this 
regard,  and  in  many  communities  it  has  been  made  a  criminal  offence 
to  fail  to  give  notice  of  the  presence  of  cases  of  infectious  disease  at 
the  place  of  production  of  milk  or  among  those  engaged  in  its  distribu- 
tion and  sale. 

According  to  Anderson,'''  an  outbreak  of  typhoid  fever,  due  to  con- 
tamination of  a  milk  supply,  is  characterized  by  the  sudden  outbreak 
of  an  unusual  number  of  cases  followed  by  a  rapid  decline ;  by  the  ap- 
pearance of  an  unusual  number  of  cases  among  customers  of  a  certain 
dairy  ;  by  the  unusual  incidence  of  cases  among  users  of  milk  ;  by  an 
excess  of  cases  among  the  well-to-do  as  compared  with  the  poor ;  and 
by  the  finding  of  the  typhoid  bacillus  in  the  suspected  milk.  It  is,  to 
be  sure,  very  rare  that  the  typhoid  bacillus  can  be  isolated  from  milk, 
but  it  should  be  attempted,  and,  if  successful,  is  conclusive. 

Diphtheria. — A  large  number  of  epidemics  have  been  reported  in 
which  a  positive  connection  with  the  milk  supply  appears  to  have  been 
fairly  well  made  out ;  but  so  far  as  is  known,  there  is  no  connection 
between  any  disease  of  the  cow  and  that  which  we  know  as  diphtheria, 
although  a  number  of  outbreaks  of  diphtheria  have  been  reported  as 
traced  to  garget.     The  specific  organism  of  diphtheria  may  be  intro- 

1  Edinburgh  Medical  .Journal,  1858,  p.  993. 
^  Am.  Jour.  Pub.  Hygiene,  May,  1909. 


MILK   AS  A    FACTOn.    IN    'I'lll':  smiCAh    OF   hlSFASE.         I.')? 

(lii(!(!(l  into  Miilk  (Voni  llic  (ll:-(li;iru's  oC  pcisoiis  ciiiidoycii  in  llic  li;in(|- 
lin<»-  ;in(l  (list.riWiition  of  milk  licroic  tJicy  lijivc;  rccovr^nid  llioroiij^lily 
(Voni  iJic  (lis('JiS(^  J)r.  J.  W.  11.  iMn; '  fonnd  flic  hMcillns  of  (li|)li(licriu 
in  siunpios  ol"  inilk  .supplied  l(»  ;i  l:irtr<'  scliool  wlicrc  a  nuniIxT  of  cawH 
of  the  discilHC  had  occMrrcd.  Il  lias  hem  roiind  i<  pciti  <||y  in  HilHjH!(;t('<l 
milk  by  otlun's,  including'  liowhill,  Klein,  I)ean,  Todd,  and  Mar-hall. 
'VW\  last  inciiiioncMl  (ound  ^  an  unusually  virulent  .strain  in  milk  .snp- 
po.scd  (()  hav(!  caused  two  (^ascs  of  the  <liscase. 

or  an  outhrc.ak  oC  72  oa.scs  reported  by  the  author,'  the  f;ause  was 
fbimd  to  have  been  disseminated  in  milk  whicli  wa.s  handled  by  the 
|)erson  who  at  tlm  sanu^  time  was  luusinj:;  a  child  sick  witii  the  disejiM-. 

"Of  tlu!  2.'>  di|)litlieria,  c|)i(l((mics  reported  as  sjiread  by  milk  and 
compiled  since  1  .S})r)  by  Trask,'  IT)  occurnid  in  the  United  States  and 
8  in  (irciat  IJritain  ;  cases  of  the  di.sease  occurred  at  the  producinj^  iartn, 
distributint^  <lidry,  or  milk  shoj)  at  such  a  time  as  to  have  been  the  po.s- 
sibUi  eau.se  of  the;  outbreak  in  1  <S  cases;  the  di.seasfid  |)er.son  nu'Iked  the 
cows  in  4  ;  the  same  person  ntir.sed  the  sick  and  handled  tlie  milk  in  ]  ; 
the  outbreak  was  supposed  to  be  due  to  disease  of  the  cows  in  2;  all 
cases  of  the  disease  wore  rcjiortcd  as  living  in  hou.seholds  supplied  with 
the  suspected  milk  in  15  instances;  measures  taken  upon  the  pre.sump- 
tion  that  milk  was  the  carrier  of  infection  were  reported  as  followed  by 
subsidence  of  the  outbreak  in  5  cases  ;  the  Kleb.s-Loffler  bacillus  was 
isolated  from  the  suspected  milk  in  2  of  the  epidemics." 

Cholera. — Undisputed  evidence  of  the  connection  between  milk  and 
Asiatic  cholera  is  not  very  common.  There  is  some  disagreement  as  to 
the  viability  of  the  cholera  organisms  in  milk;  thus,  He.s.se^  found  that 
fresh,  raw  milk  exerts  a  destructive  influence  on  them  ;  that,  in  fact, 
they  begin  to  die  as  soon  as  they  are  mixed  Avith  it.  He  found  that 
they  die  at  ordinary  room  temperature  within  12  hours,  and  at  incu- 
bator temperature  in  from  6  to  8  hours.  The  age  of  cultures,  the 
nature  of  the  culture  media,  and  the  addition  of  the  latter  to  the  milk 
with  the  bacteria,  appear  not  to  affect  the  re.sult.  iSterilized  milk  was 
found  to  be  a  better  culture  mediiun.  Basenau  ®  disagrees  with  Hesse. 
He  found  that  uncooked  milk  does  not  kill  the  organisms  in  10  houi^j, 
that  they  are  active  after  38  hours,  and  that  up  to  the  point  of  coagu- 
lation of  the  milk  they  increase  considerably  in  number.  He  found 
that  in  polluted  milk  they  remain  active  at  least  32  hours  at  different 
temperatures  (room  temperature,  24°  and  37°  C),  and  that  they 
remain  active  even  after  the  milk  has  coagulated. 

AVeigmann  and  Zirn  "  found  that  the  length  of  time  cholera  bacteria 
remain  active  depends  upon  the  ratio  they  bear  to  the  number  of  other 
organisms  present,  and  that  in  order  to  survive  for  many  hours  they 
would  have  to  be  added  to  milk  in  exceediufflv  lar^e  numbers. 

1  British  Medical  Journal,  September  2,  1889. 

-  Journal  of  Hygiene,  VII.,  1907,  p.  32. 

^  Boston  ]Medical  and  Sursfical  Journal,  June  27,  1907. 

*  Hygienio  Laboratory  Bulletin  No.  -41,  p.  36. 

^  Zeitschrifi  fiir  Hygiene  und  Infectionskrankbeiten,  XVII.,  p.  238. 

^  Arcbiv  fiir  Hygiene,  XXIII.,  p.  170. 

^  Centi-alblatt  fiir  Bakteriologie,  etc.,  189-4,  No.  8. 


138  FOODS. 

The  evidence  that  cholera  can  be  disseminated  through  the  agency 
of  milk  is  exceedingly  limited,  and  about  the  only  case  free  from  doubt 
is  that  recorded  by  Simpson,'  Avho  relates  that  9  cases  of  cholera 
occurred  suddenly  on  a  ship  hi  the  harbor  of  Calcutta,  10  men  of  whose 
crew  had  obtained  milk  from  a  native.  One  drank  but  little  and 
escaped,  4  died  of  undoubted  cholera,  and  5  were  very  sick  with  diar- 
rhoea. Eight  others  who  used  condensed  milk  only,  and  those  who 
used  no  milk  whatever,  were  unaffected.  It  was  learned  that  the 
vendor  had  diluted  the  milk  about  one-fourth  with  water  from  a  tank 
to  which  dejections  from  cholera  patients  had  gained  access  and  in  which 
the  clothes  of  the  patients  were  Avashed. 

Scarlet  Fever. — In  December,  1885,  occurred  what  has  become  com- 
monly known  as  the  Hendou  outbreak  of  scarlet  fever,  due  to  a  disease 
of  cows,  and  since  that  time  a  number  of  other  epidemics  have  been 
traced  apparently  to  a  common  milk  supply.  In  the  Hendon  case,  a 
number  of  cows  were  or  had  been  sick  with  an  infectious  eruption  of 
the  udders,  and  there  can  be  no  doubt  that  the  disease  under  considera- 
tion was  spread  through  the  agency  of  milk  coming  from  this  dairy ; 
but  other  cows  having  the  same  disease  caused  no  trouble,  and  the  pos- 
sibility of  contamination  from  human  sources  could  not  be  excluded 
absolutely.  A  number  of  other  outbreaks  of  the  disease  have  some- 
what doubtfully  been  ascribed  to  similar  teat  eruptions,  but  in  no  case 
is  the  evidence  conclusive.  On  the  other  hand,  there  is  undoubted 
evidence  that  the  disease  has  many  times  been  spread  by  milk  from 
farms  where  children  and  others  were  sick  with  it. 

In  tracing  epidemics  of  this  and  other  diseases  to  a  common  cause, 
there  is  always  danger  of  lending  too  much  importance  to  coincidence, 
and  of  coming  thereby  to  unwarranted  conclusions.  As  an  illustration, 
the  following  case  may  be  cited:  In  1897,  in  one  of  the  outlying 
wards  of  Boston,  a  large  number  of  cases  of  scarlet  fever  occurred 
with  some  suddenness  among  children  chiefly  of  the  well-to-do  class. 
Naturally  there  was  much  disturbance  of  the  public  mind,  and  an  in- 
vestigation was  undertaken  immediately.  It  was  ascertained  that 
nearly  all  of  the  families  concerned  were  supplied  by  one  milkman, 
who  "raised"  all  the  milk  which  he  handled,  and  the  responsibility  for 
the  outbreak  was  at  once  laid  at  his  door.  His  premises  were  ex- 
amined by  the  health  authorities  and  found  to  be  in  excellent  condition. 
No  case  of  disease  or  indisposition  had  occurred  in  his  family  or  among 
his  help  within  a  number  of  months,  nor  had  he  or  anybody  on  the 
place,  so  far  as  could  be  ascertained,  been  in  contact  with  any  case  of 
scarlet  fever  or  of  any  other  infectious  disease.  His  cows  were  examined 
by  a  thoroughly  competent  veterinarian  and  pronounced  in  every  respect 
healthy.  Nevertheless,  public  excitement  ran  so  high  that  his  business 
fell  away  very  considerably.  Had  a  single  cow  shown  the  slightest 
evidence  of  an  eruptive  disease  of  the  teats,  the  epidemic  might  have 
been  hailed  as  another  Hendon  outbreak,  and  been  quoted  in  sanitary 
history  as  a  noteworthy  example.  The  fact  that  the  great  majority  of 
1  Indian  Medical  Gazette,  May,  1887. 


MILK  AS  A    FACTOll   IN   TlIK  SI 'ILK  A  I)   OF  DISH  ASH.         ]'.'/,) 

cnHOH  ()(!(;iirr(!(i  :unonj^  liis  pufroMH  wuH  oasily  (^xplniiiuldc,  lor  lie.  wjwj 
known  to  l)(^  ii  cui'i'lnl,  rlcjinly,  IiomcmI,  dealer,  and  was,  tlienifon;,  tint 
vr.ry  sort  of"  man  U>  alii-a(;l,  the  pacliciihir  chi-s  wliosc;  liornctH  wen; 
invaded.  Tlu;  children  alleeUMl  belonged  to  closely  allilial*'*!  ^ronp.s  of 
j)liiytn!it(!H.  Furtluir  investipjalion  revealed  the  fact  ihat  the  lirKt  rsiHC 
was  of  a  laxl  whose,  family  was  not  a  cnstonK;!'  of*  IIk;  siisjieeted  dealer, 
and  that,  inunediately  heCoi'c!  taking  to  his  bed,  Ik;  had  heen  playing 
with  a  nntnl)(!r  of  (hose;  who  were  muou^  tin;  uc.xl  to  he  seized.  'IhcHe 
in  their  turn  had  be(!n  associated  with  others,  and  ko  the  infection  had 
spread.  Thus,  wiiat  niif^ht  have  served  as  a  most  useful  example  of  a 
milk-horiK'  ei)idennc  of  se;irlet  f(!V(!r  fell  to  the  ground,  ;iiid  the  unfor- 
tunate dealer  was  al)solve(l  from  r(!Si)onsil)ility, 

"Of  the  51  scarlet  fever  epidcmuvs  reported  as  spre;id  by  milk  com- 
piled by  Trask,'  25  occurred  in  the  United  States  and  2G  in  Great 
Britain  ;  all  eases  enumerated  in  the  outbreak  were  reported  as  living 
in  houses  su|)j)lied  with  the  suspected  milk  in  27  of  the  ej)idemics  ;  a 
case  sullcrini>;  from  the  disease  at  su(!h  a  time  as  to  have  been  the  pos- 
sible source  of  infection  was  found  at  the  producint::  firm,  the  distribut- 
ing dairy,  or  milk  shop  in  35  cases  ;  the  outbreak  was  su])pose<l  to 
have  been  due  to  bottles  returned  from  infected  households  and  refilled 
without  previous  sterilization  in  3  cases  ;  the  diseased  person  or  persf)n8 
were  mentioned  as  handling  the  milk  or  milk  utensils  in  3  ;  the  sick 
milked  the  cows  in  12  ;  the  same  person  nursed  the  sick  and  milked 
cows  in  1 ;  the  outbreak  was  supposed  to  be  due  to  disease  of  the  cow 
in  2 ;  it  was  reported  that  measures  taken  upon  the  presumption  that 
milk  was  the  cause  of  the  epidemic  were  followed  by  abatement  at  the 
outbreak  in  22  cases." 

Typhoid  Fever. — There  can  be  no  doubt  that,  in  the  spread  of  typlioid 
fever,  milk  plays  a  part  only  second  in  importance  to  that  of  drinking- 
water.  A  very  great  number  of  epidemics  have  been  traced  beyond 
a  possibility  of  dispute  to  milk  coming  from  firms  where  cases  of  the 
disease  have  occurred.  The  contamination  is  brought  about  by  the 
hands  of  the  milkers  or  other  handlers,  who,  in  addition,  assist  in 
nursing,  or  by  the  addition  of  infected  water,  or  through  washing  pails, 
cans,  and  other  vessels  in  such  Avater. 

From  time  to  time,  tabulated  analyses  of  outbreaks  supposed  to  be 
due  to  contaminated  milk  have  been  published,  but  a  very  large  pro- 
portion of  the  cases  included  are  based  on  very  insufficient  evidence, 
sometimes  exceedingly  slight,  siieh  as  that  a  cow  had  drunk  from  Asater 
into  which  drainage  from  the  barnyard  had  had  access.  But  within 
recent  vears,  a  nmnber  of  extensive  epidemics  in  this  country  and  else- 
where have  been  traced  with  as  much  definiteness  to  the  milk  supply, 
as  have  others  to  the  water  supply,  and  with  the  same  and  only 
defect  that  the  bacteriological  proof  has  been  lacking.  As  in  the 
case  when  outbreaks  occur  from  polluted  water,  when  attention  is 
drawn  to  the  possible  cause,  the  bacteriological  evidence  is  no  longer 

*  Hygienic  Laboratory  Bulletin,  No.  41,  p.  29. 


140  FOODS. 

obtainable,  the  conditious  having  changed  during  the  period  of  in- 
cubation. 

The  State  Board  of  Health  of  jNIassachnsetts  has  traced  a  number 
of  extensive  epidemics  to  the  use  of  polluted  milk,  but  in  no  instance 
has  the  organism  been  found  in  the  milk.  In  the  city  of  Boston  also, 
where  the  local  authorities  keep  a  constant  eye  on  the  reports  of  typhoid 
fever  cases  with  particular  reference  to  the  possibility  of  dissemination 
through  milk,  a  number  of  small  outbreaks  have  been  traced  definitely 
to  milk  supplies  derived  from  small  farms  where  persons  sick  with  the 
disease  were  nursed  by  those  w^ho  had  milked  the  cows  and  handled  the 
milk,  and  in  these  instances  also  the  bacteriological  evidence  is  lacking. 

That  the  organism  can  retain  its  vitality  in  milk,  and  even  in  sour 
milk,  has  definitely  been  settled.  Hein  found  the  organism  in  sour 
milk  at  lo°-18°  C.  after  thirty-five  days,  but  not  after  forty-eight. 
Hesse  has  found  it  in  sterilized  milk  after  four  months.  Drs.  Fraeukel 
and  Kister,^  having  reason  to  believe  that  the  unusual  amount  of  ty- 
phoid fever  at  Hamburg  during  the  summer  of  1897  was  due  in  part 
to  infected  buttermilk,  undertook  the  study  of  the  question  whether  B. 
typhosus  can  exist  in  that  fluid,  concerning  which  point  there  had  been 
more  or  less  of  conflicting  testimony.  Obtaining  some  samples,  they 
first  investigated  the  number  and  identity  of  the  contained  bacteria, 
and  learned  that,  while  the  number  varied  Avidely,  the  species  were 
always  about  the  same.  Finding  no  pathogenic  organisms,  they  steril- 
ized specimens  in  test-tubes  a  half  hour  a  day  for  three  days,  then 
planted  the  typhoid  bacillus  in  them  and  kept  them  at  diiferent  tem- 
peratures ;  on  ice  and  at  22°  and  37°  C.  Loops  were  taken  from  each 
from  time  to  time  and  planted,  and  each  yielded  positive  results.  The 
specimen  kept  at  room  temperature  was  under  observation  nine  days  ; 
the  others  were  not  examined  after  the  third.  The  specimens  of  fresh 
buttermilk  containing  all  its  bacteria  w^ere  planted  and  kept  under  the 
same  conditions,  and  from  tliem  the  same  results  were  obtained.  Yet 
there  was  this  difference,  that  there  was  always  a  diminution  in  the 
number  of  the  pathogenic  organisms,  and  this  was  the  more  marked, 
and  sometimes  veiy  rapid,  with  increasing  temperatures. 

A  typical  example  of  the  spread  of  typhoid  fever  through  the  medium 
of  milk  is  shown  in  the  following  description  of  an  epidemic  reported  to 
the  State  Board  of  Health  of  Massachusetts  :  ^ 

In  September,  1905,  X,  a  farmer,  after  having  been  in  poor  health 
all  summer,  and  after  a  two  weeks'  trip  to  Maine,  was  taken  sick  with 
typhoid  fever.  The  fever  ran  for  21  days  :  then  he  had  a  relapse, 
and  in  all  he  was  in  bed  8  weeks.  In  January,  1906,  Mrs.  X  became 
ill.  She  ran  no  fever  and  did  not  think  she  had  typhoid.  She  was  in 
bed  but  1  week,  and  considered  herself  merely  nervously  tired.  Since 
his  sickness  X  has  been  in  unusually  good  health.  He  has  had  no 
jaundice  and  no  abdominal  pain. 

^  Miinchener  medicinische  Wocheiischrift,  February  18,  1898. 

"  Monthly  Bulletin  of  the  State  Board  of  Health  of  Mass.,  Dec,  1909. 


MILK   AS    A    FACTO  n    IN    Til  I!  SI'llllA  I)    OF    P/SFASF.         Ill 

In  !!)()()  X  l)('j^;ui  t<>  l<<(|)  'J  cows,  ;iii(l  .since  tliut  time  caw.-  oC  tv- 
plioid  iov(!r  liiivo  occMincd  niuon^  liiH  milk  cUHtomerH  uh  fbllowH  : 

No.  of  CiiHOH. 

September,  1 !)()() 1 

April,  l'.K)7 2  (poHKil)ly  :{) 

May,  l'.)()7 1 

June,  VMH 1 

Ht'|)tciiil)CT,  l'.K)8 '2   (pdMsihle  cji.HCH  wiifi  to  l)i:  riiHtom«;rH  f)f  X) 

March,  I '.»()!) 1 

AugiLst,  I !)()!) ] 

September,  J !)()'.» 2 

Total II   (or  possibly  12  cases) 

These  (';i.se.s  of  tvplioid  fever  liave  been  efjnfined  1o  ;i  residence  por- 
tion of  tlie  town  ;il)()nt  ii;df  a  mile  S(|n:ire,  eentei"iii^  about  X's  lionse. 
Tlie  region  is  in  the  better  j)ortion  of  tlie  town,  well  elevated, 
with  good  hygienic!  conditions,  and  not  (ilose  to  the  mills  or  the 
river. 

The  peo[)le  arc  seemingly  of  moderate  means,  not  foreign  born, 
and  of  good  intelligen(;e.  The  honses  have  separate  cesspools.  There 
is  no  town  sewer.  The  water  supply  is  the  same  all  through  the 
town.  The  ice  for  the  whole  town  comes  from  the  same  scMirce — the 
river. 

There  is  a  well  in  the  neighborhood  used  by  a  large  number  of 
people.  Several  of  the  typhoid  cases  did  not  use  this  well,  and  many 
other  uninfected  persons  did  get  some  of  their  drinking  water  there. 
X  did  not  use  this  well. 

The  hygienic  condition  of  X's  place  is  quite  unsuited  for  the  produc- 
tion of  milk.  The  cesspool  is  not  carefully  sealed.  The  barn  is  filthy 
and  fly  infested.  An  unguarded  jn'ivy  drains  into  the  cellar,  Mhere 
the  manure  and  a  pig  are  ke]it.  Complaints  have  been  made  by  the 
neighbors  of  the  smell  from  the  place. 

X  has  kept  two  cows,  which  have  yielded  him  about  two  8i-quart 
cans  daily.  He  milks  the  cows  and  strains  the  milk  himself.  Mrs.  X 
washes  the  cans.  The  milk  is  peddled  about  the  neighborhood  by  X 
soon  after  it  is  milked.      It  is  not  iced. 

Specimens  of  feces  and  urine  from  X  showed  no  typhoid  liacilli  in 
the  feces,  but  there  was  an  abundant  growth  of  motile  bacilli  in  the 
urine.  The  bacilli  corresponded  in  cultural  and  agglutination  char- 
acters to  typhoid  bacilli. 

X  was  informed  of  his  condition  and  forbidden  to  distribute  any 
more  milk. 

At  the  beginning  of  the  year  1910,  four  and  a  half  years  after  his 
typhoid  fever  attack,  this  man  shows  a  constant  typhoid  bacilluria. 
He  has  no  symptoms  of  cystitis,  and  feels  better  than  he  did  before 
being  sick. 

A  year  later  it  was  found  that  several  more  cases  of  typhoid  fever 
occurred  in  the  same  town,  and  investigation  brought  out  the  fact  that 


142  FOODS. 

this  farmer  X,  although  forbidJen  to  sell  his  milk,  had  been  giving 
away  to  his  neighbors  an  excess  which  he  had,  in  the  absence  of  his 
wife.  Those  individuals,  however,  who  were  unfortunate  enongh  to 
accept  these  gifts,  promptly  came  down  with  tyjihoid  fever,  thus  show- 
ing that  the  larmer,  with  his  filthy  habits,  had  been  again  responsible 
for  infecting  his  milk  supply. 

Another  ei)idemic  reported  to  the  Massachusetts  State  Board  of 
Health  affected  59  persons  who  took  breakfast  at  a  certain  hotel  on 
Labor  Day,  1909.  This  epidemic  was  traced  to  a  waitress,  who,  in 
the  prodromal  stage  of  typhoid  fever,  had  access  to  and  undoubtedly 
did  infect  a  can  of  milk.  This  can  of  milk,  improperly  iced  and  there- 
fore of  a  tem])erature  favorable  to  the  growth  of  the  bacilli,  was  used 
at  breakfast  by  the  affected  persons. 

"Of  the  179  typhoid  epidemics  reported  as  spread  by  milk  com- 
piled by  Trask,^  107  occurred  in  the  United  States,  43  in  Great 
Britain,  23  in  continental  Europe,  3  in  Australia,  1  in  New  Zealand, 
and  2  in  Canada ;  all  cases  enumerated  in  the  outbreak  were  reported 
as  living  in  houses  supplied  with  the  suspected  milk  in  96  of  the  epi- 
demics ;  a  case,  suffering  from  the  disease  at  such  a  time  as  to  have 
been  the  possible  source  of  infection,  was  found  at  the  producing  farm, 
distributing  dairy,  or  milk  shop  in  113  cases;  the  outbreak  was  sup- 
posed to  have  been  due  to  bottles  returned  from  infected  households 
and  refilled  and  distributed  without  previous  sterilization  in  4  cases ; 
the  diseased  person  or  persons  were  mentioned  as  handling  the  milk  or 
milk  utensils  in  2  ;  the  sick  milked  the  cows  in  6  ;  the  same  person 
nursed  the  sick  and  handled  the  milk  or  milk  utensils  in  6  ;  same 
person  was  mentioned  as  nursing  sick  and  milking  cows  in  10  ;  ice 
cream  was  given  as  the  infective  medium  in  3  ;  whipped  cream  in  1  ; 
typhoid  dejecta  were  reported  as  thrown  on  the  ground  in  such  a  way 
as  to  have  more  than  probably  contaminated  the  well  water  used  for 
washing  the  milk  utensils  in  4 ;  in  many  cases  mention  was  made  of 
special  incidence  of  the  disease  among  persons  in  the  habit  of  drinking 
milk ;  the  Eberth  bacillus  was  isolated  from  the  milk  in  1  case 
(Konradi) ;  it  was  reported  that  measures  taken  upon  the  presumption 
that  milk  was  the  cause  of  the  epidemic,  and  looking  to  the  removal  of 
this  as  a  factor,  were  followed  by  abatement  of  the  outbreak  after  due 
allowance  for  the  usual  period  of  incubation  from  the  distribution  of 
the  last  infected  milk  in  78  of  the  cases." 

In  reporting  milk  epidemics,  some  of  the  points  of  special  interest, 
as  given  by  Trask,^  are  the  following  : 

"  1.  The  number  of  cases  of  the  disease  existing  in  the  involved 
territory  during  the  time  covered  by  the  epidemic. 

"  2.  The  number  of  houses  invaded  by  the  disease. 

"  3.  The  number  of  invaded  houses  supplied  in  whole  or  in  part, 
directly  or  indirectly,  by  the  suspected  milk. 

^  Hygienic  Laboratory  Bulletin  No.  41,  p.  24, 
2  Ibid.,  p.  47. 


Mlfjh'  AS  A    FACTO/:.   IN  TIHC  SI'IiHAD   OF  DISK  ASF.         M3 

"1.  'V\\i.\  iiuiribcr  of  casoH  ()c,<Miriiii[^  in  invaded  Iioiisch  ko  huj)- 
pliod. 

"5.   Tlio  iiiiriil)(!r  of  houses  sii|)j)li(!d  witli  IIk;  HiiH|)(;(;t<'<l  milk. 

"G.  TIk!  rcliitivo  proportion  of  Iioiikch  ho  BUppli(!d  to  tliow.  hnj)|.li<d 
by  otlicr  dairies. 

"7.   'l^lio  tinie  covered  hy  llie  epidernif,. 

"8.  Tlio  location  of  ilio  case  or  cascH  from  wliieli  llie  milk  hef^ame 
contaniinaied. 

"9.   Tlio  relation  of  i\\<\  (tri^inal  c.aso  to  tli(!  milk. 

"  10.   Tlu!  timo  i-cilation  of  IIk;  original  case  to  tlie  epi<lemic. 

"  11.   The  sp(H;ial  inchkwice  of  tiic  (hscase  among  milk  drinkers. 

"12.  The  elimination  of  other  common  carriers  of  infc-ction. 

"13.  The  effect  upon  tin;  e|)idemic  of  closing  the  dairy  or  taking 
such  measures  as  will  eliminat(!  jiossihility  of  milk  cont,"iniinati(jn  i'rom 
the  sus[)eeted  focus. 

"  14.  The  linding  of  tlie  specific  organism  in  the  milk." 

When  a  typhoid  e})idemic  occurs  it  oftentimes  takes  several  days 
before  the  cause  of  the  ej)i(letniG  can  be  located  and  eliminat^'d.  During 
tiiis  time,  however,  the  health  oflieer  can  be  doing  very  efficient  work 
through  advice  to  the  inhabitants  of  the  region  affected.  Information 
desiral)lo  at  such  a  crisis  has  been  very  well  epitomized  by  Hill, 
Epidemiologist  to  the  Minnesota  State  Board  of  Health,  in  an  article 
entitled,  "The Typhoid  Tourniquet,"  in  the  American  Journal  of  Public 
Hygiene,  May,  i{)Oi).  Hill  states  that  on  finding  a  tyj)hoid  outbreak 
in  a  town,  we  issue  in  the  papers,  display  on  the  streets,  and  address  to 
every  householder  the  following  })lacard  : 


To  the  Cltizois  of . 

Typhoid  Fever  is  Epidemic  in . 

The  Minnesota  State  Board  of  Health  is  investigating  this  epidemic 
to  find  its  exact  source.      Meantime  govern  yourselves  as  follows  : 

1.  Typhoid  fever  is  contracted  solely  by  the  mouth.  If  you  do  uot 
put  the  poison  of  typhoid  fever  into  your  mouth  you  will  never  contract 
typhoid  fever.     Therefore,  iratch  the  mouth. 

2.  Do  not  eat  or  drink  anything  (water,  milk,  oysters,  fresh  vege- 
tables, or  anything  else)  unless  it  has  been  first  boiled,  broiled,  baked, 
roasted,  fried,  or  otherwise  thoroughly  heated  through  and  through. 

3.  Do  rvithont  all  food  or  dri7ik  which  has  not  first  been  thus  heated. 
(Canned  or  bottled  foods  or  drinks,  other  than  milk  or  water,  are  not 
included  in  this.) 

4.  If  living  in  the  same  house  with  a  typhoid  fever  patient,  do  not 
handle  your  own  food,  or  food  intended  for  any  one  else,  even  if  it  has 
been  heated,  except  with  hands  that  have  been  thoroughly  rrashed  with 
soap  and  very  hot  water.  (Prefembly  also  with  antiseptic  ;  ask  your 
physician  about  the  antiseptic  to  use.)      Wash  before  every  meal  in  this 


144  FOODS. 

way,  and   before  cooking,  serving,  or   eating   anything,  or  putting   the 
fingers  in  the  mouth. 

5.  If  there  are  flies  abont,  see  that  all  food  and  drink  is  j)rotected 
from  them  at  all  times.  Flies  often  carry  typhoid  poison  to  foods  and 
drinks. 

6.  TJie:poison  of  typhoid  fei'cr  does  not  show  itself  for  tioo  weeks  after 
it  enters  the  body.  Tlierefore,  for  the  next  two  weeks  ty])hoid  cases 
may  develop  from  ty])hoid  poison  already  taken  in.  But  any  case 
which  develops  on  and  after  (a  date  two  weeks  later  than  the  date  of 
the  placard)  will  be  due  solely  to  neglect  of  this  notice  and  failure  to 
carry  out  minutely  the  directions  here  given. 

Cholera  Infantum. — In  every  large  community,  it  has  become  cus- 
tomary to  expect  as  a  normal  condition  a  large  death-rate  among  chil- 
dren with  the  advent  of  hot  weather.  This  increased  death-rate  is 
limited  very  largely  to  the  very  early  age  periods  and  to  children  fed 
on  cows'  milk,  and  while  children  of  the  poor  are  the  ones  most  com- 
monly attacked,  those  of  the  Avell-to-do  are  by  no  means  free.  During 
the  siege  of  Paris,  the  infant  mortality  was  reduced  to  a  half  of  its 
yearly  average,  although  the  general  death-rate  had  doubled.  This 
unusual  condition  was  attributed,  no  doubt  correctly,  to  the  fact  that 
mothers  were  obliged  to  nurse  their  infimts  wlien  they  could,  on  account 
of  the  great  scarcity  of  cows'  milk  and  other  foods. 

The  common  milk  bacteria  are  ordinarily  harmless,  but  it  appears 
that  some  species  under  certain  conditions  produce  toxins  in  sufficient 
amounts  to  cause  gastric  and  intestinal  disturbances.  According  to 
Baginsky,!  a  large  part  of  the  annual  amount  of  cholera  infantum  is 
due  to  these  products  (see  under  Gargety 

Dr.  E.  W,  Hope^  investigated  over  a  thoiisand  cases  of  autumnal 
diarrhoea,  and  found  that,  of  233  deaths  of  infants  under  three  months, 
only  16  had  not  received  other  than  their  natural  food.  That  is  to  say, 
the  deaths  among  artificially  fed  children  under  three  months  of  age 
were  fifteen  times  as  numerous  as  among  those  nursed.  In  no  less  than 
22  per  cent,  of  the  whole  number  of  fatal  cases,  other  members  of  the 
household  had  suflPered  from  diarrhoea.  The  most  striking  instance  of 
the  communicability  of  the  disturbance  was  that  at  an  infimts'  home  in 
which  were  10  children  under  the  age  of  five  months,  all  in  perfect 
health.  An  infant  of  two  months  was  admitted  in  July  with  vomiting 
and  diarrhoea,  and  within  a  few  days  6  of  the  other  infants  and  the 
nurses  were  sick  in  the  same  way.  The  4  other  children  were  taken 
away  at  once.  The  admitted  child  and  the  6  that  became  infected  all 
died.     The  4  that  were  taken  away  were  saved. 

Bacteriological  examination  of  milk  has  shown  the  presence  of  ex- 
tremely active  organisms,  including  JB.  ejiteritidis  sporogenes  of  Klein,^ 
which  has  l)een  found  by  its  discoverer  in  the  ileum  contents  of  chil- 

1  Berliner  klinische  Woohenschrift,  1894,  Nns.  43  and  44. 

2  Public  Health,  July,  1899. 

3  Centralblatt  fiir  Bacteriologie,  etc.,  XXII.,  Abth.  I.,  Nos.  20  and  21 ;  XXIII., 
Abth.  I.,  No.  13. 


MILK  AS  A    FACTOn    IN    'I'llE  SI'llKAD    OF   DISFASF.  1  ITj 

dreii  lind  adiilLs  willi  (ll;irili<i:il  coiHlitions,  Iml  not  in  ;i  r-(,n<lili'in  of 
health.  It  liJlS  been  (oiind  1))'  Anchcwc-  in  (lie  (n.vdliiirj^cH  oi'  chhcs  of 
K|)()riuli(;  (M;in-liu';i,  (.("  :i<lnlls,  iind  l>y  Khin  in  three  (liU'crcnt  oiifhrciikH 
iUnon<i;  llic  inni:il('S  of  ;i,  sin<jle  lio:-|)il;il.  ll  i-  ;i  eommon  .s'lprophytc 
fotiiid  in  Si^vvii^c,  in  pollnied  ri\'eiv,  :in<l  in  ni;inni-e(l  ^;ir<l(!n  !-oil,  and  in 
very  connnoidy  deireled  in  milk,  llie  use  of  wliidi  has  not  hecn  fol- 
lowed by  untoward  n'snlls.  Under  oerl;iin  imknowii  coiiditioiis,  it 
l)e(H)nu!S  hif^hly  palho<j:;('nic,  wnd  recent  milk  cnlliires  arc  inteti.sely 
virul(Mit  when    Inocnlaled   sMixMitancoiisly   in   ^'nin(^i-|)i^^-^. 

It  is  j)rol)al)le  that  to  this  orjranism  was  due  an  onthrcak  of  milk- 
poisoninjr  in  Malta,  deserihed  and  investi<^ated  by  J.  Zainmit.'  In  one 
village,  T)  fainilics  eomprising  12  ])crson8  were  seized  with  vomiting, 
diarrhd'a,,  an<I  cramps,  and  2  children  snccinnbed.  Post-mortem  exam- 
ination revealed  iiofliing  excej)t  (H)ngestioii  of  some  of  the  viscctra.  Snb- 
sequently,  in  another  village,  17  ju'rsons  in  5  honses  were  attacked  with 
severe  gastro-enteritis  and  collapse.  The  symptoms,  which  came  on  in 
all  cases  about  three  hours  after  drinking  milk,  included  vomiting, 
diarrluxia,  acute  pain  in  the  stomach  and  bowels,  cramps  in  the  extrem- 
ities, weak  and  irregidar  pidse,  and  cold  and  clammy  skin.  The  |>er- 
sons  concerned  in  both  outbrejiks  obtained  their  milk  i'voxn  the  same 
dealer,  whose  cans,  which  had  a  sour  smell,  yielded  on  bacteriological 
examination  a  bacillus  having  all  the  characteristics  of  the  one  men- 
tioned. Families  which  were  su]ipli(>d  by  the  same  de;der,  but  directly 
from  the  goats,  showed  no  symptoms,  and  the  goats  themselves  were 
free  from  diae;ise. 

Andrewes^  has  described  3  much  more  extensive  outbreaks,  referred 
to  above,  due  to  the  same  organism,  in  one  of  which  the  offending  food 
was  found  to  be  rice  pudding  made  with  milk.  The  first  and  second 
outbreaks,  in  which  no  one  article  of  food  could  be  incriminated,  in- 
volved respectively  59  and  146  patients;  the  third  involved  86.  In 
all  3  outbreaks,  the  great  majority  of  the  attacks  were  mild,  but  in  some 
of  the  more  severe  cases,  the  discharges  contained  mucus  and  blood. 
In  all  3,  the  organism  was  found  in  the  stools,  and  in  the  second,  it  was 
found  in  the  milk  given  out  on  the  previous  day.  lu  the  third,  it  was 
impossible  to  obtain  any  of  the  milk,  but  the  pudding  made  with  it 
yielded  the  organisms,  in  s]>ite  of  the  heat  to  which  the  compound  had 
been  subjected  during  its  preparation.  It  was  found  by  direct  experi- 
ment that  the  interior  of  such  a  pudding  did  not  attain  a  temjterature 
above  98°  C.  during  cooking,  a  temperature  below  that  necessary  for 
the  destruction  of  the  spores,  which  are  among  the  most  resistant 
known. 

1  British  Medical  Journal,  ^Slay  12,  1900,  p.  1151. 

2  The  Lancet,  January  7,  1899. 
10 


146 


FOODS. 


Fig.  2. 


WATER 

C.G120 ^65^ 


Feser's  lactoscope. 


Analysis  of  Milk. 

For  ordinary  purjxjses  of  determining-  the  quality  of  milk,  the  pres- 
ence or  absence  of  added  water,  and  whether  it  has  been  i-obbed  of  its 
cream,  a  coniplete  chemical  analysis  is  by  no  means  always  necessary, 

since  much  may  be  learned  from 
Fig.  3.  simple  inspection  by  means  of  the 
lactodensimeter  and  the  lactoscope. 
The  lactodensimeter  (Fig.  3),  or 
lactometer,  is  merely  a  large  hy- 
drometer with  a  stem  graduated  to 
show  specific  gravities  ranging  from 
1.015  to  1.040.  The  lactoscope, 
invented  by  Professor  Fcser,  is  an 
instrument  designed  to  indicate  the 
approximate  fat  content  of  milk. 
It  consists  of  7  glass  cylinder,  into 
the  base  of  which  a  smaller  cylinder 
of  white  glass,  closed  at  the  top 
and  mounted  on  a  metallic  base,  is 
fitted.  The  larger  cylinder  is  grad- 
uated along  the  side ;  the  smaller 
one  bears  a  number  of  black  hori- 
zontal lines.  The  instrument  is 
shown  in  Fig.  2. 

The  principle  of  the  instrument 
is  based  upon  the  fact  that  the 
opacity  of  milk  is  due  mainly  to 
the  fat  globules  in  suspension,  and 
that,  therefore,  the  richer  a  milk 
is  in  fat,  the  greater  is  its  opacity, 
and  the  more  it  must  be  diluted 
to  reduce  the  opacity  to  such  an 
extent  as  to  permit  the  passage  of 
light. 

The  method  of  use  is  as  follows  : 
Four  cc.  of  the  specimen  are  de- 
livered from  a  pipette  into  the  cylinder  through  the  opening  in  its  upper 
end,  and  then  water  is  added  in  small  portions  and  thoroughly  mixed 
by  inversion  of  the  instrument,  the  orifice  being  kept  closed  by  the  tip 
of  the  forefinger.  As  soon  as  the  successive  additions  of  water  have 
reduced  the  opacity  of  the  mixture  to  such  an  extent  that  the  black 
lines  on  the  white  cylinder  can  be  discerned  so  distinctly  that  they  may 
be  counted,  the  height  of  the  liquid  on  the  scale  is  noted  and  the  per- 
centage of  fat  indicated  is  read.  Four  cc.  of  skimmed  milk  will  re- 
quire so  little  water  that,  when  the  lines  can  be  seen,  the  level  of  the 
mixture  will  be  very  low  on  the  scale,  while  with  rich  milk  it  will  be 


ANAl,YS/S  OF  MII.K.  147 

eorr('S])f)H(liiiu;ly  lii^li,  mihI  willi  civ'utii  the  whole  cyliiiilf  r  will  !)<•  fillc<l, 
und  v\v,\\  {\\VM  (\\r.  lines  riinnof,  he  rrindc  oii(. 

(/oiitrol  jinulyscs  show  Ih.il  (he  in-i iiiniciit  givcH  very  fairly  awurate 
I'csiiIIh.  Ncithf!!'  of  these  inslidHHiils  jiIoik;  (;!Ui  Ik;  rlcjMiiuiefl  ii[)on 
(o  in(li(!;it(!  the  iriKr  (|u;ili(y  of"  milk,  excepting  iti  fh<!  i::\m\  (A'  saruplcss 
which  WW,  either  v(!rv  jjjood  or  very  had.  '\\\r  specide,  jfravity  al'»ii(!  in 
(ispecially  lalhieioiis  as  ;i  ^iiid(3  lor  t Ik-  loHowiii^  rwiHons  :  The  specific 
gravity  of  iionii:il  milk  at  r)l)°  V.  raiif^es  hetwoen  1.021)  and  l.O.'M. 
'V\w.  removal  of  cream  caus(!S  it  to  rist; ;  tli(!  addition  of  water  (Rinses  it 
to  faU.  A  normal  milk  wIkmi  rohbed  of  its  ca'cam  may  show  a  sjMtcifio 
•gravity  of  1. ()-'>(!,  and  then  if  a  small  amonnt  of  water  is  added,  the 
jrravity  is  hron^ht  down  to  l.().'>2;  that  is  to  say,  within  normal  limits. 
Thns,  a  milk  after  being  doubly  treated  so  as  to  reduce  its  nutritive 
value,  niiiy  show  a  normal  sj)ecific  gravity,  and,  on  this  t<,'st  alone,  bo 
(biassed  as  pure.  Nor  is  this  the  only  (»bjection  to  a  system  of  insj)ec- 
tion  of  this  most  important  food  based  upon  the  use  of  the  hurtometer, 
since  milks  exceptionally  rich  in  tat  have  a  specific  gravity  below  the 
normal,  and  thus  may  be  condemned  as  watered. 

The  lactoscope  alone  is  also  not  to  be  dejicuded  upon  in  all  Cti.';e>;, 
since  a  milk  whi(;h  shows  a  normal  content  of  fat  may  be  oik;  of  con- 
siderable richness  in  that  constituent  and  extensively  watered.  Thus, 
a  specimen  containing  originally  4.50  per  cent,  of  fat  may  be  watered! 
very  considerably,  and  yet  show  3.75  per  cent,  by  the  lactoscope. 

By  combining  the  use  of  both  instruments,  however,  the  fallacies  of 
either  arc  exposed.  A  normal  specific  gravity  shown  by  the  one  and  a 
normal  fat  content  revealed  by  the  other  will  indicate  that,  even  if  the 
milk  has  been  tampered  with,  it  yet  possesses  average  richness.  A 
normal  specific  gravity  with  a  low  percentage  of  fat  will  indicate  skim- 
ming and  watering  ;  low  specific  gravity  with  normal  or  low  fat,  water- 
ing ;  and  high  specific  gravity  with  low  fat,  skimming.  Low  specific 
gravity  with  very  high  fat  will  indicate  unusual  richness  ;  thus,  cream 
has  a  very  low  specific  gravity,  due  to  its  preponderance  of  fat.  As  a 
test  of  the  accuracy  of  this  process  of  examination,  the  author^  caused 
to  be  analyzed  under  his  supervision  1,714  specimens  which  appeared 
by  those  tests  to  be  of  good  quality,  and  of  this  number  but  8  were 
found  to  have  deviated  materially  from  the  statute  requirement  of  13 
per  cent,  of  total  solids. 

Determination  of  Specific  Gravity. — In  taking  the  specific  gravity 
by  means  of  the  lactodensimeter,  the  milk  is  mixed  thoroughly,  in 
order  to  insure  homogeneity,  by  pouring  from  one  vessel  into  another ; 
a  cylinder  of  suificient  depth  to  allow  the  instrument  to  float  freely  is 
filled  with  the  milk,  and  the  instrument  is  carefully  inserted,  not 
dropped,  down  to  the  bottom,  and  then  released.  When  it  comes  to 
rest,  the  reading  of  the  stem  at  the  level  of  the  surface  of  the  liquid  is 
noted.  It  should  be  borne  in  mind  that  air  bubbles  are  retained  rather 
tenaciously  by  the  milk,  and  tend  to  lower  the  density,  and,  therefore, 

1  Thirty-first  Annual  Report  of  the  Inspector  of  Milk,  Boston,  1SS9,  p.  11. 


148 


FOODS. 


Fig.  4. 


in  mixing  the  milk,  too  violent  action  nuist  be  avoided,  and  a  short 
time  should  be  allowed  for  the  bubbles  present  to  rise  to  the  suri'ace 
and  escape. 

Inasmuch  as  the  gravity  varies  with  the  temperatiu-e,  and  the  instru- 
ment is  graduated  for  59°  F.,  either  the  milk  should  be  brought  to 
that  temperature,  or  a  correction  should  be  made  accord- 
ing to  the  deviation  above  or  below  that  point.  If  the 
milk  is  colder,  the  reading  will  be  too  high,  and,  if 
warmer,  too  low.  It  is  more  convenient  to  make  a  cor- 
rection for  temperature  than  to  heat  or  cool  the  speci- 
men to  the  normal  point.  The  deduction  of  a  half  de- 
gree of  gravity  for  each  five  degrees  of  temperature  below 
59°,  or  the  addition  of  the  same  amount  for  each  four 
degrees  above  59°,  will  be  found  to  be  approximately 
accurate  corrections. 

Determination  of  Fat. — For  the  accurate  determina- 
tion of  fat,  several  methods  are  in  use,  including  the 
following  : 

I.  The  Paper-coil  Extraction  Method. — This  process 
requires  strips  of  thick  filter-paper,  free  from  substances 
soluble  in  ether  and  alcohol,  about  6.25  by  62.5  cm.,  and 
a  Soxhlet  extraction  apparatus.  The  most  approved  form 
of  the  latter  consists  of  three  separate  pieces  which  fit 
together  by  ground-glass  joints  (see  Fig.  4).  The  top 
and  bottom  pieces  are,  respectively,  an  upright  Liebig 
condenser  and  a  flask.  The  middle  piece,  which  is  the 
part  in  which  the  extraction  process  occurs,  consists  of  a 
. ,  N_>^  glass  cylinder,  closed  at  the  bottom,  from  which  a  nar- 
v::~|  rower  cylinder  with  open  end  projects  downward.     The 

two  cylinders  are  connected  by  a  side  tube  which  opens 
into  the  upper  portion  of  each,  and  also  by  a  siphon 
which  opens  from  the  side  of  the  bottom  of  the  large 
cylinder,  extends  upward,  then  turns  upon  itself,  pierces 
the  middle  part  of  the  wall  of  the  lower  cylinder,  and 
terminates  within  and  just  below  its  lower  end. 

When  in  use,  the  substance  to  be  extracted  is  placed 
within  the  upper  cylinder,  upon  the  bottom  of  which  is 
placed  a  wad  of  absorbent  cotton,  which  prevents  the 
entrance  of  solid  particles  to  the  siphon  tube,  or  it  is  con- 
fined within  a  cartridge  of  thick  filter-paper  which  fits 
loosely  within  the  cylinder.  When  the  cartridge  is  used, 
it  is  best  to  plug  its  open  end  with  absorbent  cotton,  in  order  to  pre- 
vent the  escape  of  fine  particles  of  the  contained  substance. 

The  three  separate  parts  are  joined  together  and  then  mounted  on  a 
water-bath.  The  ether  or  other  extracting  medium  is  contained  in  the 
flask,  the  exact  weight  of  which  has  been  determined.  The  heat  of  the 
water-bath  causes  the  ether  to  volatilize,  and  the  vapor  passes  upward 


Soxhlet  extrac- 
tion apparatus. 


ANAI.VSIS   OF   MIIJ-C.  H9 

tliroil^li  Ui(i  Hide  lillx!  info  I  lie  cxI  ciH^lor  mikI  llictx-c  lo  I  lie  coimIciixt, 
wIkm'c,  (5(>iniii<i;  in  (loiitjicl  wIlli  tlic  cold  siirflicf  of  llic  iiiiiir  tiil)c  lli*  rcof, 
it  (!()n(l(!iiscs  luid  (iiJIs  ii|)()ii  (lie  siilihliincc  lo  l)c  cxt  r;i<lcd.  Ah  iIic  proc- 
(!,s,s  continiKss,  (Ik;  coiidiiiiHc^d  li(|iiid  iicciiinnl.ilc.s  ;iiid  jriadiially  riwo  until 
it  r(^:ic,lies  tlu;  bend  of  tlx;  si|)lion,  wliifli,  when  full,  bcf^itiH  to  ad  ;ind 
(lis('li;ii'<;('S  downward  inio  tlic'  ll;isi<  iinlil  tlic  entire  li(|nid  in  fctnnied  to 
its  starting-point.  Diiiinn^  its  ;u;einnnl;ilion,  it  ;iels  npon  tlic  snijstanec 
witliin  the  cylinder,  nnd  cxtnictH  moro  or  l(!s.s  of  the  liit  or  other  siih- 
Ktiuuie,  as  tlio  (nisi;  may  he,  which  is  (!arried  in  solntion  into  th(!  fhtsi<. 
The  vohitih/atioM  (-ontinnes,  and  the  process  is  repeated  a^a in  and  a^ain 
as  lonjij  as  is  necu'ssaiy,  and  in  this  way  tlie  whole  of"  tin;  extraet<;d 
matter  is  final ly  witliin  the  flask,  since,  hein^  itself"  non-volatile,  it 
remains  behind,  while  the  iiipiid  hy  whi.-.h  it  is  extracted  is  sent  con- 
tinually on  its  errand.  On  tlu;  completion  of"  the  process,  the  ether 
is  sent  up  atj^ain  into  the  cylinder,  and  before  it  i-eaciics  the  l(!V(!l  of  the 
siphon  tile  Mask  is  disjointed.  The  reinaininir  ether  is  expelh-d  cau- 
tiously, and  the  flask  with  its  contents  is  placed  in  an  air-bath,  tnain- 
taiued  at  100°  C,  and  dried  initil  its  weight  is  constant.  The  incrcjuse 
in  tlu!  weight  of  the  flask  rei)resents  the  amount  of  matter  extracted. 

In  determining  the  fat  of  milk  by  this  process  the  method  is  as  fol- 
lows :  To  one  of  the  strij)s  of  filter-pa])er,  made  into  a  coil,  a  definite 
weight  of  milk,  about  5  grams,  is  applied  in  either  of  two  ways.  A 
small  beaker  containing  about  the  required  amount  is  weighed  and  then 
tlie  coil  is  tlirust  into  it,  ke])t  there  until  nearly  the  whole  has  been 
absorbed,  and  then  carefully  Avithdrawn  and  placed  dry  edge  downwai'd 
upon  a  sheet  of  glass.  The  beaker  is  then  weighed  again,  and  the  loss 
in  weight,  which  represents  the  amount  of  milk  absorbed,  is  noted  ;  or 
the  beaker  containing  the  milk  and  a  small  pipette  is  weighed,  and  then 
the  necessary  amount  of  milk  is  transferred  to  the  coil  from  the  pipette, 
after  which  operation  the  weight  of  the  beaker,  pipette,  and  the  remain- 
ing milk  is  noted,  and  the  difference  set  down  as  the  weight  of  the 
milk  absorbed.  The  coil  is  then  dried  in  an  air-bath  at  100°  C.  for  an 
hour  or  more,  at  the  expiration  of  which  time  it  is  ready  for  insertion 
into  the  extractor. 

After  it  has  been  acted  upon  by  the  ether  about  a  dozen  times,  the 
flask  is  detiiched  and  treated  as  above  mentioned.  After  being  allowed 
to  cool,  the  weight  is  noted  and  the  percentage  of  fat  calculated  arith- 
metically. 

ExajVIPLE. — The  amount  of  milk  abs<M-bed  by  the  coil  was  4.950 
grams.  The  increase  in  the  weight  of  the  flask  was  0.173  gram.  Then 
the  amount  of  fat  present  in  the  sample  is  obtained  by  the  equation, 
4.95  :  0.173  :  :  100  :  .r,  Avheroin  x  =  3.49. 

2.  The  Werner-Schmidt  Method. — In  this  process,  equal  volumes  of 
milk  and  hydrochloric  acid,  about  100  cc.  of  each,  are  mixed  in  a  test- 
tube  and  boiled  for  about  a  minute  and  a  half,  or  heated  ou  a  water- 
batli  or  steam-bath  until  the  mixture  is  dark  brown  in  color.  It  is 
then  cooled,  and  the  mixture  shaken  with  30  cc.  of  ether.      \Vhen  the 


150  FOODS. 

two  liquids  have  separated,  the  supernatant  ether  is  withdrawn  by 
means  of  a  pipett>e  or  blown  out  with  the  assistance  of  a  double  tube 
such  as  is  used  in  wash-bottles,  the  delivery  tube  extending-  into  the 
ether  layer  very  nearly  as  far  as  the  line  of  demarcation  between  the 
ether  and  the  acid  mixture.  The  operation  is  repeated  with  several 
fresh  smaller  portions  of  ether,  and  the  whole  of  the  ether  used  is 
collected  in  a  weighed  tlask.  Then  the  ether  is  distilled  off,  and  the 
Hask  with  its  residuum  of  fat  is  heated  to  constant  weight  in  an  air- 
bath,  cooled,  and  weighed.  The  process  may  be  shortened  considerably 
by  treating  the  milk  in  a  graduated  tube  and,  after  thorough  shaking 
with  ether,  removing  an  aliquot  part  of  the  latter  by  means  of  a  pipette 
and  evaporatmg  to  dryness.  From  the  weight  of  this  residue,  the 
amount  of  fat  in  the  Avhole  volume  of  ether  can  readily  be  determined. 
Since  the  milk  taken  is  measured,  and  not  weighed,  a  correction  must 
be  made  for  gravity. 

Example. — Amount  of  milk  used  =  10  cc.  Specific  gravity  of 
specimen  =  1.032.  AVeight  of  milk  used  =  1.032  X  10  =  10.32 
grams.  Amount  of  fat  found  =  0.397  gram.  Percentage  of  fat  in  the 
original  milk  =  x  in  the  equation,  10.32  :  0.397  :  :  100  :  x ;  x  =  3.84. 

3.  The  Babcock  Centrifugal  Method. — In  this  process,  equal  volumes 
of  milk  and  sulphuric  acid  are  mixed  in  flasks  of  special  design  with 
narrow,  graduated  necks,  and  then  whirled  in  a  centrifugal  machine  for 
a  definite  length  of  time.  On  the  completion  of  the  process,  the  details 
of  which  are  given  below,  the  fat  in  a  pure  condition  is  within  the 
graduated  neck,  and  the  percentage  is  read  directly  off. 

The  kind  of  flask  used  is  shown  in  Plate  III.  It  has  a  capacity  of 
about  40  cc.  The  graduated  portion  of  the  neck  has  a  capacity  of  2  cc. 
The  details  are  as  follows  :  17.6  cc.  of  the  milk  are  measured  by  means 
of  a  ])ipette  and  introduced  into  the  flask.  Then  an  equal  volume  of 
sulphuric  acid,  specific  gravity  1.800,  is  added,  and  the  two  liquids  are 
mixed  thoroughly  by  gentle  rotaiy  motion.  Then  the  flask  is  placed 
in  a  centrifugal  machine  made  especially  for  the  purpose,  and  whirled 
for  five  minutes,  at  the  expiration  of  which  time  hot  water  is  added  up 
to  the  beginning  of  the  neck.  The  flask  is  whirled  again  for  two 
minutes,  and  more  hot  water  is  added  so  as  to  bring  the  fat  layer  well 
u])  into  the  neck.  After  further  whirling  for  one  minute,  the  depth  of 
the  fat  layer  is  determined  by  reference  to  the  scale. 

This  process  gives  sufficiently  accurate  results  for  all  practical  pur- 
poses, and  is  in  common  use  at  experiment  stations  in  this  country.  It 
is  much  used  at  creameries  for  determining  the  butter  value  of  milk 
sent  in  from  the  surrounding  country. 

The  employment  of  sulphuric  acid  having  a  higher  specific  gravity 
than  that  given,  say  1.820,  is  objectionable  in  that  it  frequently  happens 
that  it  is  impossible  to  obtain  a  clear  fat  layer.  The  fat  itself  may  be 
turned  a  very  dark  color,  and  the  sugar  of  the  milk  may  be  attacked 
to  such  an  extent  that  charred  portions  of  it  will  separate  and  accumu- 
late within  and  beneath  the  column  of  fat,  and  so  prevent  a  satisfactory 
reading.     If  the  acid  used  is  weaker  than  1.800,  all  the  casein  may  not 


IM  ,A'I  )■.    Ill 


8 

■T: 
6 

■  5 

4 

-3 

-2 

I 


Babcoek  Flask,  showing  Fat  in   Neck. 


yl  7V/I /.  r,S7.S'  (>F  MILK.  151 

be  held  In  Holiitioii,  iiiid  portions  oC  it  iii;iy  tninj/lf  with  the  liiL  and 
destroy  the  aeciiiiicy  o("  tlic  tcsl. 

In  Piute  III.  is  shown  flic  \\\i  liiyer  in  the  slein  mh  it  should  he;,  fr<!e 
from  iiltenition  of  color  iuid  I'roni  r^harred  sn^^ar  iind  j)artif;Ies  of  rascin. 
It  will  l)(!  observed  th;it  tlu;  lin<!  of  dcjniarc^ation  between  the  water  atid 
the  ("at  in  th(!  stem  is  v(!ry  sharp.  For  eream,  a  fl;i.-^l<  with  u  mueh 
broader  neck  in  employed. 

4.  The  Babcock  Asbestos  Method. —  Tn  this  method,  tlu;  dried  t/)t;il 
solids  obtjiincd  by  ihe  method  described  below  (No.  2)  are  extraefe«l  in 
a  Soxidet  (^\tra(•tion  iipparatiis. 

Determination  of  Total  Solids. —  I.  W'c-i^^h  into  a  flat-bottomed 
l)latinnm  dish  oC  about  "1  inelujs  (J)  cm.)  diameter,  o  ^rams  of  milk. 
PhuH',  on  a  water-bath  tor  an  hour  and  a  half.  Jiemove  to  a  hf)t-air 
bath,  maintained  at  100°  i).,  until  its  \V(!i<!;ht  is  constant.  Cool  in  a 
desiccator  and  wei_t>;h.  The  dilfenmee  between  this  weight  and  that  of 
the  dish  alone  represents  the  total  solids  of  the  amount  of  milk  taken, 
and,  multiplied  by  20,  expresses  the  percentage  of  total  wdids  in  the 
sample.  If  for  any  reason  it  is  desired  to  use  tlie  total  soli<ls  for  ex- 
traction in  the  Soxhlet  apparatus,  the  dish  may  be  partly  filled  before 
weighiuo;  with  fine,  clean,  dry  sand,  or  with  freshly  ignited  woolly 
asbestos.  One  objection  to  the  use  of  the  total  solids  in  this  way  i.s 
that  it  is  extremely  diflicult  to  remove  the  whole  amount  from  the  dish, 
to  the  sides  and  bottom  of  which  a  portion  will  a<lhere  with  great  ten- 
acity, and  can  be  removed  only  by  burning.  To  obviate  this  diffi- 
culty, Dr.  C.  L.  Spanlding  has  suggested  lining  the  platinum  dish  with 
very  thin  tinfoil,  which,  after  the  weight  of  the  total  solids  has  been 
noted,  is  withdrawn  with  the  sand  or  asbestos,  and  with  it  inserted  into 
the  extraction  ap])aratus. 

Formerly,  the  residue  of  the  milk  dried  in  the  dish  alone  without 
sand  or  asbestos  was  nsed  for  the  determination  of  flit  by  the  Wanklyn 
process,  which  consists  in  filling  the  dish  with  freshly  distilled  naphtha 
or  with  ether,  and  allowing  it  to  act  upon  the  residue  and  dissolve  out 
the  fat,  several  portions  being  nsed,  after  which  the  dish  is  dried  ag-ain 
and  weighed,  and  the  loss  in  weight  taken  as  the  measure  of  the  fat 
contained.  Inasmuch  as  the  solvent  cannot  penetrate  the  horny  layer 
which  forms  on  the  bottom  of  the  dish,  not  all  the  fat  am  thus  be  ex- 
tracted, and  the  figures  obtained  are  ordinarily  about  0.5  too  low. 

2.  The  Babcock  Asbestos  Method. — In  this  process,  the  milk  is 
weighed  into  a  cylinder  of  perforated  metal  or  into  a  filter-paper  cart- 
ridge filled  loosely  with  freshly  ignited  woolly  asbestos,  subjected  to  a 
temperature  of  100°  C.  until  the  weight  is  constant,  and  then  cooled 
and  weighed.  The  gain  in  weight  represents  the  total  solids  of  the 
amount  of  milk  taken.  The  cylinder  may  then  be  slipped  into  the 
extraction  apparatus  and  used  for  the  determination  of  fiit. 

3.  Determination  of  Total  Solids  by  Formula. — Knowing  the  correct 
specific  gravity  and  the  amount  of  fat,  it  is  possible  to  determine  fairly 
accurately  the  amonut  of  total  solids  by  the  use  of  the  formula  of 
Hebner  and   Richmond.     This  formula  is  as  follows:  F=  0.859  T 


152  FOODS. 

—  0.2186  G,  in  whioli  F  represents  fat,  T  the  total  solids,  and  G  the 
figures  of  the  speciiic  gravity  beyond  the  first  decimal  ])laoe. 

Exa:mple. — Tlie  speeitie  gravity  of  a  specimen  of  niilU  is  found  to 
be  1.030,  and  its  fat  content  3.95.  Then  applying  tlie  Ibrnnda,  we 
have 

•    3.95        =  0.859  T—  (0.2186  X  30),  or 
3.95        =  0.859  T  —  6.558,  or 
0.859  T  =  6.558  +  3.95  =  10.508,  and  T=  12.23. 

lu  other  words,  multiply  0.2186  by  the  figures  expressing  specific 
gravity,  add  the  percentage  of  fat  to  the  product,  and  divide  the  result 
by  0.859. 

The  formula  may  also  be  used  to  determine  the  percentage  of  fat, 
the  specific  gravity  and  total  solids  being  known. 

Determination  of  Milk  Sugar. — The  amount  of  lactose  may  be 
determined  either  chemically  or  by  means  of  the  polariscope. 

1.  Method  by  Fehling  Solution. — Reagents  required:  Solution  A. 
Dissolve  34.639  grams  of  pure  sulphate  of  copper  in  distilled  water 
and  dilute  to  a  liter.  Solution  B,  Dissolve  173  grams  of  potassium 
sodium  tartrate  (Rochelle  salt)  m  distilled  water,  add  100  cc.  of  sodium 
hydrate  solution  of  1.393  specific  gravity,  and  dilute  the  mixture  with 
distilled  water  to  a  liter. 

In  making  a  determination,  10  cc.  of  each  solution  are  mixed  in  a 
boiling  flask  of  about  300  cc.  capacity.  The  amount  of  copper  con- 
tained in  10  cc.  of  solution  A  requires  for  its  reduction  0.050  gram 
of  dextrose,  or  0.0667  gram  of  lactose. 

Process. — Into  a  porcelain  evaporating  dish  of  suitable  size,  dis- 
charge from  a  pipette  25  cc.  of  milk.  Add  three  or  four  times  as  much 
water  and  heat  to  40°  C.  Add  acetic  acid,  a  drop  at  a  time,  with  con- 
stant stirring,  until  the  mixture  separates  into  curds  and  a  fairly  clear 
whey.  Transfer  the  whole  to  a  graduated  500  cc.  flask,  and  dilute  with 
water  to  the  500  mark.  Filter  a  portion  through  a  dry  filter,  and  use 
the  filtrate  for  titration.  Dilute  the  mixed  reagents  in  the  boiling  flask 
with  water  and  boil  over  a  Bunsen  flame.  From  a  burette  graduated  in 
tenths,  add  the  filtrate  from  the  curds  a  little  at  a  time,  and  continue  the 
boiling  after  each  addition.  As  the  blue  color  begins  to  appear  faint, 
the  addition  should  be  made  cautiously,  in  order  not  to  overstep  the 
end  reaction.  As  soon  as  the  blue  color  is  discharged  completely,  note 
the  reading  of  the  burette. 

The  calculation  is  exceedingly  simple.  Since  0.0667  gram  of  lactose 
is  required  to  reduce  the  copper  in  the  reagent,  it  follows  that  that 
amount  of  the  substance  is  contained  in  the  number  of  cc.  of  the  whey 
used,  and  the  percentage  is  obtained  by  the  application  of  the  rule  of 
three. 

Example. — The  color  is  discharged  by  24.3  cc.  of  the  diluted  whey. 
Then  in  the  whole  amount  of  milk  taken  the  amount  of  sugar  will  be 
X  in  the  equation  24.3  :  0.0667  :  :  500  :  x.  x  =  1.372.  The  amount 
of  milk  taken  was  25  cc,  hence  in  100  cc.  the  amount  would  be  5.49, 


ANALYSIS   Of   MILK.  15,'} 

and  this  junoiinl.  (Ii\'i(l<'(l  by  llic  spcf-ifH;  {^r;i\i(y  ^n\fH  the  ixTrcrita^:''  \>y 
W(!i}^lit.  Supposing  (Ik;  spccriCic,  frruvity  to  Im-  I.O.'W),  for  ('xarnpK;,  tluj 
100  <;<!.  of  Jiiilk  \v(;i^li  I  0.>  ^raiiiH,  and  llu;  \u'ycA'i\injj;('.  ol'  hiif^ar  will  ho 
X  ill  the  (!<piatIoii  lO-'i  :  100  :  :  0.4!)  :  x.  x  o. .'>.'}.  Ina.sniiich  an  the; 
uuiaiis  ol"  llie  first  (^(piiitioii  nvv.  conslaiits,  tlu;  rcrkoiiiri}.';  resolves  ifsc^lf 
into  dividing  fonr  times  (heir  |)roduet,  .'>.'). .'>o,  or  1. '>.'}.  1  hy  the  niiinher 
of  ee.  used,  and  dividing  this  result  \)y  the  .specific  gravity  of  the 
specimen. 

2.  Method  of  Polariscopy. — Tlu;  delerniiiKitiuii  uf  lacto.sc  and  other 
sugars  l)y  means  of  the  j)olaris(tope  eomhines  the  ;i(l\ant}igc.s  of  accu- 
racy and  of  rajjidity.  The  instruments  in  eouiiiHMi  use  arc  of  two 
kinds  :  those  of  which  the  normal  sucrose  weight,  that  is  ix)  say,  the 
amount  of  sucros(^  whi(Oi,  dissolved  in  water  and  made  u|)  to  100  c<;., 
will  show  100  degrees  on  the  scale  when  observed  through  a  2t)0  mm. 
tube,  is  2G.048  grams,  and  those  in  Avhich  it  is  Kj.ll)  grams.  Of  the 
former,  the  Vent/kc-Scheibler  and  the  Schmidt  and  Ilacnsch  modifica- 
tion, and  of  the  latter  the  Laurent  instrument,  may  be  regarded  as 
types.  The  Schmidt  and  TTaenseh  triple  field,  half-shadow  instrument 
possesses  the  advantage  of  doing  away  with  the  matching  of  colors, 
and  hence  may  be  used  by  those  who  are  color-blind,  and  even  with 
those  not  so  afflicted  gives,  on  the  whole,  the  most  satisfactory  results. 

Process. — Into  a  flask  graduated  on  the  neck  at  102.0  cc.  if  the  in- 
strument used  is  one  of  which  the  sucrose  normal  weight  is  20.048 
grams,  weigh  05.95  grams  of  milk,  or  into  one  graduated  at  101,0  cc, 
if  it  is  one  of  the  other  class,  weigh  40.99  grams,  add  1  cc.  of  solu- 
tion of  mercuric  nitrate  of  pharmacopa?ial  strength,  shake  well,  and 
dilute  with  water  up  to  the  mark.  Filter  through  a  dry  filter- pa  per, 
fill  the  200  mm.  observation  tube,  and  note  the  reading  of  the  scale 
when  the  field  of  observation  is  uniform.  The  reading  divided  by  2 
equals  the  percentage  by  weight  of  lactose. 

The  w^eights  05.95  and  40.99  represent  twice  the  normal  lactose 
weights  of  the  respective  types  of  instruments.  The  graduations  102.0 
and  101.0  are  adopted  instead  of  100  cc,  since  the  dried  precipitated 
curds  from  the  respective  amounts  of  milk  of  average  specific  gravity 
have  a  bulk  equal  to  the  excess  over  100  cc. 

Determination  of  Ash. — The  ash  may  be  determined  by  igniting 
the  residue  obtained  in  the  determination  of  total  solids,  provided  no 
other  substance  has  been  introduced  into  the  dish  with  the  milk.  The 
ignition  should  be  conducted  at  a  low  red  heat  until  the  ash  is  perfectly 
white.  Then  the  dish  is  cooled  in  a  desiccator  and  again  weighed.  The 
difference  between  this  final  weight  and  the  original  weight  of  the  empty 
dish  represents  the  amount  of  mineral  matter  in  the  amount  of  milk 
taken.  Or  a  larger  amount  of  milk,  say  20  grams,  may  be  evaporated 
with  a  few  cc.  of  nitric  acid  and  the  residue  ignited  as  above. 

Determination  of  Proteids. — Having  determined  the  total  solids, 
fat,  sugar,  and  ash,  the  proteids  may  be  reckoned  by  difference — that 
is,  by  subtracting  the  sum  of  the  fat,  sugar,  and  ash  from  the  total 
solids,  or  they  may  be  determined  directly  by  the  Kjeldahl  process. 


154  POODS. 

^vhiL'll  dcpcuds  upon  the  couvcrsiuu  of  the  nitrogenous  matter  into 
ammonium  sulphate,  which  then  is  decomposed  by  an  excess  of  strong 
alkali,  ammonia  being-  set  free.  This  is  expelled  by  heat,  condensed 
with  the  acoonipanying  steam,  and  received  in  acid  of  known  strength. 

The  process  is  as  follows  :  Into  a  Kjeldalil  digestive  flask  introdnce 
a  detinite  weight,  say  5  grams  of  milk,  about  0.7  gram  of  mercuric 
oxide,  and  20  cc.  of  sulphuric  acid  of  1.840  specihc  gravity,  free  from 
nitrates  and  ammonium  sulphate.  Place  the  flask  in  an  inclined  posi- 
tion and  heat  below  the  boiling-point  of  the  acid  for  from  five  to  fifteen 
minutes,  or  until  frothing  ceases.  Then  raise  the  heat  until  the  mixture 
comes  to  boiling,  and  continue  the  process  until  the  liquid  is  clear  and 
has  a  very  pale  straw  color.  This  will  require  ordinarily  less  than  an 
hour.  Withdraw  the  lamp,  and  drop  in,  in  small  quantities  at  a  time, 
permanganate  of  potassium,  until,  after  shaking,,  the  licpiid  acquires  a 
permanent  green  or  purple  color.  This  addition  is  not  always  or  even 
usually  necessary  to  secure  complete  oxidation,  but  since  it  is  sometimes 
required,  it  is  best  to  make  it  a  part  of  the  routine.  Allow  the  contents 
to  cool,  and  then  transfer  them  with  about  200  cc.  of  distilled  water, 
plus  sufiicient  for  thorough  rinsing,  to  a  distilling  flask  of  about  550  cc. 
capacity,  fitted  with  a  rubber  stopper  and  a  bulb  tube  connected  with  a 
very  long  Liebig  condenser,  the  delivery  end  of  which  is  fitted  with  a 
glass  tube  bent  at  right  angles,  so  that  it  may  dip  beneath  the  surface 
of  the  acid  into  which  the  distillate  is  to  be  received.  Add  a  few  pieces 
of  pumice  or  granulated  zinc,  or  about  0.5  gram  of  zinc  dust,  to  pre- 
vent bumping,  and  25  cc.  of  a  4  per  cent,  aqueous  solution  of  sulphide 
of  potassium,  to  prevent  the  formation  of  compounds  of  ammonium 
and  mercury,  which  are  not  wholly  decomposable  by  alkalies.  Shake, 
and  then  add  of  a  saturated  solution  of  sodium  hydrate,  free  from 
nitrates,  sufficient  to  make  the  reaction  strongly  alkaline,  pouring  it 
down  the  side  of  the  flask  so  as  not  to  mix  at  once  with  the  acid  con- 
tents. Next  connect  the  flask  with  the  condenser,  mix  the  contents  by 
gently  rotating,  and  apply  the  flame.  Distil,  and  receive  the  distillate 
in  a  vessel  containing  50  cc.  of  decinormal  sulphuric  acid.  When  about 
175  cc.  have  passed  over,  it  may  be  assumed  that  all  ammonia  has  been 
expelled,  and  then  the  distillate  is  titrated  with  decinormal  alkali,  using 
cochineal  or  methyl-orange  as  an  indicator.  From  the  diflPerence  in 
strength  of  the  decinormal  acid,  the  amount  of  ammonia  is  calculated, 
and  from  this  the  amount  of  nitrogen ;  and  this  multiplied  by  6.38 
gives  the  total  proteins. 

Detection  of  Added  Water. — One  of  the  most  difficult  problems 
which  comes  to  the  food  and  drug  analyst  is  that  of  determining 
whether  a  sample  of  low  standard  milk  is  such  because  it  comes  from 
a  variety  of  cows  normally  giving  such  low  standard  milk  or  whether 
the  deficiency  in  quality  is  due  to  the  addition  of  water.  In  deter- 
mining this  question  the  use  of  the  Zeiss  immersion  refractometer  is 
of  the  greatest  assistance.  This  method  of  analysis  was  first  thor- 
oughly investigated  by  Leach  and  Ly thgoe  ^  of  the  Food  and  Drug 
1  Report  of  the  State  Board  of  Health  of  Mass.,  1903,  p.  483. 


ANAIjVS/S  (J I''  MILK. 


155 


T)cpartm(iiii  of  \\\v,  Mussuclmsclls  Shilc-  iJoard  of  IIciilili.  "  Tlic  c/di- 
■striiction  of  IhiH  iii,struiri(!iit  i.s  .siidi  llint,  jis  its  iiuinc  imjilics,  it  m;iy 
b(!  directly  iiimicrscKl  in  ;i  .solution,  tlu;  (Jcfrpco  of  icriac.tioii  of  wliicli, 
within  limits,  may  he  dctcrmincid  upon  an  arbitrary  Hcale."  Fig.  5 
sliowH  this  inslrnnicni.' 

'rh(!  us{' of  (Jiis  rnctliod,  as  now  cnihodicd  in  tlic  |)iaclicc  of  the  Amo- 
ciation  of  Odicial  Ati^i-icnllnral  ('hcinists,  is  as  followH^:  *' 'I'o  100  cubic 
(;cnlinu>tcrs  of  milk  at  a  l(!m|)('ra.tiir(!  ol"  about  20"  C.  add  2  cubic  c(^nti- 
mctcrs  of  25  per  cent,  acetic  acid  (sp.  gr.  1.0.'i50)  in  a  beaker,  an<l 

Fio.  T). 


Zeiss'  immersion  refractometer. 


beat  the  beaker,  covered  with  a  watch-glass,  iu  a  water-bath  for  twenty 
minutes  at  a  temperature  of  70°  C.  Theu  place  the  beaker  in  ice 
water  for  ten  minutes,  and  separate  the  curd  from  the  serum  by  filtra- 
tion through  a  12.5-ceutimeter  plaited  filter. 

"  Transfer  about  35  cubic  centimeters  of  the  serum  to  one  of  the 
beakers  that  accompanies  the  control-temperature  bath  used  in  connec- 
tion with  the  Zeiss  immersion  refractometer,  the  bath  being  of  the  type 

1  For  a  detailed  description  of  this  instrument  the  reader  is  referred  to  the  Journal 
of  the  American  Chemical  Society,  Vol.  XXVI.,  October,  1904. 
"  Keport  of  the  State  Board  of  Health  of  Mass.,  1906,  p.  383. 


156 


FOODS. 


with  openings  in  the  top  for  ten  beakers.  Place  the  beaker  in  one  of 
the  o})enings,  use  the  groiuul  glass  strip  at  the  bottom  of  the  bath,  and 
by  means  of  the  regular  n'fractometer  heater  or  similar  cleviee  maintain 
a  coustiint  temperature  of  exactly  20°  C  in  the  water  surrounding  the 
beaker,  using  a  delicate  thermometer,  reading  to  tenths  of  a  degree. 
Innuerse  the  end  of  the  refractometer  in  the  serum  in  the  beaker,  and 
when  the  tem])erature  is  exactly  '20°  C.  take  the  reading  on  the  scale. 

"  If  the  tem})erature  varies  from  20°  C,  the  reading  may  be  cal- 
culated on  that  basis  by  means  of  a  correction  table.  A  reading 
below  39  indicates  added  water,  between  39  and  40  the  same  is 
suspicious." 

Another  method  for  the  detection  of  added  water  in  milk  depends 
upon  being  able  to  show  abnormal  chemical  or  physical  constants 
which  can  be  explained  only  by  the  addition  of  water,  there  being  no 
test  which  will  distinguish  between  the  water  which  may  be  added  to  the 
milk  and  the  water  naturally  present.  It  is  incumbent,  therefore,  upon 
per.^ons  engaged  in  the  chemical  examination  of  milk  to  become  familiar 
with  the  chemical  and  physical  properties  of  milk  of  known  purity. 

A  study  of  the  published  analyses  of  milk  shows  an  extreme  vari- 
ance, yet  if  we  study  the  methods  of  analysis  in  connection  with  the 
figures,  a  great  deal  may  be  explained  by  incorrectness  of  the  methods 
then  in  use.  In  general,  all  milk  completely  drawn  from  healthy  cows 
will  vary  between  the  following  limits :  ^ 


Extreme  limits 
(per  cent.). 

Usual  limits 
(per  cent.). 

Herd  milk 
(per  cent.). 

Total  solids 

10.0-17.0 
2.2-  9.0 
2.1-  8.5 
0.6-  0.9 
7.5-11.0 
4.0-  6.0 

10.5-16.0 
2.8-  7.0 
2.5-  4.5 
0.7-  0.8 
7.7-10.0 
4.2-  5.5 

11.8-15.0 

Fat 

Proteins 

Ash 

Solid'i  not  fat 

3.2-  6.0 

2.5-  4.0 
0.7-  8.0 
8.0-  9.5 

4.3-  5.3 

If  we  depend  upon  the  solids,  fats,  or  proteins  to  indicate  added 
water,  it  is  evident  that  considerable  adulterated  milk  will  escape  detec- 
tion, but  if  a  minimum  figure  is  employed  for  ash,  solids,  not  fat  or 
sugar,  more  adulterated  milk  will  be  discovered.  The  most  successful 
methods  for  the  detection  of  added  water  are  based  upon  the  milk-sugar 
content,  and  for  this  purpose  it  is  usual  to  prepare  a  milk  serum,  be- 
cause the  most  variable  constituents  (the  fat  and  the  proteins)  remain 
in  the  curd,  while  the  serum  will  contaiK  the  sugar  and  the  ash,  which 
are  the  least  variable.  The  serum  may  be  prepared  by  allowing  the 
sample  to  sour  spontaneously ,2  by  heating  with  acetic  acid  ^  or  calcium 
chloride,*  or  by  treating  in  the  cold  with  asaprol  citric  acid  solution  ^ 

*  Personal  communication  from  H.  C.  Lythgoe,  Chemist,  Food  and  Drug  Depart- 
ment, Mass.  State  Board  of  Health. 

2  Matthes  and  Muller,  Zeit.  ofientl.  Chem.,  X.,  173. 

3  Leach  and  Lythgoe,  Jour.  Amer.  Chem.  Soc,  XXVI.,  1195. 

*  .\ckerman,  Zeit.  Nahr.  Genussm.,  XIIL,  369. 

5  Baier  and  Neumann,  Zeit.  Nahr.  Genussm.,  XIIL,  369. 


ANA/A'SIS   OF  MII,K.  157 

or  copper  ,siil|)lial,('.'  'Hie  (;o[)j)(!r  hiiI|>Ii;i(c  iimIIi'kI  ii-ciI  in  flic  food 
iiiH[K!(!tion  Jaborutory  of  tJic  MasH.  iStutx;  Jioanl  ol'  IIcmIiIi  i-,  a-  follow-  : 

"Dissolve  72.5  ^raiiiH  of  (!ryHtalli/('<l  copper  -njpli.ilc  in  \val,«-r  aii<i 
dilute  to  1  liter.  This  .solution  nlioiild  l)c  iKljii-lcd,  if  n<;c('H.sary,  ho 
that  if,  will  r('fra(!t  at  oG  on  the;  wale  of  (he  Zeiss  inMnersion  refrarto- 
mciter  at  20°  (..,  or  iiave  a  specific  ^lavify  of  I.04|;{  at  20'^  C,  <;orn- 
parcd  with  wafer  at  I"  (!.  To  one  xolnnie  of  I  he  copper  Holntion  add 
i'oiir  volumes  of  sweet  milk,  shake  well,  and  filter.  The  filfrafe  will 
usually  he  (ilear  aCtxii"  tlu;  fn-st  lew  drops  have  [)aHH(!d  through.  A 
defei'minaf Ion  of  the  refraction  (»r  specific  gravity  may  Im;  made  upon 
the  clear  serum,  and  if  below  tin-  miuinuirn  for  pun;  jnilk  the  Hamj)lo 
may  be  declared  watered. 

"If  the  satnj)l(>  is  sour  it  should  be  liltcjred  and  determination.S  of 
refratition,  spe(M(ic  (gravity,  or  ash  made  upon  the  s(;rum." 

The  examination  of  412  samples  of  milk  of  known  |)urity  fn)m  indi- 
vidual cows,  3G1  being  obtained  by  the  Massachusetts  Stat<j  i>oard  ol' 
Health,  and  51  being  examined  in  the  New  Jersey  Board  of  Health, 
gave  the  following  results  : 

The  samples  varied  in  total  solids  from  17.17  per  cent,  to  10.12  j»er 
cent.,  in  fat  from  7.7  per  cent,  to  2. .'35  per  cent.,  in  solids  not  fat  from 
10.05  per  cent,  to  7.55  per  cent. 

The  refractions  of  the  copper  serum  were  found  to  be  between  the 
following  limits  : 

Refraction. 

36.0  to  36.4 29  samples. 

36.5  to  36.9 32 

37.0  to  37.4 70 

37.5  to  37.9 79        " 

38.0  to  38.4 96 

38.5  to  38.9 66 

39.0  to  39.4 28 

39.5  to  40.0 ■  12 

412  samples. 

The  examination  of  the  milk  of  28  herds  of  cows  gave  the  following 
results  : 

Refraction. 

37.1  to  37.4 4  samples. 

37.5  to  37.9 12 

38.0  to  38.4 5        " 

38.5  to  38.7 ._T_ 

28  samples. 

It  is  not  necessary  to  possess  a  refractometer  in  order  to  examine 
serum  ;  in  fact,  it  is  a  waste  of  money  to  purchase  one  if  it  is  to  be  used 
for  no  other  purpose,  or  unless  so  many  samples  are  to  be  examined 
each  day  that  the  saving  in  time  would  more  than  offset  the  price.     The 

specific  refraction  of  the  copper  serum  .   —  is  not  exactly  a  con- 

^  ^  ^  n-  +  2       ff 

stant,  decreasing  slightly  as  the  refraction  grows  less,  but  it  is  suf- 
ficiently uniform  for  refraction  yalues  between  34  and  38,  that  if  we 

1  Lythgoe,  Eeport  ISIass.  State  Board  of  Health,  1908. 


158 


FOOBS. 


know  the  refractiou  at  20°  C.  we  may  calculate  the  specific  gravity  at 
20°  C.  compared  with  water  at  4°  C.  by  the  formula — 

«,2 1  1 

!*- \  .  -±-  =  0.20526. 

^2  -j-  2      cP^ 

The  value,  of  n^  correspoudiug  to  the  scale  reading  of  36  on  the 
immersion  refractometer  is  1.34124.  Substituting  in  the  above  for- 
nuda  we  find  that  d'f^  =:  1.0245;  therefore,  if  a  refraction  less  than  36 
indicates  added  water,  the  same  may  be  said  of  a  specific  gravity  less 
than  1.0245  at  20°  C.  referred  to  water  at  4°  C. 

The  relation  between  the  refraction  and  gravity  of  the  serum  from 
spontaneously  soured  milk  is  expressed  by  the  formula — 


w2  +  2 


^.  =  0.20607. 


As  38.3  ^  represents  the  lowest  refraction  at  20°  C,  the  lowest  grav- 
ity at  f  C.  is  1.0229. 

For  the  purpose  of  studying  the  influence  of  added  water  upon  milk 
a  sample  of  milk  above  the  average  in  solids  not  fat  and  refraction  was 
obtained,  and  to  this  sample  water  was  added  in  varying  amounts.  The 
samples  were  then  analyzed  and  the  results  appear  in  the  following  table : 

Composition  of  a  Sample  of  Milk  System^atically  Watered. 


Solids 
(per  cent.). 

Fat  (per 
ceni.). 

Solids  not 
fat  (per 
cent.). 

Copper  serum. 

Added 

water 

(per  cent.). 

Refraction, 
20°. 

Specific 
gravity, 

20° 

40 

rfl  —  \      1 
n2  +  2  ■  3' 

Solids  (per 
cent.). 

0 

13.18 

4.20 

8.98 

38.5 

1.0272 

0.20529 

6.09 

10 

11.86 

3.78 

8.08 

36.4 

1.0249 

0.20526 

5.57 

20 

10.54 

3.36 

7.18 

34.4 

1.0233 

0.20523 

5.05 

30 

9.23 

2.94 

6.29 

32.4 

1.0211 

0.20520 

4.56 

40 

7.91 

2.52 

5.39 

]      30.6 

1.0194 

0.20518 

4.10 

50 

6.59 

2.10 

4.49 

1      28.6 

1.0174 

0.20516 

3.54 

A  study  of  the  above  table  shows  that  each  5  per  cent,  of  added 
water  lowers  the  refraction  by  one  scale  division,  and,  therefore,  in 
order  to  detect  10  per  cent,  of  added  water  in  milk  the  milk  before 
watering  must  give  a  serum  refracting  below  38. 

Detection  of  Added  Coloring-  Matters. — Annatto. — To  about  100 
cc.  of  milk  in  a  cylinder  about  1.5  inches  in  diameter,  add  a  few  cc.  of 
sodium  carbonate  solution,  to  insure  a  strongly  alkaline  reaction  during 
the  examination,  and  then  introduce  a  strip  of  heavy  white  filter-paper 
about  0.5  by  5.5  inches,  and  set  the  whole  away  in  a  dark  place  over 
night.  If  any  annatto  color  is  present,  it  will,  through  selective 
affinity,  pass  from  the  milk  to  the  fibre  of  the  paper,  Avhich  thereby 
acquires  a  salmon  tint,  the  depth  of  which  is  dependent  naturally  upon 
the  amount  of  the  substance  present.     The  strip  is  withdrawn  from  the 

1  Lowest  of  125  known  purity  samples. 


iM.A^ri':  IV 


A.  Strip  of  Filtei'  Paper  Dyed  by  Immersion  in  Milk  Colored  with  Annatto. 

B.  Same  after  Treatnient  -with  Solution  of  Protochloride  of  Tin. 


PLATI':   V 


/■ 


c 

.    / 

■  ■'  ..L  Z^'      L     I'    1    ,''n 

^    I. 

<.  0/,'     '  L  1-,     i  (      i    ^ 

«» 

■  ..      r              ,       -^                     \  • 

^  ■'■•  ;v-.^  Vo  '  ,, 

(- 

*' 

,   -i.i. 

J    ^ 

V. 

Fig.     I.      Fron-i   Un>-oloiv-d   ' 
Fi.i 


ANALYSIS  01''  MII.K.  I-'/) 

milk,  washed  ^'ciilly  in  niiniiii^  \v;ilcr,  mid  l;ild  iipoii  ;i  |)i<c(;  r,!'  |):i|)cr 
of  the  HJUIK!  kind  as  itsrll'.  I  C  s<»  nnidi  as  I  |»art  of  iIk;  aiuiatlo  i-olii- 
tion  in  1()(),()()()  is  prcscnl,  tli»'  stiip  will  show  a  <li~liiic)  salmon  fiiiL. 
On  (li|)i)inji;  (he  s(ri|i  into  slannoiis  (-Idoridc  solnlion  the  color  Ih 
(;lijiii[!:;('d  to  pink. 

Anoth(!r  tncdiod,  \>y  iiicans  o("  which  all  the  (-((lor  in  Ihc  atnonnt  of 
milk  o|)(!nit(!d  upon  nuiy  Ik;  (lonccnt rated  in  ;i  lorni  best  adapted  lor 
preservation  and  for  exhibits  in  eourt,  is  as  follows:  (.'oaf^iilate  from 
100  to  150  e,e.  of  the  specimen  hy  the  a|)pli('a)ion  ol"  lutjit  and  aeetic 
acid,  and  separate  (Ik;  eoa<!;nlnni  hy  sh-ainin^  throujih  a  jiicce  of  eliccse- 
elotli.  Tlu!  eolorinu;  niaflcr,  hciii^  insoluble  in  acid  niccfia,  is  pre<-i|)i- 
tated  with  the  curd,  wlii(;h,  however,  will  show  to  the  eye  H(^ireely  any 
indication  of  its  j)resenee.  The  curd  is  ])laced  in  a  m«;rtar  and  tritu- 
rated with  50-75  cc.  of  ctlicr,  which  next  is  transferred  to  a  stopj)er(Kl 
sei)aratin<2:  funnel  and  shaken  with  10  ee.  of  a  1  j)er  cent,  solution  of 
caustic  sochi.  When  the  two  liquids  l)econu;  sej)arated,  the  latter, 
which  now  contains  the  annatto  color,  is  drawn  off  into  two  poreelain 
or  f:;lass  dishes  about  an  inch  in  diameter,  in  csich  of  which  a  disk 
of  lilter-pa|K'r  is  placed.  They  are  then  set  aside  in  the  dark  and 
left  over  ni<i;ht.  The  disks  are  then  removed  and  washed  in  fresh 
water.  If  annatto  is  present,  they  will  have  acquired  a  color  varying  in 
depth  according  to  the  amount  of  the  dye  in  the  sample.  One  disk  is 
immersed  in  stannous  chloride  solution,  the  other  in  weak  sodium  car- 
bonate, and  then  dried  and  mounted  on  a  white  card.  The  colors 
yielded  by  a  specimen  of  milk  to  which  no  unusual  amount  of  the 
adulterant  has  been  added  are  shown  in  Plate  IV. 

Caramel. — Pour  125  to  250  cc.  of  the  suspected  sample  into  an  equal 
volume  of  95  per  cent,  alcohol,  and  filter.  The  filtrate,  if  not  perfectly 
clear,  should  be  returned  and  passed  through  until  it  is  quite  free  from 
turbidity.  Any  caramel  present  will  be  in  solution  in  the  alcoholic 
filtrate,  and  may  modify  considerably  its  color,  which  normally  is 
yellowish  or  greenish  according  to  season,  the  latter  obtaining  in  spring 
and  summer.  To  100  cc.  of  the  filtrate  add  2  cc.  of  solution  of  basic 
acetate  of  lead,  which  will  precipitate  the  caramel  together  \vith  any 
remaining  proteids,  the  precipitate  showing  a  slight  brownish  color 
if  caramel  has  been  used  in  sufficient  amount  to  bring  about  the 
improved  appearance  which  is  the  object  of  its  employment.  Filter, 
wash  with  distilled  water,  and  dry  in  an  air-bath.  According  as  the 
amount  of  caramel  present  is  large  or  small,  the  horny  residue  on  the 
filter-paper  will  have  a  more  or  less  deep  chocolate  tinge.  The  residue 
yielded  by  a  pure  milk  will  be  either  almost  colorless,  or  yellow,  or 
slightly  ineliued  to  brownish,  but  not  to  chocolate  color.  The  appear- 
ance of  the  two  kinds  of  residue  is  shown  in  Plate  V. 

Caramel  may  also  be  shown  if  we  proceed  according  to  the  second 
method  described  for  the  detection  of  annatto.  The  curd,  after  being 
freed  from  the  whey  and  triturated  with  ether,  gives  up  to  this  solvent 
only  fat  and  annatto.  If  caramel  or  anilius  are  present,  the  curd  ^vill 
appear  brownish  in  the  one  case  and  more  or  less  intensely  yellow  in 


160  FOODS. 

the  other.  If  the  curd  is  now  shaken  with  hydrochloric  acid,  one 
of  the  following  changes  will  be  observed :  If  anilin-orange  is  present, 
the  color  becomes  bright  pink  almost  immediately  ;  with  caramel  it 
becomes  gradually  brownish  blue ;  if  neither  is  present,  the  change  is 
to  blue. 

Anilin-orange. — See  preceding  })aragraph,  A  more  direct  method  is 
proposed  by'Lythgoe.'  Place  15  cc.  of  milk  in  a  porcelain  dish  and 
add  about  the  same  volume  of  hydrochloric  acid  (specific  gravity  1.200). 
Agitate  gently,  to  bring  about  thorough  mixing  and  to  break  up  the 
resulting  curd  into  rather  coarse  lumps.  If  anilin-orange  is  jiresent, 
the  curd  will  be  colored  pink  ;  if  none  is  present,  it  will  be  white  or 
yellowish. 

Detection  of  Preservatives. — Borax  and  Boric  Acid.—  These  sub- 
stances are  detected  easily  either  in  the  milk  itself  or  in  the  ash  after 
ignition  of  the  residue.  In  the  latter  case,  moisten  the  ash  with  a 
drop  or  two  of  strong  sulphuric  acid,  and  after  a  few  minutes  add  3  or 
4  cc.  of  strong  alcohol.  Dip  a  strip  of  turmeric  paper  into  the  mixt- 
ure and  allow  it  to  dry  without  the  aid  of  heat.  In  the  presence  of 
either  of  the  substances  sought  for,  the  paper  will  have,  when  dry,  the 
characteristic  red  color  due  to  boric  acid,  instead  of  the  yellow  color 
which  will  be  maintained  in  its  absence.  While  the  paper  is  drying, 
place  the  dish  in  a  dark  place  and  ignite  the  contained  alcohol.  If 
boric  acid  or  its  sodium  compound  is  present,  the  flame  will  show  at 
its  outer  edge  a  characteristic  greenish  coloration.  This  is  shown  most 
strongly  directly  after  the  alcohol  is  ignited. 

In  the  original  milk,  the  test  may  be  made  in  the  following  manner : 
Mix  a  few  drops  of  the  milk  and  an  equal  amount  of  fresh  tincture 
of  turmeric  in  a  small  porcelain  dish  and  evaporate  on  a  water-bath  to 
dryness.  Moisten  the  surface  of  the  residue  with  dilute  hydrochloric 
acid,  and  dry  again.  If  either  of  the  substances  is  present,  the  residue 
will  be  light  pink  to  dark  red  in  color,  and  the  addition  of  a  drop  of 
ammonia-water  will  change  this  to  a  green  or  greenish  blue,  according 
to  the  amount  of  the  preservative  present. 

Salicylic  Acid. — 1.  Coagulate  about  75  to  100  cc.  of  milk  with 
mercuric  nitrate  solution  or  hydrochloric  acid,  and  separate  the  whey 
by  filtration.  Shake  the  whey  with  ether,  decant  the  ether  into  a 
watch-glass,  and  allow  it  to  evaporate.  To  the  residue  on  the  watch- 
glass,  apply  a  drop  of  neutral  ferric  chloride.  If  salicylic  acid  is  pres- 
ent, the  characteristic  purple  coloration  is  produced.  2.  Mix  the  milk 
with  phosphoric  acid  and  strain  through  cloth.  Place  the  liquid  in  a 
flask,  connect  with  a  condenser,  and  distil.  Test  the  distillate  with 
ferric  chloride  from  time  to  time.  Any  salicylic  acid  pi-esent  will  go 
over  with  the  steam,  most  of  it  toward  the  end  of  the  operation. 

Formaldehyde. — Many  processes  for  the  detection  of  this  substance 
in  milk  have  been  devised,  some  exceedingly  simple  and  others  quite 
complicated.  Those  which  give  the  best  results  and  the  greatest  satis- 
faction are,  on  the  whole,  those  which  are  the  simplest  in  application 
1  Eeport  of  Massachusetts  State  Board  of  Health  for  1900,  p.  647. 


ANA/,YSIS   OF   MII.K.  161 

nnd  r(!<|iilr(;  iJic  Iciisl  ex  pciidil  iii-c  <»C  fimc  'I'lic  If-t  -lionM  Ix'  ;ip|.rH(| 
wiiliiii  ;i,  ((;w  <l:iy.s  ;i,Clcr  tlic  :i<l(lit ion  <.f  the  preHervative,  Hinw;  :i(t<T  ;i 
tiino  it  c-juuiot  !)(•  (Ic(cc((<l. 

1.  Ml-ynioi)  l'.^■  I)i;''()i.oi;i/,i;i)  l''f:(ilsiNK, — 'I'lmm^^li  ;i  Holntion  of 
(iKilisiiK!  1  :  500  pass  a,  ciiitciiI,  of  siil|»liiirous  aci<l  ^^as,  obtained  l»y 
licaiiiifi;  (!()pp(!r  wife  or  loll  with  siilpliniic  acid,  until  tlx-  color  is  din- 
(•,lijirf!;(Hl.  l*rcs<M'V(!  ill  a,  frliiSH-Htopporcd  bolllc  To  I  0  cc.  oC  milk,  add 
1  v.v.  of  tli(^  vea<i;<'iit  and  let  stainl  ten  iiiiiiiitcs.  Add  2  «■<•.  of  hfroii^ 
liydrocliloric,  acid  and  siiakc;  or  stir  briskly.  Tlic  folor  whirli  af)pf^irH 
in  the  first  instance  is  disi^hargcid  eoinph^lely  by  the  aeid  if  no  formal- 
dehyd(!  is  preH(!nt;  otherwise,  :i  violet-blue  tinge  remains.  Jf  the  an)onnt 
present  is  hirge,  the  end  color  will  be  correspondingly  int^jnse.  This 
method  will  deteet  tlie  admixture  of  1  part  of  formalin  in  50,000  of 
milk.  If  the  milk  be  distilled  (irst,  and  tlu;  first  i)art  of  the  distillate 
trea,t(Hl  with  fnchsin(>  solution,  the  (est  is  delicate  to  the  extent  of  re- 
vealing 1  part  in  500,000. 

2.  Method  hy  Piiloroglucin. — Add  to  10  cc  of  milk  in  a  test- 
tube  2  or  8  cc.  of  a  0.10  per  cent,  solution  of  ))hlorogiuein  and  5  to 
10  drops  of  a  10  ]K'r  cent,  solution  of  sodium  hydrate,  and  shake.  In  the 
presence  of  formaldehyde  a  gradual  red  coloration  appears;  otherwise,  no 
such  change  is  observed.  This  test  is  said  to  reveal  1  part  in  50,000, 
but  such  a  claim  appears,  according  to  the  experience  of  the  author  and 
others,  not  to  be  justified. 

3.  MKTiroD  BY  Ferric  Chloride. — Mix  in  a  porcelain  dish  10 
cc.  each  of  milk  and  hydrochloric  acid  (specific  gravity  1.200)  and  1  drop 
of  ferric  chloride  solution.  Heat  and  stir  vigorously.  If  formaldehyde 
has  been  added,  a  violet  color  will  appear  before  the  boiling-])oint  is 
reached,  varying  in  intensity  according  to  the  amount  present.  This 
process  is  exceedingly  delicate,  and  will  detect  1  part  in  500,000  in 
the  fresh  condition. 

4.  Method  by  Commercial  Sulphuric  Acid. — This  test  is  ex- 
ceedingly delicate  and  very  easily  applied.  It  cannot  be  performed 
with  pure  sulphuric  acid,  since  the  presence  of  a  trace  of  iron  is  neces- 
sary. If  one  desires  to  use  a  pure  acid  rather  than  the  ordinary  com- 
mercial grade,  the  addition  of  a  very  small  amount  of  ferric  chloride 
will  be  sufficient. 

Take  about  15  to  20  cc.  of  milk  in  a  test-tube  and  jwur  about  5  cc. 
of  the  acid  gently  down  the  side  so  that  it  shall  pass  under,  rather  than 
mix  with,  the  milk.  Let  stand  a  few  minutes,  and  then  note  the  color 
at  the  junction  of  the  two  liquids.  If  formalin  is  present,  even  in  the 
slightest  traces,  a  violet  coloration  appears  at  the  line  of  junction.  In- 
asmuch as  pure  milk  will  show  a  somewhat  purplish  color  when  in 
contact  with  strong  sulphuric  acid,  a  color  which  may  readily  be  mis- 
taken at  first  for  that  due  to  formaldehyde,  and  since  also  the  chariing 
that  occurs  at  the  line  of  junction  will  often  obscure  the  i-eactiou,  the 
process  as  originally  recommended  is  somewhat  faulty.  The  objections 
are  removed,  ho^Yever,  by  diluting  the  strong  acid  with  water  so  that 
its  specific  gravity  is  reduced  from  1,840  to  1.700.  The  action  of  the 
11 


162  FOODS. 

stronger  acid  on  pure  milk  is  shown  in  Plate  VI.,  Fig.  1,  nliicb  shows 
the  dark  color  due  to  charring  and  the  purplish  color,  above  spoken  of, 
due  to  the  same  cause. 

In  Plate  VI.,  Fig.  2,  is  shown  the  appearance  of  the  line  of  junction 
of  pure  milk  and  the  diluted  acid.  It  will  be  observed  that  the  color 
produced  is  but  a  faint  yellow.  In  Plate  VL,  Figs.  3  and  4,  are 
shown  the  zones  produced  in  milk  containing  formaldehyde  in  the  pro- 
portions of  1  part  to  25,000  aud  1  to  50,000  by  the  use  of  the  diluted 
acid.  As  may  be  inferred,  the  reaction  is  produced  rather  more  slowly 
with  the  weaker  acid.  It  is  best  to  allow  the  contact  to  continue  at 
least  an  hour  before  noting  a  negative  result. 

5.  Luebert's^  Method  by  Potassium  Sulphate. — Place  5  grams 
of  coarsely  powdered  potassium  sulphate  in  a  100  cc.  flask  and  dis- 
tribute over  it  5  cc.  of  milk  by  means  of  a  pipette.  Then  pour  care- 
fully down  the  side  of  the  flask  10  cc.  of  sulphuric  acid  (specific  gravity 
1.840),  and  allow  the  whole  to  stand  quietly.  If  formaldehyde  is 
present,  a  violet  coloration  of  the  potassium  sulphate  occurs  within 
a  few  minutes,  and  gradually  diffiises  through  the  entire  liquid. 
If  none  is  present,  the  mixture  will  at  once  assume  a  brown  color, 
which  rapidly  changes  to  black.  This  test  is  sensitive  to  1  part  in 
250,000. 

Cliromates. — Froidevaux^  recommends  dissolving  the  ash  of  about 
10  cc.  of  milk  in  a  few  drops  of  water  acidulated  with  nitric  acid  and, 
after  neutralizing  with  magnesium  carbonate,  adding  a  few  drops  of  test- 
solution  of  nitrate  of  silver,  whereby  a  red  precipitate,  chromate  of 
silver,  is  formed.  As  a  control  test,  he  recommends  taking  up  another 
portion  of  ash  with  water  acidulated  with  sulphmnc  acid,  and  adding 
little  by  little  cincture  of  guaiacum.  In  the  presence  of  chromates, 
an  intense  blue  color  is  produced,  which  disappears  very  quickly.  This 
process  will  detect  1  part  in  50,000.  Guerin  ^  claims  greater  delicacy 
for  the  following  method  :  To  5  or  10  cc.  of  milk  add  2  drops  of  a  1 
per  cent,  solution  of  sulphate  of  copper  and  2  or  3  drops  of  freshly 
prepared  tincture  of  guaiacum.  Pure  milk  gives  a  greenish  color,  while 
milk  containing  1  part  in  100,000  will  give  an  intense  blue,  which 
reaches  its  maximum  in  a  few  minutes. 

Methods  of  Distinguishing  between  Raw  and  Cooked  Milk. — To 
determine  whether  or  not  milk  has  been  cooked,  Saul  *  recommends  the 
addition  of  1  cc.  of  a  1  per  cent,  solution  (fresh)  of  ortol  (Orthometh- 
ylaminophenol  sulphate)  to  10  cc.  of  milk,  and  then  1  drop  of  com- 
mercial hydrogen  peroxide  solution.  Raw  milk  develops  a  red  color 
almost  immediately,  but  milk  heated  beyond  75°  C.  remains  unchanged. 

Dupouy  ^  gives  the  following  tests  : 

1.  Guaiacol.  Equal  volumes  of  milk  and  a  1  per  cent,  solution  of 
guaiacol  in  water  are  mixed  and  then  treated  Avith  hydrogen  peroxide. 

1  Journal  of  the  American  Chemical  Society,  September,  1901,  p.  682. 
=*  .Journal  de  Phannacie  et  de  Chemie,  1896,  p.  155. 
•^  Chemiker  Zeitung,  1897,  p.  174. 

*  British  Medical  .Journal,  March  24,  1903. 

*  Journal  de  Pharmacie  et  de  Chemie,  1897,  p.  397. 


PLATL   VI 


I- 1  (J.  I 


\nn.  n 


Fic|.    1.      Coloration   Produced  by  Con'-"-i''~-"-="  '    -^n  i  ,^i , ,  i ,-;  .    a,;  ■ 
Contaet,  witU  Pure  Milk. 

Fui.  '"^       r"    ■     .ation    Produced    by    Suipimrie    Ae; 
ih  Pure  Milk. 

Fie),  y.      Coloration    Produced    by    Sulphuric    Acid    of   Sp.    Gr.     1.~j2 
with  Milk  Containing  I  Part  of  Formaldehyde  in  25.000. 

FicT.  ^-      Coloration    Produced    by    Sulphuric    Acid    of  Sp. 
with  Milk  Containing  1  Part  of   Fornialdehyde 


contact 
i  n  Contaet 
in    Contact 


ANALYSIS  OF  MILK.  \('>''> 

TIk!  iiniri(!(li;it(^  product  ioii  of  ;i  yellow  coloi-  iii<lif%'it<!H  that  tho  H[M!cimcn 
JiaH  not  bcciii  boilcid. 

2.  lIy(lr()(|iiiiionc.  'I'liriu;  <;c,.  of  milk  ;iic  mixed  witii  1  re.  of  u 
fresh  10  j)(!r  (v.dL  !1(|1Icoiih  .solution  of  hydio(jiiiiioii(;  and  1  ">  drops  of 
hy(lro}r(!ii  |)(!ro.\id('.  If  th(!  milk  Iwis  not  hccn  hoilcd,  a  row;  color  im- 
m(!<liat(!ly  ai)p('iirs,  and  in  a  few  miniif<',s  (rn^cii   cry.stal.s  an;  dcpoHit4;<l. 

.'}.  I'yrocatccliin.  Ivjiinl  volumes  ni'  raw  milk  and  an  afjncon.s  10 
j)er  rvul.  .solution  of  pyi'ociateeliin  ant  brought  tofrcthcr  and  trr^Jited 
witli  liydrojijcui  peroxide.  Willi  raw  milk  a  yc^llowish-hroun  eolor  is 
produc.(!(l  ;    with  boiled  milk  no  eolor  a|)p(;ars. 

4.  c/-Nai)hthol.  Uaw  milk  jrives  with  an  a(jueoii,s  solution  f»f 
«-na])hthol  and  hydrogen  peroxide  a  violet-blue  eol(;r.  Jioileil  milk 
gives  none. 

Storeh's  method'  i.s  as  follows:  To  10  ec.  of  milk,  add  1  di'op  of  a 
0.2  per  cent,  .solution  of  hydrogen  peroxide;  and  2  dro|)s  of  a  2  per 
cent,  solution  of  j)-j)hcnylenediamin  and  shake  violently.  If  the  milk 
has  not  been  heated  to  78°  C.  (172.4°  F.),  an  immediate  blue  color 
will  ai)pear;  if  it  has  been  heated  to  80°  C.  (178°  F.),  the  blue  color 
appears  in  about  a  half  minute  ;  and  if  it  has  been  heated  higher  than 
this,  the  blue  will  not  appear  at  all.  Sour  milk  should  be  neutralized 
with  lime-water.  Formaldehyde  prevents  the  change  to  blue,  but 
permits  the  occurrence  of  a  faint  red.  The  p-phenylenediamin  solution 
keeps,  in  dark  glass,  about  two  months. 

Bernstein^  propo.ses  the  following:  To  50  cc.  of  milk,  add  4.5  cc. 
of  normal  acetic  acid,  shake  gently  until  coagulation  occurs,  and  filter. 
Heat  the  filtrate.  If  the  milk  has  not  been  pasteurized,  a  heavy  pre- 
cipitate of  lactalbnrain  will  form.  The  higher  the  milk  has  been 
heated,  up  to  90°  C.  (194°  F,),  the  smaller" will  be  the  precipitate; 
and  if  it  has  been  heated  beyond  this,  no  precipitate  at  all  will 
form. 

Detection  of  Gelatin  in  Cream. — For  the  detection  of  gelatin  in 
cream,  to  which  it  sometimes  is  added  to  give  it  body,  Stokes '^  recom- 
mends the  following  procedure  :  Dissolve  a  quantity  of  mercurv  in 
twice  its  weight  of  strong  nitric  acid  (specific  gravity  1.420) ;  dilute 
with  water  to  25  times  its  bulk.  To  about  10  cc.  of  this  solution  add 
a  like  quantity  of  the  cream  and  about  20  cc.  of  cold  water.  Shake 
the  mixture  vigorously,  let  stand  for  five  minutes,  then  filter.  If 
much  gelatin  be  present,  it  w'ill  be  impossible  to  get  a  clear  filti'^te. 
To  the  filtrate,  or  to  a  portion  of  it,  add  an  equal  bulk  of  a  saturated 
aqueous  solution  of  picric  acid.  If  gelatin  be  present,  a  vellow  pre- 
cipitate will  immediately  be  produced.  The  whole  operation  is  perfonued 
in  the  cold,  and  if  the  mercurv  solution  is  ready,  the  test  will  not  take 
more  than  ten  minutes.  Picric  acid  will  show  the  presence  of  1  part 
of  gelatin  in  10,000  parts  of  water. 

^  Zcitscbrift  fiiv  Untersuchmis:  der  Xahrungs-  und  Genussmittel,  1901,  p.  S9S. 
'^  Zeitscbrift  fiir  Fleisch-  mid  Milchhygiene,  1900,  p.  80. 
*  The  Analyst,  December,  1897. 


164  FOODS. 

Detection  of  Sucrate  of  Lime  in  Cream. — Lythgoe's  modifica- 
tion of  Baier  and  Neumau's  test  for  detecting  sucrose,  as  given  by 
Leaeli '  is  as  follows  : 

''To  25  cc.  of  milk  or  cream,  add  10  ee.  of  a  5  per  cent,  solntion 
of  nranium  acetate,  shake  well,  allow  to  stand  for  5  minutes,  and  filter. 
To  10  cc.  of  the  clear  filtrate  (in  the  case  of  cream  use  the  total  filtrate, 
which  will  be  less  than  10  cc.)  add  a  mixture  of  2  cc.  saturated  am- 
monium raolybdate  and  8  cc.  dilute  hydrochloric  acid  (1  part  25  per 
cent,  acid  and  7  parts  water),  and  ])lace  in  a  water-bath  at  a  tempera- 
ture of  80°  C  for  5  minutes.  If  the  sample  contains  sugar,  the  solution 
will  be  of  a  Prussian  blue  color.  This  should  always  be  compared  in  a 
calorimeter  with  the  standard  Prussian  blue  solution,  prepared  by  add- 
ing a  few  drojis  of  potassium  ferrocyanide  to  a  solution  of  1  cc.  of  1 
per  cent,  ferric  chloride  in  20  cc.  of  water." 

BUTTER. 

United  States  Standard. — Standard  butter  contains  not  less  than 
82.5  per  cent,  of  butter  flit.  By  acts  of  Congress,  approved  August 
2,  1886,  and  May  9,  1902,  butter  may  also  contain  added  coloring 
matter. 

This  valuable  milk  product  is  the  result  of  violent  agitation  of  cream 
until  its  fat  coalesces  into  granular  particles,  which  are  then  separated 
from  the  residual  buttermilk,  "  worked  "  to  expel  as  much  of  the  latter 
as  possible,  and,  with  or  without  the  addition  of  salt  and  coloring  mat- 
ter, formed  into  "  prints  "  or  "  pats,"  or  packed  in  bulk  in  boxes  and 
firkins.  Its  natural  color  varies  with  the  season,  the  so-called  June 
butter,  made  when  the  cows  from  whose  milk  it  is  produced  are  feeding 
on  grass,  being  bright  yellow,  while  that  made  when  they  are  stalled, 
and  fed  on  hay  and  other  winter  feed,  being  almost  white.  The  popu- 
lar demand  being  for  a  yellow  article  the  year  round,  it  is  customary 
to  secure  this  color  out  of  season  by  the  addition  of  annatto  and  other 
harmless  vegetable  coloring  agents,  the  use  of  which  has  almost  uni- 
versally the  sanction  of  law. 

The  flavor  is  influenced  much  by  the  character  of  the  feed,  by  the 
care  exercised  in  manufacture,  by  the  amount  of  added  salt,  by  age, 
and  by  the  conditions  of  storage.  Like  milk,  it  absorbs  odors  very 
readily,  both  those  which  improve  and  those  which  impair  its  flavor. 
Taking  advantage  of  this  fact,  it  is  the  custom  in  the  valley  of  the  Var 
and  in  some  other  localities  to  place  the  freshly  made  product  in  prox- 
imity to  jasmine,  violets,  tuberoses,  and  other  flowering  plants,  in  order 
that  their  fragrance  may  be  absorbed.  This  practice  is  known  as 
"  enfleurage."  The  most  delicately  flavored  butter  under  natural  con- 
ditions is  that  to  which  no  salt  has  been  added,  but  it  has  the  disad- 
vantage that  within  a  short  time  it  acquires  a  "  cheesy  "  flavor,  due  to 
decomposition  processes.  Owing  to  its  lack  of  keeping  qualities  and 
to  the  very  general  preference  for  a  more  pronounced  taste,  the  addi- 

1  Food  Inspection  and  Analysis,  1909,  p.  197, 


BUTTER.  I'J' 


(joii  of  suli,  ill  varying:;  iuiioiitits  is  liic  nil''.  liuttcr  of  j/ood  (|ii:ilily 
liiiM  but  .sli^'lit  odor,  hut,  iJial  \vlii<li  liiis  iiii(lcr^'oiic  tin-  (oiiimx.ii  cludijrf^ 
(liK!  to  l)iu;t<!riiil  iic-tioii  has  (lie  clKii-.Htcrislif  odor  and  f;i-tc  of  laiicidity. 
This  is  diK!  to  d('coni])OMilioii  oC  iIh'  Mmdl  anioiint  oC  .iiid  which  iH  <*n- 
Inn^lcd  in  ihc  inal<iiiij;',  and  which  caiinol  wholly  he  cxchuh-d.  The  (at 
itscIC,  vvlicii  sc|)ara(c<l  (Voiii  Ihc;  curd  hy  iiichiiijr,  keeps  iiii(;haii^M-d  for 
h)nf>;  |)(M'iods.  In  rancid  hnticr,  hiityric  and  other  acids  arc  Hhcralcd, 
and  otluii-s,  as  forniicr,  an;  formed  hy  al)sorj)tion  of  oxy^rvu.  Under 
Konio  nnnsiial  coiKhtions  not  wholly  un(h'rstood,  huttor,  withont  bccom- 
ini>'  rancid  in  tiu!  usual  sense,  iiiider<rocs  a  chaii^a-  to  a  |»er(eefly  white 
siihstaiicc  with  a  marked  tallowy  odoi-. 

IJnttcr  varies  (nmsiderably  in  (tom|)osiiion,  hut  a  fair  average  may  he 
stated  as  follows  : 

Fat ^'«W 

Water 12.00 

Curd 1-00 

Salts 2.50 

Lactose f'-''^*^' 

It  may  l)c  made  to  contain  a  much  higher  percentage  of  water,  with 
correspondingly  less  fat. 

The  fat  is  composed  of  glycerides  of  two  groups  of  fatty  acids,  which 
have  been  mentioned  in  the  description  of  milk.  Those  of  the  in- 
soluble non-volatile  acids,  oleic,  stearic,  and  ]>abnitic,  constitntc  about 
92.25  per  cent,  of  the  whole ;  and  those  of  the  solulile  volatile  acids, 
butyric,  caproic,  caprylic,  and  capric,  make  up  the  remainder.  It  is 
to  the  second  group  that  butter  o\ves  its  distinctive  flavor. 

The  amount  of  water  depends  largely  upon  the  thoroughness  with 
which  the  buttermilk  is  worked  out.  In  order  that  more  water  may 
be  held,  and  thus  a  greater  profit  realized,  some  makers  employ  gelatin 
as  an  adulterant.  One  gram  of  this  substance  will  take  up  about  10 
grams  of  water,  and,  when  mixed  with  butter  in  the  right  ])ropor- 
tion,  will  hold  water  in  the  above  ratio  without  affecting  the  consi.stence 
injuriously.  Others  employ  glucose  both  for  this  purjjose  and  as  a 
preservative. 

The  salts  include  those  natural  to  milk  and  those  added  for  the  pre- 
vention of  rapid  decomposition.  The  usual  addition  is  common  salt, 
but  the  use  of  boric  acid  and  borax  is  extending  gradually. 

Apart  from  the  use  of  preservatives  and  of  ageuts  to  assist  in  retain- 
ing water,  butter  is  not  much  subject  to  adulteration,  exce}>tiug  in  the 
sense  that  substitution  of  an  article  of  less  value  when  butter  is  called 
for  is  a  form  of  adulteration.  This  substitute  is  known  variously  as 
artificial  butter,  butterine,  oleomargarine,  and  marg-arine.  Under  the 
United  States  statutes,  all  butter  or  substitutes  therefor  made  to 
resemble  it,  containing  fats  other  than  cream,  shall  be  knoMTi  as  oleo- 
mai'g-arine. 

Following  the  original  process,  oleomargarme  is  made  from  fresh 
beef  suet,  which,  after  being  cooled,  washed,  and  cut  into  very  fkie 
pieces  by  machinery,  is  subjected  to  a  temperature  of  about  11 C^  F. 


166  FOODS. 

for  several  liours,  in  order  to  separate  the  fat  from  the  tissue.  It  is 
then  drawn  off  and  kept  for  a  time  at  80°  to  90°  F.,  at  which  tem- 
perature the  stearin  solidifies,  and  then  is  separated  by  pressure  from 
the  "oleo-oil."  The  latter  is  churned  with  milk  or  witli  milk  and  gen- 
uine butter,  colored  witii  annatto,  and  otherwise  treated  like  butter. 
At  the  present  time,  olet)margarine  is  made  not  alone  from  beef  suet, 
but  to  a  much  greater  extent  from  "  neutral  lard,"  a  product  of  leaf 
lard.  Cotton-seed  oil  is  used  to  some  extent,  but  naturally  it  is  not  so 
well  adapted  to  the  purpose  as  the  solid  fats. 

Oleomargarine  has  been  misrepresented  to  the  public  to  a  greater 
extent  probably  than  any  other  article  of  food.  From  the  time  of  its 
first  appearance  in  the  market  as  a  competitor  of  butter,  there  has  been 
a  constant  attem]it  to  create  and  foster  a  prejudice  against  it  as  an 
unwholesome  article  made  from  unclean  refuse  of  various  kinds,  a 
vehicle  for  disease  germs,  and  a  disseminator  of  tapeworms  and  other 
unwelcome  parasites.  It  has  been  said  to  be  made  from  soap  grease, 
from  the  carcasses  of  animals  dead  of  disease,  from  grease  extracted 
from  sewer  sludge,  and  from  a  variety  of  other  articles  equally  unadapted 
to  its  manufacture.  The  publication  of  a  great  mass  of  untruth  cannot 
fail  to  have  at  least  a  part  of  its  desired  effect,  not  solely  on  the  minds 
of  the  ignorant,  but  even  on  those  of  persons  of  more  than  average 
intelligence.  So  a  prejudice  was  created  against  this  valuable  food 
product,  but  it  is  becoming  gradually  less  pronounced. 

The  truth  concerning  oleomargarine  is  that  it  is  made  only  from  the 
cleanest  materials  in  the  cleanest  possible  manner ;  that  it  is  equally  as 
wholesome  as  butter ;  and  that  when  sold  for  what  it  is  and  at  its 
proper  price  it  brings  into  the  dietary  of  those  who  cannot  afford  the 
better  grades  of  butter  an  important  fat  food  much  superior  in  flavor 
and  keeping  property  to  the  cheaper  grades  of  butter,  which  bring  a 
higher  price.  Oleomargarine  cannot  be  made  from  rancid  fat,  and  in  its 
manufacture  great  care  mast  be  exercised  to  exclude  any  material  how- 
ever slightly  tainted. 

Oleomargarine  is  not  and  cannot  be  made  from  fats  having  a  marked 
or  distinctive  taste,  and  its  flavor  is  derived  wholly  from  the  milk  or 
genuine  butter  employed  in  its  manufacture.  It  contains,  as  a  rule, 
less  water  than  does  genuine  butter,  and  consequently  any  difference  in 
food  value  is  in  its  favor.  It  imdergoes  decomposition  much  more 
slowly,  and,  indeed,  may  be  kept  many  months  without  becoming  rancid. 
Much  has  been  said  concerning  its  digestibihty,  and  alarmists  have  gone 
so  far  as  to  claim  that  it  is  very  indigestible,  and  likely  to  prove  a  pro- 
lific cause  of  dyspepsia,  quite  forgetting  that  the  materials  from  which 
it  is  made  have  held  a  place  in  the  dietaries  of  all  civilized  peoples  since 
long  before  butter  was  promoted  from  its  position  as  an  ointment  to  that 
of  an  article  of  food.  Many  comparative  studies  have  been  made  on  this 
point,  and  the  results  in  general  have  shown  that  there  is  little  if  any 
difference.      H.  Liihrig  ^  has  proved  by  careful   experiment  that  the 

^  5^itschrift  fiir  Untersuchung  der  Nahrungs-  und  Genussmittel,  June,  1899,  p.  484. 


lill'I'TKIl.  107 

two  iivv.  (,()  ;ill  inlcnls  :iii(l  purposes  r-XHcllv  .'ililsc  in  point,  oC  dij^f.-ti- 
l)ilily. 

()l<;()niiirji;!irin(!  lias  been  (lie  siihjcci  oC  a  vjist  Jiriiouiit  of  nrHtric^ive 
l(!^isl!ili()n  vvlici'cvcr  it.  is  made  or  sold.  This  Iijih  br-cn  psLsscd  in  tiu; 
iii(,ercs(,  of"  dairynicM  and  Ix-cransc  of  llio  («IH(!  willi  wliidi  it  rnav  Ik- 
sold  (raiidulcndy  as  hnlicr  at  hntfcr  j)ri(;(!H.  To  the  practice  of  fraud 
in  its  retail  sale,  is  due  wvy  lart^ely  tlie  passage  of  proliihitivc  lawH, 
many  of  vvliieli,  however,  have  been  declared  iinconstitiitional.  In 
Massadlinset.ts,  for  example,  it  had  at  one  tim(^  a  verv  larjfe  sale,  and  in 
tli(^  v\\\  of  l)Oslon  alone  were  nearly  200  licensed  dealers.  IJiit  tin* 
imomit  of  fraudulent  dealing  was  so  ^reat  that  the  J^e^islaturc  pas.s<Kl 
an  act  prohibitiiifj^  its  sale  if  it  contained  any  ingredient  c^UHJng  it  to 
look  lilvc  butter;  in  other  words,  no  annatto  or  (»ther  substane*-  which 
would  cause  it  to  bo  yellow  could  be  used  in  its  mamifactnre.  Since  its 
natural  color  is  almost  white,  and  since  white  butter  does  not  a|)peal  to 
the  eye,  the  result  was  practically  the  \\itlidrawal  of  the  article  from 
Open  sale. 

In  Germany,  on  account  of  fraudulent  ))ractices  in  the  adulteration 
of  butter  with  oleoiuarG^arinc,  the  government  passed,  in  1897,  a  statute 
re(|uirin<:!;  the  latter  to  contain  10  per  cent,  of  oil  of  sesame,  so  that  any 
subseipieut  admixtiu'e  with  butter  may  rejidily  be  detected  l)y  Bau- 
douin's  reaction.  This  is  a  red  coloration  brought  about  when  oil  of 
sesame,  furfurol,  aud  hydrochloric  acid  are  brought  together;  and  it  is 
sufficiently  delicate  to  show  the  adulteration  of  butter  with  2.5  per 
cent,  of  oleomargarine  containing  the  oil  in  the  proportion  stated. 
Experiment  has  shown  that  butter  made  from  the  milk  of  cov;s  fed  on 
sesame  does  not  yield  the  reaction,  but  the  fat  of  the  milk  of  goats  fed 
partly  on  sesame  has  been  found  to  give  it. 

The  principal  chemical  dilierence  between  butter  aud  oleomargarine 
lies  in  the  relative  amounts  of  glycerides  of  the  soluble  and  insoluble 
fatty  acids.  Genuine  butter-fat  contains  nearly  8  per  cent,  of  butyrin, 
caproin,  caprin,  and  caprylin,  while  the  artiticial  product  contains  these 
glycerides  only  as  they  are  introduced  in  the  amount  of  milk  or  butter 
with  which  it  is  churned,  for  they  are  not  present  in  suet,  lard,  and 
other  animal  fats. 

Of  late  years,  high-grade  butter  has  found  another  formidable  com- 
petitor in  what  is  known  variously  as  renovated  butter,  process  butter, 
and  hash  butter.  The  material  from  which  this  is  made  is  gathered 
from  dairies  scattered  over  a  wide  expanse  of  couutiy,  and  ditfers 
widely  in  color,  texture,  age,  and  flavor.  It  is  melted,  purified  of  its 
rancidity  by  washing,  given  the  desired  yellow  color,  aud  rechurned. 

Butter  as  a  Carrier  of  Disease. — Since  milk  is  known  to  be  a  car- 
rier of  the  germs  of  certain  diseases  under  some  conditions,  the  possi- 
bility that  butter  may  act  in  the  same  way  suggests  itself,  and  the  more 
strongly  since,  in  ordinary  creaming  of  milk,  all  but  a  very  small  pro- 
portion of  the  bacteria  rise  with  the  cream.  Ordinary  butter  contains 
millions  of  bacteria  to  the  gram,  but  whether  the  pathogenic  forms  can 
long  survive  has  not  been  investigated  very  extensively,  except  in  the 


168  FOODS. 

case  of  the  bacillus  of  tuberculosis.  The  bacteria  of  cholera  and 
t}'^hoicl  fever  have  been  known  to  survive  several  days  after  being 
planted  in  butter,  but  boycMid  this  we  have  little  knowledge. 

Brusaferro,  in  1891,  produced  tuberculosis  in  a  rabbit  through  the 
injection  of  butter  made  from  the  milk  of  a  cow  with  a  tuberculous 
udder.  Roth,  in  1894,  got  similar  results,  and  found,  moreover,  that 
2  out  of  20  market  samples  of  butter  used  by  him  yielded  positive  re- 
sults. Sehuchardt  got  negative  results  from  42  samples,  while  Ober- 
miiller  found  the  bacillus  in  every  sample  of  Berlin  butter  used  in  his 
first  series  of  experiments.  Dr.  Lydia  Rabinowitsch '  examined  80 
samples  obtained  partly  in  Berlin  and  partly  in  Philadelphia,  and  found 
genuine  tubercle  bacilli  in  not  a  single  instance.  She  did,  however, 
find  a  spurious  organism,  Avhich  produced  in  guinea-pigs  changes  which 
required  very  careful  examination  for  the  determination  of  its  non- 
tuberculous  character.  It  was  present  in  28.7  per  cent,  of  the 
samples.  Petri  ^  found  it  in  37.2  per  cent.,  the  genuine  bacillus  in 
32.4  per  cent.,  and  neither  the  one  nor  the  other  in  30.4  per  cent. 
Oberm tiller,^  using  salted  butter  in  a  second  series,  determined  that  the 
injection  of  the  butter-fat  itself  introduced  a  cause  of  irritation,  and 
used,  therefore,  in  his  next  set  the  watery  fluid  separated  from  the 
butter  by  heat  and  centrifugation.  Four  samples  out  of  10  from  the 
same  source  as  his  first  lot  gave  undoubted  evidence  of  the  presence  of 
genuine  tubercle  bacilli.  Otto  Korn  *  found  them  in  28.5  per  cent,  of 
samples  purchased  in  Freiburg,  and  Dr.  C.  Coggi  ^  in  only  2  out  of  1 00 
samples  purchased  in  Milan,  though  in  a  number  of  them  the  spurious 
organism  was  present.  Morgenroth^  has  subjected  oleomargarine  to  a 
similar  investigation,  since  milk  is  used  in  its  manufacture,  and  has  re- 
ported positive  results  from  9  out  of  20  samples.  Annett^  examined 
28  samples  of  oleomargarine  (15  from  Berlin  and  13  from  Liverpool), 
and  found  virulent  tubercle  bacilli  in  only  1. 

We  have  as  yet  no  evidence  whatever  that  tuberculosis  has  ever  been 
spread  through  the  agency  of  butter,  but  the  subject  deserves  most 
thoughtful  consideration. 

As  regards  the  possible  transfer  of  the  typhoid  bacillus  through  but- 
ter, Lumsden*  quotes  Bruck  as  having  demonstrated  the  bacillus  typho- 
sus in  butter  27  days  after  the  butter  had  been  experimentally  infected 
with  this  organism.  It  would  appear,  however,  as  pointed  out  by 
McCrae,"  that  danger  from  this  source,  under  ordinary  conditions,  would 
be  quite  small,  owing  to  the  presence  of  many  vigorous  saprophytes, 
the  washing  out  of  large  numbers  of  bacteria  in  the  buttermilk,  and 
the  salting  process  incident  to  the  making  of  butter. 

»  Zeitschrift  fiir  Hygiene  iind  Infectionskrankheiten,  XXVI.,  p.  90. 

2  Arbeiten  aus  dem  kaiserlichen  Gesundheitsamte,  1898,  p.  27. 

3  Hygienische  Rundschau,  1899,  No.  2. 

4  Archiv  fiir  Hygiene,  XXXVI.,  p.  57. 

5  Giornale  della  R.  Societa  italiana  d'igiene,  July,  1899,  p.  289. 
^  Hygienische  Rundschau,  1899,  No.  21. 

7  The  Lancet,  January  20,  1900. 

^  Hygienic  Laboratory  Bulletin  No.  41,  p.  151. 

8  Osier's  Modern  Medicine,  Vol.  II. 


n UTTER.  169 

Analysis  of  Butter.  Ordinarily,  ihc  cxainiiiatioii  of  l,iitl(r  i-  lim- 
ited to  tlic  d(!tenniniiti<)ii  of  wlicllKir  or  nol  if  is  mixed  uitli  or  rcpliu^Kl 
by  ohiornar^iirinc,  hiil  for  ilic  dcfcnninatioii  of  it-  food  value  it  Ih 
n(!(!(!S,4ai'y  to  a-H(!erlaiii  the  |)i'o|)ortioii-  of  f;il  .md  writer.  it  in  .Mtnui- 
times  of  inlci'cst  also  to  determine  the  .-imoiinl  of  -alt  and  the  pre-^-nce 
of  oiJier  pr(;s(!rvatives. 

Determination  of  Water. — W(!igh  ;i  gram  ov  t\so  ol'  tin'  -;imple  into  a 
platinum  dish,  kmcIi  as  is  used  in  the  analysis  of  milk,  ;ind  dw  to  eon- 
stant  \V(^it;lit  on  a  water-bath. 

Determination  of  Fat. —  Ivxtraet  the  residue  from  the  jxceedin^^  r|e- 
terniinution  with  elher  or  freshly  distilled  naphtha,  beting  careful  not  to 
remove  any  of  tlie  particles  of  curd  or  salt.  The  ])roce.sH  of  extraction 
is  very  simple,  consisting  in  filling  the  dish  about  half  full  of  the;  W)]- 
vent  and  after  a  short  time  decanting  it  carefully  into  another  ve.«sel, 
and  repeating  the  operation  until  nothing  is  extracted,  "^i'he  solvent, 
or  an  aliquot  part  thei'eof,  may  be  evaporated  in  a  weighed  Ijeaker,  or 
the  dish  may  again  be  heated  to  a  constant  weight  and  the  fat  deter- 
mined by  difference.  The  residue  now  represents  the  eurd,  lactose,  aiifl 
mineral  matters. 

Determination  of  Salt,  etc. — Ignite  this  residue  at  as  low  a  tempera- 
ture as  ])Ossible,  and  thus  burn  oW  the  casein  and  lactose.  Their  conj- 
bined  weight  is  ascertained  by  weighing  the  dish  anew.  AVhat  now 
remains  in  the  dish  is  mineral  matter,  comprising  the  salts  natural  to 
milk  and  those  added.  Common  salt  may  be  determined  by  treating 
the  final  residue  with  water  acidulated  with  nitric  acid,  and  titrating  in 
the  usual  way  with  standard  solution  of  silver  nitrate,  using  potassium 
chromate  as  an  indicator. 

Another  method  of  determining  salt  is  as  follows  :  Shake  a  known 
weight,  5-10  grams,  of  the  sample  with  hot  water  in  a  stojjpered  sep- 
arating funnel  until  it  is  melted  completely,  let  stand  until  the  fet 
gathers  on  the  surface  of  the  water,  and  then  draw  off  the  latter  through 
the  stopcock.  Repeat  the  operation  with  successive  portions  of  al)out 
20—25  cc.  of  hot  water  until  a  few  drops  of  the  washings,  tested  with 
silyer  nitrate,  fail  to  show  a  cloudiness,  due  to  silver  chloride.  Allow 
the  combined  washings  to  cool,  and  then,  in  an  aliquot  portion,  deter- 
mine the  chlorine  by  standard  silver  nitrate  solution  in  the  usual  way. 

Determination  of  the  Nature  of  the  Fat. — To  determine  whether  or 
not  a  specimen  is  or  contains  oleomargarine,  an  examination  of  the 
nature  of  the  fat  is  necessary.  As  has  been  pointed  out,  geuuiue  butter 
contains  a  considerable  amount  of  volatile  fatty  acids,  while  the  artifi- 
cial product  contains  very  little ;  but,  on  the  other  hand,  the  genuine 
article  is  correspondingly  poorer  in  the  insoluble  non-volatile  fatty 
acids.  It  is  upon  these  differences  in  the  two  kinds  of  fat  that  the 
determination  of  the  question  of  genuineness  depends.  The  usual 
examination  is  limited  to  the  determination  of  the  volatile  fatn-  acids 
in  a  given  weight  of  the  melted  fl\t  freed  from  water,  curd,  and  s;dt. 
The  fat  is  saponified,  the  resulting  soap  is  dissolved  in  Avater  and  then 
decomposed  by  means  of  sulphuric  acid,  and  the  volatile  fatty  acids, 


170  FOODS. 

thus  frwJ  from  combination,  are  then  distilled  over,  and  their  amount 
estimated  by  means  of  deeinormal  sodium  hydrate.  Fi\-e  grams  of 
genuine  butter-fat  will  }'ield  an  amount  which  will  require  at  least  24 
cc.  of  the  alkali  for  complete  neutralization,  while  an  equal  weight  of 
oleomargarine  yields  so  small  an  amount  that,  as  a  rule,  less  than  1  cc. 
is  required.  Mixtures  give  results  between  these  limits,  and  from  them 
one  can  estimate  approximately  the  proportion  of  butter  j^resent. 

Process. — Heat  a  small  piece  of  the  sample  on  a  water-bath  in  a 
suitable  beaker  until  it  is  melted  completely,  and  the  contained  water, 
salt,  and  curd  have  collected  at  the  bottom.  Decant  a  sufficient  amount 
of  the  supernatant  fat  into  a  dry  filter  and  allow  it  to  pass  into  a  shal- 
low beaker.  AMien  about  10  grams  have  been  collected,  place  the 
beaker  in  a  basin  containing  water  and  ice,  and  allow  the  fat  to  become 
hard.  Place  a  small  filter  paper  on  one  of  the  pans  of  the  balance  and 
counterbalance  it  exactly  with  weights  on  the  other.  Then  weigh  out 
as  rapidly  as  possible  2.5  grams  of  the  fat,  transferring  it  to  the  paper 
by  means  of  a  spatula.  Place  the  paper  and  fat  in  a  300  cc.  Erlen- 
meyer  flask,  add  10  cc.  of  a  20  per  cent,  solution  of  caustic  potash  in 
70  per  cent,  alcohol,  and  then  place  the  flask  on  a  water-bath.  In  a 
short  time,  especially  with  gentle  rotation  of  the  flask,  the  fat  becomes 
completely  saponified.  Continue  the  heat  until  the  alcohol  is  expelled, 
and  remove  the  last  traces  of  the  vapor  by  blowing  into  the  flask  with 
a  bellows  or  by  swinging  it  in  the  air.  Add  50  cc.  of  hot  water,  and 
when  the  soap  is  brought  completely  into  solution,  add  25  cc.  of  10 
per  cent,  sulphuric  acid.  The  latter  breaks  up  tlie  soap,  setting  free 
both  the  soluble  and  insoluble  fatty  acids,  the  latter  in  the  form  of 
curds.  Connect  the  flask  with  a  Liebig  condenser,  after  introducing 
several  pieces  of  pumice  stone  to  prevent  bumping,  and  then,  with  the 
flask  supported  on  a  square  of  wire  netting  over  a  Bunsen  lamp,  distil 
slowly  until  50  cc.  have  been  collected.  Titrate  the  distillate  with 
deeinormal  sodium  hydrate,  using  pheuolphthalein  as  an  indicator. 
With  the  amount  of  fat  taken,  at  least  12  cc.  of  the  alkali  will  be 
required  for  neutralization,  if  the  specimen  is  genuine  butter. 

Many  analysts  prefer  to  employ  5  grams  of  fat  and  correspondingly 
larger  volumes  of  water,  and  to  distill  110  cc,  whereof  100  is  titrated. 
Some  prefer  also  to  carry  on  the  process  of  saponification  in  a  round- 
bottomed  flask  under  pressure.  Some  measure  the  fluid  fat  directly  into 
a  weighed  flask  from  a  pipette,  and  ascertain  the  amount  taken  by  re- 
weighing  after  the  fat  has  cooled  and  solidified.  The  saponifying  agent 
is  applied  in  different  forms,  and  many  other  variations  in  detail  are 
recommended,  but  the  end  result  is  practically  the  same.  The  process 
described  has  been  found  in  the  experience  of  the  author  to  be  most 
satisfactoiy. 

The  Leffmann-Beam  process  has  much  to  recommend  it,  particularly 
in  the  saving  of  time.  The  saponifying  agent  is  prepared  by  mixing 
20  cc.  of  50  per  cent,  caustic  soda  solution  and  180  cc.  of  pure  concen- 
trated glycerin.  To  5  grams  of  fat  in  an  Erlenmeyer  flask  add  20  cc. 
of  this  solution,  and  then  heat  over  a  Bunsen  flame  until  saponification 


JHJTTICIL  171 

i'h  o()t)i|)l('i(\  TIi!m  r(;(|iiin'.4  hut  ;i  few  niiniifcs  ;  \hc,  f;otii|)l«'f ion  of  flu; 
])ro(!c,ss  ifs  sliowii  hy  (Ik;  r\vAV  coiKlItioii  oC  flic  iiiixliirc.  'V\u'  sfciji  in 
(JiJutxid  willi  I.'>'^)  <:c.  ol"  l)(»il('(l  wjifcr,  .'iddcd  :il  firsl  in  very  nrnall  nrnouiitH 
to  piXiVcsnt  ioiiniinn-.  'I'licn  5  rv.  of"  dilute  suljthuric  ju-id  (200  cc.  in 
1000)  iiro  iiddcd,  Mud  (lie  |)i(|):ii;il  ion  is  r(;:idy  lor  ininicdiiite  dihtiila- 
tion.  Distil  110  cc,  niix  tlioroiijiliiy,  juid  jkiss  ihrouMli  ;i  dry  filt<!r, 
titritte  100  cc,  ;ind  lo  llic  rcsull  ;idd    ,',,   lor  llic  rcnininiiiji;  10  cc. 

IfoiK!  wishes  lo  delernilne  I  lie  ;iiiioiiiil  of  iii.-oliiltle  fiifty  acidw,  it  may 
hv  don(!  in  tlu;  iollovvin^  iiiiuinei',  i>iil  it  should  \)v.  snid  tliat  the  [)rfK:<?s« 
re(|uir(!s  much  tnore  time,  and  that  the  rcsult.s  are  not  always  satisfac- 
tory, since  the  iipjuu-  limit  in  the  cas(!  of"  hiitter  is  ho  near  the  lower 
limit  in  that  of  oleniarj^arine  that  sani])les  yieldiii}.'-  results  clow;  to  the 
dividing  line  may  need  further  analysis  hefore  ;iii  inHjUaliried  oj)inion 
of  the  nature  of  the  s))e(rimen  can  he  \i\\('n.  A  mixture  of  genuine 
hutter  and  oleomargarine  may  give  r(!sults  well  within  the  normal  limits 

of  l)Utt(H-. 

l^ROCESS. — Into  a  wcigiied  beakcir  decant  a  few  grams  of  the  fat,  and, 
when  the  latter  has  eooled,  ascertain  the  amonnt  taken  by  reweighing. 
Saponify  as  a])ove  described,  evaporate  the  alcohol,  dissolve  the  soap 
in  water,  and  decompose  it  by  the  addition  of  an  excess  of  acid.  Heat 
until  the  preci])itated  insoluble  acids  are  melted,  then  allow  the  whole 
to  cool.  When  the  fatty  layer  has  assumed  the  character  of  a  solid 
crust,  break  a  small  hole  through  it  at  a  point  on  its  circumference  and 
another  on  the  opposite  side.  Weigh  a  funnel  and  a  dried  filter  fif 
snitable  size,  place  the  latter  wdthin  the  former,  wet  it  thoroughly,  and 
then  filter  the  liqnid  from  beneath  the  crust.  Break  up  the  crust,  add 
boiling  water,  and  transfer  the  whole  to  the  filter.  Wash  repeatedly 
with  boiling  water  until  the  washings  have  no  longer  an  acid  reaction, 
then  let  drain  until  no  more  w^ater  is  discharged.  The  filter-paper 
being  wet,  the  melted  fatty  acids  do  not  pass  through  with  the  wash- 
ings. Place  the  funnel  and  its  contents  in  the  beaker  and  dry  in  an 
air-bath  at  100°  C.  to  constant  weight.  The  increase  in  the  combined 
weights  of  the  beaker,  funnel,  and  paper  represents  the  amount  of  in- 
soluble fatty  acids  in  the  amount  of  fat  taken. 

Examination  of  Fat  by  Means  of  the  Butyro-refractometer. — A  sim- 
ple and  quick  method  of  ascertaining  the  nature  of  butter-fat  with- 
out recourse  to  chemical  analysis  is  that  by  means  of  the  butyro-refract- 
ometer or  other  instrument  designed  for  the  purpose  of  measuring  the 
refractive  index.  The  instrument  is  shown  in  Fig.  6,  with  the  prism 
casing  wide  open.  Its  application  requires  so  little  time  that,  after  a 
little  practice,  a  person  working  alone  can  examine  readily  15  or  20 
samples  in  an  hour.  The  method  of  use  is  as  follows  :  The  surface  ^-1 
and  that  to  which  it  is  opposed  when  the  prism  casing  is  closed  should 
first  be  cleaned  by  means  of  a  soft  piece  of  linen  moistened  with  alcohol 
or  ether.  Place  the  instrument  so  that  the  surface  of  the  prism  B  is 
horizontal,  then  apply  2  or  3  drops  of  the  clear  fat,  best  from  a  small 
filter  paper  held  between  the  fingers.  Close  the  prism  casing  and  fasten 
it  by  means  of  the  pin  C.     The  surfaces  of  the  two  prisms   are  now 


172 


FOODS. 


separated  from  eacli  other  only  by  the  very  thin  layer  of  fat.  With 
the  instrument  in  its  original  position,  the  mirror  I)  adjusted  so  as  to 
illuminate  the  field  clearly,  and  the  upper  part  of  the  ocular  so  atljusted 
that  the  scale  within  is  most  clearly  defined,  read  ofl'  at  what  point  of 


the  scale  the  line  between  light  and  shade  falls. 


Since  the  degree  of 


Zeiss  butyro-refractometer. 

refraction  is  influenced  by  the  temperature,  it  is  necessary  to  have  some 
means  of  determining  accurately  the  temperature  of  the  specimen 
between  the  prisms.  This  is  secured  in  the  following  manner  :  A  cur- 
rent of  warm  water  is  conducted  by  means  of  a  rubber  tube  connected 
with  the  inlet  E  into  the  prism  casing,  thence  through  the  rubber 
tube  F  to  the  upper  part,  from  which  it  escapes  through  the  outlet  G. 
The  bulb  of  a  thermometer  projects  into  the  current  of  water.  The 
standard  temperature  for  observations  with  this  instrument  is  25°  C, 
and  at  this  temperature  natural  butter,  which  has  a  refractive  index  of 
1.459-1.462,  will  give  a  reading  of  from  49.5  to  54  on  the  scale, 
while  oleomargarine,  which  has  a  refractive  index  of  1.465—1.470, 
will  show  58.6  to  66.4,  and  mixtures  of  the  one  with  the  other  will 
give  from  54  upward,  according  to  the  percentage  of  oleomargine 
present. 

According  to  Wollny,  to  whom  the  invention  of  the  instrument  is 
largely  due,  any  specimen  which  at  a  temperature  of  25°  C  gives  a 
higher  reading  than  54  will  invariably  be  found  on  chemical  analysis 
to  be  adulterated ;  but  he  suggests  that,  in  order  to  remove  all  chance 
of  adulterated  butter  escaping  detection,  this  limit  be  reduced  to  52.5, 
and  that  all  samples  giving  the  latter  reading  be  examined  chemically. 


CJIKICSK 


173 


Willi  tfrnpcniturcH  oIIkt  llian  25'"  (J.,  it  is  mtwmwry  \a)  niiikc  cjyv- 
ixsciioiis  «)('  OS^t)  (>('  ;i  scjilc  division  lor  v;\f\\  lU'^rvi'  ( ".  Tlif  follfjwin^ 
tabic  hIiows  IIk;  nuixiiiiiuii  Yvin\'\u\r  for  |)iirc  huflcr.s  al  dWWmwt  U'.u\- 
jKM'aliircH  : 


Temp. 

He.  fllv. 

'rem  p. 

8c.  dlv. 

Temp. 

8c.  dlv. 

Temp, 

SC,  dlT, 

25° 

r)'lS^ 

;5i° 

49.2 

37° 

45.9 

43° 

42.r, 

26 

r)i.<,) 

;{2 

4H.(; 

:      38 

45.3 

44 

42.0 

27 

51.4 

HS 

4K.1 

39 

44.8 

45 

41.5 

28 

no.H 

34 

47.5 

40 

44.2 

29 

r)0..s 

35 

47.(1 

41 

43.7 

30 

49.8 

36 

4(1.4 

42 

4.3.] 

There  are  other  processes  for  the  investigation  of  the  character  of 
butter-fat,  including  tlic  determination  of  the  specific  gravity,  melting- 
point,  iodine  abKori)tion  lunnlxir,  and  .saponification  of|nivalent ;  but  for 
all  j)racticnl  pur])ose,s  the  dctcnnination  of  the  refractive  index  or  of 
the  volatile  fatty  acids  is  ordinarily  sufficient,  and  the  other  determi- 
nations are  merely  corroborative. 


CHEESE. 

United  States  Standard. — Standard  cheese  is  the  sound,  solid, 
and  ripened  product  made  from  milk  or  cream  by  coagulating  the 
casein  thereof  with  rennet  or  lactic  acid  with  or  without  the  addition  of 
ripening  ferments  and  seasoning,  and  contains  in  the  water-free  .'^nb- 
stance  not  less  than  50  per  cent,  of  milk  fat.  By  Act  of  Congress, 
approved  Jiuie  9,  1896,  cheese  may  also  contain  added  coloring  matter. 

For  thousands  of  years  cheese  has  been  known  as  a  very  valuable 
food,  and  much  attention  has  been  paid  to  different  methods  of  manu- 
facture. At  the  present  time  many  varieties  are  made,  their  nature 
depending  upon  that  of  the  raw  material,  the  method  of  producing  the 
curd,  the  proportions  of  the  several  constituents,  and  the  method  of 
ripening.  Most  varieties  are  made  from  cows'  milk ;  some  are  made 
from  that  of  ewes,  and  others  from  that  of  goats. 

The  milk  is  used  either  in  its  natural  condition,  or  skimmed,  or  with 
the  addition  of  cream.  Generally,  it  is  used  in  its  natural  condition. 
Whatever  the  kind,  the  following  is  the  general  process  of  manufact- 
ure. The  milk,  with  or  without  coloring  matter  as  desired,  is  heated 
to  80°  F.  or  above,  and  then  curdled  by  means  of  rennet  or  by  the 
acids  formed  by  the  ordinary  milk  bacteria.  Usually,  rennet  is  em- 
ployed ;  sometimes,  sour  whey.  The  coagulation  should  be  complete 
in  from  forty  minutes  to  an  hour.  Too  rapid  coagulation  causes  the 
curd  to  be  hard,  tough,  and  unsuitable  for  the  subsequent  manipula- 
tion ;  too  slow  action  produces  a  soft  curd  difficult  to  work  and  not 
uniform  in  character.  After  the  process  of  coagulation  is  complete,  the 
curd  is  cut  or  broken  into  small  pieces,  and  the  whey  is  drawn  off. 
Then  the  curd  is  gathered  into  a  heap  and  covered,  and  allowed  to 
stand  for  an  hour  or  longer,  during  which  time  its  increasing  acidity 
assists  in  its  hardening  and  promotes  the  separation  of  the  remaining 


174  FOODS. 

whov.  "\Vhen  the  curd  has  attained  the  proper  consistence,  it  is  placed 
in  a  cheese  press  and  subjected  to  t^radually  increasino-  pressure,  and 
after  this  process  is  completed  it  is  removed  to  the  curing-  [)lace.  For 
the  proper  ripening  of  cheese,  it  is  essential  that  the  curd  be  of  the 
proper  consistence  throughout,  and  that  only  tlie  favorable  organisms 
be  present,  and  these  in  not  too  great  abundance. 

The  curd  produced  by  the  action  of  sour  whey  is  highly  acid  and 
inclined  to  be  greasy.  Owing  to  its  high  degree  of  acidity,  it  is  not  a 
favorable  ground  for  the  growth  of  many  of  the  bacteria  to  which 
is  due  the  production  of  the  diifereut  kinds  of  flavor,  and  so  the 
number  of  varieties  possible  of  manufacture  by  sour  whey  is  limited. 
Rennet,  on  the  other  hand,  produces  a  curd  which  is  elastic  and  not 
greasy  or  sticky,  and  which  is  a  good  culture  medium  for  the  bacteria 
whose  assistance  is  needed.  It  acts  best  in  milk  which  is  slightly  acid, 
for  if  the  milk  is  neutral  or  only  very  slightly  acid,  the  coagulation 
proceeds  very  slowly  and  the  curd  will  not  contract  sufficiently  to  expel 
the  whey  ;  if  the  milk  is  too  acid,  the  process  of  coagulation  is  too 
rapid  and  the  product  too  tough.  A  soft  curd  retains  too  much  whey, 
and  the  fermentation  of  the  milk  sugar  of  the  whey  causes  "  huffing," 
or  swelling,  for  the  prevention  of  which,  preservatives  sometimes  are 
employed.  The  bacteria  concerned  in  the  process  of  ripening  exist  in 
the  original  milk  or  in  the  air  of  the  place  of  manufacture.  Sometimes 
the  varieties  which  produce  cheese  "  faults "  gain  a  foothold  on  the 
premises,  and  can  be  eradicated  only  by  means  of  thorough  cleaning 
and  disinfection.  The  ripening  process  is  carried  on  at  about  70°  F. 
It  is  essentially  a  process  of  decomposition,  in  which  enzymes,  bacteria, 
and  moulds  are  concerned ;  and  for  the  production  of  the  same  kind 
of  cheese  the  same  varieties  of  organisms  must  be  present,  and  the 
particular  variety  producing  a  particular  flavor  must  find  the  conditions 
such  as  are  favorable  to  its  predominance.  It  is  not  possible  to  start 
with  milk  that  is  entirely  sterile,  and  then  to  inoculate  with  the  par- 
ticular varieties  wanted,  since  to  sterilize  milk  completely  requires  the 
application  of  such  a  degree  of  heat  as  will  produce  changes  in  the 
casein,  interfere  with  the  proper  action  of  the  rennet,  injure  the  con- 
sistence of  the  curd,  and  destroy  the  enzymes. 

Ripening  does  not  proceed  satisfactorily  when  the  curd  has  been 
produced  through  the  action  of  acids.  In  ordinary  ripening,  the  casein 
is  attacked  by  the  organisms  present,  and  ammonia,  leucin,  tyrosin,  and 
several  kinds  of  fatty  acids  are  produced.  The  latter  unite  with  the 
lime  salts,  which  up  to  this  point  have  been  in  combination  with  the 
casein.  The  acids  formed  include  butyric  and  valerianic.  From  the 
lactose,  we  have,  in  addition,  lactic  acid.  The  process  goes  on  at  differ- 
ent rates  with  different  kinds  of  cheese,  and  it  may  be  short  or  long. 
In  the  production  of  certain  forms  of  American  and  English  cheeses, 
the  individual  specimens  are  sealed  hermetically  in  tin  boxes  and  kept 
at  a  favorable  temperature  for  as  long  as  four  years,  the  boxes  being 
turned  each  day.  The  ordinary  grades  of  cheese,  however,  undergo 
comparatively  short  periods  of  ripening. 


CIIKKSK.  1 76 

Composition  of  Cheese. — Tlu;  (toinposifion  (»C  vhccMv.  vjirics  vory 

\n\\c\\  ;ic(',(»i(liii^'  (<»  tlic  iLiidrc  of  llic  favv  riiiilcrinl  und  flif  proff^H 
of  iiiiumfiM^lin'c.  Tlic  liil  shows  (lie  ji;r(!nt(!.st  vari.-itioii  in  ainoiini, 
•M'X'AWiVuv^  as  lli(i  (iliccsc,  is  made  from  wlioh;  rnilU,  Hl<iiiitii(<l  milk,  or 
milk  (!iii'i('lK!<l  willi  ciH^aiii.  Tlic  most  ♦■ommoii  Arncrican  clir-cm-  Jh 
nuulc!  iVom  whole  milk,  as  arc  also  the  IcafJiii;.'-  varieties  of  Kiifrljsh 
clicc!S(!,  as  (.'heddar  and  C'lieshir-e.  The  familiar  Ivlam  (Diitehj  ehec^st; 
is  ma<ki  iVom  i)UTtially  Hkimmcd  milk.  I']ii^^lisli  Stillon  Ih  a  tyiw;  of 
cIkh'Sc  mack;  from  milk  eiiriehed  wilh  cream.  The  cheese  richest  of  all 
in  fat  is  wliat  we  know  as  cream  cheese,  lait,  strictly  s|)eakin}r,  tiiiH  in 
not  (^licesc  at  all,  bein^i;  sim|)ly  fresh  curd  very  rich  in  fat  and  nf)t  snb- 
j(K5ted  to  any  process  of  ripeninii;.  'I'Ik;  clu;(!ses  pooivst  in  fat  are  tho.se 
made  from  skimnuHl  milk.  They  arc  tou^h,  dry,  and  of  hut  little  flavor, 
and  such  as  they  liave  is  inclined  to  Ix'  un|)leasant.  Amei-ican  elieoscs 
of  good  (]uality  may  be  said  in  general  to  contain  about  .'50  parts  of  fat, 
80  of  proteids,  30  of  water,  and  the  remainder  salts.  TIk;  leading 
English  cheeses,  excepting  Stilton,  contain  rather  more  waiter  (alM»ut  30 
per  cent),  and  corresjwndingly  less  fat.  Swi.ss  chee-se  has  practi«dly  the 
same  composition,  but  contains  rather  more  proteids  and  corresjxmd- 
ingly  less  fat.  Skimmed  milk  cheeses  are  particularly  rich  in  proteids, 
containing  often  as  high  as  50  per  cent.  With  the  exception  of  tho.se 
made  from  skimmed  milk,  it  may  be  said  in  general  terms  that  cheese 
is  about  one-third  fat  and  one-third  proteids. 

Of  the  many  varieties  of  cheese  put  up  in  small  bidk,  mostly  for  use 
as  a  relish  rather  than  as  a  substantial  article  of  diet,  the  following 
may  be  mentioned  :  Roquefort  is  made  from  the  partly  skimmed  milk 
of  ewes  ;  it  does  not  vary  much  in  its  percentage  of  fat  and  proteids 
from  American  and  English  cheeses.  Gorgonzola  is  very  similar  to 
Roquefort  in  composition  and  also  in  the  method  of  manufacture. 
Both  are  ripened  with  the  assistance  of  moulds,  \vhich  arc  mixed  with 
the  curd  with  the  powdered  bread  crumbs  on  Avhich  they  have  been  cul- 
tivated, and  the  cheeses  are  inoculated  also  after  being  shaped.  Parmesan 
cheese  is  made  from  partly  skimmed  goats'  milk  ;  it  is  xery  rich  in 
proteids  but  contains  only  about  half  as  much  fat  as  American  cheese. 
Camembert  cheese  is  a  soft  cheese  containing  rather  more  than  50  per 
cent,  of  water  and  about  20  per  cent,  each  of  fat  and  proteids.  It  is 
ripened  by  a  peculiar  process  which  gives  it  a  much  n^ore  pronounced 
and  ])ermeating  odor  than  almost  any  other  known  variety. 

Adulteration  of  Cheese. — At  the  present  time,  the  only  extensive 
form  of  adulteration  of  cheese  consists  in  the  substitution  of  lard  for 
the  usual  and  proper  kind  of  fat.  Lard  and  skimmed  milk  colored 
with  annatto  are  mixed  together,  heated  to  about  140°  F.  in  tanks, 
and  enudsionized  with  the  assistance  of  appropriate  machinery  ;  the 
niixture  then  is  coagulated  in  the  same  way  as  in  the  ordinary  process 
of  making  cheese.  Such  cheese  is  designated  in  the  United  States 
statutes  as  "filled  cheese,"  which  includes  "all  made  of  milk  or 
skinuned  milk  Avith  the  admixture  of  butter,  animal  oils  or  fats,  v^^e- 
table  or  any  other  oils,  or  compounds  foreign  to  such  milk." 


176  FOODS. 

A  decree  promulgated  in  Belgium  on  September  21,  1899,  defines 
cheese  us  a  product  obtained  from  ])ure  milk,  skimmed  milk,  milk  co- 
agulateil  bv  the  aid  of  rennet  or  acitlitication,  or  any  other  product 
obtained  bv  heating  milk  mixed  or  not  with  coloring  matter,  salt,  and 
spices,  and  subjected  to  pressure  and  fermentation.  It  forbids  the  sale, 
except  when  properly  labelled  in  such  way  as  to  reveal  its  true  nature, 
of  all  cheese  containing  any  other  sulistancc  than  those  mentioned,  such 
as  oleomargarine  or  other  foreign  fat,  j)otatoes,  and  bread.  An  excep- 
tion is  made,  however,  in  favor  of  Roquefort,  in  which  bread  crumbs 
are  present,  not  as  an  adulteration,  but  for  the  serving  of  a  useful  pur- 
pose. The  sale  of  cheeses  mixed  with  mineral  matter  other  than  salt 
and  with  antise]>tics  in  general  is  forbidden. 

In  some  parts  of  Germany,  bean  meal  and  potatoes  are  used  to 
some  extent  as  adulterants,  and  there  and  elsewhere  a  great  variety  of 
substances  are  said  to  have  been  used  to  a  greater  or  less  extent  in 
times  gone  by.  In  general,  it  may  be  said  that,  aside  from  lard  and 
other  foreign  fats,  the  only  adulteration  of  any  importance  consists  in 
the  admixture  of  preservatives.  These  are  added  more  commonly  to 
skimmed  milk  cheeses  than  to  those  of  good  quality. 


Analysis  of  Cheese. 

Determination  of  Water. — Cut  the  specimen  into  small  bits  or 
thin  slices.  AVeigh  out  about  5  grams  in  a  platinum  dish  containing 
sand  or  asbestos  fiber,  and  dry  to  constant  weight. 

Determination  of  Ash. — Ignite  the  dried  residue  at  as  low  a  tem- 
perature as  possible,  and,  after  cooling,  note  the  increase  in  weight  over 
that  of  the  dish  and  its  original  contents. 

Determination  of  Fat. — Triturate  about  25  grams  of  the  specimen 
in  a  mortar  with  an  equal  bulk  of  fine  beach  sand.  Transfer  the  whole 
to  a  Soxhlet  extractor,  and  proceed  in  the  manner  described  under  the 
Analysis  of  Milk. 

Determination  of  Proteids. — Proceed  in  the  manner  given  under 
Analysis  of  jSIilk,  using  about  2  grams  of  the  sample. 

Determination  of  the  Nature  of  the  Fat. — For  the  detection  of 
foreign  fats,  the  method  of  procedure  is  the  same  as  described  under 
the  Analysis  of  Butter,  after  obtaining  the  fat  in  a  pure  condition. 
The  residue  obtained  in  the  determination  of  the  amount  of  fat  will 
serve  for  this  purpose. 

Cheese  as  a  Cause  of  Poisoning. 

For  many  years,  cheese  has  been  known  to  be  an  occasional  cause  of 
single  and  multiple  cases  of  poisoning,  and  various  theories  concerning 
the  nature  of  the  poisonous  agent  have  been  promulgated.  It  was  not 
until  1884  that  the  cause  was  revealed  by  Professor  V.  C.  Vaughan, 
whose  attention  was  drawn  to  outbreaks  in  Michigan  during  1883  and 


(iiii':i':si<:  as  a  caiis/':  of  roisosiNd.  177 

1884,  in  wlilcli  more  lliaii  .'>()()  jKsrKoriH  wen;  'AYvrXfA.  lie  trartcd  flic 
wli<)l(!  tr()iil)l((  lo  l,w('lv(!  (liirciciit,  rliccscH,  (Vf)rri  HCNcral  of  \vlii<'li  he 
i.solnlcd  tli(!  |)oi,soiioii.s  juiticiplc,  a  ploriiaiii,  (o  wliicli  lie  ^avc  tlic  iiaiiic 
'' tyro((>xi(!oii."  Tlic  syinphtms  olisccxcd  In  (lie  ontbrcMk"  rcfi-ncd  lo 
incliKk^d  voniitiii<^,  (lian'li(i';i,  ;il»(loiniii;il  |i;iin,  (li\iic-s  jiihI  coiK^lricfioii 
of  tlu!  tlii'oal.,  f('(!l)l(!  and  iirc^nl.-ir  pulse,  ;iiid  nuiiked  esanosi.s.  In 
,soni(!  (!as(!M,  voiniliii^  iiiid  (liaifli(e;i  were  followed  hy  marked  nervonH 
|)rosl  ral  ion.       In  some  (Ik;  pnpils  were  dilaled. 

Williin  a  sliorl,  (inu!  after  V:in<;lian',s  dis(;overy,  llic  pftison  was  found 
by  Wiilkiee, '  in  some  (ilieese  (li,i(  was  i\\(\  cause  of  poisoning,'-  of  not  Icsh 
than  50  ]KM-s()ns  out  of  ;il)on(  (10  w  lio  had  <'a(en  of  it.  The  onset  appeared 
in  from  two  to  four  hours.  The  most  e(»nstant  and  sevcro  .symptorn.s 
were  vomitiuii;  and  ehills.  "^riiese  were  sueeec^ded  by  severe  cpipistric 
pain,  (■,ram|)s  in  the  le<»;s  and  feet,  ])Ui'fz;in^''  and  ^rij)in^'-,  numbnc^ss  esjK-- 
cially  marked  in  the  le^s,  and  very  m;irked  ])rostralion.  N'omitin^-  and 
diarrJKra-  lasted  from  two  to  twehc  hours  ;  ehills  and  ei-amps  from  one 
to  two  hours.  No  deaths  occurred,  and  all  recovered  within  three  day.«. 
The  severity  of  the  symptoms  bore  no  relation  to  the  amount  ejitcn  ; 
some  of  the  severest  cases  were  of  persons  who  at(!  })ut  s])arinLdy. 

More  recent  work  by  Vaughan  and  his  associates  and  others  has 
demonstrated  that  tyrotoxicon  is  not  the  only  cause  of  cheese-,  milk-, 
and  ice-cream-poisoning,  and  that  it  is,  indeed,  a  somewhat  rare  poison. 
Other  toxic  substances  have  been  isolated  from  cheeses  that  yielded  no 
tyrotoxicon. 

Section  4.     VEGETABLE   FOODS. 

The  vegetable  foods  may  conveniently  be  divided  into  several  classes 
as  follows  : 

1.  Farinaceous  seeds  : 

(a)  Cereals  ;  (/;)  Legumes. 

2.  Farinaceous  preparations. 

3.  Fatty  seeds  (nuts). 

4.  Vegetable  fats. 

5.  Tubers  and  roots. 

6.  Herbaceous  articles  ("  vegetables  "). 

7.  Fruits  used  as  "  vegetables." 

8.  Fruits  in  the  narrower  sense. 

9.  Edible  fungi. 

10.  Saccharine  preparations. 

The  words  fruit  and  vegetable  are  capable  alike  of  broad  and  narrow 
meanings.  In  the  strict  sense,  the  cereals,  legumes,  nuts,  and  manv  of 
the  articles  commonly  called  vegetables  are  fruits ;  but  popular  usage 
has  narrow^ed  the  latter  term  to  include  the  pulpy  substance  enclosing 
the  seeds  of  various  trees  and  plants,  and  only  such  as  are  pleasant  to 
the  taste  and  edible  in  the  raw  state,  with  the  single  exception  of  the 
quince,  which  is  edible  only  when  cooked.  A'egetables  in  the  ordi- 
nary sense  include  any  part  of  herbaceous  plants,  as  the  stem,  root, 

^Medical  News,  Julv  16,  1S87,  p.  69. 
12  .  .  1- 


1 78  FOODS. 

leaves,  and  frnitv  products  used  commonly  in  the  cooked  state  or 
in  the  form  ot"  salads.  Thus,  in  the  popular  usage  of  the  terms, 
squashes  and  melons,  which  are  the  fruits  of  plants  of  the  same  family, 
are  classed  respectively  as  vegetables  and  fruits,  and  the  cereals  and 
nuts  are  classitied  under  neither  head. 

First  in  importance  of  vegetable  foods  are  the  farinaceous  seeds ; 
they  are  of  very  higli  nutritive  value  and  easily  digested. 

1.  Farinaceous  Seeds. 

{(()  CEREALS. 

The  cereals  include  wheat,  rye,  barley,  oats,  corn,  buckwheat,  and 
rice.  They  are  very  largely  starchy,  and  agree  in  general  composition  ; 
but  they  differ  in  the  proportions  in  which  their  several  constituents  are 
present.  These  include  proteids,  carbohydrates,  ether  extractives, 
mineral  matter,  aud  moisture.  The  proteids  include  a  large  number  of 
closely  related  compounds,  as  yet  only  imperfectly  studied,  which  will 
be  mentioned  in  the  consideration  of  each  member  of  the  group.  The 
carbohydrates  include  those  which  are  soluble,  sugar  and  dextrin,  and 
those  which  are  insoluble,  starch,  cellulose,  pentosans,  and  gelactans 
(H.  W.  AViley).  The  ether  extractives  include  fats,  resins,  chlorophyll, 
and  volatile  oil  "  which  constitutes  the  source  of  the  odorous  quality 
possessed  by  the  grain "  (AViley).  The  mineral  matters  are  chiefly 
phosphates  of  calcium,  and  magnesium,  silica,  and  salts  of  sodium  and 
potassium.  The  cereals  contain  also  certain  ferments,  the  most  impor- 
tant of  which,  and  the  only  one  which  has  been  studied  with  any 
thoroughness,  is  diastase.  This  acts  upon  starch,  converting  it  into 
sugar.     The  others  include  some  which  act  upon  the  proteids. 

Wheat. 

Wheat  is  classed  very  properly  as  the  most  useful  of  the  vegetable 
foods.  The  grain  consists  of  a  hard  outside  layer  which  is  indi- 
gestible and  useless  as  food,  and  the  cortex,  softer  and  more  friable, 
which  yields  flour  of  high  nutritive  value.  The  hard  outside  layer, 
which  constitutes  the  greater  part  of  bran,  irritates  the  alimentary 
canal,  and,  while  useful  to  some  extent  in  conditions  of  habitual  con- 
stipation, should  be  avoided  in  all  irritable  conditions  of  the  bowel. 
It  causes  waste  by  unduly  promoting  peristalsis,  so  that  much  of  the 
nutritive  portion  is  hurried  along  in  an  undigested  condition. 

The  proteids  of  wheat  include,  according  to  Osborne  and  Voorhees,^ 
a  globulin,  an  albumin,  a  proteose,  gliadin,  and  glutenin.  The  two 
last-mentioned  constitute  between  80  and  90  per  cent,  of  the  whole ; 
in  the  presence  of  water  they  unite  to  form  the  very  important  substance 
gluten,  so  essential  in  the  conversion  of  flour  into  bread.  According 
to  Wiley,  they  unite  in  almost  equal  proportions  ;  but  in  the  opinion 
of  E.  Fleurent,^  the  closer  the  composition  of  gluten  approaches  the 

1  American  Chemical  Journal,  XV.,  p  392.  ^  Comptes  rendus,  1898,  p.  126. 


PLA'J'E   VII 


Wheat  Starch,     x   285. 


o 


r       ^ 


Rye  Starch.     X  28§. 


w  1 1  HAT  FLorrn.  170 

rol.'iiioii  of  25  p;irt,s  of  •rliilcnin  lo  T")  of  j/li:i(IIii,  \\]<-  iiiorr;  v;i]iial»l«; 
the  (lour. 

The  carl)()li)(lr:i(cs  coiiHliliilc  (lie  L'ic.'il'i'  |';ir>  "f  wliciit  aH  well  jls  of 
the  other  cci-i'Mls.  They  inchidc  -lnifh,  liy  llir  the  most  important, 
celhiloHc,  sii<i,'iU's,  (Icxiriii,  :iihI  ;i  iiiiiiilxi' of  (»th<r  coiiipoimdH  oi  e^»in- 
pjinitive  iiiiim|)ort:iiicc.  'I'hc  st;irch  ^rniiuh's  ;ir<'  cxcccdin^rly  v;iri;il)le 
in  .si/e,  riui^ini;'  (Vom  ;il)i»iil  0.002  lo  O.Oo  nun.  in  (liiiniclcr.  '\']\<y  urc 
cireular  and  ll;il,  iind  ni:iny  oC  thr'ni  shown  <'(iitr;d  hihini  ;ind  fon- 
eentrio  rini;',s.  'I'hc  1;iII<t  ;ippc;ii-  willi  j^rciifer  diHliin'liws.>-  in  flonr  that 
lias  been  snhjected  (o  heal,  as,  (or  instance,  in  tiie  hakin^''  of  rraekerH. 
The  wide  variations  in  siz<^  are  illnstrated  in  Tlatc  \'II.,  I''i}r.  1.  The 
oth(>r  earl)(tln(lr;ites  exist  in  hut  V(>ry  small  projxtrl  ions. 

Composition  of  Wheat. — The  vast  nnmlHr  of  analyses  of  wheat 
show  important  variations  in  the  |)ei-('cnt;i^e  of  its  several  constituents, 
for  its  ([uality  is  indnencied  (ronsidenihly  hy  clinijitc,  character  of  the 
soil,  and  other  conditions.  According  to  J  I.  \V.  Wiley,'  a  ty|)ical 
American  wheat  of  the  best  quality  should  yield  api)roxiniately  the 
following  results  : 

Moisture lf>-W) 

Proteids 12.2o 

Ether  extract l-7o 

Crude  liber -'-40 

Starch,  etc "I'-'-t 

Ash •    1-70 

100.00 

These  figures  do  not  vary  materially  from  the  averages  of  a  large 
number  of  analyses  of  samples  of  miscellaneous  origin  compiled  by 
Konig,  excepting  in  the  proportions  of  moisture  and  starch,  in  which 
respects  Wiley's  typical  specimen  shows  superior  value,  being  less  rich 
in  the  one  and  richer  in  the  other  constituent. 

Wheat  Flour. 

In  the  manufiicture  of  flour,  the  wheat  kernels  are  subjected  first  to 
a  process  of  thorough  cleaning,  and  then  are  cracked,  crushed,  and 
ground  until  the  required  state  of  fineness  is  attained,  the  bran  and 
other  undesirable  portions  being  removed  by  bolting.  All  flour  is  by 
no  means  the  same  in  composition  and  quality ;  in  fact,  several  gratles 
of  flour  may  be  made  from  the  same  wheat  by  the  employment  of 
diflerent  processes  of  manufacture.  Flours  are  graded  according  to 
color  or  appearance,  those  which  make  the  whitest  bread  ranking  high- 
est, although  not  equal  in  nutritive  value  to  those  classed  as  low  grade. 
The  flours  of  the  several  grades  are  known  commercially  as  "■  patent," 
"  family,"  "  bakers',"  and  other  names  which  to  the  public  have  no 
special  significance.  Typicid  flours  of  the  grades  known  as  '"high- 
grade  patent "  and  '•  bakers' "  should  have,  according  to  Wiley, 
approximately  the  following  composition  : 

1  U.  S.  Department  of  Agriculture,  Division  of  Chemistry,  Bull.  13,  Fart  9,  p.  1189. 


180  FOODS. 

Moisture.  Proteids.  Ether  extract.  Carbohydrates.       Ash. 

Patent 12.75  10.50  1.00  75.25  0.50 

Bakers' 11.75  12.30  1.30  74.05  0.60 

The  average  compo.sition  of  210  samples  of  wheat  flour  of  high  and 
niediuni  grades  and  of  grades  not  indicated  is,  as  given  by  Atwater 
and  Bryant,  as  follows : 

Moisture 12.00 

Proteids 11.40 

Ether  extract 1.00 

Carbohvdrates 75.10 

Ash  .    '. 0.50 

100.00 
Thirteen  samples  of  low  grade  averaged  as  follows  : 

Moisture 12.00 

Proteids 14.00 

Ether  extract 1.90 

Carbohvdrates 71.20 

Ash  .    ■ 0.90 

100.00 

It  will  be  noticed  that  the  high  grade  flours  are  poorer  in  proteids 
and  fat,  and  correspondingly  richer  in  starch.  Other  grades  of  flour 
include  those  known  as  graham  and  entire  wheat.  Graham  flour  is 
understood  generally  to  be  a  product  containing  all  of  the  constituents 
of  the  original  grain  in  their  same  proportions.  When  it  came  first 
into  use,  such,  indeed,  it  was ;  but  at  the  present  time  it  is  an  unbolted 
or  partially  bolted  product  of  thoroughly  cleaned  and  dusted  wheat. 
Entire  wheat  flour  is  understood  also  to  contain  all  of  the  original  con- 
stituents of  the  grain,  but  is,  in  fact,  made  from  wheat  deprived  of  its 
outer  coverings.  It  makes  a  somewhat  dark-colored  bread  which  is 
very  palatable. 

Parenthetically,  it  may  not  be  out  of  place  to  refer  here  to  the 
absurd  views  maintained  by  a  large  part  of  the  community  as  to 
the  superiority,  from  a  hygienic  standpoint,  of  foods  containing  all  of 
the  constituents  of  the  cereals  from  which  they  are  prepared.  It  is 
difficult  to  understand  how  the  nutritive  value  of  any  food  can  be 
increased  by  the  retention  of  matters  which  are  completely  indigestible 
and  to  a  certain  extent  irritating  to  the  digestive  tract.  It  is  argued 
that  an  all-wise  Creator  made  wheat,  for  example,  in  the  form  in  which 
we  see  it,  and  that  it  is  not  for  us  to  attempt  to  improve  it,  as  we  think, 
by  discarding  the  outer  layers.  But  this  sort  of  reasoning  might  be 
extended  so  as  to  favor  the  consumption  of  the  peel  of  oranges,  the 
bones  of  fish,  the  feathers  of  birds,  and  other  innutritions  and  undesir- 
able waste  ]:)roducts. 

Preparations  of  Wheat  Flour. — Bread. — First  in  importance  of 
the  preparations  of  wheat  flour  is  bread.  In  the  broad  sense,  bread 
includes  all  forms  of  baked  flour,  whether  leavened  or  unleavened ; 
in  the  common  use  of  the  term,  it  includes  only  those  in  which  leaven- 
ing agents  are  used,  the  other  forms  being  designated  as  pilot  bread, 
crackers,  biscuits,  etc. 


WHEAT  FLOUR.  181 

Tho  adiipinbility  of  wlicjil-  (lour  for  ItrcMl-mukinK  is  iliic  to  itH  j^luton 
C()iil<!iit.  TliiH  Hiil)s(;iiic(',  by  reason  of  \\<  l(ii;i(it\',  is  cwpnlilc  of  cn- 
tari^Iiiifij  tlu!  f^iiH  f^ciicraicd  iti  flu;  j)ro(:('.ss,  and  liv  icasoii  of  if.s  solidifi- 
cation by  b<'at,  (iirnislics  a  porous  or  sjion^y  prodnel  easily  p<'netrat<'d 
and  ac^icd  upon  \)\  Ihe  gastric,  juice.  Nof  all  r-ereals  an-  e;ip;ible  of 
bcitifij  made  inio  bre;id,  since,  ;is  will  \)v  seen,  in  nio,-t  of  tlietn  this 
very  essential   ;i!i;eul    is   lackinj:;. 

Foi"  tlie  pre|)ara(iou  of  bread  of  ^ood  (|ii;ilit\,  the  llonr  slioidd  con- 
tain not  nnieli  in  e.\<'ess  o("  (lie  a\'era^e  anionni  ol  inoisdire,  and  should 
be  so  cohesive  that,  alVer  b(^in<i,'  eoni|>ressr'd  in  the  hand,  it  will  keep  its 
shape  on  bein}>;  released. 

In  th<!  niakinu;'  of  bi'ead,  ihe  (lour  is  mixed  with  warm  water  or  milk, 
salt,  and  yeast,  kne.'ided  into  a  si  ill"  donj^h,  and  set  aside  in  a  warm 
place.  The  yeast  attacks  tiie  suj^ar  and  sjilits  il  int<»  alcohol  and  car- 
bonic acid  ^as ;  the  latter  by  its  evolution  and  ex])ansion  causes  the 
douf^h  to  l)ee()me  ]iorous  and  to  "rise."  The  fei-mentative  process 
gives  rise  also  to  variable  amounts  of  lactic  and  acetic  acads.  The 
raised  dough  is  then  baked  in  suital)lc  j^ans,  and  its  porous  character 
is  increased  by  the  further  ex])ansi()n  of  the  gas  by  heat  and  is  made 
permanent  by  the  solidification  of  the  gluten  by  the  same  influence. 
If  the  fermentation  is  not  allowed  to  proceed  far  enough,  the  resulting 
bread  will  be  soggy  or  "heavy";  if  too  far,  it  will  be  sour. 

In  place  of  yeast  as  a  leavening  agent,  bicarbonate  of  sodium,  com- 
monly known  in  the  household  as  saleratus,  and  baking  powders  are 
employed  very  extensively.  For  the  evolution  of  carbonic  acid  gas 
from  sodium  bicarlxMiate,  the  presence  of  an  acid  is  necessaiy,  and  this 
is  secured  by  the  use  of  sour  milk.  First,  the  flour  is  mixe<l  thor- 
oughlv  with  tlie  bicarbonate  and  then  made  into  a  dough  with  the  milk. 
Bread  made  by  this  process  is  rarely  of  good  quality,  since  it  is  difficult 
to  determine  the  pro]:)er  amounts  of  the  two  agents  for  the  best  results, 
and  any  excess  of  the  bicarbonate  causes  discoloration  and  disagreeable 
flavor.  A  better  plan  is  to  employ  baking  powder,  which  consists  of 
sodium  bicarbonate  and  an  acid  salt  combined  iu  such  proportions  that 
all  of  the  available  gas  is  set  free  from  the  alkaline  salt  and  no  unplea.<- 
antly  tasting  residue  is  left.  The  only  advantage  possessed  by  baking 
powders  is  the  saving  of  time  and  labor ;  the  resulting  i)read  is  dis- 
tinctly inferior  to  that  made  with  yeast.  The  composition  of  the  vari- 
ous classes  of  baking  powders  will  be  stated  farther  on. 

Another  process  of  securing  leavening  is  that  of  spontaneous  fermen- 
tation brought  about  by  the  enzymes  present  normally  in  flour.  This 
process,  known  as  "salt  risiug,"  is  not  in  common  use,  requires  much 
more  manipulation  than  any  other,  possesses  no  advantages,  and,  there- 
f(^re,  deserves  no  further  mention. 

Freshlv  baked  bread  is  much  less  digestible  than  that  which  has 
been  kept  a  day  or  two.  Its  softness  favors  its  clogging  during  mas- 
tication into  a  close  mass  which  is  attacked  less  easily  by  the  gastric 
juice.  In  this  country,  however,  it  is  the  almost  universal  custom 
to  eat  bread,  particularly  iu  the   form  of  breakfast  rolls,  not  only  in 


182 


FOODS. 


the  fre.sh  conditiou,  but  also  lu)t  from  the  oven.  When  bread  is  kept 
for  a  day,  it  loses  part  of  its  moisture  and  acquires  increased  firmness 
and  friability,  which  help  maintain  its  porosity  during  mastication. 

The  following  table  by  Helen  W.  Atwater^  gives  the  composition  of 
various,  sorts  of  bread  and  some  other  food  materials  : 


Food  material. 


Wheat  bread : 

From  hard  Scotch  Fife  spring 
wheat,  Minnesota — 

Graham  Hour 

Entire-wheat  flour 

Standard  iKiteut  Hour  .  .  . 
Second  putt'Ut  lUiur    .   .   .   . 

First  patent  Hour 

From      Oregon      soft      winter 
wheat — 

Graliam  flour 

Enlire-wlieat  flour 

Straight  grade  flour    .... 
From    Oklahoma  hard   winter 
wheat- 
Graham  flour 

Entire-wheat  flour  .  .  .  .  . 
Straight  grade  flour  .... 
Straight  grade  flour  with  14 

per  cent,  bran       

Straight  grade  flour  with  7 

per  cent,  germ 

From  miscellaneous  flours — 

High  grade  patent 

Standard  grade  patent .  .  . 
Medium  grade  patent    .   .   . 

Low  grade  patent 

White  bread,  average 

Rolls 

Crackers 

Macaroni 

Corn  bread  (johnnycake) 

Rye  bread 

Rye-and-wheat  bread 

Beef,  ribs : 

Edible  portion 

As  purchased 

Veal,  leg : 

Edible  portion 

As  purchased    

Mutton,  leg: 

Edible  portion 

As  purchased 

Cod  steaks : 

Edible  portion 

As  purchased    

Hens'  eggs : 

Edible  portion 

As  purchased 

Butter 

Milk,  whole 

Potatoes : 

Edible  portion 

As  purchased    .   .  , 

Apples : 

Edible  portion 

As  purchased 

Chocolate,  as  purchased 


Num- 
ber of 
analy- 
ses. 


198 
20 
71 
11 

5 
21 

1 


Refuse. 


Per  ct. 


16.8 
11.7 
17.7 
9.2 
li.2 


20.0 
25.6 


Water. 


Per  ct. 

47.20 
49.16 
44.13 
42.10 
44.40 


38.55 
39.95 
34.95 


42.20 
41.31 
37.65 

43.20 

38.00 

32.9 
34.1 
39.1 
40.7 
35.3 
35.7 
6.8 
10.3 
38.9 
35.7 
35.3 

55.5 
39.6 

71.7 
63.4 

63.2 
51.9 

79.7 
72.4 

73.7 
65.5 
11.0 
87.0 

78.3 
62.6 


63.3 
5.9 


Protein. 


Per  ct. 
7.76 
7.45 
7.75 
7.75 
7.48 


6.11 
5.70 
5.41 


10.65 
10.60 
10.13 

9.50 

11.07 

8.7 
9.0 
10.6 
12.6 
9.2 
8.9 
10.7 
13.4 
7.9 
9.0 
11.9 

17.5 
12.7 

20.7 
18.3 

18.7 
15.4 

18.7 
17.0 

13.4 

11.9 

1.0 

3.3 

2.2 
1.8 

.4 

.3 

12.9 


Fat. 


Per  ct. 

1.27 

1.14 

.90 

.72 

.71 


1.12 

1.09 

.89 


1.12 

1.04 

.64 

.84 

1.13 

1.4 

1.3 

1.2 

1.1 

1.3 

1.8 

8.8 

.9 

4.7 

.6 

.3 

26.6 
30.6 

6.7 

5.8 

17.5 
14.5 


.5 

10.5 
9.3 

85.0 
4.0 

.1 
.1 

.5 
.3 

48.7 


Carbohy 
dratcs. 


Per  ct. 

42.82 
41.73 
46.90 
49.16 
47.14 


52.68 
52.39 
57.85 


44.58 
46.11 
51.14 

45.55 

49.12 

56.5 
54.9 
48.3 
44.3 
53.1 
52.1 
71.9 
74.1 
46.3 
53.2 
51.5 


18.4 
14.7 

14.2 
10.8 
30.3 


Ash. 


Per  ct. 
0.95 
.52 
.32 
.27 
.27 


1.54 
.87 
.90 


1.45 
.94 

.44 


.91 


1.3 
1.1 
1.5 
1.8 
1.3 
2.2 
1.5 
1.0 


1.1 
1.0 


1.0 


1.2 
1.0 

1.0 
.9 

3.0 
.7 

1.0 


.3 

.3 

2.2 


Bread  may  acquire  unwholesome  properties  on  keeping,  due  to  changes 

brought  about  in  the  presence  of  moisture  by  micro-organisms.     Good 

bread  is  only  slightly  acid  ;  but  if  kept  in  a  moist  state,  it  is  likely  to 

become  markedly  so,   and  then  may  cause  gastric  derangement  and 

1  Farmers'  Bulletin  389,  U.  S.  Department  of  Agriculture,  p.  38. 


Wif/'iAT  FLO  nil.  183 

diiirrlifm  in  those  not,  li;il)i(ii;il<<l  to  its  ii-c  l'i<;i<I  in  lliiH  cori'lit ion  Ih 
Uii(l(!rj2;(>in^  rcriiicnlnlivc  clinn^cs  ilml  me.  li;i.^t<;ii<:il  l)y  the  body  t<;rn- 
jMinitiirc,  willi  (•(ni,s('(|ii(!iit  (tvoliilion  >>i'  }i:;iHoouH  pHKhuttM  wWu-h  muwj 
lliiliii('ii(!(!  ;iii(l  (lisconirofl,  uiid  of  irritiiliii^  cotiipoiiiKls  \vhi<-h  iiidiKu; 
ubdomiicil  piiin  :uid  (Hiirrhfr!:!.  lircad  iriudc  fruiii  old  :iiid  p:irti;dly 
HpoihMl  (lour  is  likiily  to  h;i\'c  ;i  distiiKjtly  Hour  insU'.  and  to  \}c  nnwhoh-- 
Horne  in  \\\v,  inaiiiicr  above;  dcs(;fib<!d.  Motddy  brwid  also  is  likcjy  to 
be  a  (!aiis(!or  (li!i;<"s(iv(!  d('ranjj:;('Micnt. 

(/OM  POSITION  oi''  WiiKAT  I>im;ai). — Since  whcat  flour  itself  is  of  vari- 
able coin])()sitioii,  and  since  in  (he  domestic  inannfactiin!  of  any  artiftle 
of  food  the  jirocesses  employed  an;  .subject  to  slij^ht  or  eonsidendde 
variations,  analyses  of  wheat  bi-ead  necessarily  must  show  ^rwit  differ- 
ences in  the  pi-oportions  of  the  several  (ronstitnents.  Averages  obtained 
from  cxandnation  of  samples  of  all  sorts  and  of  miseellaneons  ori^dri 
can  hardly  represent  the  composition  of  bread  of  {^ood  avoraj^c  or  high 
qnality. 

Toast. — In  the  process  of  toasting,  a  large  part  of  the  moisture  is 
drivcni  oif,  the  surfaces  are  scorched,  greater  tirmness  is  acquired,  and 
the  product  is  more  easily  digestible.  Good  toast  cannot  be  made  from 
perfectly  fresh  bread,  on  account  of  the  moisture  present,  which  cause.s 
soffiriuess :  it  can  be  made  only  from  bread  at  least  a  day  old.  The 
slices  should  not  be  thick,  since  then,  while  tlie  surface  is  scorched,  the 
interior  acquires  increased  softness  under  the  action  of  lieat  and  be- 
comes less  digestible  than  the  original  bread. 

Rusks  are  much  like  toast.  Instead  of  being  subjected  to  the  direct 
a(!tion  of  hot  coals,  the  brejid  slices  are  baked  for  a  time  in  a  modemtely 
hot  oven. 

Pulled  Bread  is  the  crumb  of  freshly  baked  loaves  pulled  out  in  small 
masses  and  baked  agahi  like  rusks. 

Crackers,  or  biscuits,  are  preparations  made  from  unleavened  dough 
and  baked  so  dry  as  to  be  brittle.  They  keep  well  for  a  long  time 
without  losing  their  palatability.  If  not  properly  stored  and  cared  for, 
they  may,  of  course,  become  damp,  musty,  and  mouldy.  In  composi- 
tion they  vary  but  little  from  the  flour  of  which  they  are  made ;  they 
are  drier,  and  what  they  lack  in  moisture  they  make  up  in  fat,  which, 
in  the  form  of  butter  or  lard,  is  added  to  prevent  them  from  becoming 
too  hard  and  dry. 

Other  preparations  of  wheat  flour  include  cakes,  which,  on  account 
of  the  contained  butter,  eggs,  and  sugar,  are  richer  than  bread ;  pastry, 
which,  on  account  of  its  content  of  lard,  is  more  difficult  of  digestion  ; 
and  flour  puddings,  wdiich,  being  very  "■  close,"  require  nmch  time  for 
digestion  and  often  cause  sensation  of  weight  and  oppression. 

Macaroni,  spaghetti,  and  vermicelli  are  preparations  made  with  haixi 
wheat  rich  in  gluten.  The  flour  is  made  into  a  stiff  paste  with  hot 
water,  and  the  compound  then  is  pressed  through  holes  or  moulds  in  a 
metal  plate  and  dried.  They  are  exceedingly  nutritious,  but  they  are 
not  as  easy  of  digestion  as  other  preparations  of  wheat,  on  account  of 
their  closeness.     They  were  flrst  made  on  a  small  scale  in  Sicily,  but 


184  FOODS. 

now  are  produced  in  enormous  amounts  in  Italy,  France,  Cermany,  and 

otlier  countries.  In  their  manufacture,  American  wlieats  are  not  held 
in  hifjh  esteem,  containing:  not  sufficient  gluten  and  too  much  starch. 
The  best  wheat  for  the  jnirpose  comes  from  a  particular  district  in 
Russia  and  from  Algeria.  Ft)rmerly,  a  grain  from  southern  Italy  was 
reo-arded  as  the  most  suitable. 

Adulteration  of  Flour. — Up  to  within  comparatively  recent  years, 
flour  has  not  been  much  subject  to  adulteration.  Occasionally,  certain 
mineral  substances,  as  magnesium  carbonate,  gypsum,  and  ground  chalk, 
have  been  reported  in  European  samples  ;  but  such  have  been  employed 
as  adulterants  very  rarely,  if,  indeed,  at  all  in  American  flours.  Alum 
has  been  added  sometimes  to  flour  of  inferior  quality  to  improve  its 
color  or  to  check  beginning  decomposition.  Whether  this  addition 
is  objectionable  from  a  hygienic  standpoint  is  a  subject  over  which  there 
is  decided  disagreement.  It  is  believed  by  some  that  the  amount  of 
alum  added  is  sufficient  to  exert  an  injurious  effiict  on  the  digestive  tract 
on  account  of  its  astringent  action,  and  to  bring  about  constipation  and 
dyspepsia  ;  others  believe  that  it  can  do  no  harm  whatever,  either  to  the 
consumer  or  to  the  nutritive  value  of  the  food ;  and  still  others  hold 
that,  while  it  is  not  injurious  to  health,  it  lessens  the  nutritive  value  of 
the  flour  by  forming  insoluble  aluminum  phosphate,  and  thus  depriving 
the  system  of  the  phosphates  which  otherwise  would  be  absorbed.  It 
is  a  fact  that  flour,  treated  with  alum  on  account  of  begmning  deteriora- 
tion, has  caused  untoward  effects,  but  it  would  be  impossible  to  deter- 
mine how  much  influence  should  be  ascribed  to  the  alum  and  how  much 
to  the  products  formed  by  the  fermentative  processes  in  operation  before 
the  adcUtion.  The  weight  of  evidence,  however,  is  in  favor  of  the  view 
that  alum  is  not  incapable  of  producmg  injury  when  taken  into  the 
system  habitually  in  small  amounts,  and  that  it  should  be  excluded 
from  all  articles  of  food  intended  for  man. 

On  account  of  the  growing  tendency  to  mix  other  mill  products  of 
inferior  value  with  wheat  flour,  such,  for  instance,  as  rye  and  corn 
flour,  a  law  was  passed  by  Congress  in  June,  1898,  to  meet  the  evil, 
and  mcidentally  to  make  it  a  source  of  revenue.  All  adulterated  flour 
is,  by  the  act  referred  to,  designated  as  "  mixed  flour,"  which  term  "  shall 
be  understood  to  mean  the  food  product  made  from  wheat  mixed  or 
blended  in  whole  or  in  part  with  any  other  grain  or  other  material,  or 
the  manufactured  product  of  any  other  grain  or  other  material  than 
wheat."  Under  the  provisions  of  the  law,  all  persons  engaged  in  the 
business  of  making  mixed  flour  are  required  to  pay  a  special  annual 
tax,  every  package  must  be  labelled  plainly,  the  names  of  the  ingred- 
ients being  set  forth,  and  upon  every  package  of  196  pounds  a  tax  of  4 
cents  shall  be  paid.  Under  the  regulations  of  the  Treasury,  the  term 
"  mixed  flour  "  is  held  not  to  include  "  the  milling  product  from  corn, 
rye,  buckwheat,  rice,  or  other  cereals  than  wheat  put  upon  the  market 
as  the  flour  or  meal  derived  from  such  cereals,  although  the  product 
may  contain  a  percentage  of  wheat  flour." 


nVE.  185 

Tlio  cl(!t(!cii(tn  of  ()tli(!r  cfTC'ils  !ui(l  stiintlicH  if)  wheat  flour  i.s  aox'orn- 
[)lisli<!<l  l)OsL  by  jikjuiih  <»f"  tin;  tfiicrosooix;,  since,  a.s  will  ap[M:ar,  (tJif:li 
has  its  characteristic  appearance.  According  to  V<>^(;I,  70  y)er  cent, 
alcohol  (;on(ainin^  5  p<^r  ccni.  of  hydi-ochloric  acid  remains  colorlesH 
•dllvr  heino^  used  to  (ixtract  pun;  wheat  or  rye,  turns  pale  yelh)W 
if  barley  or  oats  be  prescul,  and  orarige-y(;llow  if  mixed  with  pea 
flour. 

Bleaching  of  Flour. — Witliin  the  last  f(;w  years  there  has  been  in- 
trodiKu^l  in  the  (lonr  indnst-iy  a  process  by  whidi  flour  is  blejirihwl 
throngh  tlu;  use  of  nitrotij(!n  peroxich;.  Ac(;ording  to  Leach,'  "  Nitro- 
gen peroxide  destroys  almost  immediately  the  yellow  color  which  is 
associated  with  the  fat  of  the  flour,  thus  increasing  the  whiteness  of 
the  ])rodu(!t.  It  also  combines  with  the  moistun;  of  the  flour,  forming 
nitrons  and  nitric  acids,  the  nitrous  acid  (free  or  combined]  being  espe- 
cially noteworthy  because  of  the  (!ase  of  detection." 

Whether  or  not  this  bleaching  of  flour  constitutes  a  menace  to  the 
public  health  is  still  undecided.  As  a  test  for  the  bleaching  of  flour. 
Leach"  gives  the  following  test,  based  on  observations  of  Alway  : 

"  Gasolene  test.  Place  25  grams  of  the  flour  in  a  four-ounce,  wide- 
mouthed,  glass-stoppered  bottle,  add  sufficient  gasolene  to  nearly  fill 
the  bottle,  shake,  and  allow  to  settle.  If  the  flour  is  unbleached  the 
gasolene  will  be  distinctly  yellow;  if  bleached,  it  will  remain  nearly 
colorless." 


Rye. 

In  external  appearance,  rye  presents  a  close  resemblance  to  wheat, 
but  the  kernels  are  darker  in  color  and  smaller  in  size.  It  is  bv  no 
means  so  important  as  wheat  as  an  article  of  food  in  this  countiy,  but 
in  some  parts  of  Europe  it  constitutes  the  main  food  supply  of  the 
petisantry. 

According  to  Wiley,  a  typical  American  rye  should  have  approx- 
uuately  the  following  composition  : 

Moisture 10.50 

Proteids 12.25 

Ether  extract 1.50 

Crude  liber 2.10 

Starch,  etc 71.75 

Ash L90 

100.00 

American  rye  is  smaller  than  that  groAvn  abroad,  and  contains  less 
moisture.  The  proteids  of  lye  are  more  like  those  of  wheat  than  those 
of  any  other  cereal,  and  in  consequence  rye  stands  next  to  wheat  in 
adaptability  for  bread-making.  The  yield  of  gluten  is  inferior  in 
amount  to  that  obtainable  from  wheat. 

^  Food  Inspection  and  Analysis,  1909,  p.  325. 
a  Ibid.,  p.  321. 


186  FOODS. 

The  starch  of  rye  is  much  like  that  of  wheat.  The  granules  are 
rather  more  variable  in  size,  the  smallest  of  each  kind  being  about 
equal,  but  the  largest  of  rve  somewhat  surpassing  those  of  wheat. 
There  is  but  one  point  of  difference  in  microscopic  appearance  which 
has  any  value  in  detecting  the  admixture  of  rye  with  wheat,  namely, 
that  a  certain  fair  proportion  of  the  larger  sized  granules  of  rye 
present  irregular  crosses  or  fractures.  This  is  illustrated  in  Plate 
yil.,  Fig.  2. 

Bread  made  from  rye  flour  is  but  little  inferior  in  nutritive  value  to 
that  from  wheat,  but  it  is  less  pleasing  to  the  eye,  being  of  a  brownish 
tint,  and  it  has  a  peculiar  sour  taste,  not  altogether  agreeable  on  first 
acquaintance.  Not  uncommonly,  its  use  by  one  not  habituated  to  it 
causes  a  tendency  to  diarrhcea,  which,  however,  is  soon  overcome. 

Barley. 

This  important  cereal  is  used  mainly  in  the  manufacture  of  beer,  and 
but  to  a  limited  extent  as  a  food.  Deprived  of  its  husk  and  rounded 
and  polished  by  attrition,  it  is  known  as  "  pearl  barley,"  and  in  this 
form  is  used  more  or  less  in  the  preparation  of  barley-water,  a  drink 
for  invalids.  In  its  composition,  barley  is  very  similar  to  wheat  and 
rye,  but  as  its  proteids  yield  no  gluten,  it  cannot  be  made  into  bread. 
It  is  mixed  sometimes  with  wheat  flour  for  purposes  of  bread-making, 
but  the  product  is  less  palatable  and  less  digestible  than  ordinary 
bread. 

Wiley  gives  the  following  as  the  approximate  composition  of  a  typi- 
cal American  unhulled  barley  : 

Moisture 10.85 

Proteids 11.00 

Ether  extract 2.25 

Crude  fiber 3.85 

Starch,  etc 69.55 

Ash 2.50 

100.00 

The  proteids  include,  as  in  all  cereals,  a  number  of  complex  sub- 
stances, chief  of  which  is  hordein.  The  starch  granules  are  like  those 
of  wheat,  but  are  less  variable  in  size.  (See  Plate  VIII.,  Fig.  1.)  In 
the  manufacture  of  malt  from  barley  for  brewing,  a  peculiar  nitroge- 
nous product,  diastase,  is  formed,  which  has  the  property  of  converting 
starch  to  sugar. 

Oats. 

Oats  are  much  used  as  human  food  in  the  form  of  oatmeal,  which  is 
the  product  of  grinding  the  kiln-dried  seeds  deprived  of  the  husk. 
The  meal  has  a  peculiar  taste,  which  is  both  sweet  and  bitter. 

The  composition  of  unhulled  American  oats,  as  given  by  Wiley, 
is  as  follows : 


/^ 


pj.A'i'ii:  VIII 

F\n.\i 


■^ 


Barley  Starch.       :  28?^ 


Oats  Starch.     ^     286. 


CORN.  1H7 

MoiHliin! 1"W 

l>n.t..i<lH l'-i-'X> 

K(lirr(^xl.i!i('l '♦••''''' 

(!ru.l.,  r.l..,r lii-'X' 

Stjiivh,  (■(,(; -'^-^^^ 

AhI. •"-■^" 

lod.oo 

The  mciin  coinposil.ioii  (»f  oatmeal,  luironliii^  to  lilylli,'  i-  as  follow'.s! 

Moistures l^--''-^ 

IVoU-i.ls 11.7» 

]<^il «.04 

Ku^iir 2.22 

I)(\x(riii  ;iii(l  K">'i 2.04 

Stiucl. •'Jl-17 

Fiber 10.83 

Ash 3.05 

100.00 

The  proteids  of  oats  yield  no  j;luten,  and  hence  this  artielo  of  diet 
cannot  be  made  into  bixiad,  thouii;h  with  water  it  eun  h(!  made  into  thin 
cakes,  which  arc  most  ])alat;ib]e.  V-At  is  present  is  greater  abundant 
than  in  any  other  eerciil.  The  starch  grannies  are  very  small  i)f>ly- 
hedra  which  show  neither  hilnm  nor  concentric  rings.  They  tend  to 
adhere  together  in  masses  of  variable  size,  which  are  disintegrated 
easily  by  tritnration  in  a  mortar.  The  single  granules  are  shown  in 
Plate  VIIL,  Fig.  2. 

Oatmeal  is  a  very  nntritions  article  of  diet,  used  largely  as  a  break- 
fast food  in  the  form  of  porridge.  It  has  a  somewhat  laxative  action, 
and,  therefore,  should  not  be  eaten  in  irritable  conditions  of  the  bowel. 
It  is  also  likely  to  disagree  with  some  dyspeptics,  because  of  its  ten- 
dency to  cause  acidity  and  heartburn. 

Com. 

In  the  American  usage  of  the  word,  corn  includes  the  several  varie- 
ties of  Indian  corn  or  maize.  In  England,  the  term  is  applied  gener- 
ally to  wheat,  rye,  oats,  and  barley,  and  more  specifically  to  wheat ;  in 
Scotland,  it  commonly  means  oats.  In  the  United  States,  com  is  in 
many  ways  the  most  important  of  the  cereals,  constituting  in  some 
parts  of  the  country  the  chief  bread  food,  and  being  the  main  source 
of  starch  and  glucose. 

The  chief  varieties  are  dent  corn,  showing  a  depression  in  the  outer 
end  of  the  kernel ;  flint  corn,  having  a  hard  smooth  exterior ;  sweet 
corn,  rich  in  sug-ar  and  shrivelling  when  ripe ;  and  }>op-coru,  a  very 
flinty  variety  with  small  kernels,  which  contain  a  considerable  amount 
of  oil,  which,  in  the  process  of  roasting,  explodes  and  causes  the  extru- 
sion of  the  starchy  interior  in  the  form  so  universally  familiar.  The 
variety  in  most  common  use,  from  which  the  several  kinds  of  meal, 
hominy,  and  samp  arc  derived,  is  the  flint  com.  Hominy  is  the  prod- 
uct obtained  by  grinding  coarsely  the  kernels  deprived  of  the  hull  by 
soalving.     Samp  is  the  whole,  or  practically  the  whole,  of  the   kernel 

^  Foods:  Their  Composition  iiiitl  Analysis,  Loudou,  1S96,  p.  210. 


188  FOODS. 

minus  the  germ  and  hull.  Indian  meal,  or  corn  meal,  is  the  product 
obtained  hv  iirindini;,-  the  kernels  betM'ecn  stones  or  by  other  ])rocesses 
of  milling-,  and  removing-  more  or  less  of  the  bran  by  sifting  or  bolt- 
ing. According-  to  the  process  employed,  we  have  coarse  and  fine,  and 
■white  and  yellow  meal.  Prepared  without  removal  of  the  germ,  which  is 
rich  in  oil,,  the  product  is  prone  to  become  rancid  and  mouldy  on  keeping. 
From  a  large  number  of  analyses,  A\'iley  deduces  the  following  as 
the  approximate  composition  of  typical  Indian  corn  : 

Moisture 10.75 

Pioteids 10.00 

Ether  extract 4.25 

Crude  fiber 1.75 

Starch,  etc 71.75 

Ash 1.50 

100.00 

The  average  of  19  analyses  of  samples  of  sweet  corn  by  Clifford 
Richardson,  quoted  by  Wiley,  shows  : 

Moisture 8.44 

Proteids 11.48 

Ether  exti-act 8.57 

Crude  fiber 2.82 

Starch,  etc 66.72 

Ash 1.97 

100.00 

The  composition  of  fine  meal  is  given  by  Wiley  as  follows  : 

Moisture 12.57 

Proteids 7.13 

Ether  extract 1.33 

Total  carbohydrates 78.36 

Ash 0.61 

100.00 

The  lowered  percentages  of  proteids  and  fats  here  shown  are  due  to 
the  removal  of  the  germ,  rich  in  fat,  and  of  the  finer  envelopes,  rich 
in  proteids. 

The  proteids  of  corn,  as  determined  by  Chittenden  and  Osborne,  are 
made  up  of  several  globulins,  including  myosine  and  vitelline,  two 
classes  of  albumins,  and  two  of  zeins.  The  starch  granules  are  poly- 
hedral with  rounded  angles,  and  have  a  punctiform,  sometimes  stellated, 
hilum.  They  are  much  larger  than  those  of  oats,  which  they  resemble 
somewhat  in  form.     They  are  shown  in  Plate  IX.,  Fig.  1. 

On  account  of  its  deficiency  in  gluten,  corn  meal  is  not  well  adapted 
to  the  making  of  leavened  bread,  but  it  is  used  in  many  forms  of  sub- 
stitutes therefor.  It  is  mixed  with  salt  and  water,  sometimes  with  the 
addition  of  milk  or  eggs,  and  baked  into  not  over-thick  cakes,  which, 
according  to  the  method  of  preparation  and  baking,  are  known  as 
johnnycake,  corn  dodger,  corn  pone,  and  corn  bread.  Sometimes,  yeast 
and  baking  powder  are  employed.  Corn  meal  is  used  extensively  in 
the  form  of  hasty  pudding,  or  corn  mush,  and  of  Indian  pudding.  In 
whatever  form  used,  corn  meal  is  a  most  nutritious  and  wholesome  food. 


PLATE    IX 


o 


V 


c 


<p 


o 


Q^ 


(D 


°-g     (^  o 


CD 


w 


Corn  Starch.     X  288. 


FIG.    2 


J  "^^^V    J'df^ii^ 


6  % 


Rice  Starch,     x  285. 


RICE-  B  UCK  [Vni'JA  T.  180 

Rice. 

Rico  Ih  t\u'.  priii(!i|);i,I  food  of"  ii,  very  hw^c.  \y,ivi,  (;stiiii;it<<l  .it  ;il)OiJt  a 
third,  of  tli(!  Iiimiiiii  nu'c.  J><!i"K>  '^^  ^^'"  '"'  f^*'")  <'"♦'  I"""'  '"  |"'"t<;idH, 
fill,  uiid  miiicr;d  iiinflcr  lo  siifiHfy  mIoiic  tlio  iwa'Ah  of  tlic  Ixtdy,  tlic  <\c- 
fi(;ion(ri(!S  nrv  met  by  oilier  vc^cbihlc!  prodiicts,  us  hc-ins  and  ju-as,  wliiffi 
are  rich  in  thiisc  (lon.stitiK^iits. 

The  form  in  which  ri(!c  is  Hccn  in  Ihc  household  is  the  icsuit  of  a 
polishiiiji;  proci^ss  wlii(^h  removos  lh(!  reddish  cuticle;  which  the  j^ain 
shows  on  removal  of  I  Ik;  husk'.  Wiley's  fi^iin;s,  r(;pr(',sentin^  the  com- 
position of  typical  jxdished  rice,  are  as  follows  : 

Moistmo 12.40 

I'n.lcidH  .    .    .  ' 7.50 

EtluT  extract 0.40 

Crude  fiber 0.40 

Starch,  etc 78.80 

Ash _  o.r>o 

100.00 

Rice  is  the  richest  of  the  cereals  in  starch,  and  the  ))oorest  in  all  other 
respects.  The  proteids  have  not  yet  been  studied  systematically.  Its 
starch  is  very  easily  digestil^le,  and  is  very  useful  in  all  disordered  con- 
ditions of  the  di<2;estive  tract  when  other  solid  foods  c;annot  l)e  borne. 
Under  the  microscope,  the  starch  granules  are  .'^een  to  l)e  much  like 
those  of  corn,  but  are  much  smaller  and  have  shaqicr  angles.  They 
are  separated  less  easily  from  one  another,  and  are  commonly  in  groups 
of  variable  size.      They  are  shown  in  Plate  IX.,  Fig.  2. 

Rice  cannot  be  made  into  bread,  but  sometimes  is  mixed  with  wlieat 
flour,  in  order  to  give  whiteness  to  the  bread.  It  is  used  most  com- 
monly in  the  freshly  boiled  condition  or  in  the  form  of  ]iuddiugs.  The 
most  approved  method  of  cooking  it  is  steaming.  This  has  the  advan- 
tage of  not  taking  away  any  of  the  already  deficient  proteids  and  salts, 
which  to  some  extent  are  extracted  in  boiling,  and  also  that  it  leaves 
the  kernels  distinct  in  themselves,  and  not  aggregated  in  the  form  of  a 
soggy  mush,  such  as  is  produced  often  by  improper  boiling. 

Buckwheat. 

This  valuable  cereal  is  used  very  extensively  in  this  country-  as  a 
breakfast  food  in  the  form  of  pancakes  eaten  hot  with  syruji  or  with 
butter  and  sugar.  As  it  is  devoid  of  gluten,  it  cannot  be  made  into 
bread. 

The  composition  of  typical  American  buckwheat  is  given  as  follows : 

Moisture 12.00 

Proteids 10.75 

Ether  extract 2.00 

Crude  fiber 10.75 

Starch,  etc 62.75 

Ash 1.75 

100.00 


190  FOODS. 

The  crude  fiber  is  removed  veiy  largely  in  the  nullint];:,  and  is  almost 
■wholly  absent  from  the  white  flour,  a  sample  of  ^vhich,  aual}-zed  by 
AVilev,  had  the  following  composition  : 

Moisture 11.89 

Protoids 8.75 

Ethor.oxtract 1.58 

Crude  fiber 0.52 

St;uch,  etc 75.41 

Ash 1.85 

100.00 

Buckwheat  is  the  most  expensive  of  the  cereals,  and  consequently  is 
the  most  sabjeet  to  adulteration  with  the  cheaper  members  of  the  class. 
The  admixture  is  detected  readily  by  the  microscope,  since  the  starch 
granules  have  a  very  characteristic  appearance,  being  small  and  angu- 
lar, and  of  nearly  uniform  size.  Ordinarily  they  are  seen  in  fairly  large 
masses  which  are  not  disintegrated  in  the  process  of  milling.  The 
starch  is  shown  in  Plate  X.,  Fig.   1. 

(b)  LEGUMES. 

This  group  comprises  peas,  beans,  and  lentils.  It  is  characterized 
by  richness  in  proteids,  which  may  be  present  in  more  than  double  the 
amount  found  in  wheat.  The  chief  proteid  is  legumin,  which  much 
resembles  casein,  and  is  known  commonly  as  vegetable  casein.  Accord- 
ing to  E.  Fleurent,^  the  proteids  of  this  group  consist  of  vegetable 
casein,  composed  of  legumin  and  glutenin,  and  vegetable  fibrin,  com- 
posed of  albumin  and  gliadin.     Thus  : 

-17-      ,  ,1  ■     f  legumin 60.95 

Vegetable  casein  |  g,,-^^^j^ 30_g5 

T7-      i  ui     cu  •       f  albumin 0.64 

Vegetable  fibrin    |  gjj^ji^ 7.76 

100.00 


Their  high  content  of  proteids  makes  them  more  satisfying  than  other 
vearetable  foods,  and  enables  them  to  act  as  a  fair  substitute  for  animal 
food.  The  millions  of  rice-eaters  who,  by  reason  of  poverty  or  religious 
scruples,  are  denied  the  use  of  animal  food,  depend  upon  the  legumes 
to  supply  the  demands  of  the  body  for  nitrogen.  The  East  Indian, 
for  instance,  has  no  difficulty  in  satisfying  his  bodily  needs  with  a  hand- 
ful of  beans  added  to  his  daily  ration  of  rice.  While  legumes  possess  a 
very  high  nutritive  value,  they  must  be  ranked  as  much  more  difficult 
of  digestion  than  the  cereals.  They  require  prolonged  boiling  when 
cooked  whole,  but  are  prepared  more  quickly  and  digested  more  com- 
pletely when  ground  into  meal  and  cooked  with  milk.  Even  under 
the  most  favorable  conditions,  a  large  part  of  the  proteids  is  lost  in  the 
excreta.     Rubuer  has  shown  that  a  fifth  to  a  third  is  not  digested  and 

'  Comptes  rend  us,  1898. 


PLATE   X 


Buckwheat  Starch,     x  285. 


I 
4 


;^f%.; 


Pea  Siaieli.  2So. 


ri'LiS     lilCANS.  lf)l 

;il)S(»rl )('(!,  wlicrcuH  In  flic  case  of  bread   the  jtrofci*!   Iohh   \h  Ichh  than  a 

.S(!V('lll  ll. 

SoiiH!  iiidividiials  arc  oMi^^cd  fo  forc^f)  tlio  uho  of  [xyiH  and  Iicjiiik,  on 
a<^5()unl,  of  (laiiilcMcc  due  In  (lie  ((»rrnati«)n  f>f  Hulpliiirclfcd  liydr<>^(!n 
fVoni  tli(!  siilplmr  in  I  lie  Ic^iiiiiin.  Tlii.s  ol)j(!<!tio!i  docs  not  •'i|)|>ly  to  len- 
tils, sin(!('  (licy  (M)iilain  no  siilpliiir. 


Peas, 
'^riic  av('i"a<;'e  of  (J  I  analyses  of  peas,  eoMi[)Iled  l>y  Kidiit^,  is  as  follows  : 

Moisture \\.'.)'.) 

ProUiida 22.80 

Fat 1.79 

Cnido  (iluT hA^ 

Htaiv.h,  etc 52.:iG 

Asli _   2.58 

I'OO.OO 

When  dried  peas  heeonie  old,  no  amount  of  boilinf^;  will  make  them 
soft,  and  they  should  then  be  soaked  and  ei-ushed  and  cooke^l  in 
some  other  way.  The  inuuature  pea,  so  hitrhly  prized  as  a  sj)rin^  and 
summer  vegetable,  has  a  very  different  composition.  Five  analyses, 
compiled  by  Atwater  and  Bryant,'  yielded  the  following  average  results  : 

Moisture    .    ' 74.6 

Proteids 7.0 

Fat 0.5 

Carbohydrates,  including  fiber 16.9 

Ash '. 1.0 

100.0 

The  canned  pea  appears  to  coutaiu  considerably  less  nutriment.  Of 
88  samples  reported  by  the  same  authorities,  none  contained  less  than 
77.5  per  cent,  of  water,  and  some  contained  as  much  as  02.7.  Their 
average  composition  was  as  follows  : 

Moisture 85.3 

Proteids 3.6 

Fat 0.2 

Carbohydrates 9.8 

Ash    .  ■ Ll 

100.0 
The  starch  granules  of  peas  are  represented  in  Plate  X.,  Fig.  2. 

Beans. 

There  are  many  varieties  of  beans  belonging  to  the  two  large 
groups,  the  broad  beans  and  the  kidney  beans,  but  their  composi- 
tion is  in  general  quite  similar.     Forty-one  analyses  of  broad  beans 

^  Loco  citato. 


192  FOODS. 

and    10    of  kidney    beans   compiled   by    K5uig   give   the    following 
averages  : 

Broad.  Kidney. 

Moisture 14.7(5  13.74 

Pioteids 24.27  23.21 

Fat 1.61  2.14 

Crude  tiber 7.09  8.(>i) 

Starch,  etc 49.01  53.67 

Ash _3.26  __3.55 

100.(10  100.00 

Eleven   analyses  compiled  from   American     sources   by    Atwator  and 
Bryant  yield  averages  not  materially  different. 

Five  analyses  of  string  beans  in  the  fresh  state  and  29  of  canned 
samples  yield  the  following  averages,  showing,  as  in  the  case  of  peas, 
that  the  canned  variety  is  less  nutritious  : 

Fresh.  Canned. 

Moisture 89.2  93.7 

Proteids 2.3  1.1 

Fat 0.3  0.1 

Total  carbohydrates 7.4  3.8 

Ash 0^8        L3 

100.0  100.0 

The  Soja  bean,  which  has  been  recommended  highly  in  some  quarters 
as  a  suitable  food  for  diabetics,  is  remarkable  for  its  high  content  of 
fat,  and  contains,  in  addition,  so  large  an  amount  of  starch  as  to  make 
it  quite  unsuited  to  the  dietary  of  the  diabetic.  Konig  has  compiled 
21  analyses  from  all  sources,  and  Jenkins  and  Winton  ^  have  collected 
10  more  from  American  sources.  The  two  groups  give  the  following 
averages  : 

TfnmV  Jenkins 

^o^^S-     and  Winton. 

Moisture 9.51  10.80 

Proteids 33.41  33.98 

Fat 17.19  16.85 

Crude  fiber 4.71  4.79 

Starch,  etc 29.99  28.89 

Ash 5.19  4.69 


100.00         100.00 


Bean  starch  is  shown  in  Plate  XI.,  Fig.  1. 


Lentils. 


Lentils  are  the  most  nutritious  of  the  legumes,  but  are  not  a  popular 
food  in  this  country,  excepting  among  certain  of  the  foreign-born 
population.  Their  use  is,  however,  on  the  increase.  The  averages  of 
14  analyses  compiled  by  Konig  are  as  follows  : 

1  Experiment  Station  Bulletinj  No.  llj  Washington,  1892. 


PLATE    XI 


Bean  Starch.     :<  28S. 


^'Ur_c 


Q:fi^; 


o  , 


cf 


o. 


Arrowroot  Starch.     \  285. 


SA(J()    AJUiOWROOT.  193 

MoiHliire 12M 

I'n.lcidH 2.'j.70 

I<'i.t \.H'.) 

Oriidi!  (lIxM- 3,57 

HtiiTch,  etc ry.iAQ 

AhIi _  3.04 

IW.OO 

2.  Farinaceous  Preparations. 
Under  this  head  ;ir(!  iiicliKlcd  sa^o,  (upioc;!,  and  arrowroot. 

SAGO. 

Sajijo  iH  dcM'ived  from  thv,  pitli  of"  IIk;  sfciiis  of  a  miiiil)cr  of  spocioH 
of  ]);ilins,  ^V\h)  pith  is  extracted  and  ground  to  a  |)o\vdcr,  wliifli  tli(;n 
is  mixed  with  wtitcr  and  stniiiied.  The  stanih  j^raiiidcs  pass  throiip^h 
with  the  water,  and  are  deposited  as  a  sediment,  which  constitutes  the 
sajTO  flonr.  From  the  Hour,  made  into  a  paste,  the  various  forms  of 
granulated  sa<2;;o  are  preparc^d. 

Sago  is  an  important  starch  ))reparation,  and  sei'vcs  as  a  light  and 
digestihle  food  for  invalids  and  dyspeptics,  but  its  use  is  not  restricted 
to  these  alone.  It  absorbs  the  li(piid  in  which  it  is  cooked,  and  becomes 
soft  and  transparent,  but  retains  its  original  form. 

TAPIOCA. 

Tapioca  is  derived  from  a  thick  fleshy  tuberous  root  called  "  mani- 
hot."  The  starch,  which  is  extracted  by  a  method  similar  to  that  em- 
ployed in  the  preparation  of  sago,  is  heated  in  a  moist  state  on  hot 
plates  and  stirred  with  iron  rods,  and  thus  forms  irregular  masses  of 
transparent  granules.  lu  the  process  of  heating,  many  of  the  starch 
granules  become  ruptured,  and  are  then  partially  soluble  in  cold  water. 
Tapioca,  like  sago,  is  useful  for  both  sick  and  well. 

ARROWROOT. 

Arrowroot  is  a  pure  form  of  starch  from  the  tuberous  root  of  the 
maranta.  Its  name  is  derived  from  the  fact  that  the  maranta  root  is 
believed  to  counteract  the  effects  of  arrow  poison.  It  is  used  chiefly 
as  a  bland  article  of  food  in  the  sick-room  in  the  form  of  light  pudding 
or  other  desserts,  but  may  be  combiued  with  other  starch  foods  and 
made  into  bread.  There  are  several  varieties,  the  best  of  Avhich  come 
from  Bermuda  and  Jamaica.  Corn  starch  is  employed  frequently  as  a 
fair  substitute.     Arrowroot  starch  is  shown  in  Plate  XL,  Fig.  2. 

3.  Fatty  Seeds  (Nuts). 

Nuts  are  rich  in  fat  and  proteids.  but  contain  uo  starch.     They  are 
of  high  nutritive  value,  but  on  account  of  their  riehuess  in  fat  they  are 
not  easily  digested,  even  when  reduced  to  a  finely  divided  state. 
13  ' 


194  FOODS. 


ALMONDS. 


Ill  the  countries  where  they  are  i)rodiieeJ,  the  almond  is  eaten  both 
in  the  oreen  and  dry  conditions.  The  ripe  kernel  has  a  skin,  with  a 
bitter  tUsagreeable  taste.  When  this  is  removed  by  soaking  for  a  time 
in  warm  water,  the  almond  is  kno^\^l  as  "  blanched." 

There  are  two  varieties  of  almond,  the  sweet  and  the  bitter,  both  of 
which  contain  more  than  50  per  cent,  of  oil,  about  half  as  much  jiro- 
teid  material,  gum,  sugar,  and  crude  fiber.  Both  contain  enuilsin,  a 
substance  which,  in  the  presence  of  water,  acts  upon  the  glucoside 
amygdalin,  present  only  in  the  bitter  variety,  to  form  hydrocyanic  acid, 
glucose,  and  benzoic  aldehyde.  On  account  of  this  reaction,  the  bitter 
almond  is  not  always  safe,  and  fetal  results  have  occurred  from  its 
ingestion. 

When  almonds  are  baked,  they  are  made  more  brittle,  and  are  re- 
duced more  easily  to  a  powder. 

COCOANUTS. 

The  fleshy  white  kernel  of  the  cocoanut  contains  about  70  per  cent, 
of  fat.  The  milky  interior  is  chiefly  water,  but  contains  nearly  7  per 
cent,  of  sugar. 

WALNUTS. 

All  of  the  trees  of  the  genus  Juglans  yield  nuts  classed  as  walnuts. 
The  different  varieties,  though  varying  in  outward  appearance  and  in 
taste,  have  practically  the  same  composition.  They  contain  about  60 
per  cent,  of  fat,  about  16  per  cent,  of  proteids,  and  about  7  per  cent, 
of  sugar  and  gum.  The  hazel  nut,  which  belongs  to  the  oak  family 
has  about  the  same  composition. 

PEANUTS. 

The  peanut,  known  also  as  ground  nut  and  goober,  is  less  rich  in  fat, 
but  richer  in  proteids  than  other  nuts.  It  contains  about  45  per  cent, 
of  the  former  and  about  30  per  cent,  of  the  latter. 

CHESTNUTS. 

The  chestnut  is  not  of  this  class,  but  for  convenience  will  be  con- 
sidered here  rather  than  with  the  farinaceous  seeds,  in  which  class  it 
properly  belongs.  It  contains  but  little  fet  and  proteids,  about  15  per 
cent,  of  sugar,  about  25  per  cent,  of  starch,  and  about  50  per  cent,  of 
moisture.  It  is  very  indigestible  in  the  raw  .state,  and  even  when 
cooked  is  very  trying  to  the  digestion  of  those  with  weak  stomachs. 
It  is  used  very  extensively  as  a  food  by  the  French,  Spanish,  and  Ital- 
ian peasantry  in  various  cooked  forms,  and  largely  in  the  form  of  bread. 


VEdETAIlLI':  FATS    (JlJVJ-:   OIL.  19o 


4.  Vegetable  Fats. 


The  vcgctjiblo  fiits  include!  tlu;  oils  (Ksrivfid  fifHii  flic  relive,  ci)ttfjn- 
sccd,  poarnit,  and  oIJkt  Hcc^d.s.  Tlicy  an;  used  in  the  j)n'f)aratir)n  (>{ 
salads  and  for  iiyinj^.  Tiie  most  important  are  the  two  first  m(;n- 
tiondd. 

OLIVE  OIL. 

United  States  Standard. — Olive;  oil  is  the  oil  ohtaincd  from  tlio 
sound,  mature!  fruit  of  tlic  (;ul(ivat(,'d  (dive;  tree  (Olca  (Mirojucii  Jv.j,  jinrl 
subjected  to  the  usual  refining  processes;  is  free  from  rancidity;  has  a 
refractive  index  (25°  C.)  not  less  than  1.40()O  and  not  exceeding 
1.4680  ;  and  an  iodine  mimher  not  less  than  7i)  and  not  exceeding  DO. 
Virgin  olive  oil  is  olive  oil  ohtaincd  from  the  first  pressing  of  carefully 
selecteti,  hand-picked  olives. 

Olive  oil  is  a  bland  fixed  oil  derived  from  the  fruit  of  the  many 
varieties  of  the  olive  tree.  It  is  known  by  various  names  which  desig- 
nate the  grade,  but  is  sold  for  the  most  j)art  as  virgin  oil,  which  is  the 
choicest  grade  of  all  and  not  extensively  marke^ted.  A'^irgin  oil  is  made 
from  the  choicest  olives,  about  three-fourths  ripe,  whicli  are  bruised  only 
slightly  in  the  mill,  so  that  only  the  olive  pulp,  and  not  the  stone,  Ls 
crushed.  The  crushed  mass  is  gathered  in  a  heap,  and  the  oil  is 
allowed  to  drain  away  without  pressure  or  other  influence  of  any  kind. 
The  product  has  a  greenish  tint  and  a  far  more  delicate  taste  than  that 
made  in  the  manner  to  be  described. 

In  the  manufacture  of  the  grades  ordinarily  seen  in  the  market,  the 
olives,  both  pulp  and  stones,  are  gronnd  into  an  oily  paste,  which  is 
packed  into  bags  made  of  woven  grass.  These  are  placed  in  piles  and 
subjected  to  pressure.  As  the  oil  drains  away,  boiling  water  is  applied 
to  the  bags  to  keep  up  the  flow,  and  that  which  is  thus  obtained  con- 
stitutes the  lower  grade.  Sometimes,  the  pressed  pulp  is  thrown  into 
water  and  separated  from  the  broken  kernels,  which  sink  to  the  bottom. 
The  pulp  is  then  gathered  up  and  pressed  again.    • 

On  account  of  the  cost  of  pure  olive  oil,  adnltemtion  with  other 
cheaper  oils  is  practised  very  extensively.  The  principal  adulterant 
is  cotton-seed  oil,  which  is  exported  from  this  country  in  large  quantities 
for  this  and  other  purposes.  J\luch  of  the  oil  sold  in  this  country  as 
olive  oil  is  cotton-seed  oil  put  up  in  the  cheapest  kinds  of  bottles, 
adorned  with  gandy  labels  bearing  inscriptions  often  not  remarkable  for 
accuracy  in  the  nse  of  the  French  language.  The  author  has  seen,  for 
example,  labels  which  indicated  that  the  contents  of  the  bottles  had 
been  "  virginated." 

Adulteration  of  olive  oil  to  only  a  slight  extent  with  the  cheaper 
oils  is  by  no  means  easy  of  detection,  but  %vhen  the  fraud  is  fairly  ex- 
tensive it  may  be  sho^^^l  by  chemical  tests  and  by  the  use  of  the  re- 
fractometer,  the  refractive  index  of  olive  oil  being  less  than  that  of 
the  cheaper  substitutes.     The  iodine  number  and  saponification  equiv- 


196  FOODS. 

aleut  of  olive  oil  are  both  less  than  those  of  its  adulterants.  The  be- 
havior of  olive  oil  in  contact  with  nitric  acid  or  with  alcolK)lic  solution 
of  nitrate  of  silver  is  markedly  dilfcrcnt  from  that  of  the  cheaper  oils. 
Thus,  equal  volumes  of  strong  nitric  acid  and  olive  oil,  mixed  together 
and  agitated  in  a  flask,  give  a  product  which  has  either  a  greenish  tinge 
or  at  most  one  inclining  to  orange,  and  no  marked  change  is  perceptible 
on  standing  for  live  or  ten  minutes  ;  whereas  cotton-seed  oil  similarly 
treated  yields  almost  immediately  a  reddish  color,  >vhich  shortly  darkens 
and  becomes  dark  brown  or  almost  black. 

Again,  if  12  cc.  of  a  suspected  sample  are  mixed  in  a  test  tube  with 
5  cc.  of  a  2.5  per  cent,  solution  of  nitrate  of  silver  in  95  per  cent, 
alcohol,  and  placed  in  a  beaker  of  boiling  water,  the  resulting  change 
of  color  gives  indications  as  follows :  if  olive  oil,  the  color  is  greenish  ; 
if  cotton-seed  oil,  it  becomes  black ;  if  sesame  oil,  it  is  dark  reddish- 
brown  ;  if  peanut  oil,  it  is  at  first  reddish  brown,  then  greenish  and 
turbid ;  if  poppy  oil,  it  is  greenish  yellow.  For  further  details  of 
chemical  tests,  the  reader  is  referred  to  the  standard  works  on  the 
adulteration  of  foods. 

COTTON-SEED  OIL. 

United  States  Standard. — Cotton-seed  oil  is  obtained  from  the 
seeds  of  cotton  plants  and  subjected  to  the  usual  refining  processes ;  is 
free  from  rancidity,  has  a  refractive  index  (25°  C.)  not  less  than 
1.4700  and  not  exceeding  1.4725  ;  and  an  iodine  number  not  less 
than  104  and  not  exceeding  110. 

This  very  important  and  cheap  vegetable  fat  is  a  perfectly  whole- 
some and  desirable  article  of  food.  It  is  much  used  under  its  own 
name  as  a  substitute  for  lard  and  olive  oil  for  frying,  and  in  place  of 
the  latter  as  an  ingredient  of  dressings  for  salads.  It  lacks  the  fine 
flavor  of  olive  oil,  but  its  substitution  in  dressings  can  be  detected  only 
by  the  educated  palate.  From  a  hygienic  standpoint,  there  is  abso- 
lutely no  objection  to  its  use  in  the  preparation  of  foods.  The  same 
may  be  said  of  the  orther  cheap  vegetable  oils. 

5.  Tubers  and  Roots. 

In  the  cooking  of  tubers,  roots,  and  other  vegetables,  the  albumins 
and  globulins  are  coagulated,  the  fibrous  matters  in  the  cell  walls  are 
softened  and  ruptured,  the  starch  granules  swell  and  burst,  the  starch 
itself  becomes  somewhat  changed  in  character,  and  the  whole  mass  is 
made  more  digestible.  When  boiling  is  the  process  employed,  part  of 
the  mineral  matter  and  more  or  less  of  the  other  soluble  substances, 
including  certain  proteid  material,  are  extracted  and  lost. 

POTATOES. 

The  potato  is  the  most  important  member  of  this  group.  It  was  intro- 
duced into  Spain  from  Peru  about  the  middle  of  the  sixteenth  century, 
and  later,  in  1585,  into  Ireland  from  Virginia,  by  Sir  Walter  Raleigh, 


PLATE  XII 


Potato  Starch,     x  285. 


I'()TAT()FX  \[)1 

who,  in  the  following  y''i"'>  iiitn»(lii(;(!(l  it  uIho  into  lOn^^liUKl.  Prior  to 
that  time,  mid  even  later,  wluit  \v:is  known  in  lOii^rlniirl  ;is  llic  potato 
Jind  the  "  eonnnon  |)o(,uto  "  iiicnlioncd  hy  ( icinrd  in  lii.s  Ilcrhul  {\i'i\)lj, 
were  sw(!(!t  |)ot;iioeH,  'M)ii(-;i(a,"  iiitrodu(;cd  IVom  Spain. 

TIk!  av(!r;it;'es  of  l-'Jd  ;ni:ily'^es  (Anieriean  wunplesj  eonijiilcd  by 
Atwater  iind    liry;int  arc   iis    follows: 

MoiHtiire 78.3 

Proteids ii-ii 

Fat 0.1 

Total  carbohydratcH 18.4 

Ash 1.0 

HK).0 

These  fi^inxvs  dilTcr  hiil  slin-hlly  from  the  averages  of  178  analyses 
of  Knropean   sain|)les. 

The  proteids  of  the  potato  are  (ihielly  in  the  nlliiniiinons  jni(Xi  be- 
tween and  in  the  cells.  Most  of  the  mineral  matter  is  salts  of  potas- 
sium, and  this,  too,  is  almost  wholly  in  the  juice.  The  starch  was  dis- 
covered by  Lenbert  and  Georgiewsky  to  be  acted  upon  much  more 
readily  by  the  salivaiy  en/ymc  than  any  of  the  eereid  starches.  The 
starch  granules  are  much  larger  and  m(jre  irregular  in  siiape  than  any 
of  those  thus  far  shown.  The  hilum  and  concentric  rings  are  quite 
distinct.      (See  Plate  XII.) 

In  the  process  of  cooking,  the  albuminous  juice  is  coagulated  and  its 
watery  part  is  absorbed  by  the  starch  granules,  which  swell  and  con- 
sequently distend  the  cells  in  which  they  are  lodged.  The  coherence 
of  the  cells  is  reduced,  and  then  they  are  separated  easily  into  a  mealy 
mass.  If  the  watery  part  of  the  juice  is  not  wholly  absorbed,  the  cells 
are  separated  with  more  or  less  difficidty,  the  potato  remains  firm  instead 
of  becoming  mealy,  and  is  then  spoken  of  as  close,  waxy,  or  watery. 
In  this  state  it  is  digested  much  less  easily,  and  may,  indeed,  be  very 
trying  to  the  stomach.  The  same  condition  is  noticed  in  the  case  of 
potatoes  which  have  been  frozen  ;  they  are  very^  watery  and  of  inferior 
flavor  however  they  are  cooked. 

According  to  Balland,^  the  mealy  condition  is  due  not,  as  supposed, 
to  an  especially  high  content  of  starch,  but  to  a  low  percentage  of  al- 
bumin, for  a  potato  rich  in  this  substance  keeps  its  shape  and  neither 
cracks  nor  fills  apart.  He  also  points  out  that  beneath  the  skin  there 
are  three  well-defined  layers,  which  may  readily  be  seen  by  holding  a 
thin  cross-section  affiiinst  a  strono;  lio-ht.  The  outermost  is  richest  in 
starch  and  poorest  in  proteids,  but  in  the  innermost  these  conditions  are 
reversed ;  the  middle  layer  represents  the  mean  composition  of  the 
whole. 

The  loss  which  occurs  on  boiling  is  much  less  when  the  skins  are 
left  intact  than  when  removed ;  the  greatest  loss  occm's  when  the 
potatoes  are  peeled  first  and  then  soaked  in  cold  water.  When  cooked 
by  steaming,  there  is  no  loss  whatever.     The  material  lost  in  boiling 

'  Journal  de  Pharmacie  et  de  Cbemie,  1S97,  VI. 


198 


FOODS. 


a,  fiber,  pectose,  fat,  etc. ;  6,  non-albuminoid  nitro- 
genous matter:  c,  albuminoid  nitrogenous  matter; 
d,  mineral  matter.  The  hatched  portion  represents 
the  loss.    (After  Snyder.) 


has  been  determined  by  H.  Snyder  *  as  follows  :  Skins  removed,  soaked 
3  hours  :  total  nitrogen,  46  per  cent. ;  ash,  45.6  per  cent.  Skius  re- 
movetl,  not  soaked  :  total  nitrogen,  16.9  per  cent. ;  ash,  17.9  per  cent. 

Skins  not  removed  :  total  ni- 
FiG.  7.  trogen,  1  per  cent. ;  ash,  3.4 

per  cent. 

The  composition  of  the 
potato  and  the  loss  of  nutri- 
ents when  boiled  with  the 
skin  removed  are  shown  by 
Snyder  by  a  drawing,  which 
is  here  reproduced.  (See 
Fig.  7.) 

Potatoes  are  so  deficient  in 
nitrogen  that  alone  they  do 
not   constitute   a  proper  ra- 
tion, but  with  foods  rich  in  proteids,   such  as  meats,  beans,  or  peas, 
they  are  valuable  and   economical. 

The  juice  of  the  potato  contains  citric  acid  and  citrates  of  potassium, 
sodium,  and  calcium,  which  fact  accounts  for  the  antiscorbutic  value  of 
this  vegetable. 

Attention  has  often  been  called  to  the  fact  that  the  potato  belongs  to 
a  poisonous  botanical  family,  which  mcludes  belladonna,  stramonium, 
hyoscyamus,  and  tobacco,  all  jDowerful  narcotic  plants ;  and  it  has  been 
pointed  out  as  a  paradox  that  this  valuable  food  possesses  no  poisonous 
properties.  This,  however,  is  not  true,  for  the  potato  has  been  the  fre- 
quent cause  of  more  or  less  extensive  outbreaks  of  poisoning,  and  it 
has  long  been  known  that  the  normal  potato  contains  about  .006  j)er 
cent,  of  solanin,  and  that,  when  sprouting,  the  solanin  content  is  ma- 
terially increased.  Between  1892  and  1898,  many  outbreaks  of  poison- 
ing occurred  in  the  15th  (German)  Army  Corps,  which  were  traced  by 
Schmiedeberg  and  Meyer  ^  to  solanin  in  sprouting  or  completely  ripe 
potatoes.  Schmiedeberg's  assertion  that  solanin  formation  in  potatoes 
is  caused  by  bacteria  has  been  proved  by  R.  Weil,^  who  demonstrated 
that  at  least  two  organisms.  Bacterium  solaiiiferum  non-colorabile 
and  Bacterium  solaniferum  colorabile,  have  the  property  of  producing 
solanin  from  substances  normally  present. 

A  noteworthy  instance  of  potato-poisoning  is  that  recorded  by  Pfuhl.* 
Fifty-six  soldiers  of  a  company  of  the  German  Army  were  seized  with 
symptoms  of  acute  gastro-enteritis.  The  sickness  began  with  chills, 
fever,  headache,  colic,  vomiting,  and  diarrhoea.  In  a  number  of  cases 
there  was  collapse,  with  more  or  less  jaundice.  None  of  the  cases  ended 
fatally,  nor  were  there  any  relapses  or  sequelae.  Investigation  showed 
that  the  men  had  eaten  sprouting  potatoes,  a  sample  of  which  yielded 
.038  per  cent,  of  solanin,  and  that,  therefore,  those  who  had  eaten  their 

^  Department  of  Agriculture,  Office  of  Experiment  Stations,  Bulletin  No.  43,  1897. 
"^  Archiv  fiir  experimentelle  Pathologie  und  Phairaakologie,  1895. 
'  Archiv  fiir  Hygiene,  XXXVIII.  (1900),  p.  330. 
*  Deutsche  medicinische  Wochenschrift,  1899,  p.  753. 


HOOTS. 


vy.) 


full  porlioi)  of  llu;  vc^ctjihlc  IijkI  iiijjcslcd  jilxtiit  0.?,  {rnirn  of  the  poi-on, 
a  (|iiiiiiti(<y  wlii(;li  iiiiiy  easily  iii<liicc  serious  syrii|iloiiis, 

SWEET  POTATOES. 

'I'lie  aver:i|,fe  (^oinposilioii  of  Hwect  |)otiito(;H  (liO  anulyHcn)  Ih  given  hy 
Aiwaf.(!r  aii<l  I>ryaiil  as  follows  : 

Moiwlun^  09.0 

rrotci.ls l.« 

Fill 0.7 

Total  carbohydratoH 27.4 

Asli 1.1 

100.0 

Starch  constiiutos    mueli   the  f^reatcr  part  of  the   earhoiiyd rates ;    tho 
remainder  is  mainly  sn<z;ar. 

ARTICHOKES. 
The  Jerusalem  artichoke  is  so  named,  not  after  the  eity  of  Jenisa- 
lem,  but  from  a  (•()rru])tion  of  the  Italian  word  f/lra.so/c,  mejining  sun- 
flower, to  which  family  the  plant  belongs.      This  tuber  is  quite  .sweet 
to  the  tnstc,  but  it  is  not  so  agreeable  as  the  potato.  j,'jf;_  g 

It  contains  no  starch,  but  yields  about  15  per  cent, 
of  sugar.  It  is  about  twice  as  rich  in  ]iroteids  as  the 
potato.     Wheu  cooked,  it  becomes  soft  and  watery. 

ROOTS. 
The  carrot,  beet,  parsnip,  turnip,  oyster  plant,  and 
radish  agree  in  a  general  way  in  composition,  and 
may  be  considered  together.  They  are  very  poor 
in  proteids,  and  contain  but  a  small  amount  of  other 
nutrients.  All  of  them  are  valuable  on  account  of 
their  antiscorbutic  properties,  for  providing  variety 
in  the  diet,  and  for  flavoring  other  foods.  Their 
average  composition,  according  to  Atwater  and 
Bryaut,  is  set  forth  in  the  following  table  : 


Carbo- 

No. of 
analyses. 

Water. 

Proteids. 

Fat. 

hydrates 
includ- 
ing fiber. 

Ash. 

Beets     .    .    . 

24 

87.5 

1.6 

0.1 

9.7 

1.1 

Carrots .    .    . 

18 

88.2 

1.1 

0.4 

9.3 

1.0 

Ovster  plant  ^ 

1 

80.4 

1.0 

0.5 

17.1 

1.0 

Parsnips   .    . 

3 

S3.0 

1.6 

0.5 

13.5 

1.4 

Radishes  .    . 

4 

91.8 

1.3 

0.1 

5.8 

1.0 

Turnips    .    . 

19 

89.6 

1.3 

0.2 

8.1 

0.8 

a,  fiber,  starch,  fat, 
etc. :  6.  sugar :  c,  non- 
albuminoid  nitrogenous 
matter ;  d.  albuminoid 
nitrogenous  matter:   e. 

Snyder  represents  diagrammatically  the  compo-  ^u°l[ed  ^nion  repre- 
sition  of  the  carrot  and  "the  loss  of  nutrients  when  d1um-Viledpiecerw™re 
boiled.  (See  Fig.  8.)  On  account  of  the  general  re-  boiled.  (After  snyder.) 
semblance  in  composition,  this  diagram  may  be  taken  fairly  to  represent 
the  whole  group. 

'  The  figures  for  oyster  plant  are  taken  from  Konig. 


200 


FOODS. 


6.  Herbaceous  Articles. 

These  incliKle  various  leaves,  .stems,  and  shoots.  They  contain  but 
little  nutriment,  but  are  valuable  for  their  salts,  and  for  the  variety 
whicli  they  give  to  the  diet.  It  is  to  be  noted,  however,  that  in  pro- 
teids  they  are,  as  a  class,  equal  or  superior  to  the  tubers  and  roots. 
They  contain  unimportant  amounts  of  fat  and  sugar.  The  cabbage  and 
allied  plants  are  not  easily  digested,  and  on  account  of  containing 
more  or  less  sulphur,  may  give  rise  to  disagreeable  flatulence,  and  are 
not  suited  to  weak  digestions.  Spinach  is  regarded  as  slightly  laxative. 
Celery  is  not  easily  digested  in  the  raw  state,  but  is  easily  borne  when 
stewed.  Lettuce,  cresses,  and  similar  articles  for  salads  are  wholesome 
and  digestible.  Asparagus,  while  containing  but  little  nutriment,  is 
prized  particularly  for  its  delicate  flavor.  Onions  and  leeks,  being 
modified  stems,  belong  in  this  group.  They  contain  volatile  oils  which 
act  as  gentle  stimulants. 

The  following  table,  compiled  from  Atwater  and  Bryant,  gives  the 
composition  of  the  members  of  this  group  : 


Asparagus 
Cabbage  . 
Cauliflower 
Sprouts  .  . 
Celery  .  . 
Lettuce  .  . 
Spinach  . 
Beet  tops  . 
Dandelions 
Leeks  .  . 
Onions   .    . 


No.  of 
analyses 


3 
16 
2 
1 
5 
8 
3 
1 
1 
1 
15 


Water. 


91.6 
91.5 
92.3 
88.2 
94.5 
94.7 
92.3 
89.5 
81.4 
91.8 
87.6 


Proteids. 


2.1 
1.6 
1.8 
4.7 
1.1 
1.2 
2.1 
2.2 
2.4 
1.2 
1.6 


Fat. 


3.3 
0.3 
0.5 
1.1 
0.1 
0.3 
0.3 
3.4 
1.0 
0.5 
0.3 


Total 
carbo- 
hydrates. 


2.2 
5.6 
4.7 
4.3 
3.3 
2.9 
3.2 
3.2 
10.6 
6.8 
9.9 


Ash. 


0.8 
1.0 
0.7 
1.7 
1.0 
0.9 
2.1 
1.7 
4.6 
0.7 
0.6 


Fig.  9. 


a,  starch,  sugar,  fiber,  fat,  etc. ;  5, non-albuminoid  nitrogenous  matter;  e,  albuminoid  nitrogen- 
ous matter;  d,  mineral  matter.    The  hatched  portion  represents  the  loss.    (After  Snyder.) 

The   composition    of  the    cabbage  and    the    loss   incuiTcd    through 
boiling    are  shown  in  the  accompanying  figure  (Fig.  9),  by  Snyder. 


AI'I'I.ES.  201 

in  a    ^(!iicr;il    w;iy    it    Mi;i,y    I)(t    Mcccplcd    ;ih    rcproHentin^    \\u'.    f;ntiro 

7.  Fruit  Products  Used  as  Vegetables. 

ThcHC  iii(;lii(lc  (Ji(!  loiiiiito,  ciiciiiiihcr,  .s(|ii;i.sli,  |)iim|)l<iii,  c^'^-plant, 
luid  vej^ctiihle  nuirrovv.  Tlic  Inuitiln  is  coiiHimu!*!  liirf^ctly  in  th(;  raw 
state  UH  a  saliul,  and  in  scvcrMi  (-(xtkcd  forms.  Jt  contains  1(;sh  than 
G  per  cent,  of  solid  n)att(!r,  and  in  tins  respect  lia.s  about  the  same 
nutritive  vahie  as  celery  and  lettuce.  Its  chief  solid  n]att<'r  is  snj^ar. 
Its  mineral  (sonstitnents  an;  free  from  earthy  salts.  The  cMcuniher  in 
the  raw  state,  in  wlii(^h  condilion  it  is  ejiten  most  commonly,  is  not  easy 
of  dij2;estion  ;  hut  \\\w.\\  st(!\vcd,  is  li<i:ht,  wholesome,  and  aj^-n^eable.  As 
a  nutrim<Mit  it  stands  even  lower  than  the  pn^ccdin^^,  wmtaininjij  less 
than  5  per  cent,  of  solid  matter.  The  .s(ja(v<h,  pumplcin,  ver/dahle 
marrorr,  and  egg-plant  have  about  equal  nutritive  value.  They  wjn- 
taiu  about  90  per  cent,  of  water,  are  very  poor  in  proteid.s — less  than 
1  per  cent. — but  are  fairly  rich  in  carbohydrates. 

8.  Fruits. 

As  stated  above,  the  word  fruits  is  used  here  in  its  narrower  sense 
to  designate  those  ])roducts  which,  being  of  an  agreeai)le  tiiste  in  the 
raw  state,  are  suital)le  for  use  as  a  dessert.  The  agreeable  taste  depends 
upon  the  relative  proportions  of  pectin,  sugar,  gum,  acids,  and  other 
constituents.  Some  fruits  with  but  a  small  percentage  of  sugar  and 
considerable  acid  have  a  sweeter  taste  than  others  richer  in  sugar  and 
with  no  more  acid,  because  of  the  masking  of  the  free  acid  by  the  gum 
and  pectin.  Thus,  the  peach,  for  instance,  is  comparatively  poor  in 
sugar,  but  its  content  of  acid  is  prevented  from  being  prominent  by  the 
large  content  of  gum  and  pectin.  Some  fruits  contain  usually  but  little 
of  these  constituents. 

Fruits  contain  but  little  proteid  matter,  and  tlieir  chief  food  value 
lies  in  the  sugar,  salts,  and  vegetable  acids  which  they  contain.  Eaten 
in  moderation,  they  exert  a  favorable  influence  on  the  system,  but  when 
taken  in  undue  proportion  to  other  foods,  and  especially  in  unnpe  or 
too  ripe  states,  may  cause  digestive  derangements.  On  account  of 
their  richness  in  vegetable  acids  and  their  salts,  which  in  the  system 
are  decomposed  and  converted  to  carbonates,  they  tend  to  diminish  the 
acidity  of  the  urine. 

APPLES. 

In  the  raw  state,  apples  are  not  very  easy  of  digestion,  but  when 
cooked  they  are  much  more  so,  and  when  baked  are  reputed  to  be 
slightly  laxative  and,  therefore,  useful  in  habitual  constipation,  but  not 
suitable  in  the  reverse  condition.  From  the  many  analyses  which  have 
been  compiled  by  various  authorities,  it  may  be  stated  that  this  fi'uit 
contains  about  85  per  cent,  of  water,  7.5  per  cent,  of  sugar,  1  of  malic 


202 


FOODS. 


acid,  0.4  of  ash,  besides  variable  amounts  of  pectin,  peetose,  fiber,  and 
other  matters. 

PEAKS. 

Pears  are  somewhat  richer  thau  apples  iu  sugar  aud  poorer  iu  malic 
acid.     They  are  fairly  rich  in  pectin. 

PEACHES. 

In  this  fruit,  the  sugar  is  comparatively  low,  but  the  pectous  matter 
is  exceptionally  high  and  covers  the  acidity.  Peaches  contain  nearly 
1  per  cent,  of  malic  acid. 

APRICOTS. 

The  sugar  content  of  apricots  is  about  equal  to  that  of  peaches. 
The  pectous  matter  is  also  about  the  same  in  amount,  but  the  acidity 
is  higher. 

PLUMS. 

Plums  contain,  as  a  rule,  less  sugar  and  pectin  and  more  malic  acid 
than  are  found  in  peaches  and  apricots.  They  are  much  more  likely 
than  most  other  fruits  to  disagree  and  produce  derangement  of  digestion. 

CHERRIES. 

Cherries  are  notable  for  their  large  content  of  sugar,  over  10  per 
cent.,  surpassing  in  this  respect  all  of  the  foregoing.  They  contain 
somewhat  less  than  1  per  cent,  of  malic  acid  and  are  low  in  pectin. 
The  popular  idea  that,  even  in  ripe,  sound  condition,  they  are  a  danger- 
ous article  of  food  if  eaten  in  conjunction  with  milk,  has  no  foundation 
in  fact ;  but  wdien  unripe  or  unsound,  they  have  a  tendency  to  cause 
disorder  of  the  bowels. 

The  average  composition  of  the  foregoing  fruits  is  shown  in  the  fol- 
lowing table,  compiled  from  Konig  : 


Water. 

Sugar. 

Acid. 

Proteids. 

Pectin,  etc. 

Fiber. 

Ash. 

Apples 

83.79 

7.22 

0.82 

0.36 

5.81 

1.51 

0.49' 

Pears 

83.03 

8.26 

0.20 

0.36 

3.54 

4.30 

0.31 

Peaches  

80.03 

4.48 

0.92 

0.G5 

7.17 

6.06 

0.69 

Apricots 

81.22 

4.69 

1.16 

0.49 

6.35 

5.27 

0.82 

Plums 

84.86 

3.56 

1.50 

0.40 

4.68 

4.34 

0.66 

Cherries 

79.82 

10.24 

0.91 

0.67 

1.56 

6.07 

0.73 

ORANGES. 

The  orange  contains  nearly  2.5  per  cent,  of  citric  acid  and  about  4.5 
of  sugar.  The  juice  is  particularly  agreeable  in  almost  any  condition 
of  health  or  sickness,  and  is  extremely  unlikely  to  cause  any  disturbance 
of  the  system. 


'I'lic  ;iv(!r;if^n  (!()m|)()sif ion  oC  oruri^OH  (2.'}  unulyHCHj,  iicfonlin;/  fo 
Atwater  and    liryaiil-,   is  jis   IoIIowh  : 

WjiUt ^'-^ 

I'n.U.i.ls "•« 

K^it "-ii 

Total  (::ii'l)()liy(lnilcM,  iiii-liidm;,'  lilicr 11.0 

Aah "••'» 

GRAPES. 

The  jiiicy  jmlp  of  llic  grape  is  wIioIcsoiik!  and  rofri}^<!rant,  and  when 
eaten  in  l:iro(!  nniounts  exerts  a  j^enth;  laxative  aetion.  Since  the  num- 
ber of  varieties  rea(!hes  into  the  thousands,  it  follows  that  widr-  varia- 
tion in  eomposition  must  oecur. 

Twelve  analyses  compiled  by  Konig  yield  the  following  averages  : 

Water 78.17 

Sugar       H:^« 

Free  acid "•'•^ 

Proteids f'p' 

Pectous  matter 1  ■■•^> 

Fiber ''>-^'^^ 

Ash _Jh^ 

100.00 

Five  analyses  compiled  by  Atwater  and  Brjant  yield  averages  which 
are  expressed  somewhat  differently,  as  follows  : 

Water 77.4 

Proteids 1-3 

Fat ^ 1.6 

Total  carbohydrates,  including  fiber 19.2 

Ash 0.5 

100.0 

When  dried  in  the  sun  or  in  ovens,  the  product  is  raisins.  Those 
dried  in  the  sun  are  the  better.  Raisins  are  less  digestible  than  grajies, 
and  are  not  infrequently  the  cause  of  derangement  of  the  intestinal 
canal. 

What  are  known  commonly  as  dried  ciHTants  are  raisins  made  from 
small  seedless  grapes.  They  come  from  the  Levant,  and  are  shipped 
from  Corinth,  whence  their  name  in  a  corrupted  form.  They  are  ex- 
ceedingly indigestible,  and  are  likely  to  traverse  the  entire  digestive  tract 
without  undergoing  change. 

MELONS. 

The  edible  portion  of  melons  is  very  watery,  but  the  small  amount 
of  nutriment  contained  is  not  nnlikely  to  cause  in  many  pereons  di- 
gestive disturbances  accompanied  by  annoying  eructations.  Not  many 
analyses  have  been  recorded.  Storer,^  quoted  by  Konig,  has  reported 
three  analyses,  which  give  the  following  averages  : 

^  Report  of  Connecticut  Experiment  Station,  1S79,  p.  159. 


204 


FOODS. 


Water 88.09 

Proteids 0.92 

Fat 0.18 

Sugar,  etc 9.05 

Fiber 1.04 

Ash 0.72 

100.00 

Two  analy.ses  of  watermelons  noted  by  Atwater  and  Bryant  give  the 
following  averages  : 

Water 92.4 

Proteids 0.4 

Fat 0.2 

Total  carbohydiutes,  including  fiber 6.7 

Ash •    •    .    .    .    . 03 

100.0 

BANANAS. 

Bananas  and  plantains  are  among  the  most  nutritious  of  fruits ;  in 
many  parts  of  the  tropics,  they  constitute  the  chief  food  of  those  who 
are  too  lazy  to  perform  any  kind  of  manual  labor.  The  edible  part 
yields  about  20  per  cent,  of  sugar  (cane  and  invert),  about  2  of  pro- 
teids, 0.5  of  starch,  and  rather  more  of  fat. 

FIGS. 

The  fig  in  the  fresh  state  is  about  equal  to  the  banana  in  nutritive 
properties.  In  both  the  fresh  and  dried  forms,  it  is  esteemed  highly  as 
a  mild  laxative.  The  dried  fig  contains  about  30  per  cent,  of  water, 
50  of  sugar,  4  of  proteids,  and  3  of  ash  ;  the  remainder  is  chiefly  seeds 
and  fiber. 

BERRIES. 

The  various  berries  are  notable  for  their  content  of  free  acids  and 
sugar.  Two  kinds,  the  cranberry  and  the  barberry,  are  too  sour  to  be 
eaten  raw,  and  must  be  cooked  with  sugar  in  order  to  be  made  palata- 
ble. The  composition  of  the  several  members  of  this  group  is  set  forth 
in  the  following  table,  compiled  from  Konig  : 


Water. 

Sugar. 

Free 
acid. 

Proteids. 

Fiber, 
pectin,  etc. 

Ash. 

Blackberries 

Cranberries 

Currants 

Gooseberries 

86.41 
89.59 
84.77 
85.74 
78.36 
84.71 
85.74 
87.66 

4.44 
1.53 
6.38 
7.03 
5.02 
9.19 
3.86 
6.28 

1.19 
2.34 
2.15 
1.42 
1.66 
1.86 
1.42 
0.93 

0.51 
0.12 
0.51 
0.47 
0.78 
0.36 
0.40 
1.07 

6.97 
6.27 
5.47 
4.92 
13.16 
3.22 
8.10 
3.25 

0.48 
0.15 
0.72 
0.42 
1.02 

Mulberries 

0.66 
0.48 

Strawberries 

0.81 

CANK  sua  An.  200 

9.  Edible   Fungi. 
MUSHROOMS. 

Mush  rooms  nrc  rc|)iilc(l  to  he  cxlrcriicly  ridi  in  nilro^'-cii  and  other 
niitricnls,  :in<l  ;i('(!or{|inn;|y  [\\{;y  ;\vv  iccunitncndfd  ii-  ;i  \;ihi;il»lc  WxA 
material.  It  is  true  tliat  they  arc  soincwhut  J'ich  in  nitro^r-n,  but  it 
should  be  said  that  a  krfjjc  |)ro|)orti<in  (.f  thw  element  pre.scnt  Ih  in  oom- 
biuatious  (ainido  coMiixtuiids)  which  are  useless  as  food.  As  a  niattf^r 
of  fact,  the  total  solid  matter  of  mushrooms  av(!ra|;es  about  12  ]u:r  cent., 
and  is  kirf^ely  woody  matter.  Mushi-ooms  are  rather  diflicult  of  dij^eH- 
tiou,  and  arc  not  at  all  adaptcid  to  wmk  stomachs,  'i'hcy  have  been 
called  "  the  poor  man's  nuiat,"  and  much  has  becin  done  to  ena>urage 
th('  poor  to  seek  for  them  in  tlu!  (ields  and  woods,  in  ord(;r  to  add  to  the 
larder.  Inasmuch  as  th(!  market  ])rie(!  of  mushrooms  for  the  Uibles  of 
the  rich  is  generally  high,  and  since  their  food  value  is  de(;idedly  over- 
rated, it  would  ap|)ear  that,  where  there  is  a  market  for  them,  the  f)oor 
can  do  much  better  for  their  nutrition  by  disposing  of  their  findings 
and  converting  the  proceeds  into  chea[)er,  more  digestible,  more  nutri- 
tious, and  less  cloying  articles  of  food. 

Truffles  contain  more  nitrogen  than  is  found  in  mushrooms,  but  they 
arc  very  nuich  more  woody,  and  can  hardly  be  looked  upon  a.s  valuable 
from  the  point  of  view  of  nutrition. 

10.  Saccharine  Preparations. 

Sugar  was  known  to  the  ancient  Greeks  and  Romans,  and  its  manu- 
flicture  has  been  conducted  by  the  Chinese  since  the  earliest  times.  It 
is  very  sohible  and  diifusible,  and,  therefore,  is  digested  easily.  Dex- 
trose is  ready  for  assimilation,  but  sucrose,  maltose,  and  lactose  must 
undergo  first  a  splitting  process  within  the  digestive  tract. 

CANE    SUGAR. 

United  States  Standard. — Standard  sugar  is  white  sugar  contain- 
ing at  least  99.5  per  cent,  of  sucrose. 

Cane  sugar  is  obtained  from  the  sugar  cane,  sugar  beet,  sorghum, 
and  sugar  maple.  It  is  very  soluble  in  water,  but  quite  insoluble  in 
absolute  alcohol.  Heated  with  dilute  mineral  acids  or  with  citric  acid, 
it  splits  into  dextrose  and  la^vulose,  and  then  is  known  as  invert  sugar 
from  the  fact  that  the  polarization  becomes  inverted.  Cane  sugar 
rotates  the  plane  of  polarized  light  to  the  right ;  the  two  substances 
into  which  it  is  split,  dextrose  and  Irevulose,  rotate  respectively  to  the 
right  and  left,  but  the  action  of  l;i?vulose  is  so  much  the  stronger  that 
the  mixture  gives  left  polarization. 

Heated  above  180°  C,  sugar  yields  caramel,  which  is  not  a  simple 
substance,  but  a  complex  mixture  of  brown  products  of  dehydration. 
It  is  used  as  a  coloring  for  low-grade  milk  and  other  articles  of  food, 
and  somewhat  as  a  flavoring. 

Cane  sugar  is  sold  in  various  forms  :  cut  or  loaf  sugar,  granulated, 
and  powdered.    The  cheaper  grades,  known  from  their  color  as  "  brown 


206  FOODS. 

sugars,"  contain  variable  amounts  of  invert  sugar,  gummy  matters, 
and  other  impurities. 

Sugar  is  not  much  subject  to  adulteration,  though  there  is  a  popular 
idea  tliat  glucose  and  sand  arc  common  admixtures.  It  is  })robable 
that  sand  is  as  rare  an  adulterant  of  sugar  as  ciialk  is  of  milk.  Glu- 
cose rarely  is  mixed  with  sugar,  but  is  used  considerably  as  a  sub- 
stitute tor  it  in  the  manufacture  of  cheap  jellies,  jams,  and  candies. 
Sugars  that  are  somewhat  "  oflP  color  "  are  treated  sometimes  with  ultra- 
marine in  the  tinal  processes  of  manufacture.  This  corrects  the  fault 
and  makes  the  product  white.  Occasionally,  the  amount  added  is  suffi- 
cient to  cause  great  alarm  in  the  household  when  large  quantities  of 
sugar  are  made  into  syrup  with  hot  water  in  the  prejiaration  of  preserves 
and  jellies.  The  blue  material  comes  to  the  surface  as  a  scum,  and  its 
unlooked-for  appearance  gives  rise  to  suspicion  of  poison. 

MAPLE  SUGAR. 

United  States  Standards  for  Maple  Products. — Maple  sugar  is  the 
solid  product  resulting  from  the  evaporation  of  maple  sap,  and  contains  in 
the  water-free  substance  not  less  than  0.65  per  cent,  of  maple  sugar  ash. 

Maple  syrup  is  syrup  made  by  the  evaporation  of  maple  sap  or  by 
the  solution  of  maple  concrete,  and  contains  not  more  than  32  per  cent, 
of  water  and  not  less  than  0.45  per  cent,  of  maple  syrup  ash. 

This  form  of  cane  sugar  is  prized  highly  for  its  agreeable  flavor.  It 
is  a  much  more  expensive  article  than  ordinary  sugar  and  is  used  more 
as  a  confection.  In  the  form  of  syrup,  it  is  used  very  extensively  on 
buckwheat  cakes  and  with  other  cereal  breakfast  foods.  It  is  much 
subject  to  adulteration  and  substitution.  A  large  part  of  the  syrup  in 
the  market  is  wholly  artificial,  being  made  of  ordinary  sugar  or  glu- 
cose, appropriately  colored,  and  correctly  flavored  by  means  of  extract 
of  hickory  bark.  The  sugar  itself  is  imitated  in  the  same  way,  but  one 
not  infrequently  sees  specimens  which  are  absolutely  devoid  of  any  flavor 
save  that  of  brown  sugar.  The  substitution  by  flavored  cane  sugar  is 
easily  proved  by  determining  the  amount  of  precipitate  of  lead  malate 
yielded  by  5  grammes  of  the  suspected  sample  in  10  c.c.  of  water  on 
the  addition  of  basic  lead  acetate  solution.  Five  grammes  of  pure 
maple  sugar  so  treated  should  yield,  after  centrifugation,  2.5  c.c.  of 
precipitate,  while  pure  cane  sugar  yields  none.  The  presence  of  glucose 
is  revealed  by  the  behavior  of  the  specimen  under  polariscopic  analysis. 

GLUCOSE.      DEXTROSE. 

Dextrose,  or  grape  sugar,  is  inferior  in  sweetening  power  to  cane 
sugar,  and  is  not  crystallizable  to  the  same  extent.  It  is  much  less 
soluble  in  water,  but  is  soluble  in  glycerin  and  in  alcohol  of  ordinary 
strength.  It  is  found  in  grapes  and  in  many  other  fruits  and  vege- 
tables, but  always  associated  with  Isevidose.  By  fermentation  with 
yeast,  it  splits  into  carbonic  acid  and  alcohol ;  in  the  presence  of  fer- 
ments which  disorganize  proteids,  it  yields  lactic  acid.  It  exerts  a 
strong  reducing  power  on  Fehling's  solution. 


MOLASSKS.  207 

0()inrru!r(;i;i,l  jrlu(!o.s('  i.s  ()l)f,;iiii('(l  liy  lifatinj;  nfrin-li,  usually  (^)ni- 
Htiiroli,  with  (liiislasc,  or  (liliil.c  siilpliiiric  acid.  JicCon;  flic  final  pn^awK 
of  coiicoiitration  oC  iJic  soliilioii,  I  lie  aci<l  Ih  iiciitruli/cd  cornpKlrly  ijy 
the  application  of  iiiarl)l(!  diisl,  and  the  re.sultirif^  Hiiiphate  of  calcium 
and  the  exc(!SH  of  the  neutralizing^  a^(!nt  an;  rctnovcd.  The  })roduct 
ulway.s  contains  considcrahlc  jn'oportions  of  nialto-c  and  dextrin,  and  itH 
rotatory  |)<)W('r  is,  therefore,  nuich  \ryvn\v,r  than  that  of  pure  gluf;<;He, 
such  as   is  ohIainaMe   IVoni   diabetic  urine. 

Glucose  is  produced  in  enormous  ([uantitics  both  in  the  solid  form 
and  as  a  thick  colorless  syru]).  It  is  used  in  tint  manufactun;  of  cheaj) 
candies,  jams,  and  |)reserves,  in  the  bi'ewinj^  of  heer,  and  as  an  adul- 
terant of  molasses  and  honey  (see  imder  l>eer). 

MOLASSES. 

United  States  Standard. — Standard  molasses  contains  not  les.s 
than  25  per  cent,  of  water  nor  more  than  5  per  cent,  of  asli. 

Molasses  is  a  thick,  viscid,  dark-coloretl  liquid,  which  drains  away  in 
the  process  of  the  manufacture  of  su<^ar.  It  (;oiitains  from  fjo  to  72 
per  cent,  of  su^ar,  part  of  which  is  sucrose  and  j)art  fruit  sugar,  vari- 
ous salts,  gummy  matters,  extractives,  and  water.  It  is  graded 
according  to  color  from  the  cheapest,  almost  black  article  known  as 
"black  strap,"  to  tlie  finest,  which  is  light  yellowish  brown.  When 
refined,  it  is  brilliant  and  transparent,  and  is  known  as  syrup. 

All  grades,  but  especially  the  higher,  are  adulterated  extensively 
with  glucose  syrup.  This  reduces  the  sweetening  power,  but  gives 
body  and  a  finer  appearance.  The  fraud  is  detected  readily  by  the 
use  of  the  polariscopc,  since  the  adulterated  article  gives  a  much 
higher  reading,  and  on  inversion,  instead  of  giving  left  polarization, 
continues  to  give  a  reading  to  the  right  almost  as  high  as  before. 
Another,  and,  from  a  sanitary  point  of  view,  a  more  important  adul- 
terant of  molasses,  is  the  protochloride  of  tin,  known  also  as  "  tin 
crystal  "  and  "  salts  of  tin."  This  is  added  for  the  piu'pose  of  reducing 
the  amount  of  color,  thus  givmg  a  fictitious  added  value.  It  combines 
with  part  of  the  coloring  matters,  and  the  resulting  compound  separates 
and  tends  to  deposit.  Thus  a  large  proportion  of  the  amount  added 
to  a  hogshead  may  be  found  in  the  "  foot,"  or  sugar  sediment,  which  is 
used  quite  commonly  in  the  making  of  cheap  candies,  such  as  cocoanut 
taffy.  Only  a  part,  however,  is  deposited,  and  hence  a  s])ecimen  thus 
adulterated  will  yield  notable  traces  of  the  salt  on  incineration  and 
analysis.  It  is  useless  to  attempt  to  separate  the  tin  in  the  ordinary 
way  without  previous  incineration,  since  the  organic  matters  present 
prevent  precipitation  of  the  sulphide.  Inasmuch  as  the  protochloride 
of  tin  is  an  irritant  poison,  and  since  its  addition  can  serve  no  legiti- 
mate useful  purpose,  this  form  of  adulteration  should  be  prohibited  and 
punished.  Sometimes  tin  is  present  in  molasses,  not  as  an  adulterant, 
but  because  of  a  practice,  followed  by  some  makers  of  crude  sugar,  of 
treating  their  product  with  this  agent  to  improve  its  color  before  it  leaves 
the  centrifugal  machines,  and  thus  it  finds  its  way  into  the  by-product. 


208  FOODS. 

HONEY. 

Honey  is  classed  sometimes  as  an  animal  food,  since  it  is  a  product 
stored  up  liv  bees,  but  it  can  hardly  be  so  considered,  since  it  is  obtained 
from  the  nectaries  of  flowers,  although  during  its  storage  in  the  bee's 
crop  it  undergoes  some  change.  After  this  alteration  by  the  secretions 
of  the  crop,  it  is  disgorged  and  deposited  in  the  cell  of  the  honey-comb. 

Honey  is  a  concentrated  sohition  of  sugars,  chiefly  dextrose  and 
la?vulose,  with  small  amounts  of  sucrose  and  mannite,  containing  also 
small  amounts  of  wax,  organic  acids,  proteids,  mineral  matter,  pollen, 
and  odorous  and  other  principles.  The  flavor,  color,  and  odor  vary 
according  to  the  nature  of  the  flowers  from  which  the  honey  is  ol3tained. 
Sometimes,  when  derived  from  poisonous  plants,  it  has  toxic  prop- 
erties ;  this  fact  has  been  noted  by  both  ancient  and  modern  writers. 
Xenophon,  for  example,  has  recorded  most  serious  symptoms  of  intoxi- 
cation due  to  its  ingestion,  and  a  number  of  small  outbreaks  resembling 
ptomain-poisoning  have  been  reported  by  recent  writers  in  this  country. 
Xenophon  '  says  :  "  As  to  other  things  here,  there  Avas  nothing  at 
w^hich  they  were  surprised ;  but  the  number  of  beehives  was  extra- 
ordinary, and  all  of  the  soldiers  that  ate  of  the  combs  lost  their  senses, 
vomited,  and  w^ere  affected  with  purging,  and  not  one  of  them  was  able 
to  stand  upright ;  such  as  had  eaten  only  a  little  were  like  men  greatly 
intoxicated,  and  such  as  had  eaten  much  were  like  madmen,  and  some 
like  persons  at  the  point  of  death.  They  lay  upon  the  ground,  in  con- 
sequence, in  great  numbers,  as  if  there  had  been  a  defeat ;  and  there 
was  general  dejection.  The  next  day  not  one  of  them  was  found  dead  ; 
and  they  recovered  their  senses  about  the  same  hour  they  had  lost  them 
on  the  preceding  day ;  and  on  the  third  and  fourth  days  they  got  up  as 
if  after  having  taken  physic." 

Dioscorides  speaks  of  a  kind  of  honey  that  made  those  that  ate  it 
mad,  and  ascribes  its  poisonous  properties  to  the  great  abundance  of 
rose-laurel  and  other  similar  poisonous  plants.  Strabo  speaks  of  honey 
that  made  men  stupid  and  melancholy ;  and  Diodorus,  of  a  certain  kind 
in  Colchos  which  produced  such  profound  weakness  in  those  that  ate  it 
"  that  they  appeared  for  a  whole  day  together  like  dead  men." 

Honey  from  the  flowers  of  the  yellow  jasmine  has  been  known  to 
produce  serious  and  even  fatal  results,  and  that  derived  from  a  species 
of  rhododendron  growing  in  the  neighborhood  of  the  Black  Sea  has  long 
been  recognized  as  poisonous. 

The  pow^'er  of  honey  to  exert  a  medicinal  influence  is  sometimes 
turned  to  good  account.  Thus,  in  Abyssinia,  where  the  flowers  of  the 
cusso  tree  are  the  universal  remedy  for  tapeworm  and  ascarides,  with 
which  a  large  proportion  of  the  population  is  afflicted,  swarms  of  bees 
are  kept  by  order  of  King  Menelek  in  gardens  where  no  other  plant  is 
cultivated,  and  the  honey  which  they  store  has  been  found  to  have  all 
the  good  qualities  of  the  drug  with  none  of  its  unpalatability  or  un- 
pleasant effects,  such  as  nausea  and  vomiting. 

By    microscopic    examination,    which    will    show    numerous    pollen 

*  Anabasis,  Book  IV.,  Chap.  8. 


HONEY.  209 

(rriiins,  ow  v:\n  (Icicrrniiu'  rnsily  (Vom  \vli:il,  kind  nf  :i  flr)\vf:r  lioiKty  wuh 
giiLlierwI. 

Hon(!y  coiilaiiis  Jiboiil  7.'>  [xt  cciiI.  (i("  sii^rar.  In  ^■<m>^•^\\\n^^•('  of 
the  [)rc})«)M(lci';int  influ(ii(;t!  ui'  llic  l.'cvulosc  on  llic  I'olaf ion  lA'  tlic 
plane  of  |)(»l;iii/,((l  li^lil  (lie  poljiriscctpc  rending  of  a  pure  Harnple  is 
jiiniost  aJvvays  lo  llic  left  ;  wIkmi  not  to  the  left,  {\\v.  n-a«linj^  in  iK»t 
more  tlian  a,  few  (h^^iccs  to  llu;  li^iit.  'I'lie  pcrccnla^c  of  wjiter 
avenif^es  about  IH  or  19;  occasionally  .specimens  are  foimd  to  contain 
as  miH'li  as  25. 

llon(^y  is  an  impoilanl  sii<;ar  food  ;  it  is  very  ajri-ccaldf  to  flic  taste 
and  easily  assimilated.  On  aecoimt  of  its  (•(»m|)aratively  liij^di  jiriw, 
it  is  very  subject  to  adulteration  wilii  nlnccsc  mid  caiic  su^^ar.  That 
which  is  sold  in  the  comb,  the  comb  si  ill  in  its  frame,  is  almost  invari- 
ably }j^enuine.  The  extracted  honeys  sold  in  bottles  and  tumblers  are 
very  commonly  mixtures  of  the  frenuine  article  with  glucose  or  (^ne 
sugar,  and  often  contain  no  honey  whatever.  Jn  order  to  convey  the 
idea  of  genuineness,  it  is  a  common  })ractice  to  insert  a  small  piece  of 
comb.  At  least  one  ing(!ni()us  fabricator  of  glucose-honey  has  been 
known  to  add  to  each  tumbler  of  his  product  a  dciid  bee,  to  serve  as  a 
silent  false  witness  of  its  origin. 

The  detection  of  adulteration  with  glucose  or  cane  sugar  is  an  easy 
matter,  since  all  samples  so  made  give  a  strong  reiiding  to  the  right  on 
polariscopic  examination.  On  inversion  of  the  sample,  the  right- 
handed  reading  persists  if  the  adulterant  is  glucose,  and  is  changed  to 
the  left  if  cane  sugar.  It  is  said  that  inverted  cane  sugar  sometimes  is 
mixed  in  proper  proportion  to  make  an  artificial  honey  which  will  give 
the  normal  ]iolarisc(>pic  test  of  the  genuine  article  ;  and  that  to  imitate 
th(^  latter  still  fai'ther,  so  that  microscopical  examination  also  may 
attest  its  genuineness,  pollen  grains  are  added  in  sufficient  amounts. 
The  ash  of  such  a  product  alone  will  reveal  the  fraud,  smce  it  will 
contain  no  phosphoric  acid,  while  genuine  honey  contains  about  0.03 
per  cent,  of  that  substance. 

CONFECTIONERY. 

Candies  are  preparations  made  of  sugars  or  substances  containing 
them,  such  as  molasses  and  honey,  with  or  without  the  admixture  of 
other  food  materials,  such  as  nuts,  fruits,  and  chocolate,  starches  and 
fats  to  give  body  and  consistence,  and  flavoring  and  coloring  agents. 
The  addition  of  substances  which  serve  no  legitimate  useful  pui-pose, 
such  as  terra  alba,  which  is  said  to  be  added  sometimes  to  lend  weight, 
and  of  injurious  colors  and  flavors,  may  properly  be  regarded  as 
adulteration  ;  but  the  use  of  glucose  sugar,  cocoa  butter,  and  other 
substances  of  a  harmless  nature,  and  possessing  value  as  nutriment, 
cannot  be  so  regarded.  ]Many,  some  say  most,  of  the  cheaper  candies, 
contain  variable  amounts  of  glucose  and  starch,  but  nothing  is  to  be 
said  against  the  use  of  these  substances  on  the  score  of  wholesomeness. 
The  use  of  terra  alba  is  supposed  popularly  to  be  very  common,  but 
numerous  analvses  bv  manv  chemists  throughout  the  country  show 
14  ■  *  ' 


210  FOODS. 

that  this  substance  is  an  exceedingly  unconiinon  ingredient  of  even  the 
very  cheapest  candies. 

The  riavoring  agents  commonly  employed  are,  as  a  rule,  harmless. 
The  colors  used,  however,  are  not  inlVequontly  of  a  ])()ist)n()us  nature, 
especially  in  those  States  which  have  no  laws  against  food  adulteration, 
or  which,  having  them,  make  no  provision  for  their  enforcement.  These 
injurious  coloring  agents  include  the  chromates  of  potassium  and  lead, 
tin  lakes,  and  certain  of  the  coal-tar  products,  such  as  Martins  yellow, 
diuitrocresol,  and  diuitroso-resorcinol.  The  enij)loynK'nt  of  chronuite 
of  lead  and  of  chromate  of  potassium  is  frequently  denied,  but  these 
substances,  nevertheless,  are  used  not  uncomnionly,  and  have  been 
detected  bv  the  author  in  many  specimens  of  yellow  sugars  used  for 
decorating  cakes,  and  in  yellow  candies  made  in  the  shape  of  beans. 
The  majority  of  the  colors  used  are,  however,  of  a  harmless  nature. 

JELLIES  AND  JAMS. 

Jellies  are  semi-solid  glutinous  preparations  made  by  boiling  fruit 
juices  with  sugar  and  allowing  to  cool ;  jams  are  somewhat  similar 
preparations,  which  include  the  pnlp  of  the  fruit  as  well  as  the  juice. 

Many  of  the  jellies  found  in  the  shops  are  made  with  glucose  syrup, 
cane  sugar,  gelatin,  artificial  flavorings  and  colors,  and  extracts  made 
by  boiling  the  refuse  of  canning  establishments.  Jams,  likewise,  are 
largely  factitious,  being  made  with  glucose  syrup,  flavorings,  colorings, 
various  kinds  of  seeds,  and  nearly  tasteless  vegetable  tissues,  such  as 
summer  squash  and  boiled  white  turnips. 

Section  5.     BEVERAGES. 

Stimulant  Beverages  Containing  Alkaloids. 

These  include  tea,  coflfee,  and  cocoa,  and  certain  others  not  nsed  to 
any  large  extent  in  this  country.  The  alkoloids  of  these  products  are 
known,  res})ectively,  as  theine  and  caffeine,  which  are  chemically  iden- 
tical, and  theobromine,  which  is  very  closely  related. 

TEA. 

The  virtues  of  tea  were  discovered,  according  to  Chinese  tradition, 
more  than  2700  years  before  the  Christian  era.  It  was  used  first  in 
England  in  the  seventeenth  century  (about  1657),  and  came  there  into 
general  use  about  1675.      It  was  introduced  into  America  in  1731. 

Tea  is  the  dried  leaf  of  a  shrub.  Then  Chine)is!f<,  indigenous  to  China 
and  other  parts  of  Asia,  and  cultivated  in  India,  Japan,  and  Ceylon. 
Formerly,  the  varieties  of  the  plant  produced  by  different  methods  of 
long  cultivation  were  believed  to  be  distinct  species,  and  were  known 
as  T.  Jjohea,  T.  viridis,  etc.  The  differences  in  the  varieties  found  in 
commerce  depend  upon  the  age  of  the  leaves  when  gathered  and  their 
position  on  the  stem,  and  upon  special  methfxls  of  drying  and  preparing 
them  for  the  market.     The  choicest  varieties,  for  example,  are  those 


TEA.  211 

wliii'li  iiicliidc  only  ili<'  Ictiii  iiiiil  l(;i\c,-,  ;iinl  \\\i-  [HKirc-t  tlio-c  iii;i(|c  iiji 
(»("  IJk;  l;ifjj;(:sl,  uihI  coarscsL  l(•;lv<■^  Iroin  I  lie  lower  end  of  llic  Iwi;:. 

Titii  is  cliisscd  coiiiiiionly  ;is  ltccd  hv  liL'ick.  liolli  kinds  (tuiiH'  (roiri 
IJk^  siiiiic  slirni),  Liil  .irc  diirnciil  in  jioiiil  of  a;^<',  ami  ace  cured  in  dil- 
ler(Mi(j  ways.  ( J  iccn  tea  i.^  made  I'liiin  \(iiiii;_r  leave-,  wliieji  are  r<i;i-ted 
<jlii(!kly  hIioi'IIn'  al'ler  Ix-iii^i;  ^al  iieicfj,  ;ind  iImh  lulled  ;iiid  a^jiin  r'<i,i-te(|. 
Hlack  (ea,  is  l'\n\\\  older  leaves,  wliiili  ;ire  allowed  to  wilt,  and  llien  an; 
j»'alliei'e(l  into  heaps  and  leCl  witlioiil  l-niiier  niani|)nlation  for  al»ont  :i 
lialC  <lav,  dnrini;'  wliieli  lime  tlie\'  innlei'ijii  a  lernH  iit;ili\  e  prorcM.s  iind 
c-Iijuij^H!  color.  Next,  lliey  are  rolled  l»y  hand  and  then  licaU'd,  and 
tlui.so  [)nK'(\sses  nia\-  he  repeated  sexcriil  times  alternati'ly.  Finally, 
they  arc  dried  slowly  oxer  hiirninji;  charcoal. 

Tlu!  ('()ni|)osit  ion  of  lea  is  \-ery  variable,  ;ind  it  is  iinpo--ili|e  to  ;^ive 
fif>Mires  which  may  he  acci^pted  an  indicalinL:  ihe  appro.\imat<;  (;onstitii- 
tioii  of"  u  l.\pical  s|)<'cinien.  KTmii;-  has  collected  Hi  analyses,  which 
give  tli«  following:;  averau;es  : 

Moisluiv 11.49 

Nilr(.,nTii(ius  iiiiinors 21.22 

Tlu'ino l-^i'T 

Volatile  (lil 0.H7 

Fat,  rosin,  rtc ;i02 

(jfiim,  dextrin,  I'ti; T.Ki 

Tannin 12.W 

Otlicf  extractives Ifi.To 

Fil)er 20.:i0 

Asli All 

lUO.OO 
But  it  should  be  said  that  the  variations  in  tlie  anumnts  of  individual 
constituents  of  these  1<)  specimens  are  very  wide:  for  instance,  wat<'r, 
4.5!)  to  Ki.OH  ;  theine,  0.40  to  4.!)4  ;  tannin",  4.10  to  2().-S,S  ;  fil)er,  l-").!  1 
to  'io.Ot).  Draoendorti'  foniul,  in  2o  specimens,  from  1.^30  to  .3.01*  ]kt 
cent,  of  theine,  7.10  to  12.(jG  of  moisture,  and  from  24.80  to  44. oO 
per  cent,  of  total  soluble  constituents.  The  ash  of  pure  tea  is  fairly 
constant  in  amount,  and  almost  never  reache^s  as  high  as  7  per  cent.; 
usually,   between   5   and  (>   per  cent. 

Tea  shoidd  be  used  only  in  the  form  of  an  infusion,  made  by  |X)uring 
boiling  water  upon  the  requisite  amount  of  leaves,  and  allowing  it  to 
stand  a  short  while  to  "  draw."  It  is  used  not  uncommonly  in  the  form 
of  a  tlecoction  ;  that  is,  by  boiling.  This  process  is  objectionable  in  two 
ways:  first,  the  delicate  aroma  is  lost  by  the  expulsion  of  the  \ery 
volatile  essential  oil ;  and  second,  the  leaves  are  made  to  yield  all  their 
tannin  and  other  extractives,  which  tend  to  bring  about,  sooner  or 
later,  derangement  of  the  digestive  function  and  a  catarrhal  condition 
of  the  stomach.  The  finest  and  most  delicate  ]iortion  of  an  infusion 
is  that  which  is  poured  oflf  within  three  or  four  minutes,  for  in  this 
will  be  found  a  maximum  of  flavor  with  a  minimum  of  bitterness  and 
astringency.  The  excellence  of  an  infusion  is  influenced  considerably 
by  the  chai'acter  of  the  water,  which,  if  very  hard,  is  slow  in  exti-actiug 
the  desirable  soluble  constituents,  while,  if  very  soft,  it  extracts  not 
only  these,  but  far  too  mpidly  the  less  desirable  principles. 


212  FOODS. 

When  propi'rly  made,  tea  in  mtxleration  is  a  Avholesonie,  agreeable, 
and  refreshing  stimulant  beverage,  partieularly  grateful  in  eonditions 
of  mental  or  j)hysieal  weariness.  Used  in  exeess,  it  exerts  a  liarmful 
inlluenee  upon  the  uervous  system,  and  in  a  too  strong  form  injures  the 
digestive  traet  and  iunetion. 

The  abuse -of  tea  as  a  beverage  leads,  according  to  Bullard,^  to  ring- 
ing in  the  ears,  tremor,  uervousuess,  headache,  neuralgia,  hysteria, 
irregularity  of  the  heart,  dyspno'a,  dyspepsia,  and  consti[)atiou. 

Dr.  Hayes,  the  Arctic  explorer,  has  testified  to  the  value  of  tea  and 
coffee  in  enabling  men  to  endure  cold  and  hardship  of  all  sorts,  tea 
being  especially  soothing  at  the  end  of  a  hard  day's  work. 

^Miile  tea  by  itself  can  hardly  be  looked  upon  as  an  article  afford- 
ing any  important  amount  of  nutriment,  as  conunonly  consumed  it 
serves  as  a  vehicle  for  other  substances,  as  sugar,  milk,  and  cream, 
having  high  nutritive  value. 

Adulteration  of  Tea. — It  is  commonly  stated  and  generally  be- 
lieved that  tea  is  adulterated  extensively  with  other  kinds  of  leaves, 
including  those  of  the  beech,  sloe,  willow,  and  hawthorn  ;  but  at  the 
present  time,  it  is  extremely  improbable  that  such  adulterants  ever  are 
mixed  with  tea  known  to  be  intended  for  export  to  this  country. 
Whatever  the  conditions  may  have  been  prior  to  the  enactment  of  the 
national  law  governing  tea  importation,  the  fact  noAV  is  that  our  tea 
supply  is  practically  free  from  this  form  of  adulteration.  The  detec- 
tion of  spurious  tea  leaves  would  be  an  easy  matter,  since  the  genuine 
have  a  very  characteristic  appearance  which  can  hardly  be  confused 
\yii\i  that  of  any  of  the  possible  substitutes  ;  and  even  when  broken 
into  small  bits,  the  characteristic  differences  in  venation  and  serration, 
and  in  the  stomata  as  well,  are  plainly  discernible. 

More  probable  forms  of  adulteration  include  the  admixture  of 
wholly  or  partially  exhausted  leaves  ;  the  addition  of  astringent  mat- 
ters, such  as  catechu,  to  lend  color  and  apparent  strength  to  the  infusion  ; 
the  presence  of  foreign  mineral  matter ;  and   the  practice  of  "  facing." 

The  presence  of  any  large  proportion  of  exhausted  leaves  can  be 
detected  by  the  low  amount  of  total  soluble  extract  and  by  the  small 
amount  of  soluble  ash,  which  should  not  be  less  than  3  per  cent,  of  the 
weight  of  the  leaves.  The  presence  of  important  amounts  of  accidental 
or  added  mineral  matters  is  shown  in  the  total  ash,  which  in  a  genuine 
specimen  rarely  amounts  to  7  and  never  to  8  per  cent.  The  substances 
most  often  found  are  sand  and  soapstone  ;  the  first  named  is  found  some- 
times in  amounts  exceeding  25  per  cent. 

Catechu  is  applied  occasionally  to  exhausted  tea  leaves  with  the  aid 
of  solutions  of  gummy  matters,  for  the  purpose  of  adding  astringency 
and  color  to  the  infusion.  Teas  so  treated  have  but  little,  if  any,  of 
the  true  aroma,  and  their  infusions  yield  a  sediment  in  which  the  par- 
ticles of  catechu  can  readily  be  seen. 

The  object  of  "  facing "  is  to  make  the  product  appear  to  be  of 
greater  value,  and  the  practice  is,  therefore,  properly  speaking,  one 
which  comes  within  the  definition  of  fraudulent  adulteration.  Damaged 
1  Boston  Medical  and  Surgical  Journal,  April  8,  1886,  and  September  8,  1887. 


or  otliorwlno  Inrfirior  1<!!IV('S  ill-':  lic'iNil  wIlli  l*iir--i;iii  lilm-,  |iliiiiil);i^<), 
In(Iifi;(),  ii,n(l  otluir  ,siil)Hiiiiiccs,  ;iiiil  lli<-  -m.-ill  ;iiii<)iiiii  wlii-li  adlicnw  im- 
])n)V('H  (Jicir  dolor  und  ^'cncr;!!  ;i|i|ic;ii';iii<c.  'I  In-  mihhiiiiI  is  too  Kmall 
to  be  o("  ;uiy  Miiiiidiry  si^iiilicjiiicc.  Tlic  presence  of  liieinjr  materialH 
may  l>c  (IcIcciIxmI  hy  tlie  nso  of"  tin;  inicroscojx!  and  hy  clicniic^il  analyHlH. 

COFFEE. 

(\)ire(>  is  tlio  seeds  oCllie  ( 'nU'ca  Anthira,  dried  an<i  deprives]  of  tlieir 
Hcsliy  covt!rin<i;.  Tlie  (Viiil  is  a  small  |>"il|>y  hei-ry  e<»iil;iinin;r,  nsnally, 
two  seeds.  The  tree  is  said  to  liasc  oriLiinated  in  AhysHinia,  where, 
liowever,  in  tlu;  seventeenlli  ceiilnry  there  weic  few,  \['  any,  H[)ecimens, 
and  to  have  been  introdn(;('d  into  Arabia  in  the  lil'teenth  centnry.  It 
is  now  j>^rown  very  extensively  in  l>ra/.il,  -lava,  I'ern,  Ceylon,  West 
Indies,  and  other  hot  (;onntries.  'Hie  first  Kuropean  (o  mention  it  was 
Prosper  Alpinns,  of  Pachia,  who  inchided  il  in  ;in  neconnt  of"  K^ptian 
})lants,  pnblished  in  151)2.  'i'he  first  work  devoted  wholly  to  eoffce 
was  a  small  Latin  treatise,  he  sdhihcrrliiK/  potlniie  calnir,  by  Fanstus 
Nairo,  Rome,  1671.  Coflee  was  lirst  sold  in  I^ondon  by  a  Levantine, 
in  1650,  and  some  years  afterward  was  introduced  into  France.  The 
first  whole  cargo  introduced  into  this  country  arrived  in  1809,  but 
coffee  houses  were  licensed  in  Massachusetts  as  early  as  1715. 

The  world's  jn-oduction  of  eolfee  for  the  year  ended  June  30,  1000, 
was  estimated  at  almost  000,000  tons.'  This  country  alone  consumes 
more  than  the  whole  of  Europe:  in  1897  we  consumed  31 H,  170  tons 
against  305,150.  The  total  consumption  In"  Germany  was  136,390; 
by  France,  77,310;  by  England,  12,420;  and  by  Italy,  12,500  tons. 

7Vs  is  the  case  with  tea,  coffee  must  undergo  a  process  of  rf)astiug 
before  it  is  fit  for  use,  although  it  is  said  that  the  Arabians  and  other 
Eastern  peoples  make  a  decoction  of  the  raw  article  and  swallow  the 
grounds  as  well  as  the  liquid.  The  roasting  is  conducted  at  about 
200°  C.  until  the  natural  color,  which  is  greenish,  grayish,  or  drab,  is 
changed  to  a  rich  dark  brown.  During  the  process,  certain  volatile 
aromatic  principles  are  developed,  the  alkaloid  caffeine  is  dissociated 
from  its  union  with  tannin,  the  moisture  is  very  largely  expelled,  the 
sugar  is  caramelized,  gases  are  formed  (largely  carl^onic  dioxide)  which 
cause  the  berry  to  swell,  and  much  ru]ituring  of  the  cell  layers  occui's. 
The  berry  thus  loses  in  weight  and  gains  in  bulk.  The  process  must 
be  conducted  carefully,  else  the  quality  will  not  be  what  is  desired,  since 
if  the  roasting  is  not  pushed  sufficiently  far,  there  Avill  be  insufficient 
development  of  aroma  ;  and  if  it  is  carried  too  far,  the  volatile  matters 
are  expelled  and  the  ]iroduct  acquires  an  unpleasant  taste.  On  account 
of  the  volatile  nature  of  the  aromatic  principles  developed,  coffee 
should  be  roasted  only  as  the  demands  of  commerce  make  it  necessary-. 
On  long  keeping,  except  in  hermetically  sealed  containers,  it  undergoes 
extensive  deterioration.  For  the  same  reason,  the  roasted  berries 
should  be  ground  only  as  needed. 

1  Consular  Reports,  Vol.  LX..  p.  258. 


-1-t  FOODS. 

Coffee  contains  less  caifeine  (tbeiue)  than  is  found  in  tea  ;  thus,  Prag- 
endorff  found  the  amount  in  25  samples  to  vary  between  0.G4  and  2.21 
j>er  cent.,  A\hereas  in  about  the  same  number  (23)  of  samples  of  tea, 
the  range  was  1.36  to  3.09.  It  contains  consiilerable  amounts  of  fat, 
generally  over  12  per  cent.,  about  the  same  amount  of  nitrogenous 
matters,  small,  quite  unimportaut  amounts  of  sugars,  gununy  matters, 
and  other  substances,  and  about  40  per  cent,  of  fiber. 

Coffee  is  used  in  infusion  and  as  a  decoction.  Like  tea,  it  loses  its 
]>leasant  aroma  when  boiled,  but  its  decoction  is  less  bitter  and  astrin- 
gent than  that  of  tea.  In  order  to  enjoy  both  the  fragrance  of  an  in- 
fusion and  the  strength  and  body  of  a  decoction,  it  is  not  an  uncommon 
practice  to  make  first  the  one  and  ])our  it  off^  and  then,  with  a  fresh 
portion  of  water,  to  boil  the  grounds  for  a  few  minutes,  and  then  to 
mix  the  two  liquids  together. 

Coifee  acts  as  a  decided  stimulant  to  the  nervous  system,  enables  one 
better  to  perform  arduous  work,  and  diminishes  the  sense  of  fatigue. 
In  small  amounts,  it  increases  the  force  and  frequency  of  the  pulse,  but 
taken  in  excessive  quantities,  it  causes  palpitation  and  intermission, 
besides  general  nervousness  and  derangement  of  digestion.  It  has  a 
marked  inhibitory  influence  on  gastric  digestion,  and  is  more  opjiressive 
to  the  stomach  than  tea  and,  hence,  should  be  used  with  caution  by  dys- 
pc])tic^^.  A^^ith  some  persons  it  stimulates  peristalsis,  and  tlius  acts  as  a 
gentle  cathartic.     It  increases  the  secretions  of  the  skin  and  kidneys. 

Coifee  is  adulterated  very  extensively  with  a  variety  of  substances 
of  widely  diiferent  nature,  including  chicory,  dandelion,  and  other  roots, 
roasted  cereals  and  legumes,  sawdust,  date  stones,  red  slate,  acorns,  and 
other  chea]i  articles.  It  is  not  alone  in  the  ground  form  that  it  is 
falsified,  for  even  the  beans  are  miitated  with  mixtures  of  flour  and 
other  materials,  moulded  to  the  correct  shape  and  carefully  roasted  and 
colored. 

The  detection  of  adulterants  in  coffee  requires  but  little  time.  Of 
great  assistance  is  the  fact  that  coffee  conttiins  absolutely  no  starch, 
v\^hile  most  of  the  commoner  adulterants  contain  it  in  abundance. 
Therefore,  if  a  specimen  under  examination  is  boiled  and  filtered,  and 
the  filtrate  gives  a  dirty  blue  reaction  with  test-solution  of  iodine,  one 
may  l)e  sure  that  adulteration  has  been  practised.  But  not  all  of  the 
adulterants  are  starchy  in  their  nature  and,  therefore,  other  examination 
is  necessary.  Microscopical  examination  will  detect  not  only  the  starchy, 
but  the  non-starchy  matters  as  well.  Under  the  microscope,  ground 
coffee  has  a  characteristic  appearance  which  cannot  be  mistaken  for  any- 
thing else.  Chicory  and  other  roots,  date  stones,  and  all  other  berries 
and  seeds  have  their  own  characteristics.  For  the  mere  determination 
of  the  question  of  purity,  only  a  knowledge  of  the  microscopical  ap- 
pearance of  coffee  itself  is  required,  and  this  is  acquired  easily  and 
quickly  by  direct  study.  For  the  identification  of  the  adulterants 
present,  one  necessarily  should  be  familiar  with  the  appearance  of  all 
of  the  substances  used. 

Chicory  is  the  root  of  the  CicJiormm  intybus,  a  perennial  herb,  grow- 


COCOA.  21; 


iii^  wiM  .•111(1  cxlciisivclv  ciill  i\;ilii|  ill  till  r'(.iiiitr-y  ;iiiil  in  lMir<i|»c.  Tlir; 
r'oolM   ;\n\   cJciincil,  <'iii   inln  |ii(C(-,  ilii<i|    in   kiln-,  rn;i-(c(|  in  iron  cyliti- 

(Ici's,    Mild    i;n I    iiilo   :i    ri,:\v.-c    |M.\\<lri-.       Lilvc    coH'cc,   cliirory    when 

roilHlcul  (•oiiliiiiis  ;i  Nohililc  |iiiii<i|)lf  iiikI  .1  liiltd-.  It  i.s  used  hofli  aH 
jin  .'i(liill('r;iiil  ;iii(l  ;is  ;i  miU.sI  il  iilc  liii-  cnH'cc.  Mixed  willi  e<»nee,  it  lendH 
|)()|.li  eoloi-  :iiid  (l;i\ur  lo  I  lie  i  iil'ii-ii  m,  ;iiid  Ky  iii.'iiiy  is  l-e^'urded  as  ii 
desir;il)le  ;i<l(liti(m.  I  (.  itself  is  siihjeel  Id  .idiillenilioii  l.y  e|ie;i|ier  root.s, 
such  as  iiiaiii;el\\  ni/el  ;iiid  dniHielifiii. 

(/ollee  and  eliienry  l)elia\c  M-vy  dilTerenlly  when  thrown  into  cold 
WJiler  :  tlie  roiiner  iloats  and  retains  its  (inn  eonsisteiieo,  \vhil(!  the 
Ijlttor  ab.sorbH  water  very  (|iiiel<ly  and  sinks,  and  in  it.s  (lescent  Itsives 
streaks  of  color.  ( "oU'ee  which  has  been  r(»asled  too  iriiich  will,  how- 
ever, .sometimes  sink,  and  chicory  which  has  been  treaterj  with  iiitty 
siihstances  will  float.  Mixtures  of  the  two  ciii  ol'tfii  l.r  d(;tected  by 
llic^  did'ereiUH'  in  resistance  wlu'ii  |>laced  helwcen  the  tctlli.  The  par- 
ticles of  cotT'eo  are  much  harder  than  those;  ofehi('ory,  which  yield  very 
readily  to  pressure  and  also  hav(!  a  sweetish  taste. 

Interior  and  damaged  raw  cod'ees  not  ini"re(pieiitly  are  colored  and 
faced,  in  order  that  they  may  be  improved  in  ajijjearanee  or  be  made 
to  imitate  better  grades.  The  facing  agents  used  are  mixtures  contain- 
ing variable  amounts  of  ultramarine,  indigo,  clay,  gyp.snm,  cliromate 
of  lead,  and  coal  dust. 

According  to  (1.  Wirtz,'  inferior  grades  of  cotfee  are  treated  largely 
at  Antwerp,  Rotterdam,  Hamburg,  J^remen,  and  elsewhere,  by  washing, 
coloring,  and  tiually  drying  by  centrifugation  \\\\\\  sawdust,  the  result 
being  a  line  wdiite  product  of  an  apparently  greater  value. 

Package  coifees  sold  under  various  names,  such  as  "  I'^rench  Break- 
fast Coffee,"  "Vienna  (\)ine,"  and  "Eureka  Breakfast  Coffee,"  are 
rarely  anything  more  than  roasted  and  ground  cereids  and  peas.  It  is 
to  be  said,  however,  that  their  character  usually  is  indicate<l  in  the 
directions  for  use  printed  on  tlie  lal)els,  which  commonly  begin  by 
advising  the  use  of  "a  third  more  than  you  would  use  of  genuine 
coffee."  Microscopical  examination  and  the  iodine  test  will  reveal 
their  composition  very  quickly. 

Many  efforts  have  been  made  to  remove  the  caffeine  from  coffee  in 
such  a  way  that  the  good  qualities  of  cofllee  may  not  be  affected.  One 
process,  patented  in  Germany,  has  been  investigated  by  Lendrich  and 
Murdfield,-  who  found  that  while  the  process  does  not  remove  all  the 
caffeine,  the  quantity  remaining  is  from  0.14  to  0.26  per  cent.,  or 
about  \  of  that  in   untreated  cttffce. 

COCOA. 

Cocoa,  a  corruption  of  Cacao,  and  in  no  way  related  to  the  cocoanut, 
is  derived  from  the  seeds  of  the  Thcobroma  cacao,  a  native  of  tro]>ical 
America.  It  is  estimated  that  the  annual  production  of  the  .seeds 
amounts  to  about  150,000,000  pounds,  more  than  a  fifth  of  which  is 

1  Zeitschrift  fiir  I'ntei-suchung  dor  Nahniners-  nnd  Geniissmittel,  1S9S,  p.  248. 
-  Quoted  by  Leiieh,  Food  Inspection  and  Analysis,  p.  391. 


216  FOODS. 

exported  by  Ecuador  alone.  Nearly  a  tiftli  of  the  annual  crop  is  con- 
sumed M-itbin  the  United  States. 

Tiie  fruit  of  the  cocoa  tree  is  a  pod,  about  a  foot  long  and  half 
as  wide,  filled  -with  "  beans,"  or  "  chocolate  nuts,"  about  as  large  as 
almonds,  imbedded  in  five  rows  of  from  four  to  ten  each  in  a  pulpy 
matrix.  \Mien  ripe,  the  |)ods  are  gathered  and  collected  into  heaps, 
■and  left  for  a  day  or  longer ;  then  they  are  cut  open  and  deprived  of 
the  seeds,  which  are  allowed  to  undergo  a  process  of  fermentation 
in  earthen  vessels  or  in  holes  in  the  ground.  This  process,  which  must 
be  regulated  very  carefully,  has  for  its  object  the  removal  of  an  acrid, 
bitter  taste  and  consequent  improvement  in  flavor.  Sometimes,  the 
seeds  are  dried  in  the  sun  as  soon  as  removed,  but  the  product  is  then 
of  much  less  value ;  sometimes,  the  entire  pod  is  buried  until  the  pulp 
becomes  rotten  and  softened.  AVhen  the  fermentation  process  is  com- 
pleted, the  seeds  are  dried  carefully  in  the  sun,  and  then  become  hard, 
brittle,  and  reddish  or  reddish  brown  in  color. 

In  the  preparation  of  cocoa  for  the  market,  the  seeds  first  are  cleaned 
and  carefully  roasted.  As  is  the  case  with  coffee,  the  roasting  must 
be  carried  to  a  certain  point  to  insure  the  development  of  the  desired 
flavor,  but  not  so  far  beyond  as  to  impair  it.  During  this  process,  the 
thin  husks  of  the  seeds  become  more  detachable,  and  before  the  next 
operation  they  are  removed.  Then  the  seeds  are  crushed  lightly  and 
freed  from  their  hardened  germs,  and  in  this  form  are  known  as  "  nibs." 
These  are  ground  in  a  special  form  of  mill  into  a  paste  ("  flake  cocoa"), 
which  is  moulded  into  cakes  and  allowed  to  harden.  In  this  form,  the 
product  is  known  as  plain  chocolate.  The  sweet  and  flavored  choco- 
lates 'are  made  with  the  addition  of  sugar,  vanilla  beans,  cinnamon  and 
other  spices.  Inferior  vanilla  chocolate  is  made  with  artificial  vanillin 
and  coumarin,  in  place  of  the  far  more  expensive  and  better  flavored 
vanilla  bean. 

For  the  preparation  of  powdered  cocoa,  it  is  necessary  to  remove  a 
part  of  the  oil,  which,  when  present  in  its  normal  amount,  favors  cak- 
ing. This  removal  is  accomplished  by  hydraulic  pressure,  and  the 
paste  is  then  passed  through  sieves  of  exceedingly  fine  mesh. 

The  so-called  soluble  cocoas  are  prepared  with  sugar  and  starches, 
particularly  arrowroot,  but  the  cocoa  itself  is  not  soluble  in  water.  The 
apparent  solubility  is  due  to  the  fineness  of  the  powder  and  to  the  in- 
crease in  the  specific  gravity  of  the  liquid  due  to  the  sugar  in  solution, 
both  these  conditions  favoring  prolonged  suspension  without  sedimen- 
tation. Some  of  the  Dutch  soluble  cocoas  are  treated  with  alkalies, 
for  the  removal  of  the  crude  fiber  and  for  their  effect  upon  the  coloring 
matters.  These  cocoas  thereby  lose  part  of  their  natural  flavor,  but  the 
loss  is  made  up  somewhat  by  the  addition  of  fragrant  foreign  matter. 

Cocoa  Avas  introduced  into  Europe  by  the  Spaniards  after  their  in- 
vasion of  Mexico  under  Cortez,  in  1519.  It  was  not  known  in  England 
until  1657,  when  it  was  sold  first  in  London  by  a  Frenchman.  In  this 
country,  it  first  was  prepared  and  sold  at  Danvers,  Massachusetts,  in 
1771,  from  raw  material  brought  from  the  West  Indies  by  the  fisher- 
men of  Gloucester. 


BEER.  217 

Uiiliki!  tea  and  cofrcc,  wliidi  in  llicmHolvoH  can  hardly  1m;  regarded 
•AH  jiddiiiji;  Jiiiy  nut  ritriciil-  lo  the  did,  cocon  is  :iii  fxcccdiii^dy  valiinliN; 
food,  vvliich  |K»Mscss('S  I  lie  adv:inla;i;c oC  iiiiK'li  mil :  iinciil  in  y-ni:ill  ImlU, 
and  licdcc  is  |):ir(i(Mii;irly  suilcd  to  the  ndcds  of  tlio.s(!  cn^^a^^cd  in 
CXiKKlilions  rcin(»\<'<l  (Voni  cixilizcd  (-(inlcrs.  It.  makcH  a  u  liolcsorrK!, 
agreeable,  slinnilnnt  hcvciM^^c,  ;ind  is  o:i(en  in  I  lie  Corni  of  f.lioeolatc, 
and  as  an  addition  to  (•ai<es,  |>nddin;rs,  :ind  oflicr  eorn|)onn<l-.  The 
eoeoa  nihs  a,nd  |)lnin  <'liocol;ilc  conhiin  about  oO  per  cent,  of  :i  whitish 
,S()li<l  Tat  ol"  ;it;i-('c;!h!!'  \:\Ai^  ;ind  smell,  (M)innionly  known  as  eoeoa 
butter.  It  contains  v.irinblc  :unonn<s  of  (Ik;  alUaloid  thcobroinino 
(diniethylxanthine),  wliicli  is  rcl;it(d  very  elosc^ly  to  eiilliinc  nnd  tlicine 
(trinietliylxnnfhine),  and  h:is  nearly  the  sanu;  |)liysioio(ric;i|  nriion, 
althouoji  soniewhut  less  stiinnlant  and  rather  more  diin-etie.  'I'lic 
amonnt  is  said  to  avera<;e  about  l.oO  per  (■<iit.  Coeoa  is  rich  in  nitro- 
gcnons  matter,  contains  nioi'e  than  10  per  cent,  of  a  starch  with  small 
roiMul  granules,  and  ahout  .'5. 50  per  cent,  of  ash,  which  is  largely  phoH- 
phate  of  potassiinn. 

Sixteen  analyses  ol"  the  kernels,  compiled  by  Konig,  give  the  follow- 
intr  averatres : 


to 


Water 3.63 

Proteids 13.49 

Fat 40.32 

Starch l'^-2o 

Extmctives ViA^ 

Fiber 3.G5 

Ash 3.48 

iou.oo 

The  hasks,  commonly  known  as  "  shells,"  are  used  in  the  prepara- 
tion of  a  cheap  and  wholesome  beverage.  They  contain  little  lat,  but 
are  about  equal  to  cocoa  in  nitrogenous  matter,  and  contain  more  than 
40  per  cent,  of  nitrogen-free  extractives. 

Cocoa  and  chocolate  are  subject  to  extensive  adulteration  with  sub- 
stances having  much  less  commercial  value,  though  perhaps  equaUy 
nutritious.  Among  those  used,  are  starches  of  various  kinds,  as  wheat, 
rye,  potato,  arrowroot,  and  rice,  sugar,  vegetable  oils,  mutton  tallow 
and  other  fats,  Venetian  red,  clay,  and  brick  dust.  Various  flavorings 
are  employed,  such  as  vanillin,  coumarin,  clove,  mace,  cardamom,  and 
nutmeg ;  but  unless  these  are  used  under  the  name  of  vanilla  or  of 
other  flavorings  than  themselves,  they  cannot  be  regarded  as  adul- 
terations. 

Milk  Chocolate. — This  is  a  mixture  of  chocolate,  sugar,  milk 
powder,  and  cocoa  butter. 

Fermented  Alcoholic  Beverages. 

BEER. 

Beer  is  the  generic  term  which  includes  all  fermented  drinks  made 
from  malt — lager  beer,  ale,  porter,  and  stout.  As  commonly  under- 
stood, beer  is  an  infusion  of  malted  barley,   flavored  with   hops  and 


218  FOODS. 

fermented  with  yeast ;  but  on  accDunt  of  the  fact  that  wholesome  sub- 
stitutes for  malt  and  hops  niav  be  enijiloved  in  its  manufacture,  it  is 
ilotiued  also  as  a  "fermented  saccharine  iufusioii  to  which  some  whole- 
some bitter  has  been  added."  In  this  country,  the  term  beer  is 
restricted  connnonlv  to  the  product  generally  known  as  la2;er  beer. 
Porter  is  a  lu'cr  with  a  hioji  percentage  of  alcohol,  and  is  made  from 
malt  dried  at  a  high  tem])erature.  Stout  contains  less  alcohol  and  hops, 
l)Ut  more  malt  extract.  Ale  is  a  jiale  beer  containing  m(»re  hop  extract 
and  less  malt  extract  than  ]xirter  or  stout,  and  brewed  by  "  top  fermen- 
tation." 

Beer  was  made  by  the  Egyptians  many  centuries  before  the  Christian 
era.  It  is  related  that,  for  public  reasons,  the  su])])i'essiou  of  beer-shops 
was  attempted  by  their  government  more  than  forty  centuries  ago.  The 
art  of  brewing  was  taught  l)y  them  to  the  ancient  Oreeks  and  Romans  ; 
thus,  beer  was  a  common  drink  in  Greece  prior  to  700  B.  C,  and  was 
one  of  the  principal  beverages  of  the  soldiers  of  Caesar.  In  the  time 
of  Tacitus,  it  was  in  common  use  in  Germany  ;  and  Pliny  speaks  of  its 
use  in  Spain.  The  ancient  Britons,  at  the  time  of  the  Boman  conquest, 
made  it  from  barley.  At'  the  time  of  the  Norman  conquest,  the  words 
beer  and  ale  meant  in  England  the  same  thing  :  a  drink  made  of  malt 
Avithout  hops.  Later,  the  word  beer  fell  into  disuse  ;  but  in  the  fif- 
teenth and  sixteenth  centuries,  after  the  mtroduction  by  the  Flemish 
of  beer  made  with  hops,  the  term  was  revived,  and  then  meant  hop})ed 
ale.  The  use  of  hops  was  forbidden  in  1530  by  Henry  VIIL,  who 
regarded  them  as  an  adulterant,  and  in  the  first  year  of  the  reign  of 
Bichard  III.,  the  authorities  of  Loudon  laid  a  fine  of  6s  8d  on  eveiy 
barrel  of  beer  containing  them.     Later,  this  was  reduced  one-half. 

The  prejudice  against  the  nse  of  hops  in  brewing  is  expressed  by  one 

of  the  earliest  English  writers  on  dietetics,  Andrew  Boorde,^  who  says  : 

"Ale  is  made  of  malte  and  water;  and  they  the  which  do  put  any  other 

thynge  to  ale  than  is  rehersed,  except  yest,  barme,  or  godesgood,  doth 

sofysticat  theyr  ale.     Ale  for  an  Englysshe  man  is  a  natural  dryid-ce. 

Ale  must  haue  these  propertyes  :  it  must  be  fresshe  and  cleare,  it  uuiste 

not  be  ropy  nor  smoky,  nor  it  must  haue  no  weft  nor  tayle.    Ale  shuld 

not  be  drunk  under  v.  dayes  olde.    Newe  ale  is  vnholsome  for  all  men. 

And  sowre  ale,  and  deade  ale  the  which  doth  stande  a  tylt,  is  good  for 

no  man.      Barley  malte  maketh  better  ale  than  oten  malte  or  any  other 

corne  doth  :  it  doth  engendre  grose  humoures  ;  but  yette  it  maketh  a 

man  stronge.     Bere  is  made  of  malte,  of  hoppes,  and  water :  it  is  the 

natnrall  drynk  for  a  Dutche  man.    And  nowe  of  late  dayes  it  is  moche 

vsed  in  Englande  to  the  detryment  of  many  Englysshe  men  ;  specyally 

it  kylleth  them  the  which  be  troubled  with  the  colycke,  and  the  stone, 

&  the  strangulion ;  for  the  drynke  is  a  colde  drynke ;  yet  it  doth  make 

a  man  fat,  and  inflate  the  bely,  as  it  doth  appere  by  the  Dutche  mens 

faces  &  belyes.      If  the  bere  be  well  serued,  and  be  fyned,  &  not  newe, 

it  doth  qualyfy  the  heat  of  the  lyuer." 

1  A  Ojmpendyoiis  Regyment,  or  A  Pyetaiy  of  Ilelth,  Tiiade  in  Mountpylier,  coni- 
pyled  by  Andrewe  Boorde  of  Physyche  Doctour,  London,  1542. 


/;/■;/■;/.'.  219 

TIk^  imcM'wi  nicrtTi.'iiiH  nuulc;  Wccf  frotii  all  kitidH  of  ^rniins,  :iii<l  for 
fliiA'orin^'  used  oiik  hiirk,  s.-inc,  ;iinl  l(;i\i'S  ul'  flic  liiiiicl,  ;i,-|i,  :iiir|  l:iiii;i- 
risk.  II()|)S  were  iis<'(l  inoi'c  or  lc,-s  finm  I  lie  ninfli  ccnliiry,  ;iri<l  <-a\\ic 
into  j^'cncriiJ  use  in  I  lie  cIcnchI  Ii. 

Hccr  Ix'iiij;'  (lie  (•(uninoii  diliik  n\'  mo-l  l'jir(i|ic;iii  |(((p|)lc,-  licfdrc  flic 
osi;il)lisliiii('iit.  (•('  <'()l()iiics  III  Aiiidii;!,  it  (ollowcd  ii;iliir:dly  lliiil  tlic 
('.•ii'ly  scllk'i's  <<{'  (his  (■(iiiiiliN  liiuii^lil  llir  ;iit  (>('  hrcwiii^'-  uilli  tliciii. 
Ill  l(i2!>,  III*'  cull  i\;il  ion  nC  hops  li;id  liccii  c;inicd  (III  Inr  .-oiiic  lime  ill 
New  A  inslcrdiini,  :ind  Imp  rools  were  xnl  liir  (Vdiii  lOn^^land  hy  fiur 
aiidiorilics  of  MassaclniscKs.  In  iic;irl\-  ;dl  llic  colonics,  tlic  hrcwirif; 
(>(' 1)('(M'  vva,M  i'ct;'ai'dcd  as  (piilc  as  csscntiMJ  ;iii  ;iccMiiipli-|iiiicnt  of  women 
as  ilic  ahililv  (<»  make  ^ood  l)rea<l. 

Tlie  (irs(.  law  reL;ula(in<;'  llie  sak'  of  ;ilc<,||(i|ic  |)i'\-era;re-  in  Massa- 
c.lHlsctfcs  was  made  in  I  (I."!.")  ;  il  |)rescril)ed  llial  no  per-on  .-lioiild  >e|| 
win<>  or  spirits  willioiil  a  pciinll,  hiit  made  no  rcrcrence  lo  licer.  In 
t\u\  I'ollowiiii;'  year,  il  was  or(jei-cd  llial  no  one  -lioiild  clinr^n-  more  than 
a,  pciin\'  for  a  (piail  of  liccr,  and  in  Id.".?,  llial  no  iiin-kecpcr  or  vi(;- 
lualler  should  sell  am'  inloxical  ini;'  drink  lail  Im'ci- ;  ;iiid  lhi>  the\-  were 
jn'ohihitcd  iVom  hrewinii;  ihcmsclves,  hut  must  oWtaiii  from  a  licensed 
bi'cwcr.  In  (lie  ioUowino-  ycai',  owin;^-  to  the  I'act  tliat  the  only  one  of 
this  ckiss  was  nnahk'  to  meet  the  demand,  they  were  allowed  t(»  eondnct 
the  proeess  themselves.  In  KM!),  it  was  ordered  further  that  every 
inn-keeper  and  victualler  should  keep  always  on  hand  a  su|)ply  ot"  !L''ood, 
wholesome  beer.  In  1()51,  the  court  undertook  to  stimulate  the  |>rf>- 
duetion  of  a  better  o:rade  of  beer  in  the  belief  that  thereby  the  growing 
tendency  to  the  use  of  wine  and  spirits  and  the  increasing  habit  of 
drunkenness  would  he  cheeked,  and  permission  was  granted  to  charge 
one,  two,  and  tlu-ee  pence  per  qnart,  according  to  the  amount  of  malt 
used  ])er  barrel. 

A  duty  of  a  shilling  p(M'  bushel  of  imported  malt,  imposed  in  1()-j4, 
called  forth  a  ]>rotest  I'rom  Boston  merchants,  on  account  of  the  veiy 
greiit  importance  of  beer  as  a  beverage  of  the  people.  In  the  following 
yejir,  in  order  to  promote  home  prodnction  of  malt,  importation  was 
])rohibited,  bnt  this  order  was  repealed  in  1()()0.  In  1(367,  the  use  of 
molasses  as  an  adulterant  of  beer  was  ])unishable  by  a  fine  of  five 
pounds.  Similar  laws  relating  to  beer  were  passed  from  time  to  time 
by  the  authorities  of  all  the  original  colonies. 

Process  of  Manufacture  of  Beer. — The  first  step  in  the  brewing 
of  beer  is  the  preparation  of  the  malt.  The  barley  iirst  is  steejxn^l  in 
water  for  several  days,  and  then  is  removed  and  arranged  in  heaps, 
which,  after  a  time,  are  spread  ont  and  turned  repeatedly  nntil  germi- 
nation has  })roceeded  to  the  requisite  extent.  Xext  it  is  drietl  in 
kilns  at  a  temperature  below  or  about  90°  F.,  and  then  is  heated  to 
from  125°  to  180°,  according  to  the  color  desired.  This  process 
develops  flavor,  completely  checks  germination,  and  determines  the 
commercial  character  of  the  product.  The  steeping  of  the  malt  is 
done  best  in  water  containing  ci>nsiderable  <^f  the  minci-al  salts  that 
cause  hardness ;  a  soft  water  exerts  too  much   solvent  action  on  the 


220  FOODS. 

proteid  matters,  which,  soon  after  extraction,  are  likely  to  undergo 
deoompositioii.  Duvino-  the  j^rogress  of  o-eriuinntion,  the  ferment 
diastase  is  develojied,  and  ]>roeeeds  to  convert  the  starch  into  dextrin 
and  maltose.  After  the  g-erms  and  rootlets  have  been  removed  by 
proper  screening  and  sifting,  the  malt  is  crushed,  and  then  an  infusiou, 
the  "wort,"  js  made  with  Avater  at  about  160°  F.  This  is  drawu  oif 
from  the  exhausted  malt,  aud  then  boiled  for  an  hour  or  two  with  hops, 
which,  besides  giving  a  eliaracteristic  l)itter  flavor,  assist  in  claritication 
by  the  action  of  their  contained  tannin  on  some  of  the  proteid  matters. 
Then  the  boiled  bitter  wort  is  cooled  rapidly,  run  into  vats,  mixed 
with  yeast,  and  allowed  to  ferment  for  several  days,  during  which  time 
alcohol  and  carbonic  acid  are  formed  fi'om  the  maltose.  The  nature 
of  the  product  is  influenced  very  largely  by  the  purity  of  the  yeast 
and  by  the  method  of  fermentation  followed.  Top  fermentation  is 
carried  on  rapidly,  and  at  a  comparatively  high  temperature,  the  yeast 
growing  at  the  surface  ;  in  bottom,  or  sedimentary,  fermentation,  the 
veast  grows  at  the  bottom,  tiie  process  is  slower,  and  is  carried  on  at  a 
lower  temperature.  The  chief  advantage  of  the  employment  of  yeast 
which  grows  at  a  low  temperature  is  that  other,  perhaps  undesirable, 
growths  may  be  unable  to  proceed.  Whatever  the  process  of  fermenta- 
tion followed,  not  all  the  sugar  should  be  allowed  to  be  converted,  for 
then  the  flavor  would  be  not  what  it  should,  and  the  kee])ing  qualities 
would  be  impaired.  On  the  completion  of  fermentation,  the  beer  is 
separated  from  the  yeast  and  transferred  to  vats,  where  it  is  clarified. 
As  clarifying  agents,  a  variety  of  materials  are  used,  the  chief  of  which 
are  chips  or  shavings  of  certain  woods,  as  hazel  or  beech,  which  attract 
and  hold  the  particles  which  cause  turbidity.  These  materials  affect  in 
no  way  the  taste  of  the  beer.  Other  substances  used  include  gelatin, 
isinglass,  flax-seed,  and  carrageen.  After  clarification  is  accomplished, 
the  product  is  stored  for  a  time  in  storage  casks,  where  it  undergoes  a 
further  slow  fermentation  at  a  low  temperature,  after  which  it  is  ready 
for  use. 

Substitutes  for  Barley  Malt. — While  barley  is  recognized  univer- 
sally as  the  grain  best  suited  to  the  brewing  of  wholesome  beer,  any 
other  cereal  may  be  used.  Sometimes,  unmalted  grains  are  added  to 
the  malt  before  the  infusion  is  made,  for  the  diastase  of  the  malt  is 
capable  of  converting  not  only  the  starch  with  which  it  naturally  is 
associated,  but  a  large  amount  of  other  starches ;  and  so,  rice,  corn, 
and  other  cereals  may  be  employed.  Glucose  and  cane  sugar  are  used 
somewhat,  but  the  product  is  decidedly  inferior  in  quality,  since  these 
substances  are  lacking  in  some  of  the  elements,  as  proteids  and  min- 
eral matters,  which  contribute  to  the  desirable  character  of  the  best 
beers. 

Concerning  the  use  of  glucose,  which  adds  strength  to  the  wort,  there 
can  l)e  no  objection  on  the  score  of  being  in  any  way  deleterious  to 
health.  The  popular  belief  in  the  unwholesomeness  of  glucose  made 
from  corn  starch  led  the  U.  S.  Treasury  Department,  in  1882,  to 
request  an  investigation  of  the  subject  by  the  National  Academy  of 
Sciences.     This  was  conducted  by  a  committee  of  eminent  scientists, 


liPJEll.  221 

inclu<lin^  I^rofoHHors  Gib})H,  of  Harvard  ;  JJrcwor,  of  Yalo ;  K(;ifi.'-(!ii,  of 
.Foil  IIS  [I()|>l<iiiM  ;  I';ifl<('i-,  of  I'ciitisylvania  ;  ami  (  'IkmhII'I-,  of  ('oliiKihia, 
whose  <u»ii(tliisioiis  \\('r<' :  lli;ii  I  lie  |)r(K',<'HH('H  ('Iii|il<i\  dl  in  I  lie  m;iniif;u'f- 
uvv  M-r(^  iiiiol))('c,lioii;il)lc  ;  lli;il  llu'  product  is  of  cxc-J-plioiwd  purity, 
and  ill  IK)  \v;iy  iiifciidr  in  IkmIi  liCnlncss  fo  rniif  Hiip'ir  ;  and  tliaf  IImtc 
jvas  no  evidence  .'iddneed  to  show  thiil,  even  when  (.•d<eri  in  laiye  fjuan- 
titicH,  citlier  in  its  nalni;il  eondilion  or  feriiieiited,  it  has  any  injiirifMiH 
offcicts  ii|)oii  th(!  syst^^ni.  From  a,  r<;c,<mt  (;xp(;ri(!n(;<;  in  Kn^hind  it 
a|)|)ears,  liowever,  ihal  not  all  iiiMiiMfaclurers  produce  a  pun-  article  ; 
and  that  if  sulphuric  aci<l  made  from  arseiiic;d  pyrites  is  u.sed  in  the 
process,  (he  residtini;'  snL!;ir  m;i\'  contain  snnieicni  nixnic  to  (yiufw;  seri- 
ous and  even  fatal  poisonin<r.  In  Novc^mher,  I'M)!),  J)r.  E.  H,  iiey- 
nolds  '  called  attention  to  a,  number  of  cases,  cliaraciterized  by  j)aralysiH, 
wasting;  of  certain  muscles,  and  loss  of  fniietion  of  f;ertain  sensory 
nerves,  which,  after  considerable  study,  lie  decided  to  be  arsenical  poison- 
ing:;. Shortly  afterward,  an  increase  was  noticed  in  the  number  of  ca.ses 
of,  and  deaths  from,  |)eripheral  neuritis  in  different  cities  and  t^)wns,  and 
it  a|)})eared  that,  in  Manchester  and  Salford  alone,  there  were  abtmt 
3000  cases,  and  that  the  victims  were  drinkers  of  beer.  The  beer  in 
use  was  examined,  and  found  to  be  distinctly  arsenical,  and  it  was 
learned  that,  in  its  manufacture,  glucose  and  invert  sugar,  made  at  a 
factory  near  Tjiverpool,  had  been  employed.  SjK'cimens  of  the  glucose 
were  found  to  contain  from  0.02  to  0,05  j)er  cent,  of  arsenious  oxide,  and 
examination  of  the  various  beers  made  therefrom  showed  from  0.10  to 
1.50  grains  of  arsenic  per  gallon.  The  amount  of  beer  consumeti  by 
the  victims  varied  from  a  pint  to  two  gallons  per  day  ;  many  drank  a 
gallon  each.  A  parliamentary  commission,  ajipointed  U)  investigate 
the  matter,  reported  finding  from  0.56  to  9.17  grains  of  arsenic  per 
pound  of  glucose,  1.40  to  4.34  grains  per  pound  of  invert  sugar,  0.25 
to  3  grains  per  gallon  of  beer,  and  1.40  to  2.60  per  cent,  of  arsenic  in 
the  sulphuric  acid  with  >vhich  the  sugars  were  made.  Between  Xo- 
vember  25,  1900,  and  January  10,  1901,  there  were  no  less  than  36 
deaths  iu  Manchester  alone,  which  were  attributed  to  arsenic^il  poison- 
ing. The  symptoms  observed  iu  this  extensive  outbreak  began,  as  a 
rule,  with  disturbances  of  digestion,  followed  soon  by  laryngeal  and 
bronchial  catarrh  and  acute  skin  eruptions,  and  then  by  disturbances 
of  sensibility  and  motor  paralysis.  The  cases  were  grouped  into  those 
iu  which  all  the  above  symptoms  were  fairly  well  marked,  and  those  in 
which  the  principal  lesions  were,  respectively,  of  the  skin,  heart,  and 
liver,  and  paralytic. 

Substitutes  for  Hops. — Various  substances  have  from  time  to  time 
been  reported  as  being  used  in  place  of  hops  to  give  bitterness  to  beer. 
These  include  nearly  everything  having  a  bitter  taste,  such  as  strych- 
nine, chirata,  calumba,  cocculus  indicus,  aloes,  and  picric  acid.  Cocculus 
indieus  was  mentioned  in  Holland  as  early  as  1620  as  an  adulterant. 
This  and  its  active  principle  picrotcvxine,  and  picric  acid,  have  been 
employed  occasionally  in  England  and  elsewhere  ;  but  at  the  present 
time,  it  is  safe  to  say,  none  of  these  substances  is  used.  Of  476  sam- 
1  British  Medical  Journal,  Nov.  24,  1900. 


222  FOODS. 

pies  of  beer  examined  for  the  State  Board  of  Health  of  New  York,  in 
1885,  not  one  was  found  to  contain  any  \\o\)  su])stitutos  whatever. 

No  ohjootions  can  be  alloii'ed  a^-ainst  such  wliolcsomc  bitters  as  (juassia, 
gentian,  caluniba,  and  chirata.  Evidence  that  they  ever  are  em])loyed  is 
exceedingly  slight.  As  a  matter  of  fact,  there  is  no  satisfactory  sub- 
stitute for  hops,  which  give  not  alone  bitterness,  but  other  flavors  and  g, 
])eculiar  aroma,  due  to  the  resinous  matter  which  they  contain.  Tn  the 
sixteenth  and  seventeenth  centuries,  various  other  flavorings  \Ncrc  used, 
suc'h  as  sage,  eoriaudcr,  laurel  leaves,  i)epj)cr,  grains  of  I'ai'adise,  orris, 
and  essential  oils. 

Physical  Properties  and  Chemical  Composition  of  Beer. — Beer 
should  be  {)ert'cctly  clear  and  bright.  The  presence  of  any  turbidity 
denotes  either  imj)crfect  bre^\■ing  or  the  t)ccurrence  oi'  undesirable 
decomposition  processes.  The  latter  are  accompanied  generally  by  dis- 
agi'eeable  odors.  The  taste  should  be  pleasantly  bitter  and  inclining  to 
sweetness  rather  than  to  acidity.  There  should  be  a  sufficient  amount 
of  carbonic  acid  to  make  a  pleasant  im])ression  in  the  mouth,  such  as  is 
not  produced  by  flat  beer.  The  specific  gravity  ranges  from  about  1.005 
to  1.025,  averaging  below  1.020.  In  bock  beer,  which  is  a  special 
brew  containing  a  considerable  increase  in  malt  extractives,  the  specific 
gravity  is  notably  higher,  running  as  high  as  1.035,  and  averaging 
more  than  1.021. 

The  most  important  constituents  of  beer  are  the  extract  and  alcohol. 
The  extract  includes  all  of  the  non-volatile  matters  in  solution,  and 
consists  of  proteid  matters,  dextrin,  sugar,  hop  resin,  and  other  sid)- 
stances  left  as  a  residue  on  complete  evaporation.  The  amount  is  vari- 
able ;  it  is  highest  in  porter,  stout,  and  bock  beer,  and  lowest  in  the 
light-colored  lager  beers.  In  the  former,  it  averages  about  7.50,  and 
in  the  latter,  about  5.50  per  cent.  Twenty-eight  specimens  of  Amer- 
ican beers,  ales,  and  porter  collected  in  Washington,  and  analyzed  by 
]Mr.  C  A.  Crampton,'  averaged  5.53  per  cent. 

The  average  extract  of  182  analyses  of  specimens  of  beers  of  the 
lighter  kinds,  compiled  by  Konig,  is  stated  at  5.49  (range,  1.98-9.23); 
of  211  lager  beers  of  all  kinds,  at  5.78  ;  of  50  export  beers,  at  6.48  ; 
and  of  5()  bock  beers,  at  7.20. 

The  amount  of  alcohol  is  also  variable.  The  specimens  examined 
by  Crampton,  averaged  4.63  per  cent,  by  weight  ajul  5.79  by  volume. 
The  light  beers  above  mentioned  (Konig)  averaged  3.46  per  cent,  by 
weight ;  the  second  group,  3.95  ;  the  third,  4.31  ;  and  the  fourth,  4.74. 

Adulteration  of  Beer. — Beer  is  su})posed  pojudarly  to  be  exten- 
sively adulterated,  and  the  substances  alleged  to  Ijc  in  common  use 
make  up  a  list  remarkable  for  length  and  variety,  including  such  poi- 
sonous drugs  as  opium,  belladonna,  henbane,  and  strychnine,  many  of 
the  aromatics  and  aromatic  bitters,  corrosive  acids,  di-astic  cathartics, 
and  many  other  sul>stances.  The  actual  adulteration  of  beer,  however, 
is  restricted  practically  to  the  use  of  preservatives,  such  as  sodium 
fluoride  and  salicylic  acid,  of  sodium  bicarbonate  to  correct  acidity 
^  U.  S.  Department  of  Agriculture,  Division  of  Cheuiistry,  Bulletin  13,  p.  282. 


ANAi,ysi,s  o/<'  /;/';/';/;.  2L'.'i 

and   to   iiU!rcaH(i   the  "  Ix'atI,"  mikI    of  .silt   In   coi-i-icl    IckI    t;i:-tf  .-hkI   Id 
iiis|)irc  lliifsl-  ("or  inoi-c. 

'riic  use  of  |)i(  >(i'\:iti\('s  is  iIk'  oiiI\'  Uinn  oC  ;i(liill(i;il  ion  wliich  Ik 
<»r  pPMclicMl  li}<;'i('iiic  in:  [kiiImikc,  ,iii(|  in  scvcr';il  count  ri<''^  i^  |irini.-li- 
jiblo  l)y  liciiNV  |K  ii;ii(ic.-.  In  <iiiiN:in\,  |tr('scrv;if  iv<'S  mh-  i(if<r(lic|«r| 
V(!ry  sirici  l\',  cNcciil  in  lucr  Inlcndid  ('oi'  cxporl;  ;ui<l  llic  |)«'rMii.-.'-ioii 
cxt(!ii<l(Ml  IS  :icc<'|)l('(l  so  frrcly  lli;it  il  i-  v.ivi-  io  (iiid  in  tliis  (uniutry  a 
siKM^inicn  of  (icrni;in  Lolllcd  Itccr  wliicli  dues  nol  condiin  ;i  lilxfral  doHC 
(»(■  sidicvli<'  :u^id.  Mnuy  Anicriciiii  brewers  use;  this  a^M^nt  wiUi  a  {.n-n- 
i'roiis  luiiid,  under  i\\v,  henevoleni  plea  fliat  it  is  a  |)ro|»liylaelic  ajridn-l 
rlieiiniaiisni.  \\y  llie  same  |Mi>eess  of  reasoning;,  one  nii^^lit  contend  jii^t 
as  well  thaiopiiMu  in  food  and  drink  would  pre\ciil  |»ain,  and  liiniodide 
oi'  mercury  keep  the  sysl('ni  fvrv.  from  sypliililie  infeclion. 

Analysis  of  Beer. 

In  tlio  analysis  of  heor,  tlie  most  inipoi'tant  pr(»c(!sses  arc  tlic  deter- 
mination of  tlio  percentanx!  of  aI(;oliol  and  of  extract,  and  the  detection 
ol"  preservatives. 

Determination  of  Alcohol. — ^i'^or  the  determination  of  the  jK-reent- 
a_i;c  of  aU'ohol,  a  suHieiently  lars;'e  |)oi'tion  of  heer  should  he  shaken 
in  a,  capacious  flask  until  the  carl)oni<r  acid  is  c\])clled,  and  then  a 
measured  volume  should  be  subjected  either  to  distillation  or  to  partial 
evaporation  in  an  o))en  vessel. 

(<()  Determination  by  Distillation. —  Inti-oduee  into  a  llask  connected 
with  a  Liebig  condenser  100  cc.  ol'  the  well-shaken  beer,  at  60°  F., 
and  distil  into  another  flask  connected  with  the  discharirini:  end  of  the 
condenser  by  means  of  a  bent  glass  tube.  Continue  the  distillation  until 
somewhat  more  than  50  ec.  of  distillate  have  been  collected,  when  all 
of  the  contiiined  alcohol  will  have  been  expelled  and  conden.sed.  Add 
sufficient  water  to  the  distillate  to  make  100  cc.  at  60°  F.,  determine 
its  s[)eeific  gravity  by  means  of  a  picnometer  or  AVestjihal  balance  (a 
specific  gravity  spindle  is  not  sulficiently  accurate),  an<l  a.^certain  from 
this,  by  reference  to  the  appended  table,  the  percentage  of  alcohol  1)V 
weight  or  volume. 

(/>)  Determination  by  Open  Evaporation. — ddiis  jncthod  involves  le,«s 
manipulation  and  gives  e([ually  accurate  results.  The  specitic  gravity 
of  the  beer  is  determined  first  in  the  manner  above  mentioned.  Then 
place  100  cc.  at  (50°  F.  in  a  glass  or  ]iorcelain  evaporating  dish,  and 
by  the  application  of  heat  drive  off  rather  more  than  half  the  amoinit. 
Remove,  cool,  make  up  with  water  to  the  original  volume  at  60°  F., 
and  again  dotermiue  the  specitic  gravity.  Pivide  the  original  gravity 
by  the  latter,  and  the  result  C(pials  that  of  the  alcohol  which  has  been 
expelled.  Refer  to  the  table,  ;ind  obtain  therefrom  the  percentage  of 
alcohol  in  the  beer. 

The  following  table,  by  J\lr.  Fdgar  Richards,  is  the  one  used  l)y  the 
Association  of  Official  Agricultural  Chemists:' 

^  U.  S.  Departiuent  of  Agrioiiltnro.  Division  of  Chemistry,  Bulletin  Xo.  46,  Wash- 
ington, Government  Printing  Oflicc,  lSi)9. 


224 


FOODS. 


TABLES    SHOWING    PERCENTAGE    OF    ALCOHOL    BY   WEIGHT    AND 

BY   VOLUME. 

{Recalcutaied  from  the  determinations  of  Gilpin,  Drinkwater,  and  Squibb, 
by  E\l(/ar  Richards.) 


Specific 

Per.cent. 

Per  cent. 

Specific 

Per  cent. 

Per  cent. 

Specific 

Per  cent. 

Per  cent. 

gravity  at 

alcohol  by  alcohol  by 

gravity  at 

alcohol  by 

alcohol  by 

gravity  at 

alcohol  by 

alcohol  by 

6U°  F. 

volume. 

weight. 

volume. 

weight. 

60°  F. 

volume. 

weight. 

LOOOOO 

0.00 

0.00 

0.99629 

2.50 

1.99 

0.99281 

5.00 

4.00 

0.99992 

.05 

.04 

622 

.55 

2.03 

274 

.05 

.04 

984 

.10 

.08 

615 

.60 

.07 

268 

.10 

.08 

976 

.15 

.12 

607 

.65 

.11 

261 

.15 

.12 

968 

.20 

.16 

600 

.70 

.15 

255 

.20 

.16 

961 

.25 

.20 

593 

.75 

.19 

248 

.25 

.20 

953 

.30 

.24 

586 

.80 

.23 

241 

.30 

.24 

945 

.35 

.28 

579 

.85 

.27 

235 

.35 

.28 

937 

.40 

.32 

571 

.90 

.31 

228 

.40 

.32 

930 

.45 

.36 

564 

.95 

.35 

222 

.45 

.36 

.99923 

0.50 

0.40 

.99557 

3.00 

2.39 

.99215 

5.50 

4.40 

915 

.55 

.44 

550 

.05 

.43 

208 

.55 

.44 

907 

.60 

.48 

543 

.10 

.47 

202 

.60 

.48 

900 

.65 

.52 

536 

.15 

.51 

195 

.65 

.52 

892 

.70 

.56 

529 

.20 

.55 

189 

.70 

.56 

884 

.75 

.60 

522 

.25 

.59 

182 

.75 

.60 

877 

.80 

.64 

515 

.30 

.64 

175 

.80 

.64 

869 

.85 

.67 

508 

.35 

.68 

169 

.85 

.68 

861 

.90 

.71 

501 

.40 

.72 

162 

.90 

.72 

854 

.95 

.75 

494 

.45 

.76 

156 

.95 

.76 

.99849 

1.00 

0.79 

.99487 

3.50 

2.80 

.99149 

6.00 

4.80 

842 

.05 

.83 

480 

.55 

.84 

143 

.05 

.84 

834 

.10 

.87 

473 

.60 

.88 

136 

.10 

.88 

827 

.15 

.91 

466 

.65 

.92 

130 

.15 

.92 

819 

.20 

.95 

459 

.70 

.96 

123 

.20 

.96 

812 

.25 

.99 

452 

.75 

3.00 

117 

.25 

5.00 

805 

.30 

1.03 

445 

.80 

.04 

111 

.30 

.05 

797 

.35 

.07 

438 

.85 

.08 

104 

.35 

.09 

790 

.40 

.11 

431 

.90 

.12 

098 

.40 

.13 

782 

.45 

.15 

424 

.95 

.16 

091 

.45 

.17 

.99775 

1.50 

1.19 

.99417 

4.00 

3.20 

.99085 

6.50 

5.21 

768 

.55 

.23 

410 

.05 

.24 

079 

.55 

.25 

760 

.60 

.27 

403 

.10 

.28 

072 

.60 

.29 

753 

.65 

.31 

397 

.15 

.32 

066 

.65 

.33 

745 

.70 

.35 

390 

.20 

.36 

059 

.70 

.37 

738 

.75 

.39 

383 

.25 

.40 

053 

.75 

.41 

731 

.80 

.43 

376 

.30 

.44 

047 

.80 

.45 

723 

.85 

.47 

369 

.35 

.48 

040 

.85 

.49 

716 

.90 

.51 

363 

.40 

.52 

034 

.90 

.53 

708 

.95 

.55 

356 

.45 

.56 

027 

.95 

.57 

59701 

2.00 

1.59 

.99349 

4.50 

3.60 

.99021 

7.00 

5.61 

694 

.05 

.63 

342 

.55 

.64 

015 

.05 

.65 

687 

.10 

.67 

335 

.60 

.68 

009 

.10 

.69 

679 

.15 

.71 

329 

.65 

.72 

002 

.15 

.73 

672 

.20 

.75 

322 

.70 

.76 

.98996 

.20 

.77 

665 

.25 

.79 

315 

.75 

.80 

990 

.25 

.81 

658 

.30 

.83 

308 

.80 

.84 

984 

.30 

.86 

651 

.35 

.87 

301 

.85 

.88 

978 

.35 

.90 

643 

.40 

.91 

295 

.90 

.92 

971 

.40 

.94 

636 

.45 

.95 

288 

.95 

.96 

965 

.45 

.98 

ANALYSIS  OF  liKFIi. 


220 


SrH!Clfl<' 

I'or  (;(!n(,. 

IN^rrtciit.. 

."^liiicilic 

I'crriTit. 

I'er  tout. 

Hp«cin<! 

Per  wmt. 

I'f.T  Cf.Ut. 

gravity  at 

ulcohol  l.y 

iilcoliol  liy; 

uriivily  lit 

iilcohol  by 

ilcohol  liy 

griivlly  at 
'0.98273~ 

ulcdliol  Uf 

al'.'oh'>l  liy 

VOlllllHi. 

7.50 

weight..   1 

6.02 

volume. 

weight. 

VOlllUiC. 

w«;lKlit. 

0.9895!) 

0.98603 

10.50 

8.46 

13,60 

10.90 

95:5 

.55 

.0(1 

597 

.55 

.49 

267 

,65 

.94 

9^7 

.(iO 

.10 

5i)2 

.60 

,53 

262 

.60 

.98 

9K) 

.(;5 

.14 

586 

.65 

.57 

256 

.65 

11.02 

9:m 

.70 

,18 

580 

.70 

,61 

251 

.70 

.00 

928 

.75 

.22 

575 

.75 

,65 

246 

.75 

.11 

922 

.80 

.26 

569 

.80 

,70 

240 

,80 

,16 

91 G 

.85 

.30 

663 

.86 

.74 

235 

.86 

,19 

909 

.90 

.:;i 

557 

.90 

.78 

230 

.90 

Xi 

903 

.95 

.38 

552 

,95 

.82 

224 

.96 

.27 

.98897 

8.00 

6.42 

.98546 

11.00 

8.86 

,98219 

14.00 

11.31 

891 

.05 

.40 

540 

,05 

.90 

214 

.06 

.36 

885 

.10 

.50 

535 

,10 

.94 

200 

.10 

.39 

879 

.15 

.54 

529 

.15 

,98 

203 

.16 

.43 

878 

.20 

.58 

524 

,20 

9.02 

198 

,20 

.47 

8(57 

.25 

.62 

518 

.25 

,07    1 

193 

.26 

.62 

861 

.30 

.67 

513 

.30 

,11  ! 

188 

.30 

,66 

855 

.35 

.71 

507 

..35 

,15 

182 

.36 

,60 

849 

.40 

.75 

502 

.40 

,19 

177 

.40 

.64 

843 

.45 

.79 

496 

.45 

,23 

172 

.45 

.68 

.98837 

8.50 

6.83 

.98-191 

11.50 

9.27 

,98107 

14.60 

11.72 

831 

.55 

,87 

485 

.55 

,31 

161 

.55 

.76 

825 

.60 

.91 

479 

.60 

,35 

156 

.60 

.80 

819 

.65 

.95 

474 

.65 

,39 

151 

.65 

.84 

813 

.70 

.99 

468 

.70 

,43 

146 

.70 

,88 

807 

.75 

7.03 

463 

.75 

.47 

140 

,75 

,93 

801 

.80 

.07 

457 

.80 

.51 

135 

,80 

.97 

795 

.85 

.11 

452 

.85 

,55    1 

130 

.85 

12,01 

789 

.90 

.15 

446 

.90 

,59 

125 

.90 

.05 

783 

.95 

.19 

441 

.95 

,63 

119 

,95 

,09 

,98777 

9.00 

7.23 

.98435 

12.00 

9.67 

.98114 

15,00 

12.13 

771 

.05 

.27 

430 

.05 

.71 

108 

.05 

.17 

765 

.10 

.31 

424 

.10 

.76 

104 

.10 

.21 

759 

.15 

.35 

419 

.15 

,79 

099 

.15 

.26 

754 

.20 

.39 

413 

,20 

,83 

093 

.20 

.29 

748 

.25 

.43 

408 

.25 

.87 

088 

.25 

.33 

742 

.30 

.48 

402 

.30 

,92 

083 

..30 

.38 

736 

.35 

.52 

397 

.35 

,96 

078 

.35 

.42 

730 

.40 

.56 

391 

,40 

10.00 

073 

.40 

.46 

724 

.45 

.60 

386 

,45 

.04 

068 

.45 

.60 

.98719 

9.50 

7.64 

.98381 

12.50 

10.08 

.98063 

15.50 

12.54 

713 

.55 

.68 

375 

.55 

,12 

057 

.55 

.58 

707 

.60 

.72 

370 

.60 

,16 

052 

,60 

,62 

701 

.65 

.76 

364 

.65 

,20 

047 

,65 

,66 

695 

.70 

.80 

359 

.70 

.24 

042 

,70 

.70 

689 

.75 

.84 

353 

.75 

.28 

037 

,75 

,75 

683 

.80 

.88 

348 

.80 

,33 

932 

.80 

,79 

678 

.85 

.92 

342 

.85 

,37 

026 

.85 

.83 

672 

.90 

.96 

337 

.90 

.41 

021 

.90 

.87 

666 

.95 

8.00 

331 

,95 

,45 

016 

.95 

.91 

.98660 

10.00 

8.04 

.98326 

13.00 

10.49 

,98011 

16.00 

12.95 

654 

.05 

.08 

321 

.05 

.53 

005 

.05 

.99 

649 

.10 

.12 

315 

.10 

.57 

001 

.10 

13.03 

643 

.15 

.16 

310 

.15 

,61 

97996 

,15 

.08 

637 

.20 

.20 

305 

.20 

,65 

991 

1      ,20 

.12 

632 

.25 

.24 

299 

.25 

.69 

986 

.25 

.16 

626 

.30 

.29 

294 

.30 

.74 

1          980 

.30 

.20 

620 

.35 

.33 

289 

.35 

.78 

975 

.35 

.24 

614 

.40 

.37 

283 

,40 

.82 

970 

.40 

.29 

609 

.45 

.41 

278 

.45 

.86 

965 

.45 

..33 

15 


226 


FOODS. 


Specific 

Per  cent. 

Per  cent. 

Specific 

Per  cent. 

I'cr  cent. 

I     Specific 

Per  cent. 

Per  cent. 

gravity  at 

alcohol  by 

alcohol  by 

gravity  at 

alcoliol  by 

alcoliol  by 

gravity  at 

alcohol  by 

alcohol  by 

60°  F. 

!   volume. 

weight. 

00°  F. 

volinne." 

weight. 

GU°  F. 

volume. 

weight- 

0.97960 

16.50 

13.37 

0.97658 

19.50 

15.84 

0.97355 

22.50 

18.34 

955 

.55 

.41 

653 

.55 

.88 

350 

.55 

.38 

950 

.60 

.45 

648 

.60 

.93 

345 

.60 

.42 

945 

.65 

.49 

643 

.05 

.97 

340 

.65 

.47 

940 

.70 

.53 

638 

.70 

16.01 

335 

.70 

.51 

935 

.75 

.57 

633 

.75 

.05 

330 

.75 

.55 

929 

.80 

.62 

628 

.80 

.09 

324 

.80 

.59 

924 

.85 

.66 

623 

.85 

.14 

319 

.85 

.63 

919 

.90 

.70 

618 

.90 

.18 

314 

.90 

.68 

914 

.95 

.74 

613 

.95 

.22 

309 

.95 

.72 

.97909 

17.00 

13.78 

.97608 

20.00 

16.26 

.97304 

23.00 

18.76 

904 

.05 

.82 

603 

.05 

.30 

299 

.05 

.80 

899 

.10 

.86 

698 

.10 

.34 

294 

.10 

.84 

894 

.15 

.90 

593 

.15 

.38 

289 

.15 

.88 

889 

.20 

.94 

588 

.20 

.42 

283 

.20 

.92 

884 

.25 

.98 

583 

.25 

.46 

278 

.25 

.96 

879 

.30 

14.03 

578 

.30 

.51 

273 

.30 

19.01 

874 

.35 

.07 

573 

.35 

.55 

268 

.35 

.05 

869 

.40 

.11 

568 

.40 

.59 

263 

.40 

.09 

864 

.45 

.15 

563 

.45 

.63 

258 

.45 

.13 

.97859 

17..50 

14.19 

.97558 

20.50 

16.67 

.97253 

23.50 

19.17 

853 

.55 

.23 

552 

.55 

.71 

247 

.55 

.21 

848 

.60 

.27 

547 

.60 

.75 

242 

.60 

.25 

843 

.65 

.31 

542 

.65 

.80 

237 

.65 

.30 

838 

.70 

.35 

537 

.70 

.84 

232 

.70 

.34 

833 

.75 

.40 

532 

.75 

.88 

227 

.75 

.38 

828 

.80 

.44 

527 

.80 

.92 

222 

.80 

.42 

823 

.85 

.48 

522 

.85 

.96 

216 

.85 

.46 

818 

.90 

.52 

517 

.90 

17.01 

211 

.90 

.51 

813 

.95 

.56 

512 

.95 

.05 

206 

.95 

.65 

.97808 

18.00 

14.60 

.97507 

21.00 

17.09 

.97201 

24.00 

19.59 

803 

.05 

.64 

502 

.05 

.13 

196 

.05 

.63 

798 

.10 

.68 

497 

.10 

.17 

191 

.10 

.67 

793 

.15 

.73 

492 

.15 

.22 

185 

.15 

.72 

788 

.20 

.77 

487 

.20 

!26 

180 

.20 

.76 

783 

.25 

.81 

482 

.25 

.30 

175 

.25 

.80 

778 

.30 

.85 

477 

.30 

.34 

170 

.30 

.84 

773 

.35 

.89 

472 

.35 

.38 

165 

.35 

.88 

768 

.40 

.94 

467 

.40 

.43 

159 

.40 

.93 

763 

.45 

.98 

462 

.45 

.47 

154 

.45 

.97 

.97758 

18.50 

15.02 

.97457 

21.50 

17.51 

.97149 

24.50 

20.01 

753 

.55 

.06 

451 

.55 

.55 

144 

.55 

.05 

748 

.60 

.10 

446 

.60 

.59 

139 

.60 

.09 

743 

.65 

.14 

441 

.65 

.63 

133 

.65 

.14 

738 

.70 

.18 

436 

.70 

.67 

128 

.70 

.18 

733 

.75 

.22 

431 

.75 

.71 

123 

.75 

.22 

728 

.80 

.27 

426 

.80 

.76 

118 

.80 

.26 

723 

.85 

.31 

421 

.85 

.80 

113 

.85 

.30 

718 

.90 

.38 

416 

.90 

.84 

107 

.90 

.36 

713 

.95 

.39 

411 

.95 

.88 

102 

.95 

.39 

.97708 

19.00 

15.43 

.97406 

22.00 

17.92 

.97097 

25.00 

20.43 

703 

.05 

.47 

401 

.05 

.96 

092 

.05 

.47 

698 

.10 

.51 

396 

.10 

18.00 

086 

.10 

.51 

693 

.15 

.55 

391 

.15 

.05 

081 

.15 

.56 

688 

.20 

.59 

386 

.20 

.09 

076 

.20 

.60 

683 

.25 

.63 

381 

.25 

.13 

071 

.25 

.64 

678 

.30 

.68 

875 

.30 

.17 

065 

.30 

.68 

673 

..35 

.72 

370 

..35 

.21 

060 

.35 

.72 

668 

.40 

.76 

365 

.40 

.26 

055 

.40 

.77 

663 

.45 

.80 

360 

.!■') 

.30 

049 

.45 

.81 

/1;V/I/.  )',S'AS'    OF    nh'h'Ji. 


227 


S|)(l(!illc 

L'l'iivilv  at 

l'(!r  c.rnt.. 

I'cr  <'i;lll. 

K|i(;cinc 

I'lir  mill. 

]'i-r  cent. 

HfiitcM\v. 

l'«r  cent. ' 

I'cr  writ. 

illiM.liol  hy 

Illnilliil  by 

irriivlty  lit 
0.96715 

iilcoliiil  liy 

ulcoliol  by 

gruv  llv  at 

ulinAutl  hy,al(y>h<il  l>y 

Cd"  i.'. 

vmIiiiiic. 
25.50 

20.85 

vdIiiiiiu. 
28.50 

23.38 

volume. 

wclKlit. 

().!)70ll 

0,y«3(K) 

31.50 

25.94 

0:51) 

.55 

.89 

709 

.55 

.42 

353 

.55 

.98 

():{:{ 

.60 

.93 

704 

.00 

.47 

347 

.(Kl 

26.03 

O'JH 

.65 

.98 

698 

.65 

.51 

341 

.05 

.07 

{)'i:\ 

.70 

21.02 

692 

.70 

.55 

335 

.70 

.11 

018 

.75 

.06 

087 

.75 

.60 

329 

.75 

.16 

012 

.80 

.10 

681 

.80 

.64 

323 

.80 

.20 

007 

.85 

.14 

675 

.85 

.08 

316 

.85 

.24 

001 

.IM) 

.19 

669 

.90 

.72 

310 

.90 

.28 

.i)(;'js)() 

.95 

.23 

664 

.95 

.77 

304 

.95 

.33 

.•.)(;!)!)  1 

26.00 

21.27 

.96658 

29.00 

23.81 

.90298 

32.00 

26.37 

!)Srt 

.05 

.31 

652 

.05 

.85 

292 

.05 

.41 

080 

.10 

.35 

61(1 

.10 

.89 

285 

.10 

.46 

975 

.15 

.40 

640 

.15 

.94 

279 

.15 

.50 

'J()l) 

.20 

.44 

(;35 

.20 

.98 

273 

.20 

.54 

\)M 

.25 

.48 

629 

.25 

24.02 

267 

.25 

.59 

1150 

.30 

.52 

623 

.30 

.06 

260 

.30 

.63 

958 

.35 

.56 

617 

.35 

.10 

254 

.35 

.07 

949 

.40 

.61 

611 

.40 

.15 

248 

.40 

.71 

942 

.45 

.65 

605 

.45 

.19 

241 

.45 

.76 

.9()1)37 

26.50 

21.69 

,96600 

29.50 

24.23 

.96235 

32.50 

26.80 

982 

.55 

.73 

594 

.55 

.27 

229 

.55 

.84 

926 

.60 

.77 

587 

.60 

.32 

222 

.60 

.89 

921 

.65 

.82 

582 

.65 

.36 

216 

.65 

.93 

915 

.70 

.86 

576 

.70 

.40 

210 

.70 

.97 

910 

.75 

.90 

570 

.75 

.45 

204 

.75 

27.02 

905 

.80 

.94 

504 

.80 

.49 

197 

.80 

.06 

899 

.85 

.98 

559 

.85 

.53 

191 

.85 

.10 

894 

.90 

22.03 

553 

.90 

.57 

185 

.90 

.14 

888 

.95 

.07 

547 

.95 

.62 

178 

.95 

.19 

.96883 

27.00 

22.11 

.96541 

30.00 

24.66 

.96172 

33.00 

27.23 

877 

.05 

.15 

535 

.05 

.70 

166 

.05 

.27 

872 

.10 

.20 

529 

.10 

.74 

159 

.10 

.32 

866 

.15 

.24 

523 

.15 

.79 

153 

.15 

.36 

861 

.20 

.28 

517 

.20 

.83 

146 

.20 

.40 

855 

.25 

.33 

511 

.25 

.87 

140 

.25 

.45 

850 

.30 

.37 

505 

.30 

.91 

133 

.30 

.49 

844 

.35 

.41 

499 

.35 

.95 

127 

.35 

.53 

839 

.40 

.45 

493 

.40 

25.00 

120 

.40 

.57 

833 

.45 

.50 

487 

.45 

.04 

114 

.45 

.62 

.96828 

27.50 

22.54 

.96481 

30.50 

25.08 

.96] 08 

33.50 

27.66 

822 

.55 

.58 

475 

.55 

.12 

101 

.55 

.70 

816 

.60 

.62 

469 

.60 

.17 

095 

.60 

.75 

811 

.65 

.67 

463 

.65 

.21 

088 

.65 

.79 

805 

.70 

.71 

457 

.70 

.25 

082 

.70 

.83 

800 

.75 

.75 

451 

.75 

.30 

075 

.75 

.88 

794 

.80 

.79 

445 

.80 

.34 

069 

.80 

.92 

789 

.85 

.83 

439 

.85 

.38 

062 

.85 

.96 

783 

.90 

.88 

433 

.90 

.42 

056 

.90 

28.00 

778 

.95 

.92 

427 

.95 

.47 

049 

.95 

.05 

.96772 

28.00 

22.96 

.96421 

31.00 

25.51 

.96043 

34.00 

28.09 

766 

.05 

23.00 

415 

.05 

.55 

036 

.05 

.13 

761 

.10 

.04 

409 

.10 

.60 

030 

.10 

.18 

755 

.15 

.09 

403 

.15 

.64 

023 

.15 

.22 

749 

.20 

.13 

396 

.20 

.68 

016 

.20 

.26 

744 

.25 

.17 

390 

.25 

.73 

010 

.25 

.31 

738 

.30 

.21 

384 

.30 

.77 

003 

.30 

.35 

732 

.35 

.25 

378 

.35 

.81 

.95996 

.35 

.39 

726 

.40 

.30 

372 

.40 

.85 

990 

.40 

.43 

721 

.45 

.34 

366 

.45 

.90 

983 

.45 

.48 

228 


FOODS. 


Specific 

Per  cent. 

Per  cent. 

1     Specific 

1  Per  cent. 

Per  cent. 

Specific 

Per  cent. 

Per  cent. 

gravity  at 

alcohol  by 

alcohol  by 

1  gravity  at 

alcoliiil  by 

alcohol  liy 

gravity  at 

alcohol  by 

alcohol  by 

60°  F. 

volume. 

weight.' 

j      6U°  F. 

1  Toluiiie. 

weight. 

GOOF. 

volume. 

weight. 

0.95977 

34.50 

28.52 

0.95560 

j  37.50 

31.14 

0.95107 

40.50 

33.79 

970 

.55 

.56 

552 

.55 

.18 

099 

.55 

.84 

9G3 

.60 

.61 

645 

.60 

.23 

091 

.60 

.88 

957 

.65 

.65 

538 

.65 

.27 

083 

.65 

.93 

950 

-.70 

.70 

531 

.70 

.32 

075 

.70 

.97 

943 

.75 

.74 

523 

.75 

.36 

067 

.76 

34.02 

937 

.80 

.78 

516 

.80 

.40 

059 

.80 

.06 

930 

.85 

.83 

509 

.85 

.45 

052 

.86 

.11 

923 

.90 

.87 

502 

.90 

.49 

044 

.90 

.15 

917 

.95 

.92 

494 

.95 

.54 

036 

.95 

.20 

.95910 

35.00 

28.96 

.95487 

38.00 

31.58 

.95028 

41.00 

34.24 

903 

.05 

29.00 

480 

.05 

.63 

020 

.05 

.28 

896 

.10 

.05 

472 

.10 

.67 

012 

.10 

.33 

889 

.15 

.09 

465 

.15 

.72 

004 

.16 

.37 

883 

.20 

.13 

457 

.20 

.76 

.94996 

.20 

.42 

876 

.25 

.18 

450 

.25 

.81 

988 

.25 

.46 

869 

.30 

.22 

442 

.30 

.85 

980 

.30 

.60 

862 

.35 

!26 

435 

.35 

.90 

972 

.35 

.55 

855 

.40 

.30 

427 

.40 

.94 

964 

.40 

.69 

848 

.45 

.35 

420 

.45 

.99 

966 

.45 

.64 

.95842 

35.50 

29.39 

.95413 

38.50 

32.03 

.94948 

41.60 

34.68 

835 

.55 

.43 

405 

.55 

.07 

940 

.55 

.73 

828 

.60 

.48 

398 

.60 

.12 

932 

.60 

.77 

821 

.65 

.52 

390 

.65 

.16 

924 

.65 

.82 

814 

.70 

.57 

383 

.70 

.20 

916 

.70 

.86 

807 

.75 

.61 

376 

.76 

.25 

908 

.75 

.91 

800 

.80 

.65 

368 

.80 

.29 

900 

.80 

.95 

794 

.85 

.70 

360 

.85 

.33 

892 

.85 

35.00 

787 

.90 

.74 

353 

.90 

.37 

884 

.90 

.04 

780 

.95 

.79 

345 

.95 

.42 

876 

.95 

.09 

.95773 

36.00 

29.83 

.95338 

39.00 

32.46 

.94868 

42.00 

35.13 

766 

.05 

.87 

330 

.05 

.50 

860 

.05 

.18 

759 

.10 

.92 

323 

.10 

.65 

852 

.10 

.22 

752 

.15 

.96 

316 

.15 

.59 

843 

.15 

.27 

745 

.20 

30.00 

307 

.20 

.64 

835 

.20 

.31 

738 

.25 

.05 

300 

.25 

.68 

827 

.25 

.36 

731 

.30 

.09 

292 

.30 

.72 

820 

.30 

.40 

724 

.35 

.13 

284 

.35 

.77 

811 

.36 

.46 

717 

.40 

.17 

277 

.40 

.81 

802 

.40 

.49 

710 

.45 

.22 

269 

.45 

.86 

794 

.46 

.54 

,95703 

36.50 

30.26 

.95262 

39.50 

32.90 

.94786 

42.50 

35.58 

695 

.55 

.30 

254 

.55 

.95 

778 

.56 

.63 

688 

.60 

.35 

246 

.60 

.99 

770 

.60 

.67 

681 

.65 

.39 

239 

.65 

33.04 

761 

.66 

.72 

674 

.70 

.44 

231 

.70 

.08 

753 

.70 

.76 

667 

.75 

.48 

223 

.75 

.13 

746 

.75 

.81 

660 

.80 

.52 

216 

.80 

.17 

737 

.80 

.85 

653 

.85 

.57 

208 

.85 

.22 

729 

.85 

.90 

646 

.90 

.61 

200 

.90 

.27 

720 

.90 

.94 

639 

.95 

.66 

193 

.95 

.31 

712 

.95 

.99 

.95632 

37.00 

30.70 

.95185 

40.00 

33.35 

.94704 

43.00 

36.03 

625 

.05 

.74 

177 

.05 

.39 

696 

.06 

.08 

618 

.10 

.79 

169 

.10 

.44 

687 

.10 

.12 

610 

.15 

.83 

161 

.15 

.48 

679 

.15 

.17 

603 

.20 

.88 

154 

.20 

.53 

670 

.20 

.21 

596 

.25 

.92 

146 

.25 

.57 

662 

.26 

.23 

689 

.30 

.96 

138 

.30 

.61 

654 

.30 

.30 

581 

.35 

31.01 

130 

.35 

.66 

645 

.35 

.35 

574 

.40 

.05 

122 

.40 

.70 

637 

.40 

.39 

567 

.45 

.10 

114 

.45 

.75 

628 

.45 

.44 

ANALYSIS  OF  Hi: hit. 


229 


Hpeclflc 

I'or  coiit. 

I'or  <;(!nt. 

Hiii'dlic 

\'>T  cent. 

I'or  rout.  1 

HrN-niflc 

I'ftr  c<!iit. 

I'or  cunt. 

gravity  at 

ul(!oli<>l  liy 

itlcoliol  l)y 

Uriivlty  III 
(10"  F. 

alroliDl  l>y 

iilcoliol  l,y 

gruviiv  lit 

al(»>hol  liy  alcohol  Uy 

voluiiiu. 

woi^lit. 
36.4H 

VolllMU!. 

wui|{lit. 
38.75 

volutiiv. 

welKhl, 

0.94(;2() 

43.50 

0.94 1 88 

46.00 

0.93824 

48.00 

40.60 

01 2 

.55 

.5;{ 

179 

.05 

.80 

815 

.05 

.65 

()0:{ 

.60 

.57 

170 

.10 

.84 

805 

.10 

.69 

nor) 

.65 

.6'J 

161 

.15 

.89 

796 

.15 

.74 

M(\ 

.70 

.6<; 

152 

.20 

.93 

786 

.20 

.78 

57  H 

.75 

.71 

143 

.25 

.98 

777 

.25 

.83 

r,7() 

.80 

.75 

134 

.30 

39.03 

7G8 

.30 

.88 

mi 

.85 

.80 

125 

.35 

.07 

758 

.35 

.92 

.V);; 

.90 

.84 

116 

.40 

.12 

749 

.40 

.97 

514 

.95 

.8!) 

107 

.45 

.16 

739 

.45 

41.01 

.94530 

•1 1.00 

.",6.93 

.94098 

46.50 

39.21 

.93730 

48.50 

41.06 

527 

.05 

.98 

089 

.55 

.26 

721 

.55 

.11 

511) 

.10 

37.02 

080 

.60 

.30 

711 

.60 

.15 

510 

.15 

.07 

071 

.65 

.35 

702 

.65 

.20 

502 

.20 

.11 

062 

.70 

.39 

692 

.70 

.24 

4<);3 

.25 

.16 

05.", 

.75 

.44 

683 

.75 

.29 

484 

.30 

.21 

044 

.80 

.49 

679 

.80 

.M 

476 

.35 

.25 

035 

.85 

.53 

664 

.85 

.38 

467 

.40 

.;',o 

02() 

.90 

.58 

655 

.90 

.43 

459 

.45 

.31 

017 

.95 

.62 

645 

.95 

.47 

.94450 

44.50 

37.39 

.91008 

47.00 

39.67 

.93636 

49.00 

41.52 

441 

.55 

.44 

.93999 

.05 

.72 

626 

.05 

.57 

433 

.60 

.48 

990 

.10 

.76 

617 

.10 

.61 

424 

.65 

.53 

980 

.15 

.81 

607 

.15 

.66 

41 G 

.70 

.57 

971 

.20 

.85 

598 

.20 

.71 

407 

.75 

.62 

962 

.25 

.90 

588 

.25 

.76 

398 

.80 

.66 

953 

.30 

.95 

578 

.30 

.80 

390 

.85 

.71 

944 

.35 

.99 

569 

.35 

.85 

381 

.90 

.76 

934 

.40 

40.04 

559 

.40 

.90 

373 

.95 

.80 

925 

.45 

.08 

550 

.45 

.94 

.94364 

45.00 

37.84 

.93916 

47.50 

40.13 

.93540 

49.50 

41.99 

355 

.05 

.89 

906 

.55 

.18 

530 

.55 

42.04 

346 

.10 

.93 

898 

.60 

.22 

521 

.60 

.08 

338 

.15 

.98 

888 

.65 

.27 

511 

.65 

.13 

329 

.20 

38.02 

879 

.70 

.32 

502 

.70 

.18 

320 

.25 

.07 

870 

.75 

.37 

492 

.75 

.23 

311 

.30 

.12 

861 

.80 

.41 

482 

.80 

.27 

302 

.35 

.16 

852 

.85 

.46 

473 

.85 

.32 

294 

.40 

.21 

842 

.90 

.51 

463 

.90 

..37 

285 

.45 

.25 

833 

.95 

.55 

454 

.95 

.41 

.94276 

45.50 

38.30 

267 

.55 

.35 

258 

.60 

.39 

250 

.65 

.44 

241 

.70 

.48 

232 

.75 

.53 

223 

.80 

.57 

214 

.85 

.62 

206 

.90 

.66 

197 

.95 

.71 

Determination  of  Methyl  Alcohol. ^ — Method  of  Leach  and  Lythgoe.- 
— This  method  depends  upon  the  fact  that  the  specific  gravities  of  the 
two  alcohols  are  nearly  alike,  but  that  the  refractions  are  very  different. 
Starting  with  methyl  alcohol  at  0  per  cent,  (water)  and  increasing  the 

^  Personal  communication  from  H.  C.  Lythgoe,  Chemist,  Food  and  Drug  Department, 
Mass.  State  Board  of  Health. 

'  Jour.  Am.  Chem.  See,  1905,  p.  964. 


230  FOODS. 

amount  of  alcohol,  the  refraction  increases  until  it  reaches  a  maximum 
at  about  50  per  cent,  alcohol,  beyond  which  point,  with  increasing; 
alcohol,  the  retraction  diminishes  until  a])Solute  methyl  alcohol  is 
reached,  which  has  a  lower  refraction  than  water.  Witii  ethyl  alcohol, 
starting  as  before  at  0  per  cent.,  the  refraction  increases  with  increiising 
alcoholic  strength  much  more  rapidly  than  is  the  case  with  metyhl  alco- 
hol, reaching  a  maximum  at  about  78  per  cent.  It  then  decreases 
slightly,  absolute  ethyl  alcohol  having  about  the  same  refraction  as 
51  per  cent,  alcohol. 

To  determine  methyl  alcohol,  prepare  the  alcoholic  distillate  as 
usual,  determine  the  specific  gravity,  and  obtain  the  per  cent,  of  alcohol 
from  the  table.  Determine  the  refraction  of  this  distillate  at  20°  C. 
by  means  of  a  Zeiss  immersion  refractometer.  This  refraction  should 
be  then  compared  with  those  given  in  the  table  for  that  per  cent,  alco- 
hol. If  the  refraction  corresponds  to  that  of  ethyl  alcoliol,  the  alcohol 
is  pure  ethyl  alcohol.  If  it  corresponds  to  that  of  methyl  alcohol,  the 
alcohol  is  pure  methyl  alcohol.  If  it  is  between  these  figures,  the 
alcohol  is  a  mixture  of  ethyl  and  methyl  alcohols. 

Two  or  three  examples  of  actual  cases,  as  found  in  the  routine  in- 
spection of  foods  and  drugs  in  Massachusetts,  will  best  illustrate  the 
method  of  calculation.  For  determination  of  total  alcohol  from  the 
specific  gravity,  Hehner's  alcohol  tables  were  used, 

(1)  A  lemon  extract,  found  by  the  polariscope  to  contain  4.9  per 
cent,  of  lemon  oil  by  volume  and  90.20  per  cent,  of  alcohol  by  volume 
at  15°  C,  Nvas  freed  from  lemon  oil  by  diluting  four  times  with  water, 
treating  with  magnesia  in  the  regular  manner,  and  filtering.  A  meas- 
ured portion  of  the  filtrate  was  then  distilled,  and  the  distillate  made 
up  to  the  measured  portion  taken.  This  distillate  was  found  to  have 
a  specific  gravity  of  0,9736,  corresponding  to  18,38  per  cent,  alcohol 
by  weight,^  and  to  have  a  refraction  of  35,8  on  the  Zeiss  immersion 
refractometer. 

By  interpolation  in  the  table  the  readings  of  ethyl  and  methyl  alco- 
hol corresponding  to  18.38  per  cent,  alcohol  are  47,2  and  25,4  re- 
spectively, the  difference  being  21,8.  47,2  -  35.8  =  11.4,  (11,4  -- 
21.8)  100  =  52,3.  In  this  case  52.3  per  cent,  of  the  alcohol  present 
was  methyl. 

(2)  An  orange  extract  was  found  with  1.5  per  cent,  of  orange  oil 
and  83.2  per  cent,  of  alcohol  by  volume  at  15°  C.  Specific  gravity  of 
the  :^-strength  distillate,  freed  from  oil  as  in  the  case  of  the  lemon  ex- 
tract, was  0,9754,  corresponding  to  16,92  per  cent,  alcohol  by  weight. 
Refraction  of  the  distillate  at  20°  C,  was  42.0.  Readings  of  ethyl 
and  methyl  alcohol  of  16.9  strength  are,  according  to  the  table,  44,3  and 
24,5  respectively.  Difference,  19.8,  44.3-42  =  2,3,  (2.3-19.8) 
100  =  1.2.     Thus  1.2  per  cent,  of  the  alcohol  present  was  methyl, 

1  Our  methyl-ethyl  alcohol  tables  being  most  conveniently  worked  out  on  the  weight 
per  cent,  basis^  the  per  cent,  by  weight  rather  than  by  volume  of  the  dilute  distillate  is 
here  taken.  Percentage  of  total  alcohol  in  the  extract,  as  well  as  of  lemon  oil,  we  com- 
monly express  by  volume.  In  this  case  the  specific  gravity,  0.9736,  corresponds  to 
22.55  per  cent,  alcohol  by  volume.  The  per  cent,  by  volume  of  total  alcohol  in  the 
extract,  90.20  at  15°  C,  is  found  by  multiplying  22.55  by  4  to  correct  for  the  dilution. 


yi ;v. I /.  r,s7.s'  ()/'•  iiF.F.n.  231 

TiKADlNfiH    OK    Kxi'KIMMKNTAI,    MrXTCKKS    OK     \h   TKVI,    AND    IVflfVI,    A  I/.'OHOIA 


M<4liyl 

lilcoliol. 

Klbyt  alcohol. 

I'cr  ccill. 
iilcohcl    liy 

SC(ll(! 

rciidliiK, 

H|).  Ur.  ir.'M!. 

weight. 

20'^  (;. 

Ah  jiropurcfl, 

Ah  rriiiiid, 

Ah  iin.'imn.'d, 

AHrrtiirul, 

'.)i.;!(; 

.s:}.0 

per  (;t!iit. 
08.52 

per  i:ciil. 
09.88 

|H;r  cent. 

\t*:T  <«;nt. 

O.KIIH) 

22.84 

21.18 

O.HliK) 

iH.y.C) 

h\.\) 

'lo.OK 

47.41 

45.08 

41.95 

(),'.)'j;'.i» 

■17.11 

r,i.!) 

:5r).r.o 

35.42 

11.85 

11.99 

O.HIDO 

ui.  ;',(■. 

70.:', 

'22.  K4 

2:5.75 

08.52 

07.01 

().9:'.'J(') 

■i;!.-i:{ 

(I'j.-t 

21.71 

21.88 

21.71 

22.05 

o/.mm:', 

'jr,.(;  1 

:!7,'J 

11  (.2:! 

11  (.70 

0.41 

5.88 

().'.)'J07 

■IS.SC. 

77.r) 

12.21 

11.77 

:{0.05 

37.09 

■    0.1)75:} 

17.00 

:m.o 

8.50 

8.92 

8.50 

8.08 

o.'.xifu; 

2;{.i»'2 

r)0.2 

5.1)8 

0.48 

17.94 

17.44 

ScALK  Rkadincis  on  Zei.ss  Immersion  Rkfractometeb  at  20°  C.  Coruespondino 
TO  Eacu  1'kr  Cent,   hy  Wkkuit  ok  Kthyi>  and  Methyl  Alcohoia 


>1 

J3 

Sciile  r 

t'lldiiiKS. 

S 

Sciilc.  readings. 

Scale  readings. 

f-cale  readings. 

O 
O 

a 

o 
o 

o 
ja 
o 

O 
o 

"3 

o 

o 

o 

o 

Si 
o 
u 

"3 

2 

o 

o 

J3 

o 

O 

.a 
o 

V 

"3 

o 

o 

Si 

o 

4->  -t-i 

S.5f 
"-1  ^ 

"3 

"3 
14.5 

0)  bo 

"3 

"3 

=3 

"3 

V 

"3 

">% 

.a 

&4 

"3 
S 

0 

14.5 

30 

32.8 

69.0 

00 

37.9 

96.2 

90 

16.1 

98.6 

1 

14.8 

16.0 

31 

33.5 

70.4 

61 

37.5 

96.7 

91 

14.9 

98.3 

2 

15.4 

17.6 

32 

34.1 

71.7 

02 

37.0 

97.1 

92 

13.7 

97.8 

3 

1(5.0 

19.1 

33 

34.7 

73.1 

63 

36.5 

97.5 

93 

12.4 

97.2 

4 

16.0 

20.7 

34 

35.2 

74.4 

64 

36.0 

98.0 

94 

11.0 

96.4 

5 

17.2 

22.3 

35 

35.8 

75.8 

65 

35.5 

98.3 

95 

9.6 

95.7 

6 

17.8 

24.1 

36 

36.3 

76.9 

66 

35.0 

98.7 

96 

8.2 

94.9 

7 

18.4 

25.9 

37 

36.8 

78.0 

67 

34.5 

99.1 

97 

6.7 

94.0 

8 

19.0 

27.8 

38 

37.3 

79.1 

68 

34.0 

99.4 

98 

5.1 

93.0 

9 

19.6 

29.6 

39 

37.7 

80.2 

69 

33.5 

99.7 

99 

3.5 

92.0 

10 

20.2 

31.4 

40 

38.1 

81.3 

70 

33.0 

100.0 

100 

2.0 

91.0 

11 

20.8 

3:3.2 

41 

38.4 

82.3 

71 

32.3 

100.2 

12 

21.4 

35.0 

42 

38.8 

83.3 

72 

31.7 

100.4 

13 

22.0 

36.9 

43 

39.2 

84.2 

73 

31.1 

100.6 

14 

22.6 

38.7 

44 

39.3 

85.2 

74 

30.4 

100.8 

15 

23.2 

40.5 

45 

39.4 

86.2 

75 

29.7 

101.0 

16 

23.9 

42.5 

46 

39.5 

87.0 

76 

29.0 

101.0 

17 

24.5 

44.5 

47 

39.0 

87.8 

77 

28.3 

100.9 

18 

25.2 

46.5 

48 

39.7 

88.7 

78 

27.6 

100.9 

19 

25.8 

48.5 

49 

39.8 

89.5 

79 

26.8 

100.8 

20 

26.5 

50.5 

50 

39.8 

90.3 

80 

26.0 

100.7 

21 

27.1 

52.4 

51 

39.7 

91.1 

81 

25.1 

100.6 

22 

27.8 

54.3 

52 

39.6 

91.8 

82 

24.3 

100.5 

23 

28.4 

56.3 

53 

39.6 

92.4 

83 

23.6 

100.4 

24 

29.1 

58.2 

54 

39.5 

93.0 

84 

22.8 

100.3 

25 

29.7 

60.1 

55 

39.4 

93.6 

85 

21.8 

100.1 

26 

30.3 

61.9 

56 

39.2 

94.1 

86 

20.8 

99.8 

27 

30.9 

63.7 

57 

39.0 

94.7 

87 

19.7 

99.5 

28 

31.6 

65.5 

58 

38.6 

95.2 

88 

18.6 

99.2 

29 

32.2 

67.2 

59 

38.3 

95.7 

89 

17.3 

98.9 

232 


FOODS. 


(3)  6.3  cc.  of  tinetiiro  of  iodine,  after  titration  with  N/10  sodium 
thio^;nlphate  (in  the  regidar  manner  for  deterniinini;'  its  strength  accord- 
ing to  the  United  JStates  Pharmacopceia),  was  neutralized  with  N/10 
sodium  hydroxide  and  distilled,  collecting  25.2  cc.  of  the  distillate, 
corresponding  to  a  dilution  of  1  :  4  of  the  sample.  The  distillate  con- 
tained 20.92  per  cent,  alcohol  by  weight ;  refraction  27.5  at  20°  C, 
indicating  99.0  per  cent,  of  the  alcohol  to  be  methyl.  There  is  no 
doubt  that  the  alcohol  in  this  case  was  entirely  methyl,  the  slightly  high 
refraction  of  the  distillate  being  due  to  the  presence  of  a  slight  amount 
of  volatile  substance  formed  by  decomposition  of  the  tincture  of  iodine. 

The  accuracy  of  the  method  is  shown  in  a  general  way  by  a  series 
of  experiments,  the  results  of  which  are  tabulated  on  ])age  231. 

Determination  of  Extract. — The  extract  may  be  determined  di- 
rectly or,  with  the  aid  of  a  table,  from  the  specific  gravity  of  the  deal- 
coholized  beer.  The  direct  method  is  more  accurate,  and  is  carried  out 
as  follows  :  Into  an  accurately  weighed  platinum  dish,  such  as  is  used 
in  the  analysis  of  milk,  weigh  5  grams  of  beer ;  evaporate  to  complete 
dryness,  and  multiply  the  weight  of  the  residue  by  20. 

Approximately  accurate  results  are  obtained  by  reference  to  the  fol- 
lowing table,  after  Schultze-Ostermann  : 


BEER 

EXTRACT  TABLE 

Specific 
gravity. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

1.011 

2.87 

2.90 

2.92 

2.95 

2.97 

3.00 

3.03 

3.06 

3.08 

3.11 

2 

3.13 

3.16 

3.18 

3.21 

3.24 

3.26 

3.29 

3.31 

3.34 

3.37 

3 

3.39 

3.42 

3.44 

3.47 

3.49 

3.52 

3.55 

3.57 

3.60 

3.62 

4 

3.65 

3.67 

3.70 

3.73 

3.75 

3.78 

3.80 

3.83 

3.86 

3.88 

5 

3.91 

3.93 

3.96 

3.98 

4.01 

4.04 

4.06 

4.09 

4.11 

4.14 

6 

4.16 

4.19 

4.21 

4.24 

4.27 

4.29 

4.32 

4.34 

4.37 

4.39 

7 

4.42 

4.44 

4.47 

4.50 

4.52 

4.55 

4.57 

4.60 

4.62 

4.65 

8 

4.67 

4.70 

4.73 

4.75 

4.78 

4.80 

4.83 

4.85 

4.88 

4.90 

9 

4.93 

4.96 

4.98 

5.01 

5.03 

5.06 

5.08 

5.11 

5.13 

5.16 

1.020 

5.19 

5.21 

5.24 

5.26 

5.29 

5.31 

5.34 

5.36 

5.39 

5.41 

1 

5.44 

5.47 

5.49 

5.52 

5.54 

5.57 

5.59 

5.62 

5.64 

5.67 

2 

5.69 

5.72 

5.74 

5.77 

5.80 

5.82 

5.85 

5.87 

5.90 

5.92 

3 

5.95 

5.97 

6.00 

6.02 

6.05 

6.08 

6.10 

6.13 

6.15 

6.18 

4 

6.20 

6.23 

6.25 

6.28 

6.30 

6.33 

6.35 

6.38 

6.40 

6.43 

5 

6.45 

6.48 

6.50 

6.53 

6.55 

6.58 

6.61 

6.63 

6.66 

6.68 

6 

6.71 

6.73 

6.76 

6.78 

6.81 

6.83 

6.86 

6.88 

6.91 

6.93 

7 

6.96 

6.98 

7.01 

7.03 

7.06 

7.08 

7.11 

7.13 

7.16 

7.18 

8 

7.21 

7.24 

7.26 

7.29 

7.31 

7.34 

7.36 

7.39 

7.41 

7.44 

9 

7.46 

7.49 

7.51 

7.54 

7.56 

7.59 

7.61 

7.64 

7.66 

7.69 

1.030 

7.71 

7.74 

7.76 

7.79 

7.81 

7.84 

7.86 

7.89 

7.91 

7.94 

1 

7.99 

8.01 

8.04 

8.06 

8.09 

8.11 

8.14 

8.16 

8.19 

8.21 

The  figures  at  the  head  of  the  several  columns  represent  the  fourth 
decimal  ])lace  of  the  specific  gravity.  Example :  Specific  gravity, 
1.0187  ;  referring  to  1.018  in  the  left-hand  column  and  running  out 
to  the  column  headed  by  the  figure  7,  we  find  4.85  as  the  percentage 
of  extract  for  that  gravity. 


ANALYSIS  OF  I'.FJCR.  23^5 

Detection  of  Preservatives.-  The  |.iiiMi|.;iI  [ncj-crvjitivc  iihc<1  in 
b(!or  is  SMlicyllc,  iKiid  ;  ticxl  in  irii|»i»il;iii(f  i-  (luuiidc  of  hodiiirii,  wliidi, 
}i()W(W(ir,  i.s  not  used  to   ;iny  citn.sidcrnhlc   fNliiil  as  ytX  in  llii.s  country. 

Salicylic  Acid. — Tlic  ordiniiiv  nictliod  nC  extracting  by  nic^mH  of 
ctlior  and  tcslinji;  the  rcsidiu!  left  on  evaporation  of  flic  laftcr  with 
ferric  cld(»ridc,  cainiot  he  used  \\\  tlie  examination  of  Ix-er,  since  kiln- 
dried  malt  contains  a  |»rinei|ile  wliicli  p;ives  a  reaction  identical  with 
that  of  .salicylic  acid.  'I'Ik;  following;  method,  devised  hy  Spica,  i.«, 
however,  .sati.sfa(!tory  and  n^liahle  :  y\cidify  100  cc.  willi  sidplmric  acid, 
extract  with  ether,  allow  the  se|)a rated  ether  to  evaporate  sp(»nfa- 
lUioiisly,  and  warm  the  residnc;  gently  with  a  drop  of  strong-  nitri*-  acid, 
whereby,  if  .salicylic  acid  is  ])resent,  pic^ric  acid  is  formed.  The  ad<H- 
tion  of  a  few  drops  of  ammonia  or  of  sodium  hvdrafe  produces  the; 
correspond iii}>;  picratc  witli  its  brinlit-yellow  color,  wliieh  may  be 
imparted  to  a  woollen  thread  immersed  in  tiie  iicjnid. 

Fluorides. — Several  methods  are  recommended,  and  amon^''  them  the 
followin*:; : 

Method  of  IIefjoi.mann  and  Mann. — Expel  the  carbonic  acid 
fi'om  500  oc.  of  beer,  and  then  add  1  cc.  of  a  solution  containing  5  per 
cent,  each  of  calcium  and  barium  chlorides,  and  follow  it  with  0.5  cc. 
of  20  per  cent,  acetic  acid  and  50  cc.  of  5)0  per  cent,  alcohol.  Let 
stand  twenty-four  hour.s  and  filter.  Dry  the  filter  and  precipitiite  col- 
lected thereon  without  washinf>;,  and  transfer  to  a  platinum  crucible. 
Add  strong'  sulpluu'ic  acid,  and  cover  the  crucible  with  a  waxed  watch- 
glass  with  some  lines  scratched  through  the  wax  coating,  then  heat  at 
100°  C.  for  two  hours,  and  observe  the  effect  on  the  exposed  gla.ss. 
This  method  is  said  to  be  of  sufficient  delicacy  to  detect  the  presence 
of  7   milligrams  in  a  liter. 

Brand's  Method. — To  100  cc.  of  beer  made  slightly  alkaline  with 
ammonium  carbonate  and  hciited,  add  2  or  3  cc.  of  a  10  per  cent,  so- 
lution of  calcium  chloride.  Boil  for  a  few  minutes,  filter,  and  dry  the 
filter  and  contents.  Then  proceed  as  in  the  method  just  described.  In 
either  process,  it  is  best  to  place  a  lump  of  ice  in  the  concavity  of  the 
watch-glass  to  keep  the  latter  cool ;  the  water  should  be  removed  from 
time  to  time  by  means  of  a  pipette  so  that  it  may  not  overflow. 

Other  Determinations. — Of  minor  interest  are  the  determinations 
of  acidity  and  ash. 

Total  Acidity. — To  10  cc.  of  beer  freetl  from  carl)ouic  acid  by  shak- 
ing, add  a  few  drops  of  neutral  litmus  solution,  and  then  add  deciuor- 
mal  sodium  hydrate  until  the  end  reaction  is  observed.  Express  the 
results  in  parts  of  acetic  acid.  One  cc.  of  decinormal  sodium  hydrate 
equals  0.006  gram  of  acetic  acid. 

Fixed  and  Volatile  Acidity. — Concentrate  10  cc.  of  beer  to  a  third 
of  its  bulk  by  evaporation,  add  water  u|>  to  the  original  volume,  and 
proceed  as  above.  The  difference  in  results  is  due  to  the  acetic  acid 
which  has  been  driven  off.  The  fixed  acidity  is  due  chiefly  to  lactic 
acid,  and,  if  desired,  may  be  so  expressed.  One  cc.  of  the  decinormal 
solution  is  equivalent  to  0.009  gram  of  lactic  acid.  The  other  acids 
present  include  succinic,  malic,  and  tannic. 


234  FOODS. 

Ash. — The  residue  obtained  in  the  direet  determiuatiou  of  the  ex- 
tract may  be  utilized  for  the  estimation  of  the  ash.  Jt  shoukl  be  ii>;nited 
very  ciiutiously  and  at  as  low  a  temperature  as  possible  until  the  ash 
becomes  white. 

WINES. 

Properly  speaking,  Avine  is  the  fermented  juice  of  grapes,  though  the 
term  is  ajiplied  also  to  other  jn-oducts  of  fermentation  of  saccharine 
li(|uids  and  fruit  juices.  It  has  been  in  use  as  a  drink  from  the  very 
earliest  jH'riods  of  civilization.  At  the  present  time,  wines  are  pro- 
duced in  inlinite  variety  and  of  many  qualities.  The  character  and 
properties  dei)end  u])()n  a  great  number  of  factors,  including  the  variety 
of  the  gra[)e,  the  nature  of  the  soil  upon  which  the  vine  is  cultivated, 
the  climate  in  general,  and  the  state  of  the  weather  in  particular  Avhen 
the  gra]")es  are  ri])ening,  the  degree  of  ripeness  when  gathered,  the 
method  followed  in  the  preparation  of  the  must,  and  the  care  with 
which  the  other  steps  in  the  making  of  the  final  product  are  conducted. 
Of  very  great  influence  is  the  extent  to  which  the  seeds,  skins,  and 
stems  of  the  fruit  arc  allowed  to  l)e  acted  upon.  The  seeds  yield  con- 
siderable amounts  of  tannic  acid,  and  the  skins  lend  color,  flavor,  and 
to  some  extent  astringency.  The  most  important  constituent  of  the 
juice  of  the  grape  is  the  sugar,  and  this  is  present  in  greatest  abun- 
dance when  the  fruit  is  fully  ripe. 

In  the  making  of  wine,  the  first  step  is  the  preparation  of  the  must. 
The  grapes,  with  or  without  preliminary  careful  examination  and  sort- 
ing, usually  without,  are  crushed  by  machinery  or  by  the  naked  feet 
of  men,  so  that  the  juice  is  set  free.  Sometimes,  the  stems  are  first 
carefully  eliminated,  and  particularly  good  individual  grapes  are  cut 
out  and  set  aside  for  special  use.  In  the  crushing  of  the  fruit,  the 
method  of  treading  has  in  its  favor  the  fact  that  the  seeds  are  not 
thereby  affected,  and  so  do  not  give  up  so  much  of  their  astringent 
principle.  If  a  white  wine  is  to  be  made,  the  must  is  freed  at  once 
from  the  skins  and  stalks ;  but  if  the  jiroduct  is  to  be  red,  these  are 
retained  during  the  process  of  fermentation.  The  juice  of  both  the 
white  and  the  black  varieties  of  grapes  is  practically  without  color ; 
but  when  the  dark  skins  are  left  in  contact  with  the  fermenting  mass, 
the  alcohol  formed  extracts  the  yellow  and  blue  coloring  matters,  which 
become  red  under  the  action  of  the  free  acids  formed  at  the  same  time. 
The  constituents  of  the  must  are  water,  sugar,  proteid  matters,  gununy 
substances,  pectous  matter,  organic  acids  and  their  salts,  and  mineral 
matters. 

The  must,  with  or  without  the  skins  and  seeds,  is  fermented  in  vats 
of  wood,  marble,  or  stone,  the  process  starting  very  quickly,  being  in- 
duced by  organisms  which  grow  on  the  skin  itself.  The  temperatiu-e 
at  which  this  is  allowed  to  proceed  exerts  an  important  influence  in 
determininar  the  character  of  the  wine:  conducted  between  5°  and  15° 
C,  the  ])rocess  is  comparatively  slow  and  the  aroma  of  the  wine  is  rich  ; 
while  at  higher  temperatures,  the  rate  is  more  rai)id  and  the  bouquet  is 


WINKS.  2.'}5 

less  in;irl<('<l.  'I'lic  Ici'tnliKiliDii  of  llic  |)i'oc(s,s  is  rii;nl<'  cviflfiil  \>y 
(i(!H,s;i,(  ion  oC  (,li(i  cvdliition  of  (•;iil(()iii<t  ii«'i<l,  (lie  (liiiiiiiiil  ion  oi'  h|)<'«-i(ir 
^niA'ily,  :iihI  I  lie  sinkinjj;  of  ni:illcrs  uliicli  hcCorc  luul  fortncd  piiil 
of  tlid   Hcnin. 

WIicIIh'I'  ;iII  of  llic  snii'.'ii"  is  n-c<l  n|),  (Icpcnds  soincu  li;it  npon  tin; 
iiinonnt  of  piodid  nnlricnl  ni;il(ii;il  (or  the  ^rowlli  «i('  flic  orp'iiiisrnft 
hy  wliicJi  IIk!  conNcrsion  is  cniTlcd  on.  I  ("  lliis  is  cxli.'iuslcd  (irs(,  iIhtc 
will  1)(!  ;i  residue  of  snti;ir,  nnd  llie  |iiiidne(  will  l»e  eorres|»ondiiijrlv 
sweet  ;  if  lliere  is  ;in  ;il)nnd;inee  o("  |)i-oleId  in;i(ler,  llie  .>n;.r;ir  uill  lie  the 
llrsi,  to  \n\  exiijinslcd,  :ind  llie  wine  will  lie  "dr\-."  It  i~  sometimes 
liof'-cssiirv  to  iidd  nilroj^'enons  ni;illei',  sni'li  ;is  ('^■^  nlliinnin  or  ^eljifin,  in 
order  to  keep  the  process  IVoni  ee;isinti-  <*'"  '•■'ii'lv. 

As  the  pefeenliiy-e  of  ;deohol  in  llie  fei'mentinj;  nnisl  rises,  the  liit;ir- 
tnite  of  polnssinni  present  is  dejiosiled  l' r.idn;dly,  owiii^  to  its  ilisolu- 
hility  in  nleohol.  The  deposit  is  known  eonitnerei;dlv  ;is  jir^'ol,  ;mk1  is 
the  soiii'c(>  of  ere.'ini  oC  l;irt;ir. 

When  the  (irst  lennentation  is  coin|)leted,  the  nlcoholic;  licpiid  is  drawn 
off  into  casks,  in  whlc^li  it  is  kejit  for  a  number  of  months,  the  vessels 
hcincj  kept  constantly  lilled.  It  now  iindero;oes  a  second  .slow  fermen- 
tation, which  l)rin<;s  about  chan<;'es  which  are  not  imderstood  excepting 
in  their  o^foss  result,  which  is  the  production  of  tlx;  "l)r)U(juet"  or 
Ha,vor.  In  this  second  process,  there  occur  a  iiirther  dcjif»sition  of 
argol  and  an  oxidation  of  aldehyde  to  acetic  acid.  The  bonquet  is  due 
to  a  combination  of  ethers,  the  chief  of  which  is  cenanthic  ether,  sujv- 
posed  to  be  produced  from  the  alcohol  through  the  agency  of  the  organic 
acids  normally  ])reseut. 

The  wine  next  is  racked  otf  into  other  casks,  and  in  some  causes  it  is 
necessary  to  do  this  several  times.  Sometimes,  the  api)e:irance  of  the 
wine  is  such  that  "tining"  is  necessary.  This  consists  in  the  addition  of 
egg  albumin,  isinglass,  or  other  gelatinous  matter,  which  in  its  descent 
attracts  and  enmeshes  the  line  particles  of  matter  which  nttt  only  pre- 
vent brilliancy,  but  later  ou  may  impair  the  keeping  (piality  of  tlie 
wine. 

Classification  of  Wines. — Wines  are  classified  variously  according 
to  color,  strength,  sweetness,  and  content  of  carbonic  acid.  .Vccord- 
ing  to  color,  they  are  classed  as  red  or  white,  the  latter  term  applying 
not  only  to  the  very  light,  almost  colorless  kinds,  but  also  to  those 
having  a  decided  yellowish  or  even  yellowish-brown  color,  such  as  is 
possessed  by  "  white  port."  The  red  wines  include  those  generally 
known  as  Clarets  and  Burgundies,  though  both  these  kinds  exist  in  the 
white  forms.  The  white  wines  include  the  white  Clai'ets  commonly 
designated  as  Sauternes,  white  Burgundies  of  which  Chablis  is  a  type, 
the  Rhine  and  INIoselle  wines,  and  oth(M-s. 

According  to  strength,  wines  are  classed  as  natural  and  fortified. 
The  natural  wines  contain  of  alcohol  only  that  which  is  formed  in  the 
process  of  natural  fernientatiou  ;  the  fortified  wines,  such  as  Sheriy, 
Port,  and  Madeira,  contain,  besides,  a  considerable  amount  in  the  form 
of  added  spirits. 


236 


FOODS. 


According  to  their  content  of  sugar,  wines  are  classed  as  sweet  or  dry, 
Some  of  the  sweet  wines  contain  added  sugar  and  that  which  has 
escaped  the  action  of  the  yeast  plant.  lu  the  dry  wines,  all  or  nearly 
all  of  the  sugar  has  been  converted  into  alcohol.  Not  all  of  the  sugar, 
however,  in  any  wine  is  converted  into  alcohol  and  carbonic  acid,  small 
amounts  going  to  form  glycerin  and  succinic  acid. 

According  to  their  content  of  carbonic  acid,  wines  are  classed  as  still 
or  sparkling  (etfervescent).  The  natural  wines  contain  j-tractically  no 
carbonic  acid  ;  the  sparkling,  or  effervescent,  wines,  as  Cham]>agne  and 
sparkling  ]\Ioselle,  are  in  a  sense  artificial  in  that  they  are  subjected  to 
a  jn'ocess  of  fermentation  in  the  bottle,  sugar  being  added  for  the  pur- 
pose.     They  are  flavored  also  with  liqueurs. 

Composition  of  Wines. — Alcohol. — The  most  important  constitu- 
ent, the  active  principle,  of  wine  is  ethylic  alcohol.  The  higher 
alcohols,  propylic,  butylic,  and  amylic,  are  always  present  in  traces. 
The  amount  of  alcohol  is  variable,  ranging  in  natural  wines  from  6 
to  14  per  cent,  by  weight,  but  ordinarily  present  between  the  limits  of 
9  and  12  per  cent.  In  fortified  wines,  the  amount  ranges  from  12  to 
about  22  per  cent.,  but  is  usually  about  17  per  cent. 

Sugar. — While  the  amount  of  sugar  in  the  original  must  ranges  be- 
tween 12  and  33  per  cent.,  in  the  natural  finished  product  it  is  as  a 
rule  quite  low,  ordinarily  considerably  under  0.5  per  cent.,  and  often 
none  at  all.  The  sweet  Tokays  contain  exceedingly  variable  amounts, 
ranging  from  3  to  26  per  cent..  Ports  and  Madeiras  about  4,  and 
Sherries  somewhat  less ;  but  American  Ports,  Sherries,  and  Madeiras 
are  commonly  fairly  rich  in  sugar.  Domestic  Champagnes,  also,  con- 
tain notable  amounts,  but  those  of  foreign  origin,  even  those  ordinarily 
classed  as  sweet,  contain  but  small  amounts,  the  impression  of  sweet- 
ness being  largely  due  to  the  flavorings  of  the  liqueurs  added.  Four 
specimens  analyzed  by  the  author,  one  of  which  (No.  4)  is  well  known 
as  an  extra  sweet  wine,  yielded  the  following  results  : 


Brand. 

Sugar. 

Extract. 

Alcohol  by- 
weight. 

1.  Brut  Imperial  (Moet  &  Chandon) 

2.  St.  Marceaux 

3.  Dry  Imperial  (Moet  &  Chandon) 

4.  White  Seal  (Meet  &  Chandon) 

1.35 
1.52 
1.56 
4.76 

3.27 
3.21 
3.18 

6.88 

11.15 

10.38 
10.85 
10.23 

Extract. — The  extract,  or  residue,  represents  the  sum  of  the  non- 
volatile constituents,  including  sugar,  nitrogenous  matters,  tartaric  and 
other  acids,  mineral  and  organic  salts,  coloring  and  astringent  prin- 
ciples, glycerin,  etc.,  all  of  which  are  present  in  but  small  quanti- 
ties. In  "sweet  wines,  the  principal  constituent  of  the  residue  is  sugar. 
The  actual  food  value  of  the  residue  is,  apart  from  the  sugar,  practi- 
cally nil. 

Adulteration  of  Wines. — Wines  have  been  subject  to  a  wide 
variety  of  adulterations  from   the  earliest  times,  and  measures  against 


WINES'.  237 

<li('  |)r;i(;li(!(^  (){'  jliclr  so|)Iii,~l  ii-;il  ioii  wi-vi-  <iifiii-cc(l  Imij/  Ixfoic  tlione 
.'lfi,';i,iiisl.  (he  ;i(liil(ci';il  ion  oC  hiviid  ;iihI  oIIki-  luriiLs  were  llioii^lil  of. 
'^riic  ;iiH^iciil  (  Jiccks  .-iiid  IJoiikiii,-,  I'm  cx.-iiniilc,  (•ii;ic(c(l  Hlrilij»-<'lit  IjiWH 
:iii(l  ;i|)|)(»iiilc(l  uHici;ils  whose  duly  \v;i.s  to  dclcci  ;iiid  [»iiiii-li  llio-c  u  }io 
od'ciidcd. 

Al  llic  prcscnl  iiiiic,  ;idnllcr;ili<iii  of  wines  is  prafdi.sed  very  cxtcn- 
KJvely,  ;uid  Includes  llie  ;iddi(i«tn  of  water,  of  coloring  a^ontn,  of  j)re- 
S(U'V!it.ives,  o("  lilycici'lii  to  im|)!H't  sw(>etiiess  and  hody,  of  alum  to  liei^/lifi-n 
color  and  of  deeoloi-i/in^  aij^enlsto  r(!tnov(!  it,  the  suhstilution  of  uh'tlly 
artificial  eonipounds,  and  proeesses  for  the  "  imj)rovernent  "  of  the 
nalui'al  |)roduet.  Tiie  (lax'oi'inn-  and  eolminn;  agents  are  a.s  a  rule  fpiitc 
liarndess.  They  are  employed  chiefly  in  the  manufacture  of  factitif)UH 
wines,  and  not  uneomnionlv  the  same  a^^ent  serves  in  both  capacities. 
J^runes,  raisins,  dried  apples  and  ])eaches,  and  dates  arc  commoidy  fK) 
oniployed.  Various  berries,  loofwood,  alkanet,  red  beets,  coal-tar 
products,  and  a  wide  variety  of"  other  substances  are  said  to  be  used 
for  impartino;  color. 

The  addition  of  alcohol  is  recognized  as  a  legitimate  practice  in  the 
case  of  the  ibrtified  wines  ;  that  of  glycerin  has  no  sanitary  significance. 
The  amount  of  alum  used  for  heightening  color  is  so  small  as  t*>  be 
productive  of  no  harm.  The  employment  of  decolorizing  agents  is, 
like  the  substitution  of  artificial  pi'oducts,  a  fraud  pure  and  simple; 
but  the  use  of  preservatives,  such  as  salicylic  acid,  formaldehyde,  and 
sulphites,  is  objectiouable  on  account  of  danger  to  health. 

For  the  improvement  of  wines,  a  number  of  processes  are  in  v(»gue. 
Chief  of  these  is  "  plastering,"  which  consists  in  the  addition  of  g>'p- 
sum  to  the  must  for  the  purpose  of  securing  a  more  brilliant  appear- 
ance and  increasing  the  keeping  qualities.  This  agent  deconnwses  the 
potassium  bitartrate,  forming  tartrate  of  calcium  and  acid  sulphate  of 
potassium,  ^vhich  latter  eventually  is  convertefl  into  the  neutral  sulphate. 
Chaptali/.ing  consists  in  the  neutralization  of  the  acidity  of  the  must  by 
the  use  of  marble  dust,  and  the  addition  of  cane  sugar  or  glucose.  This 
process  diminishes  the  natural  acidity  and  increases  the  yield  of  alcohol. 
Galliziug  consists  in  diluting  the  must  so  as  to  reduce  its  acidity  to  a 
given  standard,  and  adding  a  sufficient  amount  of  cane  sugar  or  glucose 
to  insure  the  producti(^u  of  the  proper  alcoholic  strength. 

The  Pasteur  treatment  of  wnnes  is  resorted  to  sometimes  as  soon  as 
evidence  of  untoward  fermentations  producing  the  so-called  "  wine  dis- 
eases" appears.  The  wine,  best  in  the  bottle,  is  heated  to  from  55° 
to  65°  C  according  as  the  alcoholic  strength  is  high  or  low,  whereby 
the  existing  germs  are  killed  and  the  preservation  of  the  wine  is  made 
permanent. 

The  manufacture  of  artificial  wines  is  carried  on  extensively  in  this 
country  and  abroad,  in  spite  of  the  fact  that  fair  grades  of  the  genuine 
product  are  obtainable  at  very  low  prices.  A  number  of  hand-books 
and  guides  to  the  "art  of  blending  and  compounding"  are  pub- 
lished for  the  use  of  wholesalers  and  retailers  of  wnnes  and  liquors,  and 
from  several   of  these  the  following  are  selected  as  examples  of   the 


238  FOODS. 

methods  given:  (1)  Port:  cider,  30  gallons;  alcohol,  5  gallons; 
syrup,  4  gallons  ;  kino,  h  ]Knind  ;  tartaric  acid,  }  ]ionnd  ;  jiort  wine 
flavor,  ()  ounces.  (2)  Claret:  California  hock,  40  gallons  ;  extract  of 
kino,  S  ounces ;  essence  of  malvey  flower,  8  ounces.  (8)  Sherry  : 
e([ual  parts  of  Spanish  sherry  and  California  hock.  (4)  A\'hite  wine : 
dissolve  25  pounds  of  grape  sugar  and  1  of  tartaric  acid  in  25  quarts 
of  hot  water,  ;uld  75  quarts  of  cold  >vater  and  50  ]x>unds  of  grape 
pulp,  stir,  cover,  let  ferment  for  four  or  five  days,  and  strain. 

In  France,  an  artificial  substitute  for  wine,  known  as  "  ])i(juette,"  is 
manufactured  very  extensively  from  raisins  and  dried  apples.  It  is 
estimated  that  in  1898  no  less  than  50,000,000  gallons  were  made  and 
consu'.ned.  The  ]irocess  is  exceedingly  sim})le.  To  each  gallon  of 
water  used  are  added  1  pound  of  raisins  and  1  of  dried  api)les  ;  the 
mixture  is  placed  in  an  open  vessel  and  allowed  to  stand  three  days. 
It  is  then  bottled  with  |  teaspoonful  of  sugar  and  a  small  piece  of 
cinnamon  in  each  bottle.  It  is  said  to  be  a  pleasant  and  harmless 
l»ovorage. 

Analysis  of  Wines. 

Determination  of  Alcohol. — The  })rocess  for  the  determination  of 
alcohol  is  the  same  as  that  folhnved  in  the  analysis  of  beer,  exce])t 
that  the  distillation  or  evaporation  is  carried  farther.  At  least  60,  or 
better  75  cc,  are  collected  by  distillation  or  driven  off'  by  open  evapo- 
ration. 

Determination  of  Extract. — The  specific  gravity  of  the  de-alcohol- 
ized ^\ine  gives,  as  with  beer,  an  approximate  estimate  of  the  amount 
of  extract,  and  the  same  table  may  he  used.  The  direct  determination 
is  made  by  evaporating  50  cc.  of  the  wine  in  a  weighed  platinum  dish 
on  a  water-bath  and  drying  to  constant  weight  in  an  air-bath.  With 
s\veet  wines,  a  smaller  amount  is  preferable. 

Determination  of  Acidity. — The  total  acidity,  due  to  Intartrate  of 
potassium,  tartaric,  malic,  and  other  acids,  is  reckoned  as  tartaric  acid. 
Twenty-five  cc.  of  the  wine  are  titrated  in  the  usual  way  with  deci nor- 
mal sodium  hydrate,  1  cc.  of  which  equals  0.0075  gram  of  tartaric 
acid. 

The  volatile  acids  are  reckoned  as  acetic  acid.  Fifty  cc.  of  the  wine 
are  placed  in  a  distilling  flask  connected  by  means  of  its  outlet  tube 
with  a  Liebig  condenser,  and,  by  means  of  a  bent  tube  passing  through 
its  stopper  and  ]irojecting  well  below  the  surface  of  the  wine,  with  a 
flask  containing  250  cc.  of  water.  The  contents  of  both  flasks  are 
brought  to  the  boiling-point,  and  then  the  flame  beneath  the  wine  is 
turned  down  and  the  current  of  steam  passed  through  until  200  cc. 
of  distillate  are  collected.  This  is  titrated  with  decinormal  sodium 
hydrate,  and  the  result  is  expressed  as  acetic  acid.  The  determination 
of  the  amounts  of  the  individual  acids  is  of  no  hygienic  interest. 

Determination  of  Sugar. — The  amount  of  sugar  in  wine  is  deter- 
mined by  reduction  of  Fehling's  solution,  by  the  method  of  Allihn,  and 
by  polariscopy.      For  the  details  of  these  methods,  the  reader  is  referred 


ANA/,y.S/S   OF    WISKS.  2'V.) 

t<)  Jiiiy  of  tlu!  .staiidiinl  works  on  wine  ;iii;ilyHis,  for  (lie  Hiiiall  jimoiirit 
of  Mii^Mi-  <»i'(liii!irilv  |»i-('S(!iil  is  (if  lnif  liltic  li\  ^^iciilc  itilcrcHt,  ami  the 
(IcMcriptioii  (((■  Ihc  |)r(iccsscs  would  i(<|iiii-c  ;iii  ;iiii()iiiit  (»('  hpaa;  va«tly 
out  ol'  |)r<i[)or(  ion  (o  llic  ini|ioi't:incc  ol    the  snhjccl. 

Determination  of  Ash. — 'I'Ik-  rc-idnc  oi»lMincd  in  ilic  dctcitnin.-iiion 
of  oxtrax •-(.(•; in  be  nlili/.fd  Cor  llir  ddcrtninalion  of  tlic;i-li.  Il  -lioidd 
l)('  iii^nifcd  ill  MS  low  ;i  lcni|>rr;ilnr('  ;is  |)ossilil('. 

Detection  of  Coal-tar  Colors. — Whilf  the  |)i(--cnc<'  (.('  coal-tar 
(rolors  is  not.  diilicnil  of  (|('t<'ction,  the  idcntifK  alion  of  the  iiuiividiial 
mcndxTS  of  the  t;ron|)  is  hy  no  means  easy.  The  foljowin^r  te.-ts  jrive 
reliable^  indic^ations  of  I  he  |ii-cscnce  of  this  class  of  color-.  I'.fjiiaJ 
vohinuis  of  wine  and  el  lier,  aiiilaled  in  a  llasls,  and  let  stand  and  -epa- 
ratc,  will  show  in  I  lie  el  her  la\-er  a  vrA  coloration,  if  anilin  eohtr-  are 
present.  in  place  of  ellier,  nilro-hen/ene  may  he  used  ;  this  removcH 
fuohsin,  eosin,  and  niel  liylen-hlne,  hnt  does  not  take  n|>  any  of  the 
vc'f»;otahle  eoloi's,  safranin,  or  indieo-cjirmine.  Amyl  alcohol,  also,  will 
become  reddened  when  agitated  with  wine  containing  anilins,  but  the 
wine  must  fu-st  be  made  slie;htly  alkaline.  I  f  white  woollen  threads 
are  immersed  tor  some  time  in  the  colored  lifjiiids,  they  will  take  up 
the  colors  and  become  dyed. 

Cazeueuve's  test  is  performed  as  follows:  To  10  ee.  of  wine  add 
0.20  i2;ram  of  mercuric  oxide,  then  shake  for  one  minute,  boil,  let 
stand,  and  filter.  The  iiltrate  should  be  clear,  and  in  the  absence 
of  anilins  should  be  colorless;  if  it  is  red,  an  anilin  color  is  present. 
Absence  of  color  is,  however,  not  conclusive  evidence  of  purity,  since 
a  number  of  the  anilin  colors,  as  eosiu,  raethylen-blue,  and  others,  are 
whollv  precipitated,  and  so  do  not  ai)]iear  in  the  filtrate  Safranin, 
methyl-eosin,  Ponceau  red,  antl  a  nund)er  of  other  colors  are  precipi- 
tated ])artially  or  completely. 

A  number  of  these,  including  safranin,  Bordauix  red,  and  Ponceiiu 
red,  may  be  separated  by  the  following  process  :  To  200  cc.  of  wine 
from  which  the  alcohol  has  been  expelled,  add  4  cc.  of  10  per  cent, 
hydrochloric  acid  and  some  white  woollen  threads,  and  boil  for  five 
minutes.  Withdraw  the  threads  and  wash  them  with  cold  water  acidu- 
lated wdth  hydrochloric  acid,  next  with  hot  watcu-  similarly  acidulated, 
and  lastly  with  distilled  water  alone.  Boil  the  threads  in  50  cc.  of 
distilled  water  containing  2  cc.  of  strong  ammonia  water,  remove  them, 
and  immerse  new  ones.  Make  acid  with  hydrochloric  acid  and  boil 
for  five  minutes.  Varying  shades  of  rose-red  will  be  imparted  to  the 
threads  if  any  of  these  colors  are  present. 

Fuchsin  may  be  detected  by  the  following  methods  :  (1)  To  100  cc. 
of  wine  add  5  cc.  of  ammonia  water  and  30  cc.  of  ether,  and  shake. 
Remove  the  ether,  which  will  have  no  color,  place  it  in  a  watch-glass 
with  a  w'hite  woollen  thread,  and  let  it  evaporate  to  diyne^s.  If  even 
a  trace  of  fuchsin  is  present,  the  thread  Avill  show  a  distinct  rose-col- 
oration. (2)  Mix  2  volumes  of  wine  and  1  of  solution  of  basic  ace- 
tate of  lead,  warm  gently,  and  shake.  Filter,  add  to  the  filtrate  a 
small  amount  of  amyl  alcohol,  shake  again,  and  remove  the  amyl  alco- 


240  FOODS. 

hoi.  If  this  has  a  red  color,  it  may  ho  due  to  fuchsin  or  to  orseille. 
To  a  portion  of  the  colored  liquid  add  hydrochloric  acid  ;  if  the  color 
is  discharged,  it  was  due  to  fuchsin.  To  another  portion  add  ammonia 
water;   if  tlie  coli)r  is  chauo-ed  to  purple  violet,  it  was  due  to  orseille, 

Detection  of  Preservatives. — Salicylic  Acid. — Spica's  method  for 
detecting  salicylic  acid  in  wine  is  as  follows  :  Acidify  10  cc.  of  wine 
with  a  few  drops  of  hydrochloric  acid,  and  shake  with  an  equal  volume 
of  ether.  Remove  the  ether,  filter  it  if  necessary,  and  evaporate  to 
dryness.  Add  a  drop  of  nitric  acid,  warm  gently,  and  add  an  excess 
of  ammonia  and  1  cc.  of  water.  Immerse  a  white  Avoolleu  thread, 
apply  gentle  heat,  and  then  withdraw  the  thread,  wash  it,  and  dry  it 
l)et\yeen  pieces  of  hlotting-paper.  A  yellow  color  indicates  that  sali- 
cylic acid  was  present  in  the  wine. 

Anotlier  method,  for  which  great  delicacy  is  claimed,  even  to  a  tenth 
of  a  milligram  in  a  liter,  is  the  follo^ying  :  Acidify  50  cc.  of  wine, 
beer,  or  other  liquid  with  sulphuric  acid,  and  shake  it  with  an  equal 
volume  of  a  mixture  of  equal  parts  of  ether  and  naphtha.  Separate 
the  ether,  filter,  and  evaporate  down  to  5  cc.  ;  then  add  3  cc.  of  water 
and  a  few  drops  of  very  dilute  solution  of  ferric  chloride,  and  filter 
through  a  wet  filter.  In  the  presence  of  salicylic  acid,  the  watery  por- 
tion will  have  a  violet  color.  A  modification  of  this  method  consists 
in  extracting  with  ether  alone,  and  then  extracting  the  ether  residue 
with  naphtha ;  the  residue  on  evaporation  of  the  naphtha  is  treated 
with  water  and  very  dilute  ferric  chloride. 

Fonnaldeliyde. — To  10  cc.  of  wine,  add  a  few  drops  of  milk  known 
to  be  free  from  formaldehyde,  and  shake  in  a  test-tube.  Next  pour 
down  the  side  of  the  tube  about  4—5  cc.  of  strong  commercial  sul- 
phuric acid,  and  note  the  color  at  the  line  of  contact  of  the  two  liquids. 
(See  under  Milk.) 

Sulphites. — To  200  cc.  of  wine  (or  beer)  add  5  cc.  of  phosphoric 
acid  ;  distil  100  cc,  using  a  Liebig  condenser  with  a  bent  delivery  tube 
which  dips  below  the  surface  of  20  cc.  of  decinormal  solution  of  iodine. 
By  distilling  in  a  current  of  washed  COj,  the  danger  of  back  suction 
is  avoided.  The  reaction  which  is  brought  about  is  as  follows : 
SO,  +  2H,0  +  I,  =  H,SO,  +  2HI.  The  amount  of  SO,  may  be 
determined  by  estimating  the  excess  of  iodine  by  means  of  standard 
sodium  thiosulphate,  or  the  distillate  may  be  acidified  with  hydrochloric 
acid  and  the  contained  sulphuric  acid  precipitated  as  barium  sulphate 
by  the  addition  of  barium  chloride.  One  milligram  of  barium  sul- 
phate is  equivalent  to  0.2748  milligram  of  SO,. 

CIDER. 

Cider,  or  apple  wine,  is  the  fermented  juice  of  the  apple.  It  is  made 
very  extensively  wherever  apples  are  grown,  and  is  a  very  important 
product,  viewed  either  as  a  beverage  or  as  the  basis  of  what  is  regarded 
generally  as  the  best  kind  of  vinegar. 

A  very  large,  if  not  the  greater,  part  of  the  cider  produced  is  made 


l)fSTf/JJ':i>   ALCOHOLIC  11  EVER  AGES.  2)1 

without  spcc.iiil  can;  hy  a  very  siinplc  pnicc-s.  '\'\\i-  ;i|)|iI('.h  iik(;(1  are 
onliiiMi'ily  lliosc.  not  rii;irl<il:il»l<'  <mi  nrcoinii  oC  ,>-tri;ilI  >'\/v,  ^rccmujMH, 
ov(;r-i'i|)('n('SH,  or  hniiHcs  ;  l»iil  (iCtcn  pi  i  I'l  ri  IViiii  i-  ii.-cd  when  tlu;  rrf)p 
is  HO  jthimdanl  fli:tt  IIhtc  is  nioic  piolil  In  coiinciI  iii^^  it  into  cider  and 
vinegar  llian  in  sending;'  il  in  hnrrds  lo  market.  'I'lic  ("rnit  i.s  {/n»nnd 
to  a  |>iil|)  and  pressed,  :ind  the  juice  is  dr;i\\n  into  Icirrel-  ;ind  ;illourd 
to  ("crnicnt.  I  ("  tlic  same  arnonnt  (if  care  is  t:d\en  as  is  jriven  to  llic 
niakinj;'  oC  wine  Crorn  grapes,  tlic  product  is  of"  a  siij»crior  jrradc,  an<l 
keeps  very  well;  hnt  as  ordinarily  iniide  in  tln'  conntry,  its  life  is 
short,  unless  tre:ited  with  snlicylic  :icid  or  nthir  preservative;  to  check 
fermentation.  in  h'rance,  \\li<'re  the  yeiirly  yl<ld  i.s  very  j^(sit,  the 
best  j^raih's  are  made  with  {\\\v  remird  lo  the  ten)per:itnr(;  at  which  the 
fernu;ntation  |)r()cee(ls,  and  to  the  Importance  of  rack  I  n^^  off  and  finiiifr. 

( 'ider  of*  i:;ood  (piality  eontiiins  nsnally  from  .')  t<i  o  po-  cent.  ;ind 
sometimes  Jis  much  as  S  ])er  eeiil.  hy  wciuht  of"  alcoiiol.  \' ivy  new 
sweet  cider  may  contain  less  th:in  1  pei-  cent.  '^Flie  total  extniei,  which 
is  hir<>'ely  sujrar,  is  in  inverse  propoi'tion  to  tlie  amount  f)f  alcohol  ;  in 
average  samples,  it  amounts  to  from  4  to  (>  i)er  cent.,  while  in  new 
sweet  cider  it  is  commoidy  neiirer  \)  })er  cent.  The  free  acids,  ciiieHy 
malic,  amoimt  to  less  than  0.75  per  (;ent.,  and  average  about  0.40. 

The  adulterants  of  cider  are  water  and  salicylic  acid.  The  latter  ia 
found  very  commonly  in  that  which  reaches  the  city  markets. 

PERRY.  ^ 

Perry,  or  "pear  cider,"  is  the  fermented  juice  of  pears.  It  is  made 
in  the  same  way  as  cider.  Pear  juice  being  richer  in  sugar  than  apple 
juice,  it  follows  that  the  average  content  of  alcohol  is  somewhat  higher 
than  in  cider. 

Distilled  Alcoholic  Beverages. 

Spirits,  or  distilled  liquors,  are  the  product  of  distillation  of  fer- 
mented sugar  solutions.  Their  most  important  constituent  is  ethylic 
alcohol,  which  is  ordinarily  present  to  the  extent  of  about  45  per  cent. 
When  freshly  made,  they  contain  variable  small  quantities  of  higher 
alcohols,  furfurol,  fatty  acids,  and  other  volatile  principles,  which 
together  constitute  what  is  known  as  fusel  oil,  the  chief  constituent  of 
which  is  amylic  alcohol. 

Each  kind  of  grain  or  other  raw^  material  from  which  the  ferment- 
able sugar  solution  is  obtained  yields  a  diiferent  kind  of  fusel  oil ;  dif- 
ferent because  of  the  changing  relative  proportions  of  its  constituents, 
Avhich  include  butylic,  propylic,  aud  amylic  alcohols,  and  their  corre- 
sponding acids,  butyric,  propionic,  and  valerianic,  and  other  mattei-s. 
That  wdiich  is  foimd  in  potato  spirits  is  richest  in  amylic  alcohol,  and 
is  the  most  toxic,  while  that  from  grapes  contains  bv  far  the  least  and 
produces  the  least  harm.  During  the  process  of  aging,  the  constituents 
of  the  fusel  oil  undergo  chemical  changes  Avhicli  result  in  the  formation 
of  oenanthic,  acetic,  and  butyric  ethers,  acetate  and  valerianate  of  amvl, 
and  other  compounds,  which  together  constitute  the  aroma  or  "  bou- 

16 


242  FOODS. 

qiiet."  Thus,  a  spirit  is  iinj)ri)veil  in  two  ways  by  long'  storage  :  it 
loses  in  toxieity  and  gains  in  flavor. 

The  relative  toxieity  of  the  several  alcohols  and  of  other  eonstitnents 
of  fusel  oil  has  been  determiued  by  Dujardin-Beauinetz  and  others, 
who  show  that  the  ]wisonous  properties  increase  with  the  boiIing-])oint 
and  nioKruhir  weiglit,  Jeflroy  and  Serveaux  '  determined  the  amounts 
in  grams  necessary  j)er  kilognini  to  kill  a  rabbit,  as  follows  :  ethylii; 
alcohol,  11.70;  ])ropylic  alcohol,  3.40;  bntylic  alcohol,  1.45;  amylic 
alcohol,  0.G3  ;  furfurol,  0.24.  Daremberg^  found  by  experiment  that 
artificial  spirits  and  wines  made  with  jiure  rectified  alcohol  are  less  toxic 
than  the  gxnuiine  products,  by  reason  of  the  absence  of  the  constituents 
of  fusel  oil.  Roubinowitch,''  speaking  of  the  greater  toxicity  of  the 
higher  alcohols,  calls  attention  to  the  fact  that  the  distillates  from  cider, 
perry,  and  fermented  grains,  potatoes,  and  molasses,  are  much  more 
toxic  than  brandy. 

Most  spirits  are  colored  artificially  by  the  addition  of  harmless  col- 
oring agents,  the  mt)st  ^videly  used  of  which  is  caramel.  As  the  prac- 
tice of  coloring  is  in  response  to  the  demand  of  the  consumer  for  a 
darker  color  than  can  be  obtained  otherwise,  it  can  hardly  be  regarded 
as  an  adulteration. 

BRANDY. 

Brandy  is  obtained  by  distilling  wines  of  the  poorer  qualities,  often 
mixedj  with  the  "  lees,"  or  dregs  from  the  wine  casks,  and  the  "  marc," 
or  solid  refuse  left  after  pressing  the  grapes.  The  lees  and  marc  are 
used  also  alone  for  the  production  of  a  highly  odorous  brandy,  which  is 
much  used  for  improving  the  flavor  of  other  brandies,  and  for  giving 
flavor  to  the  artificial  brandies  made  from  pure  alcohol  and  -water. 
From  this  marc  brandy  is  obtained  the  oily  substance,  oeuanthic  ether, 
which  is  known  commercially  as  ''  oil  of  wine." 

Brandy  is  produced  very  largely  in  France,  and  much  less  exten- 
sively in  Spain,  Portugal,  and  Germany  ;  in  California  and  in  the  wine- 
groAving  region  of  the  Ohio  and  Mississippi  Valley,  it  is  produced  in 
large  quantities  and  of  most  excellent  quality. 

The  colorless  distillate  is  stored  for  some  time  in  oaken  casks,  from 
which  a  small  trace  of  tannin  and  a  varying  depth  of  amber  (tolor  are 
acquired.  The  flavor,  which  in  general  dej)ends  upon  the  kind  of 
grapes,  their  condition  when  pressed,  and  the  care  observed  in  the 
making  of  the  wine,  becomes  improved  during  storage.  The  liquor  is 
then  colored  and  l)ottled  for  the  market. 

Good  brandy  should  contain  from  39  to  47  per  cent,  of  alcohol  by 
weight,  should  have  an  agreeable  odor  and  taste,  and  should  be  free 
from  substances  added  to  impart  sharp  taste  and  apjiai'ent  strength. 
The  nearly  dry  residue  from  100  cc.  very  slowly  evaporated  on  a  water- 
bath  should  have  a  pleasant  odor,  and  its  taste  should  be  neither  sweet 
nor  sharp  ;  a  sharp  odor  points  to  the  presence  of  fusel  oil  derived  from 

1  Arcliivijs  (lu  Medecine  expdrinientale  et  d'Anatoniic  patliologifjue,  1895,  p.  569. 
^  Ibidem,  p.  719.  »  (iazctt^  des  Hopitaux,  1895,  p.  237. 


WHISK  ICY.  243 

|M)i;i(<)  or  ccnials  ;  ;i  sweet  liisle  is  iiidieiilive  of  ;ul<le(l  Kii^ar  or  glycerin  ; 
;i.ii(l  :i,  sli;ii'|»  liisle  Is  siimje- ( i\e  of  e.iyciinc  oi-  oilier  Kpiee. 

Mlieli  oC  llie  hr.'ilidv  o("  eoiiiiinicc  i  ;i  |)i|i'ely  ;irl  i(iei;il  |»ro(li|r-f  inu'lr; 
Irom  mJcoIioI  oi-  [jolnXo  s|)ir'ils,  \v;ilei-,  mid  lliixoi-iii^-.s.  'I'lie  rormiihi'  for 
iMiikiii;^'  Krandy  arc:  \vv\  iiiinieroiis,  and  iiol  a  few  i'e(|iiir<'  wlial  is  known 
as  brandy  (iSHencc,  an  ai-liclc  made  wiili  dluis  and  other  Hiiljstjine*,-.-  in 
varyint;'  |>ro|)oi'lions.  J>y  oni;  ("oniinla,  i(  is  made  with  5  parts  «»rfetian- 
tliie,  ellier,  I  of  acetic  ellier,  '5  of  tinelin-e  oC^rjdls,  1  of  tinefnre  of  |.i- 
iiufnlu,  and  100  ol' alcohol  ;  hy  another,  it  consists  of"  15  |iarts  of  a<'elic 
ethel',  12  of  sweel  spirit  of  nitre,  and  I  of  rectilled  wood  spirit.  Ono 
part,  of  either  of  these  mixdires  is  snilieieiil  to  (lavor  a  mixtnreof  1000 
j)arls  of  alcohol  and  (idO  of  water. 

As  examples  of  the  wa\'  in  whieli  fiditions  hrandy  is  made,  the  ff,|- 
lovviiifi:;  will  sefNc  :  (!)  I'oil  o  onnees  of  raisins  and  G  of  St.  JoImi'h 
bread  in  water,  liltcr,  and  make  up  to  JO  (jiiarts  ;  mix  this  with  20 
(puu'ts  of  iilcohol,  10  omiees  of  hrandy  essence,  and  \  onnec  of  essc;nce 
of  violetj  Howers.  (2)  Dissolve  1  |»onnd  of  arjrols  and  .'>  of  snpir  in  a 
<rallon  of  water,  add  tO  i^allons  of  alcohol,  \  poinid  of  acetic  ether,  2 
ounces  of  tincture  of  kino,  (5  pounds  of  bruised  raisins,  and  a  sufficient 
amount  of  caramel,  and  let  stand  for  fourteen  days ;  strain  and  bottle. 

WHISKEY. 

Whiskey  is  the  product  of  distillation  of  the  fermented  mash  of 
i>;rain  or  potatoes.  The  raw  materials  from  which  the  mash  is  made 
include  malt,  wheat,  rye,  corn,  oats,  and  potato.  In  the  process  of 
mashinii;,  the  starch  of  the  ^rain  is  chan<i;ed  to  su^ar  by  the  dia.stii.se  of 
the  malt;  and  since  this  ferment  is  capable  of  converting  other  starch 
than  that  with  which  it  is  associated,  it  is  customary  to  mix  malt  and 
raw  grain  in  the  jiroportion  of  1  to  from  5  to  1)  parts.  A  bushel  of 
grain  makes  about  2.5  gallons  of  spirits.  In  this  country,  the  grains 
employed  are  chiefly  corn,  wheat,  and  rye  ;  in  Great  Britain,  barley, 
oats,  and  rye  are  used  together ;  potatoes  are  used  to  a  greater  or  less 
extent  on  the  continent.  The  mash  for  Scotch  whiskey  is  very  com- 
monly pi-e[)ared  from  2  parts  of  malt,  7  of  barley,  and  1  each  of  oats  and 
rye  ;  that  for  Irish  whiskey  is  the  same,  with  the  exception  of  the  rye. 

As  soon  as  the  fermentation  of  the  mash  through  the  agency  of  yeast 
is  com]>lcte,  the  distillation  is  begun.  The  first  distillate,  known  as 
"  low  wine,"  is  re-distilled.  The  second  distillate  is  stronger  and  less 
rich  in  fusel  oil,  which,  being  less  volatile  than  ethylic  alcohol,  comes 
over  chiefly  in  the  later  })ortions.  The  new  whiskey  is  stored  for  sev- 
eral years,  in  order  that  it  may  acquire  the  flavor  due  to  the  formation 
of  new  compounds  from  the  constituents  of  the  fusel  oil.  During  stor- 
age, it  takes  up  a  trace  of  tannin  from  the  oak  of  the  casks. 

The  flavor  of  whiskey  depends  upon  the  nature  of  the  raw  material, 
and  largely  upon  the  aging  process.  The  disagreeable  flavor  and  odor 
of  new  wdiiskey  are  due  to  fusel  oil  ;  the  smoky  taste  of  Scotch  and 
Irish  whiskies  is  due  to  the  smoke  of  the  peat  and  turf  fires  over  which 
the  malt  is  dried.     Indian  corn  whisk v  has  a  much  different  flavor 


244  FOODS. 

from  that  of  rye  whiskey  ;  this  flavor  is  regarded  highly  by  many  to 
whom  rye  whiskey  is  unpahitable  and  insipid,  and  at  the  same  time  it 
is  so  full  that  to  others  it  is  rank  and  nauseating.  The  peculiar  flavor 
of  Bourbon  whiskey,  so-called  ix'cause  originally  produced  in  Bourbon 
County,  Kentucky,  is  due  to  the  corn  from  which,  with  ]'\e,  the  mash 
is  prepared. 

Whiskey  of  .good  quality  should  contain  about  45  per  cent,  of  alco- 
hol by  weight,  ;ind  should  yield  not  more  than  0.25  per  cent,  of  resi- 
due, which  shouUl  have  a  slightly  aromatic  odor  and  but  little  taste. 

AVhiskey  is  manufactured  very  largely  from  alcohol,  water,  and 
various  flavoring  compounds,  some  of  wdiich  can  hardly  be  looked  upon 
as  wholly  innocuous.  The  following  directions  are  taken  from  a  small 
Nvork,  the  object  of  which  is,  according  to  the  preface,  "  to  give  the  dis- 
penser of  liquors  thorough  and  practical  information  by  which  he  will 
be  enabled  to  compound,  and  blend  liquors  for  his  own  purposes,  and 
thus  secure  the  additional  profit." 

1.  Bourbon  Oil. — Take  of  fusel  oil,  64  ounces  ;  acetate  of  potassium 
and  sulphuric  acid,  each,  4  ounces  ;  and  black  oxide  of  manganese,  1 
ounce.  Dissolve  h  ounce  each  of  sulphate  of  copper  and  oxalate  of 
ammonium  in  4  ounces  of  water,  mix  all  in  a  glass  percolator,  and  let 
rest  for  twelve  hours.  Then  percolate  and  put  into  a  glass  still,  and 
distil  64  ounces. 

2.  Rye  Oil. — ]\Iix  64  ounces  of  fusel  oil,  8  each  of  oenanthic  ether, 
chloroform,  and  sulphuric  acid,  and  2  of  chlorate  of  potassium  in  8  of 
water,  place  in  a  glass  still,  and  distil  64  ounces, 

3.  BeadiiKj  Oil. — ]Mix  together  48  ounces  of  oil  of  sweet  almonds 
and  12  of  sul])huric  acid,  and  when  cool  neutralize  with  ammonia  and 
dilute  with  double  the  volume  of  proof  spirit.  "  This  is  used  to  put 
an  artificial  bead  on  inferior  liquors,"  For  making  the  lowest  grade 
of  whiskey,  one  is  directed  to  mix  32  gallons  of  alcohol  and  16  of  water, 
4  ounces  of  caramel  and  1  of  beading  (h1.  ^y  adding  oil  of  rye  or  oil 
of  Bourbon,  "  making  the  result  rye  whiskey  or  Bourbon,  as  the  case 
may  be,"  the  value  is  said  to  be  increased. 

From  another  similar  source  the  following  recipes  for  factitious 
whiskey  are  taken  : 

1.  Bourbon  Whiskey — Proof  spirit/  100  gallons  ;  pear  oil,  4  ounces  ; 
pelargonic  ether,  2  ounces;  oil  of  wintergreen,  13  drachms  in  ether; 
wine  vinegar,  1  gallon  ;  caramel  color,  a  sufficient  quantity. 

2.  Old  Bourbon. — Alcohol,  40  gallons ;  Bourbon  whiskey,  5  gal- 
lons ;  sweet  spirit  of  nitre,  2  ounces ;  fusel  oil,  2  ounces.  Mix  and 
let  stand  four  days. 

3.  Old  Rye. — Soak  a  half  peck  of  roasted  dried  jieaches,  put  them 

'  Proof  spirit  is  defined  by  an  act  of  Parliament  as  a  diluted  spirit  which  at  51°  F. 
shall  weigh  exactly  twelve-thirteenths  as  much  as  an  equal  measure  of  distilled  water. 
It  contains  half  its  volume  of  alcohol  of  sp.  ><r.  0.7939  at  60°  F.,  or  49.5  per  cent,  by 
weight,  or  57.27  per  cent,  by  volume  of  absolute  alcohol.  Its  sp.  gr.  is  0.91984.  Over 
and  under  proof  mean  that  a  spirit  is  stronger  or  weaker  than  proof  spirit,  and  the 
excess  or  deficiency  is  expressed  as  so  many  degrees  over  or  under  proof.  The  expres- 
sion, for  example,  25  under  proof,  means  that  the  specimen  consists  of  25  parts  of  water 
and  75  of  proof  spirit ;  25  f)ver  proof  means  that  100  parts  may  be  diluted  with  25  of 
water  to  bring  it  to  the  strength  of  proof  spirit. 


LiqdKinis.  245 

into  a  w(K)ll(!ii  hn^  jiikI  Ic-icJi  willi  (•oiiiiiion  uliiskciy  Kiiflicicnt  for  a 
barrel,  and  add   TjJ  dr<ips  oC  sli'on^  ;i(iiinoiii;i. 

A.  Hicolrjt.  Wlihhry. — Alcoli<»l,  M!  gallons;  ^cniiidf  Sfofi;li,  8  gal- 
lons; vviil,(;r,  1 H  omUods  ;  ;\\v,  I  ^nllon  ;  crcjisofc,  U  drojts  in  2  onnc/'H 
of  ac(;tic,  acid  ;  (M^liirjroiiic  cllicr,   1  (iiincc  ;   Immk  y,  ."'.  imnnrJ.s. 

5.  /m/i  Whiskrii. — SiUiH;  its  whovc,  siil),-.li(ntin^  Iri'-li  for  Scotrli, 
and  omitting  i\\v.  Iioiicy. 

RUM. 

Rnni  i.s  inad(!  by  distillinf:;  fermented  molasses  or  tiie  skimming's  of 
sugar  boilers,  with,  not  nncominoidy,  otli(;r  substanees,  as  f)ineapj»lcH 
and  fi^MMvas,  to  gi\'e  (l:i\'or.  Tlic  cliariicteristie  flavor  of  mm  is  due  U) 
butyric;  ether,  'i^lie  ;d(M>lioli<;  eonlcnt  of  rum  is  very  variable,  ranging 
from  .'>()  to  over  (!()  ))er  (^enl.  by  weight.  Like  other  spirits,  rum  i.s 
very  largely  ;in  artifuiial  prochict  of  aliMiliol,  \\;it<i-,  and  HavoringH 
known  as  rum  essence.  One  of  thesi;  consists  of  lo  parts  of  butvric 
ether,  2  each  of  acetic  ether,  essence  of  vanilla,  and  essence  of  violet, 
and  90  of  alcohol.  Another  consists  of  o2  j)arts  each  of  rum  ether 
and  acetic  ether,  S  of  butyric  ether,  10  of  extract  of  saffron^  and  ^  of 
oil  of  birch  cut  in  strong  alcohol.  The  rum  ether  required  is  a  product 
of  the  distillation  of  alcohol,  sulphuric  acid,  pyroligncous  acid,  and 
black  oxide  of  manganese.  Prime  Juice  is  also  a  common  addition  to 
factitious  rum  for  its  flavor  and  color. 


am. 

Gin  is  an  alcoholic  liquor  flavored  with  juniper  berries  and  a  great 
variety  of  other  substances,  including  cardamom,  {H.)riander,  cassia  buds, 
calamus,  orris,  angelica  root,  orange  peel,  licorice  powder,  and  sugar. 
It  should  contain  about  40  per  cent,  of  alcohol,  and  not  over  6  per 
cent,  of  total  residue,  including  sugar. 

Liqueurs. 

Liqueurs,  or  cordials,  are  manufactured  compounds  of  alcohol,  essen- 
tial oils,  cane  sugar,  and  coloring  matter.  They  contain  usually  about 
40  per  cent,  of  alcohol  by  weight,  and  from  25  to  50  per  cent,  of  cane 
sugar.  The  colorings  are,  as  a  rule,  of  vegetable  origin,  but  sometimes 
the  coal-tar  colors  are  employed.  Even  in  the  small  amounts  ordi- 
narily taken,  their  use  can  hardly  be  advised,  in  view  of  the  adverse 
report  (March  10,  1903)  of  the  Committee  of  the  Academic  de  Mede- 
cine,  to  whom  the  question  of  their  wholesomeness  was  referred  l\v  the 
French  government.  The  essential  oils  are  the  objectionable  ingredi- 
ents, apart  from  the  alcohol.  Especially  deleterious  is  one  which  is 
taken  commonly  with  considerable  water  before  meals,  namely,  absinthe. 
By  some  the  poisonous  constituent  is  held  to  be  the  oil  of  wormwood 
(Artemisia  absinthium),  by  others  the  oil  of  star  anise  (Illicium), 
both  of  which  it  contains.  To  which  constituent  the  blame  belongs 
is  of    no    great    consequence,  the  drink  being    one  which  should  be 


246  •  FOODS. 

shunned  above  all  others  as  a  poison,  without  regard  to  the  innoc- 
uousness  of  most  of  its  constituents;  l)nt  it  is  unlikely  that  its 
disastrous  effects  are  due  to  wormwood,  whicli  as  a  drug;  has  lit- 
tle or  no  action,  and  which  enters  into  the  comjiosition  of  another 
drink,  vernuitii,  which  enjoys  a  good  reputation,  l)ut  is  not  a  cor- 
dial. It  is  a  fortified  white  wine  in  which  certain  herbs  and  other 
vegetable  matters  have  been  infused.  The  ordinary  French  vermuth 
is  made  from  wormw^ood,  bitter-orange  peel,  water  germander,  orris 
root,  chamomile,  Peruvian  bark,  aloes,  cinnamon,  initm(>g,  centaury,  and 
raspberry,  but  many  other  substanc(>s  are  used  by  dilferent  makers. 
The  fresh  ])roduct  has  a  very  jironounced  flavor,  which  is  mellowed 
by  age.  The  wines  most  used  in  making  Fi'cnch  vermuth  are  from 
the  Rhone  Valley,  Picpoul,  and  from  the  southernmost  parts  of  France. 
Italian  vermuth  differs  materially  from  tht>  French ;  it  is  a  much 
weaker  infusion  with  a  far  more  bitter  taste.  The  materials  used  are 
in  the  main  the  same,  but  they  are  employed  in  very  dilferent  propor- 
tions.     Vermuth  contains  about  17  per  cent,  of  alcohol. 

Section  6.     CONDIMENTS,  SPICES,  AND  BAKERS' 
CHEMICALS. 

The  condiments  include  a  large  number  of  food  accessories  which, 
while  they  are  themselves  of  no  nutritive  value  in  the  amounts  which 
it  is  possible  to  eat,  serve  a  very  useful  purpose  in  imparting  flavor, 
and  in  stimulating  appetite  and  digestion.  Among  them  are  some 
which  act  through  free  acids,  some  through  volatile  oils,  some  through 
resinous  matters,  and  one,  perliaps  the  most  important  of  all,  common 
salt,  through  itself  alone.  Some  are  simple  substances  ;  as  vinegar,  salt, 
and  the  spices ;  while  others  are  combinations  of  a  number  of  ingredi- 
ents blended  according  to  definite  and,  as  a  rule,  secret  formulas ;  as 
sauces,  chutueys,  catsups,  and  curries.  Only  when  these  compounded 
articles  contain  substances  injurious  to  health  can  they  be  regarded  as 
adulterated.  The  tomato  catsups  are  preserved  very  commonly  with 
salicylic  acid  or  other  preservatives,  and  colored  with  anilin  dyes. 
Thus,  of  25  samples  of  different  makes  examined  in  1897  by  the  health 
authorities  of  San  Francisco,  20  contained  salicylic  acid,  2  contained 
this  agent  together  with  borax,  and  1  contained  formaldehyde;  16  were 
artificially  colored,  mostly  with  coal-tar  colors.  Of  39  examined  by 
the  Massachusetts  State  Board  of  Health  during  1899,  15  contained 
salicylic  acid  and  13  benzoic  acid. 

VINEGAR. 

Vinegar  is  a  weak  solution  of  acetic  acid  resulting  from  the  acetous 
fermentation  of  saccharine  solutions  which  have  undergone  alcoholic 
fermentation.  It  contains,  in  addition  to  acetic  acid,  small  and  unim- 
portant amounts  of  alcohol  and  aldehyde,  and  extractive  matters  in 
varying  amounts,  according  to  the  nature  of  the  original  liquid.     The 


VINI'XJA  R.  247 

;ut(itio  .'icid  cf)iil;i.iiic(l  in  the  |)r()<liir-,l  of  (ixid.ition  of  alfolifd  (liroiigli 
\\n\  nt^ctH^y  oC  !\I iicoiici-nKi  ticr/i^  ;i  (11111:11^  wliicli  lorniH  what  jh  known 
!i,s  ilic  "  nioiJici-  of  viii<'L;;:ir."  'I'liii-,  tln'  cliiiiip'  ('rorii  sii^'ar  io  ncA't'iv 
•,}(•](]  involves  Ivvo  sc|);ir:il('  l'ciiii(nl;il  i\<' di;!  n^'cs  llii-on|rli  lli«*  a^ciu-y  r»f 
two  (lidercnt  ora;;iiiisnis,  Stn-c/icroiiii/crs  (•crcriK'nc  and  Mi/i-oflrmifi  (ircli, 

'riicr'(!  arc  several  kinds  oC  viiiep-ir  in  eoniinon  nse,  as  follows  : 

Cider  Vinegar. —  In  lliis  eoimliy,  eider  vinrpir  is  rey^arded  very 
fi^enerally  as  the  most  desirable  kind.  it  eonfains  no  aldehyde,  about 
•l.T)!)  Jo  5. .50  per  cent,  of  iieefie  acid,  iniirked  I  races  ftf  malic  acid,  and 
abont  2  pel-  cent.  o("  jol.d  residne,  oi'  "  cider- vinejrnr  solids." 

United  State.s  Standard. — iStandard  cider  vinegar  is  tlic  product  made 
by  the  ahioholic  and  subscifpient  acetous  lermcntiition.s  of  the  jukje  of 
:ip|)les,  is  hevo-rotatory,  and  contains  not  less  (han  4  ^rams  of  acetic 
aciil,  not  less  than  1.(1  u;rams  of"  ai)|)le  solids,  of  which  not  more  than 
50  per  cent,  are  rcdueintij  suf>^ars,  and  not  less  than  0.2o  ^ram  of  apple 
ash  in  100  cc.  (20°  C.) ;  and  the  water-soluble  ash  froni  100  cc;. 
(20°  C.)  of  the  vinegar  contains  not  less  than  10  millif^rams  of  plios- 
j>liorie  acid  (P„0,_),  and  rcMjuires  not  less  than  30  cc.  of  decinormal 
acid  to  neutralize  its  alkalinity. 

Wine  Vinegar. — In  wine-])rodiicing  countries,  the  vinegar  in  com- 
mon use  is  made  from  the  cheaper  kinds  of  wine.  It  has  color  or  not, 
according  to  the  kind  of  wine  from  which  it  is  made.  The  so-calletl 
white  wine  vinegar  in  common  use  in  this  country  among  the  foreign- 
born  population  is  a  colorless  product  of  the  oxidation  of  dilute  .spirits. 
Wine  vinegar  contains  rather  more  acetic  aci<l  than  eider  vinegar,  but 
far  less  residue. 

United  States  Standard. — Standard  wine  vinegar  is  the  product 
made  by  the  alcoholic  and  subsequent  acetous  fermentations  of  tlie  juice 
of  grapes,  and  contains  in  100  cc.  (20°C.)  not  less  than  4  grams  of 
acetic  acid,  not  less  than  1.0  gram  of  grape  solids,  and  not  less  than 
O.lo  gram  of  grape  ash. 

Malt  Vinegar. — In  England,  which  is  neither  a  cider-producing  nor 
a  wine-producing  country,  the  vinegar  in  commonest  use  is  made  from 
a  wort  prepared  from  malt  and  unmalted  grain.  It  is  less  strong  in 
acetic  acid  than  the  vinegars  already  described,  but  commonly  contains 
sulphuric  acid,  which,  under  the  English  law,  is  a  permissible  admix- 
ture to  the  extent  of  not  exceeding  0.10  per  cent. 

United  States  Standard. — Standard  malt  vinegar  is  the  product  made 
by  the  alcoholic  and  subsequent  acetous  fermentations,  without  distil- 
lation, of  an  effusion  of  barley  malt,  or  cereals  whose  starch  has  been 
converted  by  malt,  is  dextro-rotatory,  and  contains  in  100  cc.  (20°  C) 
not  less  than  4  grams  of  acetic  acid,  not  less  than  2  grams  of  solids, 
and  not  less  than  0.2  gram  of  ash  ;  and  the  water-soluble  ash  from 
100  cc.  (20°  C)  of  the  vinegar  contains  not  less  than  9  millignims  of 
phosphoric  acid  (P.,0.),  and  requires  not  less  than  4  cc,  of  decinormal 
acid  to  neutralize  its  alkalinity. 

Sugar  Vinegar. — United  States  Standard.— Standard  sugar  vinegar 
is  the  product  made  by  the  alcoholic  and  subsequent  acetous  fermen- 


248  FOODS. 

tatiou  of  solutions  of  sugar,  syrup,  molasses  or  refiners'  syrup,  and 
contains  in  100  cc.  (20°  C.)  not  less  than  4  grams  of  acetic  acid. 

Glucose  Vinegar. — United  States  Standard. — Standard  glucose  vin- 
egar is  the  ]»rnihu't  ukuIo  by  the  alcoholic  and  subsequent  acetous  fer- 
mentations of  solutions  of  starch,  sugar,  or  glucose,  is  dextro-rotatory, 
and  contains  in  100  cc.  (20°  C.)  not  less  than  4  grams  of  acetic  acid. 

Molasses  Vinegar. — A  very  large  part  of  the  domestic  supply 
of  vinegar  is  manufactured  from  fermented  molasses.  It  is  made  to 
imitate  cider  vinegar  in  color,  and  is  sold  commonly  under  the  name 
of  that  article.  It  yields  about  the  same  amount  of  acid,  but  is  very 
deficient  in  residue.  The  latter  has  a  very  bitter  taste,  and  after  com- 
plete ignition  yields  an  ash  containing  no  potassium  salts,  while  that 
from  cider  vinegar  gives  a  decided  indication. 

Spirit  Vinegar. — Spirit  vinegar,  also  known  as  "  Quick  Process  " 
vinegar,  is  made  from  diluted  alcohol.  The  process  used  is  the  same 
as  that  employed  in  the  making  of  malt  vinegar  and  molasses  vinegar. 
A  series  of  suitable  vats  is  constructed  and  filled  with  beech  or  birch 
shavings  or  twigs,  which  by  appropi-iate  treatment  become  coated  with 
Jlycoderma  aceti.  The  alcoholic  liquid  is  allowed  to  percolate  through, 
and  in  its  passage  the  alcohol  is  transformed.  The  temperature  of  the 
room  is  maintained  at  about  70°  F. 

United  States  Standard. — Standard  spirit  vinegar  is  the  product 
made  by  the  acetous  fermentation  of  dilute  distilled  alcohol,  and  con- 
tains in  100  cc.  (20°  C.)  not  less  than  4  grams  of  acetic  acid. 

Adulterations  of  Vinegar. — The  principal  adulterations  of  vinegar 
are  the  addition  of  water  and  the  coloring  of  inferior  grades  so  that 
they  may  be  sold  as  cider  vinegar.  Where  laws  are  in  force  establish- 
ing standards  of  acidity  and  residue  for  cider  vinegar,  a  very  common 
fraud  is  the  addition  of  cider  jelly  or  of  a  preparation  made  from  apple 
pomace  to  a  cheap  vinegar  of  the  proper  strength,  colored,  if  necessary, 
with  caramel.  Such  compounds  always  show  but  slight  or  no  reaction 
when  tested  for  malic  acid.  The  addition  of  mineral  acids  is  not  a 
common  practice  in  this  country. 

Examination  of  Vinegar. — Acidity. — To  6  cc.  of  the  specimen 
in  a  porcelain  casserole,  add  a  few  drops  of  phenolphthalein  solution 
and  about  20  cc.  of  distilled  water.  Titrate  with  decinormal  sodium 
hydrate  solution,  adding  little  by  little  until  the  appearance  of  a  faint 
pink  coloration.  The  number  of  cc.  of  the  reagent  used,  divided  by 
10,  equals  the  percentage  of  absolute  acetic  acid. 

Residue. — Evaporate  5  grams  in  an  accurately  weighed  platinum 
dish  to  complete  dryness  over  boiling  water.  After  the  residue  is 
weighed,  it  may  be  ignited  for  its  yield  of  ash. 

Genuine  cider  vinegar  should  give  no  more  than  a  faint  cloudiness 
on  being  tested  with  nitrate  of  silver  and  chloride  of  barium  (absence 
of  more  than  traces  of  chlorides  and  sulphates),  and  should  yield  a 
fairly  copious  ])recipitate  with  solution  of  subacetate  of  lead  (presence 
of  malic  acid).  The  residue  should  not  taste  bitter  (absence  of  caramel). 
Cider  vinegar  to  which  water  has  been  added  is  likely,  according  to 


SALT.  249 

i,l)<'  iiiil-iirc  of  (Jic  wilier,  Id  sliow  iiioic  iIkim  llic  ii~ii;il  results  on  t««t- 
iiif^  for  chlorides  \\\\^\  siil|ili;il('S,  iitid  to  yu'\i\  nolnblc  tniccH  of"  lirnc. 
Molusscs  viiui^iir  ^(tiK^iully  yields  iii:irl<ed  iiidiealions  of  liiiir-  sdt-  and 
M  !noi"(!  or  1(!HH  pi'onoiiiuied  odor  of  ruin. 

LEMON  JUICE   AND   LIME   JUICE. 

IjOITIOII  juices  is  llie  ('X|»ressed  juice  of  (lie  ri|»e  frnil  <»f  (  'ilriiH  /i/iioiiinn. 
It  Ik  ii  soincnvliiit  tiirMd  yellowisli  li(|nld,  with  a  very  acid  taste  and  ;i 
slight  a<i;reeal)le  odor,  due  in  pai't  to  the  presence!  of"  a  small  trace  of 
volatile  oil  from  the  rind.  Il  shoidd  contain  about  7  to  K)  j>er  cent, 
of  citric  acid,  and  should  \ield  from  O.oO  lo  1.00  per  cent,  of"  a.sh.  Its 
specific  gravity  should  In',  not  less  than  1 .0.'iO,  and  is  usually  above 
I.OlO.  As  it  is  (piieU  to  undern()  decomj)osilioii  in  its  natural  cf)n- 
dition,  a,  number  of  methods  have  been  proposed  for  \\<  |)reservation, 
the  best  of  w  hi(^li  ap[)ears  to  be,  first  to  clarify  it  by  means  of  strong 
alcohol,  next  to  lilter  or  decant  from  the  ])recipitatcd  matters,  and  then 
to  (>xpel  the  alcohol  by  heat.  The  clear  juice  may  then  be  bottled  and 
sterilized. 

Lime  juice  is  the  expressed  juice  of  the  sour  lime,  C'ltrns  acidn,  and 
of  the  sweet  lime,  C.  limetta.  It  contains  usually  somewhat  less  acid 
than  lemon  juice,  and  has  a  lower  specific  gravity.  It  is  preserved  by 
the  same  method. 

As  antiscorbutics,  lemon  juice  and  lime  juice  are  of  about  equal  value, 
and  far  sujierior  to  vinegar. 

Adulteration. — Lemon  juice  is  much  more  subject  to  adulteration 
than  lime  juice,  but  both  are  falsified  and  imitated  extensively.  In 
fact,  it  would  not  be  overstating  the  case  to  say  that  by  far  the  larger 
part  of  the  lemon  juice  sold  in  this  country  is  wholly  factitious.  Com- 
monly, it  is  nothing  more  than  an  aqueous  solution  of  citric  acid  ;  some- 
times, it  is  flavored  with  oil  of  lemon.  Its  taste  is  much  sharper  and 
less  agreeable  than  that  of  the  genuine  article.  The  residue  is  very 
different  in  character  and  appearance,  and  leaves  practically  no  ash  on 
ignition.  Other  acids  are  used  sometimes  in  place  of  or  in  addition  to 
citric  acid.  The  one  most  commonly  employed  is  said  to  be  tartaric ; 
this  is  detected  readily  by  the  gradual  formation  of  bitartrate  of  potas- 
sium on  addition  of  the  acetate.  The  mineral  acids  are  said  to  be  added 
not  infrequently ;  they  are  detected  without  difficulty  by  the  common 
tests. 

SALT. 

The  best  grades  of  common  salt  are  white,  dry,  free  from  dirt,  and 
completely  soluble  in  water.  ]Many  specimens  of  good  quality  contain 
traces  of  chloride  of  magnesium,  which  causes  cakino:.  In  humid 
weather,  even  the  best  grade  of  salt  absorbs  moisture  sufficient  in 
amount  to  cause  it  to  lose  its  dry,  poAvdery  nature.  The  addition 
of  about  10  per  cent,  of  corn  starch  serves  to  keep  it  dry  and  pow- 
dered. 


250  FOODS. 

MUSTARD. 

Mustard  is  the  flour  oi'  llu'  seed  o['  tlio  l)ln(']c  and  llio  wliitt'  nmstard, 
Sinapis  nlxjcr  and  aS',  (iHhi.  'Tlic  lirst  luentioiicd  is  nuu'li  tlie  more  pun- 
gent <>f  the  two;  on  beino-  \\e(  witli  watei',  a  volatiU'  oil  is  developed 
from  two  of  its  constituents.  'I'hc  whiti'  inustard  yields  no  volatile 
oil  by  this  trt'atment,  but  develops  an  acrid  principle.  Jioth  varieties 
of  seeds  contain  a  bland  iixed  oil  to  the  extent  of  20-25  per  cent.  As 
this  adds  nothing-  to  the  flavor,  makes  grinding  more  difficult,  and 
exerts  an  injurious  influence  on  the  keeping  qualities,  it  is  removed 
from  the  whole  seeds  by  pressure. 

Mustard  is  largely  subjt'ct  to  adulteration  with  wheat,  rice,  and  corn 
flour,  with  the  farther  addition  of  turmeric  to  restore  the  color  lost  by 
dilution.  These  substances  are  detected  very  easily  by  means  of  the 
microscope.  Furthermore,  since  starch  is  wholly  absent  from  pure 
mustard  flour,  if  a  small  portion  of  a  suspected  sample,  boiled  in  a 
little  water  in  a  test-tube  and  cooled,  gives  a  blue  or  bluish-black 
color  on  the  addition  of  compound  iodine  solution,  it  uuquestional)ly  is 
adulterated. 

PEPPER. 

Pepper  is  the  fruit  of  Piper  nigrum,  a  perennial  climbing  shrub. 
The  unripe  berries,  dried  for  several  days  after  being  picked,  are  known 
as  Black  Pepper.  The  ripened  berries,  dried  and  decorticated,  are 
known  as  White  Pepper.  In  the  powdered  form,  in  which  they  are 
retailed  most  commonly,  both  are  adulterated  very  extensively  with 
substances  of  a  harmless  nature.  These  include  ground  shipbread, 
corumeal,  cocoanut  shells,  rice,  buckwheat,  oatmeal,  mustard  hulls, 
charcoal,  olive  stones,  and  a  variety  of  other  substances  of  little  or  no 
value,  capable  of  being  reduced  to  powder. 

The  simplest  method  of  determining  the  purity  of  this  or  any  other 
form  of  spice  is  to  reduce  a  specimen  of  the  genuine  unground  sub- 
stance to  powdered  form  and  study  its  appearance  under  the  microscope, 
and  then  to  compare  it  with  the  sample  in  question.  Each  kind  has  its 
characteristic  appearance,  and  so  with  a  little  practice  one  is  enabled  to 
determine  very  quickly  the  question  of  purity.  By  a  similar  study  of 
the  microsco])ic  appearances  of  the  common  adulterants,  these  may 
readily  be  identified  in  the  mixture.  The  chemical  analysis  is  intricate 
and  tedious,  and  not  always  conclusive. 

CLOVES. 

Cloves  are  the  flower  l^uds  of  Eur/enia  caryophyllata,  picked  while 
red  and  dried  in  the  sun.  They  contain  about  1  G  ])er  cent,  of  volatile 
oil,  easily  removed  and  of  considerable  value.  In  the  powdered  form, 
cloves  are  adulterated  commonly  with  allspice,  clove  stems,  spent 
cloves,  cocoanut  shells,  and  other  worthless  matter.  The  ])resenc(^  of 
spent  cloves  can  be  determined  only  by  estimation  of  tlie  amoimt  of 
volatile  oil  present.     Clove  stems  show  microscopically  a  very  large 


B A  KINO  POWDERS.  261 

J)r()|)ori.i(»li  o("  I  he  so-c;illc(|  sloiic  (•ell-.       Oilier  :-iil),-.|;ilic,(;.s   urc    (1(;L(:<;U:(1 
in  tlu!  iri.'iiincr  (lcsciil)c<l  iiiidci'  l'(|i|)cr. 

CINNAMON  AND   CASSIA. 

(!ilMi;un(»li  is  IIk'  inner  l);ii'l<  of  (  ' iiiiKiiiiniiniiii  zrifln hk-h m .  ('aHKia  'w> 
{\\v.  \y,\v\\  (>("  s('V<M';il  species  ol'  (  'iiiiKiiiuiiiiiiiii..  In  the  nn;_'rnMti*l  !-tjil<?, 
cinii.'inion  is  lliin  nnd  (icliejiic  ;  e;issi;i  is  lliick  :im(I  e(iin|t;ir;it ivcly 
(U);irse.  (linniinion  is  llie  rielier  in  \'<tl;itile  oil,  ;in<l  (or  iIiIh  rcawm  and 
l)('X',iUis(i  i(,  is  lonnd  iniicli  less  iihnnd.'inl  ly,  is  e<iiisider;il»ly  more  cxpcn- 
.siv(!  tliiin  cMssia.  (iroiind  (tiniiMiiion  is  priK-licMlly  ncvf-r  foniid  in  flu; 
niMi'lcct,  t\\(.\  suWslnnce  sol<l  iiiKh^r  l.Jiiil,  iiniiie  lieiri^  ;ilniost  iii\;iri;il(ly 
cnssia.  '^Plic  conunon  adidleranlw  of"  cassia  include  j^ronnd  >liij»l)rcad, 
nut  sIk^IIs,  and  cedar  sawdust. 

ALLSPICE  OR  PIMENTO. 

Allspice  is  ilie  dried  unripe  herries  o("  riiiiciild  ii/llclii'i/i-'<.  Altlionpli 
one  o("  tlie  cliea])est  ol"  spices,  it.  is  adidtcraie*!  extensi\'ely  w  itii  ^rround 
sliipbreacl,  cluircoul,  nut  shells,  clove  steins,  and  nnistinl  hulls. 

GINGER. 

Ginger  is  the  rhizome  of  Zhtf/iher  oJ/lciii(i/c.  Jt  is  one  of  the  most 
commonly  adulterated  of  condiments.  Tlie  snbstances  u.sed  include 
ground  shipbread,  rice,  mustard  hnlls,  cayenne,  turmeric,  connneal, 
clove  stems,  and  exhausted  ginger  from  the  maiuifiu'ture  of  the  tincture. 
It  is  very  rich  in  starch,  whicli  is  diiferentiated  ea.-ily  from  otiier 
starches. 

NUTMEG. 

Nutmeg  is  the  inner  kernel  of  the  fruit  of  3Tyrist}('a  frograns.  It  is 
not  eounnouly  sold  in  the  ]wwdered  condition,  but  \vheu  so  sold  is 
generally  adulterated  with  the  substances  used  as  admixtures  of  other 
spices. 

MACE. 

Mace  is  the  dried  membranous  covering,  the  arillode,  of  the  nutmeg. 
It  is  adulterated  with  wild  mace,  cornmeal,  and  other  cheap  materials. 

CAYENNE   PEPPER. 

Cayenne  is  not  a  true  ]ie])per,  but  the  powdered  pods  of  several 
species  of  Capsicum,  including  C.  annuvm  and  C  faM'u/iatnm.  Its 
appeai'anee  under  the  microscope  is  very  characteristic.  The  common- 
est adulterant  is  cornmeal.  Among  others  are  rice,  mustard  hulls, 
turmeric,  and  ground  shipbread. 

BAKING  POWDERS. 

Baking  powders,  like  condiments,  are  in  no  sense  foods,  but  being 
employed  in  the  preparation  of  bread,  in  which  are  retained  the  ulti- 


252  FOODS. 

mate  products  of  the  reactions  of  their  component  parts  upon  each 
other,  tliey  are  of  hygienic  interest.  They  are  employed  for  the  produc- 
tion, within  a  short  time,  of  a  result  which,  when  caused  by  the  action 
of  yeast,  is  only  slowly  brought  about ;  namely,  the  leavening  of  bread. 
Yeast  produces  the  leavening  gas,  carbon  dioxide,  through  slow  fermenta- 
tion of  a  part  of  the  carbohydrates  ;  while  with  the  use  of  baking 
powders,  this  gtis  is  disengaged  as  a  result  of  chemical  action  of  one  of 
the  t\:)nstituents  upon  another  in  the  presence  of  moisture,  and  chemical 
substances  foreign  to  yeast-leavened  bread  are  left  as  a  residuum  in  the 
bread.  AVhether  this  residuum  is  objectionable  on  the  score  of  its  in- 
fluence upon  the  system,  depends  upon  the  nature  of  the  ingredients  of 
the  ]X)wdcr  ;  but  aside  from  the  question  of  disadvantage  or  inferiority 
on  this  account,  it  is  a  fact,  genc'rally  acknowledged,  that  bread  made 
with  baking  powder  is  lacking  in  a  certiiin  agreeable  flavor  developed 
by  the  action  of  yeast. 

Baking  jiowders  are  combinations  of  an  acid  or  acid  salt  with 
sodium  bicarbonate  in  about  the  proper  proportions  for  chemical  union, 
together  with  an  amount  of  starch  sufficient  to  keep  the  ingredients  in 
a  dry  state,  and  hence  mutually  inactive.  When  the  combination  is 
introduced  directly  into  the  flour,  and  water  is  added  to  make  the  dough, 
the  reaction  occurs  and  carbon  dioxide  is  set  free.  They  are  known, 
according  to  the  nature  of  the  acid  salt,  as  tartrate,  phosphate,  and  alum 
powders.  Tartrate  powders  are  made  usually  with  "  cream  of  tartar  " 
(potassium  bitartrate),  but  occasionally  with  tartaric  acid,  which  is  not 
only  more  expensive,  but  is  objectionable  from  a  practical  standpoint 
on  account  of  its  readier  solubility,  which  causes  a  too  rapid  evolution 
of  gas.  The  reaction  which  occurs  between  potassium  bitartrate  and 
sodium  bicarbonate  has,  as  results,  carbon  dioxide,  water,  and  potas- 
sium sodium  tartrate,  or  "  Rochelle  salt "  ;  as  follows  : 

KHC,H406+NaHC03=KNaC4HA+C02+H20. 

The  commercial  advocates  of  other  kinds  of  powders  dwell  upon  the 
undesirability  of  aperient  substances  in  bread,  but  the  residuum  of 
Rochelle  salt  in  the  amount  of  bread  which  one  could  eat  in  a  day 
would  be  very  much  under  the  minimum  dose  from  which  any  results 
could  be  expected. 

Cream  of  tartar,  as  retailed,  is  adulterated  very  commonly  with  gyp- 
sum, chalk,  alum,  and  starch  ;  but  as  furnished  to  the  manufacturer  by 
the  refiners,  it  contains  but  a  very  small  percentage  of  a  normal  im- 
purity, tartrate  of  calcium.  The  usual  chemical  tests  and  microscopic 
examination  reveal  fraudulent  adulteration  very  quickly.  Good  speci- 
mens contain  at  least  94  per  cent,  of  bitartrate ;  and  2  decigrams, 
dissolved  in  hot  water  and  titrated  with  deci normal  sodium  hydrate, 
require  for  complete  neutralization  not  less  than  10  nor  more  than  10.6 
cc.  The  presence  of  a  small  amount  of  tartrate  of  calcium  is  of  no 
sanitary  importance  whatever,  statements  to  the  contrary  in  advertising 
matter  notwithstanding. 

The  phosphate  powders  are  made  with  acid  phosphate  of  calcium, 


FOOD  PRKHERVATION.  253 

wlii(;li  coiiImIiis  ordiiiiii'ily  more  nr  Ir.^.-  ,-iil|»li;ilc  ;i:-  ;i  ii;itiii;il  iiiijiiirity, 
'V\n'  rc^iu^l.ioii  witli  sodiiiin  l)ic;ii'l)iiii,ilc  i-  ex  |)ic.-:-;c(|  ;i-  Collowh  : 

(;nll,,(l'<),,),    j    -JNiillCO,       (iilII'O,    ,    •S■.^,\\\'^)^   i   '2C<>,   )   *2II,0. 

'riuirc!  is  no  \V('ll-a;r<itiii(lc(l  olijcd  ion  to  I  he  use;  of  tliis  cIhhh  of 
powders. 

Alum  |K»vv<I('rs  ;irc  iiiikIc  iisiimIIv  willi  sodii  :diiiii  ;iiid  a  \cv\  lar^f! 
iunoiiiM,  rrc(|ii('ii(,ly  as  lii^li  as  TjO  per  cciil.,  ofstanli  "  lilliiitr."  Tlifir 
Icavciiin^i,-  power  is  aiiiiost  invariably  f;ir  below  tlial  of  (arfrafe  and 
pliospliato  powders  of  j;'0(»d  (piality.  'I'lie  elieapest  (tIaKH  of  powders, 
the  sale  of  wliicjli  is  promoted  by  olfls  or  "|)reininms"  of  ejieap 
crockery  and  glass,  are  made  willi  alum  and  (lie  niaximnni  amount  of 
fillina;.  The  reaction  between  alum  and  ."-odiinn  biearbonafc  is 
expressed  as  follows  : 

Nii,Al,(,S()j4   I   GNallCO,,       At,(),.IIe   i    IN.-i.SO^  |   fiCX),,. 

Whether  the  alum  exerts  any  injurious  elfect  uj)ori  tlie  l)r(^d  itself, 
and  whether  the  resultintr  hydrate  or  any  excess  of  alum  has  any  sani- 
tary importance,  are  (piestions  wliieh  have  Ix'eii  the  subject  of  extensive 
controversy.  Without  rej)ro(luein<i;  tlie  arguments  and  claims  of  both 
sides,  it  sliould  be  said  that  the  weight  of  scientific  evidence  is  decidedly 
against  the  employment  of  alum  in  the  making  of  bread.  Some  of 
those  who  believe  alumina  to  be  harmless  in  the  amounts  consumed, 
regard  ])owdcrs  containing  both  alum  and  ])otassium  l)itartrate  as  higldy 
objectionable,  the  complete  precipitation  of  alumina  being  prevented. 
Powders  containing  alum  and  acid  phosphate  are  held  also  to  be  objec- 
tionable, on  account  of  the  formation  of  aluminum  jihosphate,  which  is 
supposed  to  inhibit  gastric  digestion. 

In  addition  to  sodium  bicarbonate,  ammonium  carbonate  is  used 
more  or  less  as  a  source  of  leavening  gas.  AMiile  this  agent  when 
administered  therapeutically  may  exert  a  marked  temporary  influence, 
the  amount  used  in  baking  powders  is  too  small  to  be  hurtful  to  the 
system. 

The  amount  of  starch  filling  used  in  making  baking  powders  is  very 
variable.  The  best  grades  contain  considerably  under  20  per  cent., 
and  anything  over  that  amount  may  rightly  be  regarded  as  in  the 
nature  of  unnecessary  and  fraudulent  dilution. 

Section  7.     FOOD   PRESERVATION. 

Foods  of  a  perishable  nature  are  preserved  in  many  diiferent  ways, 
but  not  all  methods  are  equally  applicable  to  all  foods.  Thus,  freezing 
and  salting,  while  well  suited  to  meats  and  fish,  can  hardly  be  employed 
with  fruit  and  vegetables  ;  and  preservation  in  sugar  syrup,  while  well 
adapted  to  fruits,  is  not  suited  to  meats.  The  methods  in  general  use 
include  the  employment  of  low  temperatures,  desiccation,  salting, 
smoking,  canning,  and  chemical  treatment. 


254  FOODS. 

Cold. — For  the  \)v>t  results  t)t' preservation  hy  cold  it  is  not  always 
essential  that  the  iood  shall  he  frozen  ;  hut  unless  the  temperature  to 
\\hieh  it  is  I'xposed  is  near  or  below  the  freezing-point,  the  iuHuence  is 
only  U'uiporary.  l^iekino-  in  it'e  serves  very  well  lor  short  i)eriods  to 
ship  meats  and  tish  throuo'h  long  distances,  an<l  to  keep  them  in  satis- 
factory condition  for  reasonable  ])eriods  in  the  homes  of  the  ct)nsumers. 
•  Tlu'ie  are  several  methods  of  aj)j)lying  cold  on  a  large  scale  in  cold- 
storage  warehouses,  ocean  steamers,  and  ])ublic  markets,  the  ])rineipal 
one  being  known  as  the  ammonia  process,  by  means  of  which  any 
desired  temperature  dowu  to  0°  F.  may  be  obtained  with  but  slight 
fluctuation,  provided  the  walls,  floor,  and  roof  of  the  space  occupied 
are  rendered  non-conducting  by  hair-felt,  iur  sjmces,  and  other  means. 
Meats  and  fish  are  preserved  indefinitely  and  without  deterioration  when 
frozen,  but  should  not  be  allowed  to  thaw  and  freeze;  eggs  and  fruits 
may  be  kept  many  months  in  dry  air  at  just  above  the  freezing-point. 

The  ad\'autages  of  cold  as  a  preserving  agent  are  that,  unlike  any 
other,  it  involves  neither  the  abstraction  of  any  constituent  of  the  food 
nor  the  addition  of  any  foreign  matter  ;  it  neither  imparts  a  new  taste 
nor  alters  the  natural  flavor;  it  causes  neither  a  loss  of  nutriment  nor 
diminished  digestibility;  and  on  the  withdrawal  of  its  influence  the 
material  is  left  in  its  original  condition.  It  shonld  be  said,  however, 
that  after  restoration  to  the  natural  condition,  the  keeping  qualities 
appear  to  be  somewhat  impaired,  and  in  consequence  the  material 
sh(juld  be  used  within  a  shorter  time  than  is  the  case  with  similar  fresh 
food  that  has  not  been  frozen. 

Drying". — Drying  is  eflicient  according  to  the  thoroughness  of  the 
process.  The  method  is  not  so  well  adapted  to  meats  as  to  vegetables, 
since  it  leads  to  more  or  less  loss  of  the  natural  flavors,  which  are  likely 
to  be  replaced  by  others  less  agreeable  in  character.  Dried  meats  are, 
moreover,  considerably  less  digestible  than  fresh  meats.  When  thor- 
oughly dried  and  properly  stored,  both  meats  and  vegetable  products 
can  be  kept  without  limit  of  time.  Drying  does  not  insure  safety 
against  parasites. 

Salting. — In  the  process  of  salting,  the  soluble  organic  constituents 
of  meat  and  fish  are  removed  in  large  part,  and  the  fibers  become 
hardened.  The  nutritive  value  and  digestibility,  therefore,  are  dimin- 
ished corres})ondingly.  Brine  salting  of  fish  is  one  of  the  oldest  proc- 
esses of  preservation  known. 

Smoking". — Smoking  consists  in  exposing  the  meat  or  fish  to  the 
action  of  the  smoke  of  wood  fires  after,  as  a  rule,  a  preliminary  salt- 
ing. The  exposed  material,  already  deprived  of  part  of  its  natural 
moisture,  becomes  dried  still  farther,  and  is  partly  penetrated  by  acetic 
acid,  creosote,  and  other  preservative  elements  of  smoke.  In  the 
quick  smoking  process,  the  meat  is  brushed  over  with  or  dipped  into 
pyroligneous  acid  at  definite  intervals,  and  finally  dried  in  the  air. 

Canning. — In  1804,  M.  Appert,  of  Paris,  discovered  that  meats  and 
other  loods  in  sealed  vessels  would  keep  indefinitely,  if,  after  being 
sealed,   they  \vere  kept  for  an  hour  in  boiling  water.      In   1810,  he 


FOOD  PJIKHKIIVATION.  255 

iiil  rodiK-cd  iJic  ihcIIkkI  hC  -ciliiit.'  llif  V(!S.S(;I  iil'lcr  iIk!  Iiculiii^  pnuroHH 
liMS  driven  mil,  I  lie  ;iii'  ,ind  iiphircd  il,  with  Hti'^'im,  ho  tliiit  wlu'ii  coolr-*! 
jl  ViKMiiirii  i.s  loniicd.  Al  llic  id'csciil-  litnc!,  (lie  cliid"  iim-IImkI  lullowcd 
is  ((»  |>!l<'l<  (Ikm'MIis  lull  :iiid  close  llietil  eoiiiplelcly,  e\<-e|»l  iiii.'  a  stiiall 
Ii(»lc,  ihcii  lo  siilijcel  llieiii  In  llie  I  em  |  lera  t  II  I'e  i.f  Ixtiliiijr  water,  or 
iiinjici-,  and  lo  r\i»r  I  lie  hole  willi  .^ohjei'.  1  liey  are  tlieii  relie.-iicd  ;iri(| 
linally  allowed  l<i  euol. 

Miieli  has  l»e(!ii  said  (or  and  against  this  method  of  |)reservin;i  loo(|-. 
The  eliiel"  ohjeetlons  have  heen  that,  the  natiii'al  aei<ls  of  the  foods  rnay 
corrode  llie  inner  snrliice  of  llie  cans  and  foriii  metallic  salts,  and  that 
(erne  |)lales,  (li;il  is  (o  sav,  slieel  iron  or  steel  c.oal<-<l  with  an  alloy  of 
two  parts  of  lead  lo  one  of  tin,  may  he  used  instead  of  the  hcst  fjiuility 
of  till  plates.  As  to  the  latter  ohjeclion,  while  there  is  in  this  con ntry 
no  lej^al  restriction  as  to  the  cliaractei'  of  the  tin  (;m|»l(»ycd,  it  is  a  fact 
that  lei'iie  plates  are  never  nsed.  With  rcjjiiard  to  the  possibility  of 
corrosion  of  the  metallic  sin-fac(^,  it  nnist  he  admitted  that  not  only  the 
V(My  acid  foods,  bnt  oven  those  whic^h  arc  nentral  and  even  alkaline  in 
reaction,  almost  inNuriahly  will  yield  traces  of  tin  ;  hnt  there  is,  at  the 
sanui  time,  ahsolntely  Jio  cvidenci'  that  the  small  amonnt  j)rescnt  in  the 
entire  contents  of  a  can  is  capable  of  cansing  the  slightest  injury. 

There  are,  it  is  true,  luunerous  cases  of  poisoning  reported  as  due  to 
nu'tallie  containination  of  canned  foods,  bnt  not  one  of  tliose  wfiich 
have  fallen  uikKm"  tlu>  view  of  the  author  will  stand  the  test  of  exclu- 
sion of  oilier  i)ossible  and  more  probable  causes.  Oi"  the  small  amounts 
ol"  tin  found  in  canned  foods,  Professor  Attfield  says  that  they  are 
undeser\ing  of  serious  notice,  and  lie  questions  that  tl)cy  represent  the 
amount  r(>gnlarly  worn  off  of  tin  saucepans  and  kettles.  Furthermore, 
it  is  the  nearly  unanimous  opinion  of  writers  of  works  on  toxicology 
that  the  only  compounds  of  tin  that  arc  in  any  way  poisonous  are  the 
chlorides,  and  even  these  are  ignored  completely  by  most  of  the  lead- 
ing authorities. 

On  the  other  hand,  there  is  no  limit  to  the  testimony  regarding  the 
very  great  value  of  canned  foods,  csj^ecially  in  military  operations  on  a 
large  scale,  and  in  expeditions  of  various  kinds  away  from  market  cen- 
tres and  other  sources  of  supply.  Lieutenant  Grecly,  Dr.  Xausen,  and 
other  Arctic  ex])lorers  are  unanimous  in  their  praise.  Greely,  for  ex- 
ample, says  :  "  No  illness  of  any  kind  occurred  prior  to  our  retreat,  and 
those  most  inclined  to  canned  fruits  and  vegetables  were  the  healthiest 
and  strongest  of  the  party."  Lord  Wolseley,  in  speaking  of  their  use- 
fulness in  hot  climates,  says  that  "  tinned  provisions,  meat  or  vegetables 
jHit  up  separately  or  combined  in  the  form  of  soups,  are  jiractically  un- 
dan\ageable  by  any  climatic  heat  "  provided  they  are  of  the  best  quality 
and  have  been  properly  cooked  and  enclosed  in  perfectly  sound  air- 
tight tins.  "  Given  these  conditions,  nothing  can  be  more  admirable  ; 
failing  them,  nothing  more  deleterious."  In  military  operations  in  the 
tro]iics,  where  beef  cattle  cannot  be  taken  along  on  the  hoof  and  re- 
frigerated beef  cannot  be  transported  overland  on  account  of  speedy 
decomposition,  canned  meats  are  indispensable. 


256  FOODS. 

How  long  properly  oaniietl  foods  will  rciiKiiu  in  good  condition,  can 
hardly  be  determined,  but  the  evidence  at  hand  points  to  indefinite 
preservation.  In  1824,  according  to  Letheby,  a  nnmber  of  tins  of 
rantton  were  cast  ashore  from  the  wreck  of  a  ship  at  Prince's  Inlet ; 
eight  years  later,  they  were  fonnd  by  Sir  John  Ross,  and  those  which 
he  opened  were  in  good  condition,  although  exposed  during  this  time 
to  alternate  freezing  and  thawing.  Sixteen  years  afterward,  they  again 
were  found  bv  men  from  the  ship  Invedlgator  ;  and  in  1868,  forty-four 
years  from  the  time  they  were  cast  ashore,  the  remaining  tins,  opened 
by  Letheby,  were  found  to  be  in  a  ])crfectly  sound  state.  TyndalP 
makes  mention  of  tins  in  the  Royal  Institution  that  had  remained  in 
good  condition  sixty-three  years. 

Professor  A.  H.  Chester,  of  Hamilton  College,  relates  that  in  the 
summer  of  1875  he  hid  a  number  of  cans  of  corned  beef  under  a 
stump  in  woods  in  the  northern  part  of  Minnesota,  and  five  years  later 
found  them  to  be  perfectly  sweet,  although  they  had  been  exposed  to 
the  heat  and  cold  of  five  successive  summers  and  winters.  Again,  a 
numljer  of  cans  of  meat  and  fruit,  washed  into  the  Genessee  River  in 
1865,  were  dug  out  of  the  mud  sixteen  years  later,  and  found  to  be 
unaltered. 

It  is  an  unfortunate  fact  that  the  cupidity  of  some  of  our  largest 
packing-houses  has  led  to  the  canning  of  what  is  practically  refuse 
meat,  from  which  the  constituents  to  which  the  desirable  flavors  are 
due  have  been  extracted,  and  that  in  consequence  the  public  mind  has 
largely  become  imbued  with  a  prejudice  against  canned  meats  in  gen- 
eral. But  it  is  not  alone  in  this  country  that  canned  meats  are  some- 
times not  what  they  purport  to  be.  It  is  related  that  in  France,  in 
1899,  a  packer  of  meats  was  sentenced  to  pay  a  fine  and  to  serve 
eight  months  in  prison  for  putting  upon  the  market  an  immense  amount 
of  canned  game  and  poultrs^,  all  of  which  had  been  made  from  the 
flesh  of  broken-down  cab  horses. 

Chemical  Treatment. — Chemical  preservatives  are  substances  or 
combinations  added  to  foods  wdth  the  object  of  delaying  or  preventing 
their  decomposition.  They  are  used  on  the  assumption  that,  while 
they  accomplish  the  desired  object,  they  are  incapable  of  exerting  any 
harmful  influence  upon  the  system  of  the  consumer — an  assumption 
tliat  has  not  been  demonstrated  as  based  on  sound  reasoning.  It  is 
assumed  that  bad  effects  cannot  be  caused,  because  they  are  not  mani- 
fested at  once  after  the  ingestion  of  small  doses  by  persons  in  good 
health  ;  but  this  Is  no  proof  that  continued  use  may  not  result  in  serious 
trouble  which  may  be  referred  t(3  some  other  possible  cause. 

It  is  said  that  the  preparations  employed  are  in  common  use  as 
valuable  remedies  in  the  treatment  of  the  sick ;  but  it  should  be  taken 
into  consideration  that,  when  used  as  remedies  in  morbid  conditions, 
they  are  given  for  only  a  limited  time,  for  the  purpose  of  counteracting 
abnormal  influences,  and  that  the  doses  are  regulated  carefully  under 
proper  professional  supervision.  Their  action  in  conditions  of  health 
1  Floating  Mattere  in  the  Air,  New  York,  1882,  p.  293. 


FOOD   PRESKRVArrON.  257 

;ui(l  (lisc.'isc  iii.'iy  he  very  (liircrcnt  ;  hiil  uhctlicr  so  (»r  not,  one  ^•^\\\  fiii(| 
no  (^X(•,lls('  ("or  llic  iiif^(!Hti()ii  ol  (iii;iti\<'  icincdicH  hy  u  pcr'-oii  in  ;i 
rilaki  ol'  liciillli,  vvlio,s(!  ,sy,sl(!ni  needs  no  -nch  .-lid,  for  indefinite  periodh 
iind  willi  no  re^^idnlion  of  (Ik;  size  u['  I  he  do,-c.  .Salicvlie  aeid,  for 
ex!iin|)l(!,  is  ii  ]'(!inedy  lioldin'i;  ;i  liinh  |)osilion  in  tli(;  treattnent.  of  rlieu- 
nialisni,  but  its  vulne  in  lliis  (-(indilion  is  no  v;did  exciiM;  lor  its  adriiin- 
i.stnition  day  in  and  day  ont  lo  those  who  never  have  felt  tli(*  twin^^e-H 
and  |)ain  of  this  disease;.  It  is  much  inon;  niasonahle  to  assnnu;  that 
(h'u^s  which  exert  a  powerCnl  inMiienee  ("or  ^'•ood  in  nifirhid  Ktates  will 
exert  an  e(|iiaJ  (K^^ree  o("  inlhicncc  for  h;iriii  in  condiiioriH  f)f'  licJiltli. 
Moreover,  it  is  to  be  considered  ihnt  the  object  of  ehernieal  treatment 
of  foods  is  not  to  benefit  the  nneonseious  eonKUinr^r,  but  to  brin^  the 
larjijest  possible  financial  I'etiirn  to  the  mannfactnrer  and  |)nrvevor,  to 
whom  the  health  of"  the  eor)sinner  may  In;  a  matter  ol"  little  eoneeni. 
In  all  fairness  to  the  consumer,  chemiwdly  preserved  foods  slif)uld  be  so 
labelled  that  the  purchaser  may  be  informed  of  the  nature  and  amount  of 
the  added  substance,  so  that  those  who  ob)(!(;t  to  the  dietetic  use  of  druj^s 
may  not  have  the  same  forced  upon  them  without  their  knowlcfl^r*.. 

The  addition  of  ])reservatives  to  foods  offered  for  sale  is  f"orbidden  in 
almost  all  civilized  countries,  and  several  governments  have  enacted  laws 
specially  directed  against  individual  drugs.  Thus,  France  names  IkiHc 
ucid,  borax,  salicylic  acid,  and  sodium  bisulphite;  Austria  names  sali- 
cylic acid  ;  (u'rmany  prohil)its  all  antiseptics,  and  especially  boric  acid 
and  borates,  and  imposes  additional  penalties  for  the  sale  of  chcmic^illy 
preserved  foods  to  the  navy.  Massachusetts  prohibits  all  preservatives 
except  salt,  sugar,  niter,  vinegar,  and  alcohol,  unless  the  purchaser  is 
informed  of  the  nature  of  the  substance  used.  In  milk,  all  preserva- 
tives whatsoever  are  prohibited  unconditionally. 

The  substances  used  as  chemical  preservatives  include  boric  acid 
and  borax,  salicylic  acid,  sulphurous  acid,  sulphites  and  sulphates, 
benzoic  acid,  formaldehyde,  hydrogen  peroxide,  sodium  fluoride,  and 
others  of  minor  importance.  INIany  of  the  commercial  preparations  in 
common  use  are  combinations  of  two  or  more  of  these  and  other  sub- 
stances. Thus,  Venzke  and  Schorer  ^  report  the  ingredients  of  38  meat 
preservatives,  analyzed  by  them,  as  follows  :  Salt,  sugar,  and  saltpeter, 
(1);  salt  and  sodium  sulphite  and  sulphate  (4);  sodium  sulphite  and 
sulphate  (4);  the  same,  plus  sugar  and  salt  (1);  salt  and  sodium  bi- 
carbonate and  nitrate  (1) ;  salt,  boric  acid,  saltpeter,  and  sodium  sul- 
phate (3);  salt,  boric  acid,  and  sodium  sulphate  (1);  salt,  boric  acid, 
gypsum,  and  sodium  sulphate  (1) ;  salt  and  boric  acid  (0) ;  salt,  salt- 
peter, sodium  and  calcium  sulphates,  and  cochiueal  (1)  ;  salt  and  borax 
(1) ;  salt,  borax,  and  saltpeter  {2) ;  salt,  borax,  and  sodium  nitrate  (2) ; 
salt,  borax,  sodium  and  calcium  sulphates,  and  salicylic  acid  (1) ;  borax 
and  sugar  (2).     The  rest  consisted   of  single  substances. 

A  large  proportion  of  24  meat  preservatives  examined  by  Kammerer 
were  found  to  be  mixtures  of  borax  and  l^oric  acid,  and  borax  and  so- 
dium sulphite ;  31  others  examined  by  Kiouka  were,  as  a  ride,  sodium 
1  Deutsche  Fleischerzeitung,  1893,  XXI.,  Nos.  20,  21,  and  24, 

IT 


258  FOODS. 

sulpliite  and  sulphato,  hut  14  liquid  prciiarntions  oonsistod  chiefly  of 
caK'iuiu  sulj)liite  and  suljihatc,  ami  sodium  sulphite,  hisulphili',  and  sul- 
phate. Kirehiuaier  has  reported  one  as  cousistinj;-  of  salieylie  acid 
and  sodium  salicN'late  and  phosphate.  Polenske  foiuul  boric  ai'id 
(about  60  per  cent.),  saltpeter  (about  12-14  per  cent.),  sugar,  salt,  and 
sodium  salicylate  (about  7.50  per  cent.)  in  a  specimen  of  sausage  salt, 
and  in  a  lunnbcr  of  other  preparations  sold  untler  fancy  names.  Of  7 
other  meat  preservatives  examined  l)y  him,'  one  contained  salt,  sodium 
sulphite  and  suli»hate,  irou  chloride,  and  vanillin,  and  the  rest  were 
combinations  already  described. 

A.  C.  C'liapman^  has  reported  a  most  extraordinary  combination  of 
aliiinimmi  sulphate,  salt,  sodium  nitrate,  benzoic  acid,  iodic  acid,  sul- 
])hurous  acid,  and  chloral. 

^Vnother,  examined  by  Tollner,  proved  to  be  ammonium  bromide, 
boric  acid,  borax,  and  sugar.  Another,  known  as  "  Mayol,"  contained 
wood  alcohol,  ethylic  alcohol,  boric  acid,  anniionium  fluoride,  and  glyc- 
erin. JNIeats  preserved  by  means  of  it  are  said  to  show  no  trace  of 
boric  acid  or  ammonium  fluoride  beneath  the  brown  coating,  which 
forms  to  a  depth  of  a  millimeter. 

In  this  country,  the  favorite  mixture  is  one  of  borax  and  boric  acid, 
and  this  is  S(»ld  under  many  ditferent  names. 

Boric  Acid  and  Borax. — These  substances  generally  are  used  together, 
for  the  reason  that,  although  the  acid  has  greater  power  as  an  antiseptic 
than  the  salt,  the  combination  of  the  two  is  still  more  efficient.  It  is 
used  very  largely  in  butter  to  the  extent  of  about  a  tenth  of  an  ounce 
to  the  pound,  and  is  dispensed  with  a  generous  hand  in  oysters,  clams, 
and  other  fish,  in  sausages  and  other  meat  products,  and  '\n  milk. 

With  regard  to  the  effects  of  boric  acid  and  borax  on  the  system, 
there  is  a  decided  difference  of  opinion  among  those  who  have  investi- 
gated the  subject,  but  it  should  be  said  that  a  number  of  the  reports 
favorable  to  the  use  of  these  agents,  ])ublished  by  commercial  houses, 
suggest  that  the  conclusions  arrived  at  were  inspired  somewhat  by 
financial  considerations.  Our  knowledge  of  possible  ill  effects  is  de- 
rived chiefly  from  the  clinical  experience  of  those  who  have  used  the 
drugs  internally  and  as  washes  and  injections.  It  is  a  fact  that  many 
patients  can  take  large  doses  of  both  substances  for  long  periods 
with  no  apparent  harm,  but  it  is  equally  true  that  small  doses  and 
local  applications  have  been  a  frequent  cause  of  serious  and  even  fatal 
results.  Deaths  have  been  reported  from  the  use  of  5  per  cent,  solu- 
tions in  washing  out  the  pleural  cavity  and  lumbar  abscesses,  and 
from  w^ashing  out  a  stomach  with  a  solution  of  half  that  strength. 
Numerous  cases  of  troublesome  cutaneous  eruptions  and  of  serious 
gastro-intestinal  disturbances  following  internal  and  external  use  have 
been  rejiorted  within  recent  years.  Plant  ^  has  shown  that  internal  use 
may  be  followed  by  acute  parenchymatous  nephritis,  and  his  conclusions 
have  been  endorsed  by  the  experience  of  Fere,  mentioned  below. 

1  Arbeiten  aiis  dem  kaiserlichen  GesiiiidhL-itsamle,  VIII.,  7).  686. 

^  Analyst,  Dec,  1898,  '  Inaugural  dissertcition,  Wiirgburg,  1889, 


FOOT)  I'llICSERVATION.  259 

In  I.S7fI,  iJic  iidniixliirc  oC  horn.x  lo  luillci-  \v;is  s;iiicli'»iMil  i(irici;illy 
in  l*'i';in('c  ;  Itiii  seven  yenrs  l;iier,  ;i  ((iniinil  tee  of  ^eien(i.'-ls,  \vli<»  in- 
vesli<;'!ii(^<l  llu;  niiiM.er  vvilJi  ^i'e;il  emc,  conrliKlcd  tli;it  eontinned  in^«-h- 
iion  is  likely  to  eansc!  (I<'(ci'i(ir;il  ion  of  lli<  Mm-mI  cmiiiii  dc-  ;  ;ni(l  wlif-n, 
sonu^whaX  Ijiici-,  (liis  (indint;'  wns  eonlirnied  i>y  l.lie  inve>-li^;i(ionK  of 
l*on(!li('l,  \\\i\  nse  of  l)oi;ix  wiis  |)i-oliii)ile<l  \)\  tlic  f:;overnnienl,  ii<it.  only 
it)  butici',  bill  in  nil  •■iilieles  of  food.  In  IS!H,  tli(!  Hiihject  was  prcwnlcrl 
by  [\h\  Kensinnlon  Vestf}'  (o  Sii-  Andrew  (/lark,  Sir  Henry  Tliornps^Mi, 
and  Professor  Lander  l^rnnlon,  who  eonenrre*!  in  |»r(»nonnein^'- borie  aeid 
in  la-ra,'e  doses,  or  in  small  doses  laken  ('oi-  jontr  jieriods,  as  danj^^eroiis  to 
luialLli.  Tlie  Ijoeal  ( iovei'nineni  llo.iid,  In  I  M!H  ,  re|ior(ed  that,  while 
lar^e  doses  ar((  nndonbledU'  injiiii<iii,^,  ihcy  li:id  not  -nnieicnt  evidence 
to  hold  (hat  ininnle  anioinit.s  added  to  food>  enii  ;d1ecl  tlienystetn  liarni- 
fully. 

As  is  well  known,  borax  has  been  used  extensively  in  the  treutrnent 
of  e})ile|)sy  und  other  diseases  of  the  nervons  system.  J^-ofessor  JI.  C. 
Wood  states  thut,  in  his  experienee,  the  most  marked  result  from  it« 
use  in  this  direetion  was  severe  ^astro-inlestinal  irritation.  Dr.  Fcr6' 
has  given  a  valnable  re})ort  of  his  results  in  the  treatment  of  122  crises 
of  epilepsy  by  this  drug,  wliieli  was  given  in  beginning  doses  of  30 
grains,  inereased  to  as  much  as  5  draelims  a  day.  Jn  more  than  70  per 
cent,  of  the  cases,  the  treatment  had  no  beneficial  result ;  in  about 
20  per  cent.,  some  temporary  or  doubtful  improvement  was  seen  ; 
and,  hi  9  per  cent.,  there  Avas  distinct  gain.  Jjut  the  great  draw- 
back was  the  frequency  of  toxic  effects  and  the  danger  of  producing 
or  aggravating  lesions  of  the  kidneys,  even  when  given  in  small 
doses.  Among  the  most  common  results  were  loss  of  a})petite  and 
burning  pain,  followed  by  nausea  and  vomiting.  Cutaneous  affections 
were  very  common,  and  complete  baldness  was  caused  not  infrequently. 
(This  result  has  been  noted  by  many  other  practitioners.)  In  some 
cases,  a  cach(>ctic  condition,  characterized  by  wasting,  a  waxy  tint  of 
the  skin,  puflfiucss  of  the  flice,  and  even  general  oedema,  was  observed. 
In  a  number  of  cases  of  general  axlcma,  urannia  developed  with  some 
suddenness. 

Dr.  Grumpelt"  has  reported  a  case  in  which  headache,  nausea,  and 
intense  dryness  of  the  skin  followed  the  use  of  an  injection  containing  a 
tablespoonful  of  boric  acid  to  the  pint.  The  effects  disappeared  with 
cessation  of  the  treatment,  but  came  on  again  Avith  its  renewal.  Dr.  J. 
J.  Evans  ^  has  found,  as  a  common  result  of  the  continued  use  of  boric 
acid  in  cystitis  and  urethritis,  an  erythema  followed  by  desquamation. 
Internal  doses  of  10  to  20  grains  twice  daily  for  five  Aveeks  caused  in 
one  instance  total  baldness. 

Experiments  on  man  aud  animals,  by  Professors  iSIattem,  Foi-ster, 
Chittenden,  and  Schleuker,  have  demonstrated  that  boric  acid  and 
borax  interfere  with  digestion  and  nutrition.  Mattern  reported 
profound  disturbances  in  dogs  after  a  few  daily  doses  of   8  grains  ; 

^  Revue  tie  M^dooine,  September,  1895. 

=*  British  Medical  Journal,  Jan.  7,  1899.  »  Ibidem,  Jan.  2S,  1899. 


260  FOODS. 

diarrhoea  and  other  signs  of  gastro-intestinal  irritation,  and  in  some 
instances  even  fatal  results  were  caused.  He  himself  took  30 
grains,  and  suifered  violent  abdominal  pain  and  diarrhoea.  Forster 
and  Sohlenker  liave  shown  that  doses  of  8  grains  have  a  decided 
etleet  in  preventing  absorption  of  nutriment  and  causing  intestinal 
irritation. 

Dr.  Annett,  of  Liverpool,  fed  a  number  of  kittens  with  milk 
containing  :20  grains  of  boric  acid  to  the  quart,  and  all  of  them  died 
in  an  emaciated  condition  at  the  end  of   the    thii-d  or  fourth  week. 

As  to  the  effect  of  these  agents  on  the  dillerent  processes  of  diges- 
tion, there  is  no  agreement.  Chittenden,  for  example,  believes  that 
boric  acid  increases  the  digestion  of  proteids,  and  that  even  25  per  cent, 
will  not  check  gastric  digestion  of  egg  albumin.  He  has  noted  also  a 
marked  stimulant  effect  on  pancreatic  digestion  of  proteids  following 
the  use  of  borax.  Leffmann  and  Beam,  and  others,  however,  have 
observed  effects  directly  contrary  to  those  reported  by  Chittenden. 
Chittenden's  first  experiments  were  made  to  determine  the  possible 
influence  of  borax  and  boric  acid  upon  the  processes  of  salivary, 
gastric,  and  pancreatic  digestion.  He  calls  attention  to  the  fact  that 
his  results  throw  no  light  upon  the  influence  of  the  agents  upon  the 
secretion  of  the  dig-estive  fluids.  He  shows  that  borax  inhibits  the 
action  of  saliva  on  starch,  and  boric  acid  in  small  amounts  increases  it, 
and  also  the  power  of  the  gastric  juice  to  digest  proteids.  Later 
experiments  by  Chittenden  and  Gies  ^  lead  them  to  the  conclusion  that 
the  two  substances  have  no  peculiar  action  on  nutrition,  and  that,  since 
elimination  is  complete  within  thirty-six  hours,  the  possibility  of 
cumulative  action  must  be  very  small,  even  when  moderate  amounts 
are  ingested  daily. 

Tunnicliffe  and  Rosenheim  ^  concluded,  from  a  series  of  metabolism 
experiments  on  young  children,  that  boric  acid  in  doses  up  to  ]  gram 
per  day,  continued  for  some  time,  exerts  no  influence  on  proteid  or 
phosphorus  metabolism,  has  no  effect  on  the  assimilation  of  fat,  and 
exerts  no  inhibitory  effect  on  intestinal  putrefaction  ;  that  borax  in  con- 
tinued doses  of  1.5  grams  may  or  may  not  improve  assimilation  of  fat, 
and  tends  to  increase  intestinal  putrefaction  ;  that  both  boric  acid  and 
borax  are  eliminated  quickly  ;  and  that  neither  will  affect  the  general 
health  and  well-being. 

Halliburton,^  experimenting  with  borax  and  milk  in  vitro,  found  that 
1  part  of  borax  in  1000  completely  prevents  the  action  of  rennet,  and 
that  smaller  amounts  delay  it. 

On  the  other  hand,  Liebreich,*  experimenting  with  dogs,  found  that 
neither  borax  nor  boric  acid  has  any  influence  on  metabolism ;  that 
boric  acid  in  saturated  solution  has  no  effect  on  the  mucous  membranes 
of  the  stomach  and  intestine,  while  borax  in  2  per  cent,  solution  has  a 

'  New  York  Medical  Journal,  February  26,  1898. 

^  .Journal  of  Hygiene,  April,  1901,  p.  168. 

3  British  Medical  .Journal,  July  7,  1900,  p.  1. 

*  Vierteljalii'sschrift  fiir  gerichtliche  Medicin,  1900,  p.  83. 


FOOD    l'ni-:.SI':iLVATION.  201 

markedly  injurious  ('(reel,  (Iioml-Ii  not  so  tmicli  ;i-  I  |i(i-  cent,  ol  -odiiiin 
hy(lrat,(!  or  O.T)  |)cr  cciit,.  oC  snllpclcr  ;  llmt  •")  jicr  r-ciit.  of  lioiic  ;i(if  I  mid 
0.25  ))(!r  cent.  o("  hctrsix  luivc  no  inlliicncc  on  L'li-I'i''  di;.'(-(  ion,  l»nt  O.o 
per  (!(!iit.  ()('  boi'.'ix  li.'is  sii^lil  inliiMlory  iiftion  ;  tlint  ncitlicr  liiis  any 
(vd'ccii,  on  {\\v.  diocslioii  oC  sljirclics  ;  and  llial  holli  arc  cliniinat'd  <|nicl<ly, 
and  liav(i  no  Irndcnc.y  lo  a('c,mnulal(!  in  the  system. 

During  a  period  of  10  weeks  the  aiiilior'  fed  l)orat(!d  rrujat  Ut  0  of 
12  heal tliy  cats,  whi(;h  were  kept  in  Heparal<!  eagcis  under  precisely  sim- 
ilar conditions.  Of  the  other  (5,  J  was  kept  as  a  control,  and  5  were 
fed  on  meat  (H)nlainin}i;  another  kind  of  preservative  The  average 
daily  dose  of  borax  ranged  from  541  to  HoT  milligrams.  J)iiring  the 
experiment  only  .'{  of  the  12  cats  showed  any  acute  sickness,  but  they 
were  all  members  of  the  borax  group.  One  of  them  died  at  the  end 
of  the  sixth  week,  but  tlu^  oth(!rs  n^covered  and  were  apparently  well 
when  the  experiment  was  lirought  to  a  (;lose.  TIk;  eals  were  killed  and 
all  (including  the  one  that  died)  were  subjected  to  careful  mieroseoj)ical 
examination.  The  control-cat  showed  no  lesions  whatever,  and  those 
fed  on  non-borated  food  showed  only  slight  iind  inconstant  changes  in 
various  organs  ;  but  the  borax-fed  animals  showed  withont  exception 
lesions  of  the  kidneys  of  the  same  general  eliaracter,  yet  differing  in 
intensity,  and  analogous  to  those  found  in  subacute  and  chronic  neph- 
ritis in  man.  In  some  cases  the  degeneration  was  of  an  intense  char- 
acter. 

Considering  all  the  evidence,  conflicting  though  it  be,  and  the  many 
reports  of  untoward  results  of  large  and  small  medicinal  doses  and 
from  absorption  of  both  agents  from  local  applications,  it  seems  not 
unreasonable  to  conclude  that  the  daily  ingestion  of  variable  amounts 
in  food  and  drink  by  persons  of  all  ages  cannot  be  wliolly  free  from 
objection.  A  very  conmion  practice  is  the  addition  of  a  mixture  of 
the  two  or  of  either  alone  to  milk,  in  the  proportion  of  1  part  in  500 
or  1000  ;  a  pint  will,  therefore,  contain  a  fair-sized  adult  dose,  an 
amount  which,  taken  twice  daily,  or  oftener,  by  a  bottle-fed  child,  can 
hardly  fail  to  have  some  effect  not  wholly  for  its  well-being. 

Salicylic  Acid. — Salicylic  acid  is  more  efficient  than  borax  and  boric 
acid  as  a  preservative,  but  cannot  be  used  so  generally,  because  of  its 
tendency  to  cause  unpleasant  flavors  in  foods  having  a  bland  taste.  It 
is  used  extensively  in  jams,  jellies,  tomato  catsups,  bottled  beers  (es- 
pecially those  from  Germany),  the  heavy  beers  innocently  consumed  by 
total  abstainers  under  the  name  of  "malt  extracts,"  fruit  juices,  soda- 
water  syrups,  cider,  wines,  and  other  saccharine  preparations,  and  pre- 
served vegetables.  Concerning  its  objectionable  nature  as  an  addition 
to  foods,  there  is  practical  unanimity.  It  not  only  exerts  an  inhibitory 
action  on  digestion,  but  acts  also  as  an  irritant,  especially  to  the  kid- 
neys, by  which  organs  it  is  excreted.  Its  addition  in  any  quantity  to 
articles  of  food  or  drink  is  forbidden  expressly  in  many  Em'opean  and 
South  American  countries.  Its  addition  to  beer  and  other  articles  in- 
tended for  export  is  permitted  in  Germany. 

*  American  Journal  of  the  Medical  Sciences,  September,  1904. 


262  FOODS. 

Sulphites. — Sodium  siil]iliite  and  bisulplntc  and  snlphiirons  acid  are 
used  more  or  less  extensively  for  ])reservii)g-  meat,  beer,  wine,  and  for 
bleaching  vegetables  (especially  asparagus  aud  corn),  put  up  in  cans 
and  glass  jars.  Scndtner  has  found  from  26.4  to  482.6  milligrams  of 
sulphurous  acid  in  32  specimens  of  such  vegetables,  and  Kiimmerer 
and  others  have  rejiortcd  amounts  ranging  from  3  to  250  milligrams 
per  liter  in  red  and  white  wines.  The  author'  found  from  O.OGl  to 
1.225  (average  0.335)  per  cent,  by  weight  of  sodium  sulphite  in  50 
specimens  of  "  Hamburg  steak  "  bought  in  the  markets  of  Boston. 

Kionke "  has  shoMU  that  large  doses  of  sulj)hites  exert  a  marked  and 
sometimes  fatally  poisonous  action  on  warm-blooded  animals,  and  that 
small  doses,  long  continued,  may  aifect  dogs  very  seriously.  The 
author  *  fed  a  number  of  cats  for  20  weeks  with  meat  containing  0.20 
per  cent,  of  sodium  sulphite,  which  is  the  amount  recommended  as  a 
preservative,  and  at  the  ex])irati(Mi  of  that  time  the  cats  were  killed 
and  examined.  In  each  case  the  kidneys  showed  extensive  degenera- 
tive changes. 

Sodium  sidphite  is  used  very  commonly  in  sausages  and  chopped 
meat  (Hamburg  steak),  both  as  a  preservative  and  to  cause  the  bright- 
red  color  of  the  fresh  meat  to  be  retained  unaltered.  Clioppcd  meat 
keeps  its  color  but  a  very  short  time,  and  as  the  purchaser  will  not 
accept  it  when  not  bright  red,  the  vendor  is  driven  to  make  its  appear- 
ance acceptable.  Thus,  the  purchaser,  insisting  upon  having  what  to 
his  eye  is  freshly  chopped  wholesome  meat,  may  be  served  with  stale 
meat  containing  a  most  undesirable  chemical  preservative.  In  1898, 
the  Imperial  Board  of  Health  of  Germany  forbade  the  use  of  sodium 
sulphite  in  foods,  because  of  its  dangerous  properties. 

Formaldehyde. — On  account  of  its  property  of  hardening  tissues, 
formaldehyde  does  not  lend  itself  to  general  use  as  a  food  preservative. 
Fish  and  meats  are  rendered  so  hard  by  very  dilute  solutions,  even  1 
to  5,000,  as  to  be  worthless  commercially.  It  is  used  most  com- 
monly in  milk  and  other  liquids,  and  acts  most  efficiently  in  delaying 
and  preventing  decomposition.  Its  use  in  milk  is,  however,  far  from 
commendable,  for  although  efficient  as  a  preservative,  it  alters  the  char- 
acter of  the  proteids,  which  are  thereby  made  less  digestible.  The 
casein,  when  precipitated,  does  not  separate  in  fine  clots,  but  in  tough, 
heavy  curds,  which  yield  only  with  much  resistance  to  pepsin  aud 
hydrochloric  acid.  Weigle  and  Merkel  ^  have  shown  that  the  proteids 
are  made  much  less  digestible,  and  their  conclusions  are  in  agreement 
with  those  of  most  investigators  of  the  subject.  Bliss  and  Novy,* 
after  a  most  careful  and  exhaustive  inquiry  into  the  effects  of  formal- 
dehyde on  the  digestive  ferments,  found  that  pepsin  and  trypsin  have 
diminished  action  upon  fibrin  which  has  been  altered  by  it  in  very 
weak  solntiou  ;  that  casein   is  altered  rapidly,  and,  as  a  result,  is  not 

1  Boston  Medical  and  Suigical  .Journal,  May  25,  1904. 
^  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXII.,  p.  351. 
•^  ForsKhiingsbericlite  iiber  Lebensniittel,  etc.,  1895.,  II.,  p.  91. 
*  Journal  of  Experimental  Medicine,  1899,  p.  47. 


FOOD   /-ni'Js/'HivA'/'/OjV.  263 

C()!i<;'iil;i(('<l  l»y  i'<'iiii('l  or,  .-il,  licsl,  vry  slow  ly,  ;iii(l  is  iiot^  rriidily  <li;;<-st<-<l 
by  tlu!  proLcolyl  ic  rcnncnls  ;  ;iii'l  tli;il  |M|)-iii  ;iii<l  icimct  ;ii-(!  tlir;niH(!lv<!H 
ii()i<  ii,ir(!<!i-(!(l  by  (:iirly  sl^ronp,' (  I  :iihI  -)  |><r  ••inlj  -Mliilidiis  iwttin^  for. 
S('.V(!riil  W(U!l<H.  I'('|)siii  w:is  CoiiikI  I<>  Ik-  ;iIT<'I<<I  <|iii(;l\ly  by  very 
(bliilxi  soliii. ions,  trypsin  (n  \)c  nITcclcd  jicfordin^'  to  liic  junonnt.  nC 
or<j;':nii('.  in;i,l.l(^r  prc-scnl,,  ;in(i  ;iniylo|)sin  :in(l  plyalin  lo  !)'■  no!  dcsf roy<;(| 
by  very  dihilc  solnlions.  'I'h(!  liillcr,  liow(;vci',  were  rmind  t<i  be  <U'.- 
slroycd  by  strong'  soliilions. 

I  lidbbiirion  '  (bnnd  tliid,  0.5  |)cr  ccnl.  oC  CoiinMlin  render,-  p-i.-lricr 
<nf;('sl.ion  <)("  (ibrin  :dinosl.  impossible  ;  iind  thiil.  0.0."*  per  ccnl,  consid- 
(iriil)ly  dchiys  it.  Jts  cllcctH  on  panereiilic  digestion  were  <'ven  more 
in!irl<(!(l. 

'rnnnicIilTe  and  Rosenlieini,'''  cxjx'i-imenting  witli  yoinig  cbildren, 
Ibnnd  that,  in  doses  oC  1  |)art  in  5,000  of  nnlk  or  1  in  l),000  of  t(.tal 
ibod  and  driid<,  rormal<leii)'de  exei'ls  no  a|)|ii'(  eiiible  cITecl  on  niO'ogen 
a,nd  ])h()Sj)lioriis  metabolism  or  on  Cat  assimilation,  but  in  larger  do.sas, 
or  long  (continued,  it  may  tend  lo  diininlsh  |)liospliorns  and  fat  a.s.sim- 
ilation,  on  ac(;ount  of  its  (vfl'cct  on  ])anci-eatie  digestion.  Wifb  dclicuto 
ciiibb-en,  tlio  1  :  5000  dose  has  a  mcasnrable  deleterious  cflcct  on  tho 
nitrogen,  ])hos])horus,  and  fat  assimilation,  and  exerts  a  slight  irritant 
a,(^tion  on  the  intestine.  They  conclude,  however,  that,  as  used,  the 
substance  lias  no  influence  on  tlie  general  health  and  well-being  of 
children.  On  the  other  hand,  feeding  experiments,  conducted  by  Dr. 
Annett  with  kittens,  demonstrated  that,  as  the  amount  mixed  with  the 
milk  was  increased,  the  retarding  action  on  their  develo])ment  was 
more  marked. 

Whatever  may  be  the  results  of  experiments  tending  to  show  the 
effects  of  formaldehyde  on  metabolism  and  growth,  everybody  who  has 
occasion  to  handle  even  very  dilute  solutions  can  testify  to  its  irritant 
eflxicts  on  the  skin  ;  and,  this  being  the  c^se,  it  seems  hardly  reasonable  to 
assort  that  the  much  more  delicate  mucous  membranes  of  the  digestive 
tract  can  be  subjected  to  its  action  and  wholly  escape  injury.  Formal- 
dehyde is  not  generally  regarded  as  a  poison  in  small  doses,  but  a  num- 
ber of  detiths  have  been  attributed  to  its  use  as  a  milk  preservative, 
though  it  should  be  said  that  the  evidence  in  these  cases  will  hardly 
bear  critical  analvsis.  One  undoubted  case  of  non-fatal  poisoning  has 
been  recorded  by  J.  Kliibcr.^  The  subject  was  a  man  of  forty-seven, 
who  swallowed  some  ajierient  Avater  into  which  formalin  had  been  intro- 
duced accidentally  He  lay  for  a  long  time  in  a  state  of  coma,  and 
had  anuria  nineteen  hours.  Formic  acid  was  eliminated  in  the  urine 
durijig  recovery. 

Hydrogen  Peroxide. — This  agent  is  recon\mended  as  the  least  danger- 
ous of  all  chemical  preservatives,  and  is  believed  by  some  to  exert  no 
deleterious  eifect  whatever.  It  is  well  adapted  for  use  in  wine,  beer, 
and  fruit  juices.     One  part  in   1,000  is  said  to  prevent  entirely  the 

'  Loco  citato. 

'^  Journal  of  Hygiene,  July,  1901,  p.  821. 

"  Miinchener  medicinische  Woolienscbiift,  October  9,  1900. 


•264  FOODS. 

alcohdlie  ferniontation  of  glucose  .<t)liitious,  and  in  somewhat  larger 
amounts  to  ])revent  the  formation  of  lactic  acid  in  milk. 

Sodium  Fluoride. — So  far  as  is  known,  sodium  fluoride  exerts  no 
prisonous  action,  but  its  eifect  on  digestion  has  not  been  studied  thor- 
oughly. Perret^  asserts  that  it  has  a  decided  influence  in  inhibiting  the 
development  of  lactic  and  l)utyric  ferments.  Using  himself  and  a 
number  of  dogs,  he  undertook  a  series  of  feeding  experiments,  and 
concluded  therefrom  that  the  salt  is  in  no  way  poisonous,  and  may  be 
used  without  danger  as  a  food  preservative.  Specimens  of  milk  con- 
taining 3  parts  in  1,000  and  kept  at  38°  C,  remained  unchanged  long 
after  the  controls  had  become  coagulated.  A  dozen  tubes  of  milk  con- 
taining it,  and  planted  with  butyric  ferment,  and  another  dozen  con- 
taining untreated  milk  similarly  planted,  were  kept  side  by  side  at  38° 
C. ;  on  the  day  following,  the  latter  were  coagulated,  but  the  former 
were  unchanged.  Subcutaueous  injections  of  the  salt  to  the  extent  of 
0.08  gram  per  kilogram  of  weight  caused  in  a  dog  slight  salivation  and 
diuresis ;  but  larger  doses  caused  marked  salivation,  diuresis,  thirst, 
and  refusal  of  food.  Intravenous  injections  of  0.10  per  kilogram  caused 
immediate  rise  of  pulse  and  respiration,  followed  by  abundant  saliva- 
tion, nausea,  convulsions,  and  death  in  thirty-five  minutes.  Leffmann 
and  Beam  -  have  noted  that  sodium  fluoride  interferes  but  little  with 
the  digestion  of  starch. 

Sodium  fluoride  appears  to  be  weak  as  a  general  preservative,  but 
prevents  alcoholic  fermentation  completely  wheu  present  to  the  extent 
of  1  part  in  2,000.  The  fluorides  and  hydrochloric  acid  are  used  by 
some  brewers  for  the  prevention  of  undesired  fermentations. 

Sodium  Bicarbonate. — This  agent  seems  to  be  as  little  objectionable 
as  any,  but  it  is  very  weak  in  its  preservative  action  and  is  too  inefi^ec- 
tive  for  general  use.  It  is  used  somewhat  in  Sweden  in  conjunction 
with  sugar  for  meat  and  fish.  A  more  common  use  is  to  overcome 
beginning  acidity  of  milk ;  against  this  is  urged  the  possibility  of 
purgative  effects  in  infants,  through  the  sodium  lactate  produced. 


Section  8.     CONTAMINATION  OF  FOODS  BY  METALS. 

Not  infrequently,  small  amounts  of  metallic  salts  are  present  in 
foods,  either  through  accident  or  by  reason  of  intentional  admixture 
for  some  definite  end.  The  most  common  are  compounds  of  copper 
and  of  lead,  and  these  are  regarded  as  of  greater  hygienic  importance 
than  the  salts  of  zinc,  tin,  and  nickel  occasionally  present. 

Copper. — Copper  gains  entrance  through  the  improper  use  of  cook- 
ing utensils  of  brass  and  copper,  and  through  the  use  of  its  salts  for 
greening  peas  and  other  vegetables  ("  reverclissage  "),  and  for  improv- 
ing flour  of  inferior  grade.  Copper  and  brass  kettles  yield  small 
amounts  to  acid,  fatty,  and  other  foods  allowed  to  stand  therein,  espe- 

'  Annates  d'Hygiene  et  de  M^decine  If^gale,  June,  1898,  p.  497. 
'^  Journal  of  the  Fi-anklin  Institute,  1899. 


CONTAMINATION    OF   FOODS   I'.Y   MKTALS.  265 

(iiiiHy  if"  (lie  ('((iilciils  ;irc  exposed  1<»  llie  ;iir.  'Ilieir  \\<\i\  \~  miieli 
fjjn'jUcr  i("  lliey  iil'e  liol  kepi-  llior'oil^rlily  e|e;iii  ;iii(|  well  poli-li<-(|. 
JioliinnJiii  '  (oiiikI  .'WI.S  iiiillijz;i'iiiii.s  oC  e(»p|)(;r  in  ;i  liter  of  hrotli  m.'ul*! 
ill  Ji,  hniKH  vessel  iiiid  ;illo\ve<l  to  stand  2  1  lionrs,  H.7  \\\\£V.  in  |()()ec. 
of  iiiiKiid  fiit  idlovved  to  st;ind  2  vvockH,  21  ni^r,  in  a  liter  of  sour 
wine,  Jind  (II  in  the  sanu!  volume  of  vinej^ar  af'(<'r  2  1  lioiir.-.  Mair  liaH 
reported  2  1  ninr,  in  a  lit(!r  of  v'\(.'i\  sonp  alter  2  1  lionrs. 

The  use  of  eoppei-  Tor  jrreeninfr  veji;elal)l(w  is  cxwjodin^'-ly  eornnion. 
It  serves  no  iisel'nl  pnr|>os(!  other  than  to  j)leasf;  tin;  eye.  The  p(5iH  or 
<»ther  veJ^(^lal)l(^s  are  boiled  in  a  very  dilnU;  solntictn  of  (!0])jK'r  suiphatti, 
<lraine(l,  washed,  and,  (inally,  j»nt  up  in  cans  or  ^lass  pirs.  Tlu;  arti- 
(ieial  eoloi',  which  is  ol'len  nnieli  more  infenselv  /ireen  tli;m  the  natural, 
is  due  to  an  ori;;uiie  eom|)ouii(l  ol"  eoppei-  w  liieh  is  in-nluhle  in  water. 
'^I'lu!  (^laini  sonu^times  urj^cd,  that  the  e<»p|)er  serves  to  (ix  the  ehlon>- 
phyll,  and  is  not  itself  I'elained,  is  jircposterous,  lor  if  a  solution  of 
cliloro|)liyll  is  healed  with  dilute  eop])er  su]|)hate,  the  eoloi-  is  destroved 
and  a  hrowu  prveipilate  is  produced  ;  wliilc  if  pericctly  white  boans  are 
boiled  for  a  short  time  in  a  solution  of  the  same  strength,  they  tiike  on 
a  de(>p-<2;reen  color  throuj^h  the  formation  of  a  new  compound  with  the 
contained  le^umin  or  some  other  jiroteid.  J*otat<tes,  bein^  very  jK>or 
in  pi-oteids,  are  affected  but  slightly  by  similar  treatment,  i>ut  eggs  may 
be  colored  intensely  green. 

The  liquor  of  canned  greened  vegetables  is  commonly  free  from 
cop]Kn',  and  the  testing  of  siK'cimeus  by  adding  ammonia  to  a  portion 
of  the  liquor,  in  the  expectation  of  ])roduciug  a  blue  color  in  ease  the 
vegetable  has  been  so  treated,  is,  therefore,  without  result.  In  order 
to  determine  the  presence  of  copper,  a  few  grams  of  the  substance  may 
be  incinerated  in  a  porcelain  capsule,  the  residue  therefrom  treated  with 
dilute  hydrochloric  acid,  and  the  filtrate  subjected  to  the  usual  tests. 

The  question  of  the  hygienic  importance  of  small  amounts  of  copper 
has  been  the  subject  of  a  number  of  extensive  investigations  on  the  part 
of  individuals  and  foreign  governments,  and  while  it  can  hardly  be  said 
to  be  proved  that  danger  can  arise  therefrom,  nevertheless  no  good 
reason  can  be  advanced  in  favor  of  the  practice  of  greening.  Two  stu- 
dents in  Ijchmaun's  laboratory  took  daily  doses  of  copper  salts  with  no 
perceptible  disturbance  ;  one  took  39  milligrams  of  copper  sulphate 
daily  for  50  days,  and  then  double  that  amount  for  30  more ;  the  other 
took  the  acetate  for  51  days  in  doses  ranging  from  16  to  9(3  milligrams. 
These  amounts  are  larger  than  an  average  eater  would  be  likely  to  take 
into  his  system  from  canned  vegetables  in  the  course  of  a  day,  for  the 
entire  contents  of  an  ordinary  tin — somewhat  less  than  half  a  pound — 
commonly  yield  less  than  50  milligrams  of  copper. 

According  to  Baum  and  Seelinger,-  whose  numerous  experiments 
extended  over  a  period  of  three  years,  small  daily  doses  are,  as  a  rule, 
completely  absorbed  and  ag-ain  eliminated  ;  larger  doses  are  not  com- 
pletely absorbed.     Complete  elimination  may  require  as  long  as  five 

^  Seventh  International  Congress  of  Hvgiene,  1891. 
•^  Zeitsclirift  fiir  olieutliche  Cliemie,  1S9S,  p.  181. 


266  FOODS. 

months  from  tbc  dato  of  the  last  dose.  Lono'-continned  ino-cstion  of 
small  doses  may  bi'in<;"  about  a  condition  of  chronic  poisoning. 

Copper  appears  to  be  a  normal  constituent  of  some  articles  of  food. 
The  assertion,  made  originally  by  Meyer,  of  Copenhagen,  that  wheat 
and  oats  often  contain  minute  traces,  esju'cially  in  their  husks,  has  re- 
peatedly been  proved.  According-  to  Lehmann,'  the  species  of  jilants 
has  far  less  iniiuence  on  the  amount  taken  up  than  the  amount  of  copper 
present  in  the  soil.  He  found  the  metal  in  a  great  variety  of  ])lants 
gi-owing  in  a  copper  soil  :  rye,  oats,  hops,  potatoes,  dandelion,  juniper, 
violets,  cherries,  etc.  In  woody  plants,  the  greatest  amount  of 
copper  is  in  the  bark.  According  to  Karsten,-  the  sjjraying  of  grape- 
vines Avith  copper  solutions  is  not  wholly  free  from  objection,  since 
that  which  adheres  to  the  fruit  may  be  sufficient  to  make  their  yield  of 
wine  toxic.  He  instances  a  number  of  cases  of  diarrluea  and  vomiting 
due  to  wine  which  yielded  traces  of  copper. 

Lead. — Traces  of  lead  are  of  common  occurrence  in  various  articles 
of  food,  especially  those  wrapped  in  foil  or  enclosed  in  cans  having  ex- 
posed seams  of  lead  solder.  A  number  of  specimens  of  wrapping-foil, 
analyzed  by  Dr.  Charles  P.  Worcester,^  yielded  lead  in  amounts  rang- 
ing from  traces  to  89  per  cent.  They  are  used  largely  for  wrapping 
cream  cheeses,  chocolate,  and  other  foods.  The  metallic  caps  used  for 
closing  glass  jars  of  preserved  fruits  and  vegetables  are  also  sources  of 
danger.  One  specimen  examined  by  Worcester  contained  93.5  per 
cent,  of  lead.  Patent  stoppers,  consisting  of  a  metallic  disk  Avith  a 
border  of  rubber,  used  in  bottles  for  summer  beverages  known  to  the 
trade'  as  "soft  drinks,"  commonly  contain  lead,  as  is  shown  by 
Worcester's  examination  of  28  specimens,  which  yielded  from  3.5  to 
50.7  per  cent.  The  contents  of  the  several  bottles  yielded  lead  with- 
out exception;  the  largest  amount  was  1.05  milligrams. 

Dr.  William  R.  Smith  ■*  has  drawn  attention  to  the  common  occur- 
rence of  lead  in  citric  and  tartaric  acids.  The  former  is  used  consid- 
erably in  making  summer  drinks,  and  the  latter  in  eflFervescing  powders 
and  baking  powders.  Of  a  dozen  specimens  examined  by  him,  only 
one  was  uncontaminated ;  the  highest  amount  found  was  0.037  per 
cent. 

At  the  present  time,  canned  foods  are  less  likely  to  show  traces  of 
lead  than  formerly,  when  the  cans  were  made  with  less  care.  In  1893, 
Wiley '^  reported  traces  in  132  out  of  248  samples  examined. 

Concerning  the  hygienic  importance  of  small  daily  doses  of  lead, 
there  is  but  one  opinion.  It  is  quite  improl)able  that  the  occasional 
use  of  canned  vegetables  containing  but  a  fraction  of  a  milligram  in  an 
entire  can  will  lead  to  serious  injury,  l)ut  the  constant  daily  ingestion 
of  appreciable  amounts  of  lead  is  likely  to  lead  to  serious  consequences 
in  at  least  a  fair  proportion  of  cases. 

*  Archiv  fiir  Hygiene,  XXVIL,  p.  1. 
^  Cheniiker-Zeitnng,  1S96,  p.  37. 

•'  29th  Anniml  Keport  of  the  State  Board  of  Health  of  MassachiisetfB,  p.  570. 

*  .Journal  of  State  iSledieine,  October,  1892. 

^  Department  of  vigriculture,  Division  of  Chemistry,  Bulletin  No.  13,  Part  VIIL 


(JONTAMINATION   OF   h'OODS   11  Y  METAI.S.  207 

l*]s|K'<M:iJly  l.o  |)(;  ;iV()i<l«''l  .'H"''  (lie  ;i'lil  <liiiil<H  v.nuUx'wuA  in  ItofllcH 
willi  Ic;mI  .slo|)|)(!l-s.  Tlic  ;inMHiiil  of  li:i.|  |,i<-ciif,  is  HIii:ill,  !i  ri<l  ;i  ii  <.f<-,a- 
sioiiiil  iii(liil^cii('<'  is  unlikely  In  cnii-c  li.nni  ;  l.nl  ci-c-  (.f  hcrifdi-  injury 
liii,V(Mt<',c,nn'('(l.  In  one,  in  wlilch  I  lif  cim -i-  <,r  t  Iif  tiunl.le  \v:ih  invcnli- 
\ri\.tvi\  \)y  \\\v.  ;nilliiti-,  llic  |i;iliinl,  ;i  l(  ni  |)(  r;i  nrc  |((|ni<r,  li;i(|  lor  utriif' 
W('('l<s  Ix'cn  pii.ssioniilcly  jiddiclcd  lo  I  Ik;  iisr;  of  :i  |)articnl:ii-  lii;iM<l  of 
(^ll'crvcsccnt  drink  known  ;is  '' sliMwhcri'y  ioiiir,"  ;i  (•:iil>on;il<d,  ;icidn- 
I.'ilcd  soinli(»n  ofsn^iir,  Ihivorc*!  willi  ;in  ;iiti(ici;d  (•()ni|)oinid  cIIki-,  ;ind 
colored  willi  :in  niiilin  dyv.  I^sidcncc  of  clironic  l(;id  |i(»i,-oriin^'  de- 
veloped widi  some  snddenness,  !ind  in  m  sliori  litne  not  f)nly  wrist-drop, 
l)ut.  mIko  t.oe-dro|)  ;i|)pejired.  Speeiniens  of  I  lie  I»ever;ij^e  were  ex:iniined, 
'V\\v.  stoppers  wer(i  almost,  pnre  lead,  and  tlie  eonlents  of  ciieli  b»jttlc 
yielded  notable  traces  of  tlie  nielal. 

Zinc. — Zine  sometimes  oeenrs  in  small  traces  in  canned  food.s  from 
the  us<^  of  ilu!  (chloride  in  solderine;.  Willi  iinproNcd  nietlKKl.s,  in  \vlii(;li 
anotlun*  flux  is  cm])]oye(l,  tins  e.ontaminalioii  is  hecomin^  nneoin?no?i  in 
tliis  class  of  foods.  It  a])p<'ars  to  he  a  common  aecideiitiii  inij)urity  in 
dried  a])|)lcs,  from  contact  with  e:alvanizcd  iron  win;  racks  on  wliieh 
they  are  ctn-ed.  Kiim merer  '  found  it  in  4  ont  of  1)  specimens  of 
Amei-ican  dried  apples  ;  the  averao;e  amount,  reckoned  as  malate,  wa.s 
0.0()r)6  per  cent.  J iujard  ^  found  it  in  .37  out  of  54  ;  in  20,  the  amount 
jiresent  ranj>;ed  from  0.03  to  0.49  gram  to  the  kilogram,  reckoned  a.s 
oxide ;  in  17,  it  was  present  only  in  traces.  We  have  no  evidence  that 
thes(>  small  amounts  are  of  the  slightest  sanitary  imjiortance. 

Nickel. — Nickel  is  emj)loyed  sometimes  in  place  of  coj)per  lor  green- 
ing peas.  About  a  quarter  of  a  gram  of  the  suljihate  suffices  for  a 
kilogram  of  peas.  It  is  dissolved  in  boiled  water  to  which  10  cc.  of 
a  2  ])er  cent,  solution  of  ammonia  are  added,  and  then  the  solution  is 
diluted  with  boiled  water  in  suilicient  amount  to  cover  the  jX'as,  which 
then  are  boiled  for  a  few  minutes,  drained,  and  washed.  According  to 
E,  Tjudwiff,'^  nickel  is  given  off  in  small  amounts  to  all  sort.s  of  foods 
cooked  in  nickel  dishes.  He  found  from  traces  to  12.9  mdligrams 
per  100  grams  of  the  food  examined.  There  is  no  evidence  that  these 
amounts  can  produce  injury. 

Tin. — Contcimination  with  compounds  of  tin  is  exceedingly  common, 
and,  so  far  as  is  known,  is  harmless  and  unimportant,  the  coni]>ounds, 
other  than  the  chloride,  being  apparently  incapable  of  produciiig  any 
physiological  or  local  action. 

Metallic  Contamination  from  Kitchen  Utensils. — Much  has  been 
said,  from  time  to  time,  ccmcm-ning  the  possible  danger  of  poisoning  by 
small  amounts  of  lead  and  other  metals  taken  up  by  foods  from  kitchen 
utensils,  and  especially  from  glazed  earthenware  ;  but  a  number  of 
extensive  investigations  have  demonstrated  that  this  danger  is  very 
remote.     Mussi  ^  has  shown  that,  if  the  tiring  of  lead-glazed  potterj" 

1  Chemikei-Zeitung,  1897,  p.  721. 

'^  Foi-schnngsboviolU  iiber  Lehensniittel,  etc.,  1897,  IV.,  p.  218. 

^  Oesterreiolie  Clioniisi-he  Zoitiins::,  1898,  I. 

*  Giornale  delta  R.  Societiv  Italiana  d'igiene,  January  30,  1900,  p.  1. 


268  FOODS. 

has  been  done  properly,  no  trace  of  lead  will  be  taken  up  by  acid  foods, 
such  as  tomato  soup,  or  even  vinegar  ;  but  he  advises  that  all  new 
vessels  should  be  cleansed  very  carefully  before  using,  on  account  of  the 
common  presence  of  lead  dust  on  the  glaze  when  fresh  from  the  kiln. 
Riche  '  also  determined  that  with  properly  tired  ware  the  danger  of 
solution  of  lead  is  practically  nil,  the  specimens  used  yielding  no  traces 
to  boiling  dilute  acetic  and  nitric  acids  and  salt  solutions.  But  im- 
properly tired  ware  will  yield  traces. 

Enamelled  ware  is  believed  commonly  to  contain  lead ;  and  the 
enamel,  having  a  dilferent  coefficient  of  expansion  from  that  of  the 
iron,  being  likely  to  crack  and  chip  off,  especially  with  careless  hand- 
ling, is  thought  to  be  dangerous  ;  but  Barthe "  found  no  trace  of  lead 
in  a  number  of  enamels  examined,  and  asserts  that  very  hard  enamels 
need  neither  lead  nor  any  other  poisonous  compounds  in  their  prepara- 
tion. This  accords  with  the  experience  of  the  author  and  other 
American  investigators,  and  it  may  confidently  be  said  that  the 
enamelled  ware  in  common  use  is  lead-free. 

Aluminumware,  which  has  of  late  come  into  extensive  use,  is  less 
acted  upon  by  acid  foods  than  tin,  but  is  affected  considerably  by 
alkalies,  the  impurities  present  in  commercial  aluminum  acting  as 
favoring  agents  to  its  corrosion.  But  the  resulting  compounds  are 
innocuous  in  the  small  amount  ingested.  This  kind  of  ware  is  kept 
clean  very  easily  and  offers  the  great  advantage  of  lightness. 

Nickelware  is  attacked  but  slightly  by  ordinary  food  materials,  and 
the  amounts  taken  up  are  without  sanitary  significance.  But  its  cost 
is  against  its  extensive  use,  and,  moreover,  it  imparts  sometimes  a 
greenish  tint,  which  is  repugnant  to  the  eye. 

1  Revue  d' Hygiene,  August  20,  1900,  p.  704. 

*  Journal  de  Pharmacie  et  de  Chemie,  1898,  p.  105. 


Cll  y\  I"I^  K  \l    I  i. 
All:. 

Alii  is  a  inixiiirc  oi*  ga.scs,  mikI  ih>(  ;i  (licinicil  roitipomifl.  (ritil 
tlic  latter  part  of  the  Heventccnili  (ciiturv  (KiODj,  il  w.-i-  >ii|i|»(im(I 
to  l)(!  Mil  (ilciiicnt,  hilt  Jean  Miiyow  tluii  proved  it  to  he  a  iiiixliin- 
of  }j:;!tse,s  ;  mikI  hier,  Lavoisier  discovered  the  two  ^ases,  oxy^rcri  ;irid 
niti-onxiii,  \vhi(Oi,  a  hiiiidrcd  years  later,  were  separated  hy  l'rie-tl(y  and 
hy  ISeheele. 

Air  is  a  colorless  and  apparently  odorless  niixtnre  of"  oxygen,  nifro- 
f»en,  a-r}2;on,  (^arhonie-  acid,  a(|neoiis  va|)or,  and  traees  of  other  siihstanees. 
It  is  not,  however,  under  ordinary  conditions  odorless,  hut,  on  the  con- 
trary, it  contains  various  s(!eiits,  to  which  we  are  so  accustomed  that, 
unless  present  in  unusual  degree,  owing  to  local  conditions,  they  are 
not  perceived.  This  is  noticed  on  returning  to  an  ordinary  atmosphere 
from  one  where  the  causes  of  the  usual  odors  are  absent  or  nearly  so, 
as,  for  instance,  from  deep  subterranean  caves  ;  or  from  a  room  where 
the  air  is  foul  and  oppressive,  as,  for  instance,  from  a  heated,  over- 
crowded hall  or  street  car.  The  air  of  the  Arctic  regions  contains  but 
little  odor,  on  account  of  the  absence  of  bodies  which  give  rise  to  (xlors, 
and  the  proximity  of  any  source  of  smell  is  noticed  (piickly.  The  ex- 
plorer Nanseu  ^  speaks  of  the  pervading  smell  of  soap  wliich  he  noticwl 
when,  after  months  of  wandering,  he  met  Jackson,  wlio  had  been  housed 
comfortably  with  all  the  common  necessities  of  man. 

AVhile  air  is  a  mixture  of  gases,  it  is  one  of  tolerably  constant  com- 
position, particularly  in  the  case  of  its  chief  constituent,  nitrogen. 
Under  the  conditions  of  life,  the  more  important,  but  less  abundant 
element,  oxygen  is  subject  to  more  or  less  variation.  In  the  presence 
of  vegetable  life,  particularly  by  day,  it  is  increased  slightly  ;  in  the 
presence  of  animal  life,  it  is  diminished  more  or  less. 

OXYGEN. 

The  normal  amount  of  oxygen  is  stated  usually  at  just  below  21  i>er 
cent,  by  volume.  A.  Leduc  gives  it  at  exactly  21,  with  78.06  of  nitro- 
gen and  0.94  of  argon.  Piiferent  observers  have  reported  the  follow- 
ing as  averages  of  large  numbers  of  analyses  of  pure  outdoor  air  : 

20.99 Scotland. 

20.98 Scotland. 

20.94 Sweden. 

20.92 France. 

20.94 Germany. 

20.92 Xorwav." 

20.95 Ensiaiid. 

20.95 Ohio. 

1  Farthest  North,  Vol.  II..  p  529. 

2t?9 


270  AIR. 

The  mean  of  a  luiiuhiT  of  analy.ses  by  Buuyen  was  20.924  by  volume, 
and  of  a  Imndivd  at  Taris  by  Regnault,  20.900.  For  the  sake  of 
conveuieiKi',  w  u  may  disivganl  the  very  slight  ditteroiice  between  21 
and  the  ligiuvs  (^)btaiiicd  by  exaet  analysis,  a  ditferenee  in  the  seeond 
phiee  of  (.leeiuials,  and  aeeept  21  as  a  normal.  .\t  great  heights,  the 
proportion  of  oxygen  is  less  than  at  the  surface.  For  instance,  on  the 
Faulhorn,  in .  Switzerland,  20.77  has  been  observed  as  the  mean  of  a 
number  of  determinations.  Under  certain  conditions,  there  is  very 
slightly  more  than  21  jiarts  ;  for  instance,  in  the  immediate  vicinity  of 
vegetation,  especially  by  day,  there  may  be  an  excess  of  oxygen,  but 
it  is  very  small;  sea  air,  taken  in  mid-ocean,  has  yielded  21.59,  but 
ordinarily  contains  less  than  21.  It  is  less,  by  very  small  fractions, 
in  the  streets  of  cities  than  in  the  open  country,  and  in  towns  than 
at  sea. 

Oxygen  is  the  element  in  air  that  supports  all  life.  It  is  constantly 
being  withdrawn  from  the  air  in  the  process  of  respiration,  and  is  re- 
turned to  it  in  chemical  imion  with  carbon  as  carbon  dioxide.  This  is 
absorbed  by  vegetation  and  split  up,  the  carbon  being  retained,  and  the 
oxygen  for  the  most  part  released  and  returned  to  the  air.  Thus,  the 
processes  of  animal  and  vegetable  life  combine  to  maintain  the  equilib- 
rium. 

All  animals  do  not  breathe  in  the  same  degree ;  birds  have  the 
most  active  respiration,  and  next  come  mammtds ;  and  all  consume 
more  oxygen  when  active  than  when  asleep. 

Oxygen  is  essential  to  the  germination  of  seeds,  and  to  the  growth 
of  plants.  Although  plants  take  up  carbon  dioxide  and  exhale  oxygen, 
they  also  breathe  as  do  animals,  absorbing  the  latter  and  exhaling  the 
former.  Even  the  anaerobic  organisms  consume  oxygen,  although 
living  where  air  is  wanting,  for  they  split  up  combinations  of  oxygen 
and  other  elements.  Thus,  in  dilute  sugar  solutions  they  withdraw 
some  of  the  oxygen  and  s]:»lit  up  the  sugar  into  carbon  dioxide  and 
alcohol. 

For  sustaining  animal  life,  it  is  essential  that  the  air  shall  contain 
not  far  from  the  normal  amount  of  oxygen  ;  that  is,  that  it  shall  be 
neither  much  diminished  nor  yet  over-rich  in  that  element.  Human 
life  is  impossible  in  air  which  contains  but  four-fifths  of  the  normal 
amount,  and  equally  so  in  an  artificial  atmosphere  containing  materially 
more  than  the  normal. 

In  man  and  animals,  the  tissues  do  not  receive  oxygen  in  the  free 
condition,  for  when  the  air  is  inspired,  the  oxygen  is  taken  up  by  the 
red  blood  corpuscles  and  unites  with  the  haemoglobin  to  form  an  un- 
stable compound,  oxyhsemoglobin,  which,  as  the  blood  circulates  through 
the  tissues,  is  decomposed  ;  the  oxygen  is  then  taken  up  by  the  cells, 
and  eventually  returned  to  the  blood  in  the  form  of  carbon  dioxide,  and 
eliminated  as  such  from  the  body.  In  an  artificial  atmosphere  con- 
taining an  excessive  amount  of  oxygen,  the  haemoglobin  becomes  sat- 
urated with  the  gas,  part  of  which  becomes  dissolved  in  the  blood  serum, 
and  then  acts  as  a  poison  to  the  tissues  and  destroys  them. 

15 


NITlLOdHN.  271 

I  liS|»ii'c(|  ;ii|-  loses  ;il)uill  ;i  (iiiiilli  <>('  i(s  (txy^cn,  jiikI  Ih  r<;flirii('<l  to 
Llic,  ;iiiiios|ilici-r  rich  in  iiii  |iiiril  \  ;  liiil.  (lill'ii.sioii  occiirK  ho  r;i|»i<lly  lliaL 
i,li(!  ii,(,nios|»liciv  (>r  ;i  iliiilJ\-  -ciilcd  city  hIiovvh  no  very  rnuU-riiil  varia- 
l,i(tii  (Voiii  (Ji;ii  <>(    I  lie  ii|icii  coiiiil  ly. 

'V\\{'.  Itiiins  ;\vi'  iicscr  lillcd  wllli  |)iii-c  air  al'ici'  ilic  lir.-t  rc.-)iiralioii 
ai  birlli,  since  (lie\  are  ne\ci-  w  linlK  ciniil  ie«l,  and  tlicy  <;oiiM'(jiiciitly 
<v»n(aiii  an  inipnre  residne  ol"  air  aCler  eacli  expiriilioii.  'J'lic  ilpjMT 
pari,  ol'  llie  res|tiralury  Iracl  is  tlie  only  part  tliat  rcccivcH  Htridly  jmn- 
air.  Professor  K'ieliet  has  (lenioiislrated  that,  if  the  rcHpiralory  tract 
!)('  Ient;lhened  arlidcially  by  means  of  a  nihWer  liiWe,  piire  air  will  never 
I'dK^li  even  (he  nppei' air-puHSUf^cs,  and  I  he  animal  will  <lie  oTa-pliyxia. 

'V\\v  amoinil  of  owi^cn  ahsorhed  varies  with  a^e,  <'<»ndition  of  licaltli, 
and  ac(i\i(A.  According;  to  I'l'oCessor  l*'oster,  an  avcraj^e  per.-on  inllal(^s 
in  24  lionrs  about  .'!  I  |)onnds  of  air,  whieii  eorres|ionds  t<»  a  little  nK»rc 
than  7  ponnds  of  o\\<;vn  ;  and  as  the  InnjiS  absorb  abont  afbnrlli  of 
the  o.wn-en  inhaled,  it,  appears  (hat  the  average  amount  ol"  oxygen 
absorbed  daily  is  neai'l}'  "1  poinids, 

NITROGEN. 

The  pi'ineipal  eonstitnent  of  the  air,  nitroiren,  takes  no  ))art  in 
respii'ation,  and  is  not  increased  in  expired  air;  bnt  altlion^di  it  is 
indilVerent  and  inert,  it  is,  nevertheless,  l)y  no  mejins  nnimportant. 
In  the  iirst  ])laee,  it  serves  to  dilute  tlic  oxygen,  so  that  the  latt<T  is 
respirable;  and  in  the  second  jilaee,  it  plays  an  important  part  in  the 
growth  of  ])lants,  the  original  source  of  all  nitrogenous  food,  for  that 
whicli  we  consume  in  the  form  of  meat  is  from  animals  that  have  built 
up  their  tissues  from  vegetaV)le  food.  As  a  diluent  of  oxygen,  it  serves 
to  prevent  too  great  activity  of  that  element,  which  cannot  be  breathed 
with  impunity  for  any  length  of  time  when  present  in  an  atmosphere 
to  a  grejitcr  extent  than  its  normal  amount. 

TIo\v  nitrogen  is  absorbed  by  plants,  we  know  only  in  ]iart.  Certain 
low  forms  (mycelia,  etc.)  seem  to  absorb  it  directly  from  the  atmos])here 
w  hen  exposed  freely  to  light  and  air.  Some  of  the  higher  forms  (peas, 
beans,  clover,  etc.)  acquire  it  through  the  agency  of  certain  micro- 
organisms which  are  present  in  nodules  in  their  roots,  and  without  which 
they  will  not  thrive.  These  micro-organisms  take  the  nitrogen  from 
the  atmosphere  and  give  it  in  some  form  to  the  ]ilants.  That  this  is 
so,  is  proved  by  the  fact  that  the  plants  will  thrive  in  a  soil  quite  free 
from  nitrogen  (in  clean  sand,  for  instance),  and  store  up  in  their  tissues 
an  amount  of  uitroyen  far  in  excess  of  that  Avhich  Avas  oriirinallv  iire-s- 
ent  in  the  seeds,  provided  these  micro-organisms  are  present  in  the 
nodules  of  the  roots.  If  they  are  not  present,  the  plants  will  not 
thrive,  but  may  be  made  to  do  so  by  the  application  of  water  contain- 
ing cultures  of  the  organisms.  Of  the  doubtless  many  species  which 
can  tix  atuuispheric  nitrogen,  or  which  aid  in  doing  so,  the  following 
may  be  mentioned:  B.  ma/afheriiim,  B.  J^norcsccns  liqucfaeicn.'i,  B.  pro- 
tcus  vulgaris,  B.  bufi/ricus,  B.  mi/coidcs,  B.  mesenterial^^  vulgatiis. 


272  AIR. 

On  the  other  liand,  certain  plants,  grown  in  the  open  air  in  soils 
free  from  nitrooen,  and  protected  from  receiving  ammonia  and  nitrates 
from  the  rain,  will  show  no  more  nitrogen  in  their  whole  organization 
than  was  present  in  the  seeds  from  which  they  sprang.  The  snbject  is 
one  which  has  been  investigated  but  partly,  and  future  research  will 
doubtless  show  that,  under  natural  conditions,  all  plant  life  takes  up 
in  some  wav.more  or  less  nitrogen  from  the  atmosphere,  as  well  as  from 
nitrogenous  compounds  in  the  soil. 

ARGON. 

Up  to  the  time  of  its  discovery,  the  element  argon  was  included 
under  nitrogen  in  the  tables  of  composition  of  the  air.  How  much  is 
present,  is  not  yet  accurately  determined.  It  was  discovered  in  1894, 
by  Lord  Rayleigh  and  Professor  Ramsay,  by  whom  later  it  was  esti- 
mated as  composing  about  0.75  per  cent,  of  the  atmosphere.  Leduc 
gives  its  amount  as  0.94,  and  Schloesing  as  0.84.  It  is  quite  inert, 
and  cannot  be  made  to  combine  with  any  other  element,  although  it  has 
been  combined  by  Berthelot  with  benzene  under  the  influence  of  electric 
discharge. 

HYDROGEN. 

According  to  the  extensive  researches  of  Armand  Gautier,  hydrogen 
is  present  in  sea  air  and  other  pure  air  in  fairly  constant  amount — about 
0.015  per  cent.  It  is  believed  to  be  due  to  various  fermentative  proc- 
esses, and  to  be  contributed  also  by  mineral  springs  and  volcanoes. 
So  far  as  known,  its  presence  is  devoid  of  sanitary  importance. 

Other  elements,  as  krypton,  neon,  and  metargon,  also  discovered  by 
Professor  Ramsay,  coronium,  discovered  by  Nasini,  and  several  others, 
are  interesting  solely  from  a  purely  scientific  standpoint. 

CARBON  DIOXIDE   (CARBONIC  ACID). 

All  air  contains  carbon  dioxide  as  a  constant  constituent.  The  nor- 
mal average  amount  in  pure  air  is  but  slightly  in  excess  of  3  parts  in 
10,000,  or  about  0.03  per  cent.,  and  not  4  parts,  as  commonly  is  stated. 
As  little  as  2.03,  and  even  1.72,  has  been  observed  in  the  air  on  moun- 
tain-tops, although  generally  we  expect  more  rather  than  less  than  the 
normal  amount  at  high  elevations. 

Carbon  dioxide  is  a  result  of  oxidation  of  organic  matter,  and  owes 
its  presence  in  the  atmosphere  to  respiration,  fermentation,  combustion, 
and  chemical  action  in  the  soil.  An  average  man  exhales  about  20 
liters  in  an  hour,  and  very  nearly  a  kilogram  ui  a  day  ;  women  exhale 
less,  and  children  and  aged  persons  still  less.  The  amount  exhaled  is 
increased  by  nuiscular  exertion  and  diminished  by  rest.  Birds  send  out 
more  in  proportion  to  weight  than  other  animals.  The  respiration  of 
millions  and  millions  of  human  beings  and  animals  is  constantly  thro\y^ 


CARBON  DIOXIDK  (CA/UlON/fJ  ACID).  '11'.) 

\\\\r  int..)  IIk;  !iim()S|)li('r('  comillcHH  ton.s  <»("  tlicf:;iH;  every  ton  of  coal 
in  l)in'nin<i:;  yields  more  llian  (17, 000  (•iihie,  feel  ;  evtrrv  eiihie  foot  of 
<!Oiil  ^'iis  yields  ;d)oiil  double  its  volume;  every  pound  of  eundic  wvarXy 
ilii-e(!  tim<'S  ils  weight,  (2.7<i!))  ;  e\ery  ^;dlon  (tC  oil  ;ind  keroHCffie,  und 
every  j)i(!ee  ol"  wood  iis(!d  iis  Cuel,  eontril)iiles  ils  proporfion.  lliij^e 
volumes  ;ire  seni,  for'tli  eonlinuMlly  Wy  (lie  soil  air,  wliieli  eonfains  it 
in  abiiiidan(!(!,  and  by  mineral  spriuf^s,  the  waters  of  wliieli  er>ntaiii  it 
under  prcsstin!.  Jt  lias  be(Mi  estimated  that,  IVom  all  Hf>iirc<!H,  5,000 
million  tons  are  discharged  annually  into  t  he  atmosphen;.  It  is  slif^litly 
more  abundant  in  cities  than  in  the  country,  and  ;it  ni^lit  than  by  day. 
It  is  highest  in  uniount  at  a  ^;iven  location  din-in^  autumn,  and  lowest 
in  winter.  It  is  more  abundant  inland  than  on  the  coast.  It  increaHcs 
somewhat  as  we  ascend  from  sea-level — acoordin^r  to  Schla^intweit,  up 
to  11,000  feet.  Its  removal  from  tlu;  atmosphere  is  mostly  through 
the  agency  of  growing  vegetation,  but  materially  also  by  absorj)tion  by 
bodies  of  water,  which,  at  ordinary  temperature  and  j)ressure,  will  take 
uj)  its  own  volume  of  the  gas.  It  lias  been  calculated  that  the  ocean 
contains  about  ten  times  as  much  as  the  whole  atmosphere.  All  green 
plants  al)sorb  it  by  day,  and  by  means  of  their  chlorophyll  break  it  up 
into  carbon  and  oxygen,  the  former  being  used  in  l)uilding  tissue,  and 
the  latter  returned  to  the  air  as  a  waste  product.  This  process  of  nutri- 
tion goes  on  only  under  the  influence  of  light,  and  consequently  by 
day ;  but  there  is  also  a  respiratory  function  that  is  active  both  day 
and  night,  and  has  the  same  effect  on  air  as  that  of  the  res])iration  of 
animals  ;  namely,  the  consumption  of  oxygen  and  discharge  of  car- 
bonic acid.  But  the  respiratory  process  has  but  a  trivial  influence  in 
comparison  with  the  chlorophy llian  function.  It  is  estimated  that  an 
acre  of  woodland  withdraws  in  one  season  about  four  and  a  half  tons, 
retains  more  than  one  and  one-fifth  tons  of  carbon,  and  returns  three 
and  a  quarter  tons  of  oxygen  to  the  air.  The  slight  increase  at  night 
is  due  supposedly  in  part  to  its  exhalation  by  plants  in  their  respira- 
tion, and  also  to  currents  of  soil  air,  which  ascends  as  soon  as  the  air 
at  the  surface  becomes  colder,  and  consequently  heavier,  than  itself. 
Puring  the  day,  the  soil  air  is  colder  and  remains  stationary. 

Carbon  dioxide  is  a  heavy  gas,  incapable  of  supporting  combustion 
or  respiration,  and  serving  no  useful  puqsose  in  animal  tissues.  It 
constitutes  about  4  per  cent,  of  expired  air,  in  which  it  is  an  excretion 
of  the  body.  It  is  in  itself  inert,  and  incapable  of  exerting  any  |X)i- 
sonous  action,  but  will  cause  asphyxia  when  present  in  sufficient  amount 
to  interfere  with  the  atmospheric  oxygen  in  the  performance  of  its 
function. 

An  atmosphere  of  respired  air,  containing  4  per  cent.,  of  carbon 
dioxide  and  about  1(3  per  cent,  of  oxygen,  will  not  support  life  longer  than 
a  short  time,  since  the  blood  cannot  get  suificient  oxygen  for  the  needs 
of  the  cells  and  tissues,  and,  in  addition,  cannot  rid  itself  of  its  COj. 
Gas  exchange  between  the  blood  and  inspired  air  depends  upon  the 
tension  of  the  gas  in  both  media,  and,  therefore,  as  soon  as  the  tension 
of  the  CO2  in  the  atmosphere  exceeds  that  of  the  COo  of  the  blood,  the 
18 


274  AIE. 

blood  corpuscles  cannot  excrete  it,  but  must  retain  it.  In  consequence, 
asphyxia  occurs. 

The  question  as  to  how  much  CO.,  is  pcrmissibU'  in  air,  has  been  an- 
sweretl  variously.  We  assume  8  parts  in  1 0,000  as  the  normal  amount, 
and  all  in  excess  as  impurity  due  to  respiration  and  combustion.  A 
total  of  ()  or  7  parts  in  10,000  is  reii;arded  by  the  best  authorities  as 
the  permissible  limit,  and  10  in  10,000  as  distinctly  harmful.  AVhen 
the  amount  reaches  10  parts  in  10,000,  the  air  begins  to  be  "close"; 
and  when  it  reaches  15  in  10,000,  it  is  likely  to  cause  headache  in  those 
unat-customed  to  impure  air.  lu  crowded  assembly  rooms,  as  churches, 
theatres,  and  schools,  the  amount  may  re;vch  100  jiarts  in  10,000  ;  and 
more  than  twice  as  much  has  been  found  in  a  Swiss  stable  crowded 
with  men  and  animals.  The  air  of  the  hall  in  which  the  (Jcrman 
Public  Health  Society  (Deutscher  Verein  fiir  offeutliche  Gesundheits- 
pflege)  met  in  Nuremberg  in  October,  1890,  contained  24.10  in  10,000 
at  the  beginning  of  one  of  the  addresses,  aud  43.20  at  its  close. 

A  large  amount  of  carbon  dioxide  may  be  present  in  air  without 
producing  any  ill  eifects,  if  there  is  plenty  of  oxygen  present.  Thus, 
Regnault  and  Reiset  have  proved  that  animals  can  live  in  a  mixture 
of  25  per  cent,  carbonic  acid,  30-40  per  cent,  oxygen,  aud  nitrogen. 

It  has  been  held  generally  that  CO^  up  to  20  :  10,000  is  in  itself 
harmless  ;  that  the  deleterious  agents  in  polluted  air  are  organic  mat- 
ters thrown  oif  by  the  skin  aud  lungs  in  company  Avitb  it ;  aud  that  it 
serves  as  a  convenient  index  of  their  amount.  It  has  been  the  custom 
to  say,  "  The  more  carbonic  acid  we  find,  the  more  organic  matter  we 
infer."  These  poisonous  organic  matters,  however,  though  much  sought 
after,  have  never  been  isolated,  although  a  number  of  observers,  using 
faulty  methods,  have  from  time  to  time  obtained  erroneous  results. 
This  subject  will  be  considered  farther  on. 

OZONE. 

Ozone  is  a  normal  but  by  no  means  constant  constituent  of  the  air. 
It  is  generally  absent  from  the  air  of  large  towns  and  cities,  and  is 
almost  never  present  in  the  air  of  an  inhabited  room  or  near  decom- 
posing matter.  It  is  found  in  minute  amounts  (maximum,  1  :  700,000) 
ill  the  open  air  of  the  country  and  sea.  It  is  most  abundant  at  sea  and 
near  woods,  and  somewhat  more  abundant  on  mountains  than  in  valleys 
and  on  plains.  It  is  more  abundant  in  the  morning  in  the  colder 
months,  and  in  the  evening  during  hot  Aveather  ;  it  is  more  abundant 
in  winter  than  in  summer.  It  is  stated  that  it  is  most  abundant  di- 
rectly after  a  thunder-storm,  but  beyond  the  fact  that  it  is  produced  by 
the  passage  of  the  electric  spark,  there  is  nothing  to  substantiate  this 
statement.  As  a  matter  of  fact,  the  origin  of  ozone  in  the  atmosphere 
is  unknown. 

Ozone  is  an  allotropic  form  of  oxygen,  consisting  of  molecules  con- 
taining three  atoms  of  that  element.  It  has  been  liquefied  under  great 
pressure  (127  atmospheres),  aud  in  that  condition,  and,  indeed,  in  the 


NIT  I  !.<><!  EN   ACIDS.  275 

}i;;i,S('<)lls  foi'm,  li;is  ;i  (Iccp  l)liH'  cnloi'.  Il  i  |(i(i'liic<(|  hy  the  |i;iv-;i;.'f  of 
l,li(!  (ilccli'ic.  s|i:irk,  by  slow  <ixi<l;ili<tii  of  |»li(ir|)lii»i'iis,  ;iiui  in  flu-  clcctnd- 
ysis  ()("  wnlcf  ;  hiil,  ;ih  Iims  Ik-cii  .s!ii<l,  il-  origin  as  a  iiortnal  {•oiistiliH-iit 
ol"  jJic  m(  iii(>s|)licrc  lias  ixil  Ixcii  ex  |)l,iliii  (|  salisfaclofily.  It  lias  an  (Hl<»r 
iKil  inilikc  llial  <»r  (iiliiird  clildrinc.  1 1  lias  very  stronj;  oxidizing  |>(i\v«t, 
iniich  iiKirc  so  lliaii  owucii,  \\lii<li  il  cxfrciscH  moHt  actively  ImiIIi  <iii 
iiiclals  and  on  oi}^ani(^  mallei';  Ikiu-c  its  abscnrc  f'ntrn  flic  air<»('  inlial)- 
ilcd  r(»onis  and  oTdcnscIv  |)oj»nlal<'d  ai'cas,  diai^^cd  willi  oipanic  matter 
and  (lust,  of  ull  sorts,  is  easily  explainable.  To  lliis  |»roj)crly,  its  diini- 
nnlion  in  atitiimn,  wlien  (le('(un)K»si(ion  |»rodiieis  are  trenerated  most 
actively,  may  projx'rly  lie  altrihiited.  lt>  |in~eiicc  in  ihe  air  of  any 
place  is  fair  evideiiee  ol"  IVeedom  iVom  oxidi/ahle  matters. 

Ozone  has  an  exeeedinijly  irrifatinti;  elleet  on  tlie  res|)iralory  mneoiis 
membranes,  and  when  inhaled  with  o.wlicii  in  ihe  |iro|)ort ion  ol'  I  part 
ill  240,  (jui(!kly  pi'odiiecs  death  in  aiiinial-  siilijeeted  lo  it.  it  is  bc- 
liovod  to  exert  a  perniinous  inlhieiiee  in  inllaiiiinatory  conditions  of  the 
hmt^s  and  bronehi,  even  when  present  in  not  nuu-li  more,  if  any,  than 
the  ordinary  ainoniit  in  the  atmos|)here.  We  aotnally  l<n«»w  little  or 
nothing  of  the  effects  of  ozone  on  the  system  in  the  amounts  ordinarily 
])resent  in  air,  but  the  absurdity  of  the  expression  so  often  nse<l,  that 
one  has  "gone  to  breathe  the  pure  ozone"  at  a  health  resort  is  nianifV-st, 

Peroxide  of  Hydrogen  (M/);;)  is  believed  to  exist  in  minute 
traces  in  the  atmosphere,  and  to  exert  some  inHueuee  in  the  jinjcess  of 
oxidation. 

AMMONIA. 

Ammonia  is  constantly  jiresent  in  the  air  in  very  slight  traces.  It 
exists  in  the  free  state  and  in  coml)ination  as  nitrate  and  carbonate. 
Daily  analysis  of  the  air  at  Montsouris  for  five  years  gave  as  a  mean 
for  ammonia  2.2  milligrams  per  100  cubic  meters.  It  proved  to  be 
highest  in  amount  in  summer  and  lowest  in  winter.  It  is  diminislied 
in  rainy  weather,  because  it  is  absorbed  by  the  rain  during  passage 
through  the  atmosphere ;  it  is  increased  with  rising  temperature  some 
time  after  rain  has  ceased  falling.  As  it  is  one  of  the  products  of 
decom]iosition  of  nitrogenous  organic  matter,  perhajis  nowhere  more 
observable  than  in  stables,  where  it  is  plainly  perceptible  to  the  sense 
of  smell,  it  is  hardly  necessary  to  point  out  that  its  sources  are  various 
and  innumerable. 

NITROGEN  ACIDS. 

Nitrous  and  nitric  acids  are  also  present  in  small  traces,  due  in  part 
to  the  union  of  atmospheric  oxygen  and  nitrogen  through  the  agency 
of  electrical  discharges,  and  in  part  to  the  action  of  ozone  on  ammonia. 
Nitric  acid  is  found  in  comparative  abundance  in  buildings  lighted  by 
means  of  the  arc  light,  but  it  is  not  probable  that  the  amount  present 
is  of  sanitary  importance. 


276  AIB. 

AQUEOUS  VAPOR. 

Aqueous  vapor  is  a  ni»niial  ooustituent  which  occurs  iu  variable 
amounts,  iuHucuced  by  a  number  of  natural  conditions,  the  chief"  of 
which  is  the  temperature.  It  is  an  invisible  gas,  lighter  than  air  and 
very  unequally  diffused.  Its  sources  are  numerous ;  some  comes  from 
the  evaporation  of  water,  some  from  soil  moisture,  some  from  the 
lungs  and  skin  of  animals  and  man,  some  from  the  leaves  of  growing 
plants,  some  from  combustion.  Indoors,  a  considerable  amount  is  com- 
municated to  the  air  through  the  combustion  of  illuminants. 

According  to  Professor  Foster,  an  adult  man  gives  off,  under  ordi- 
narily favorable  conditions,  about  4  pounds  of  watery  vapor  from  the 
skin  and  lungs  during  twenty-four  hours  ;  2|  pounds  by  the  skin,  and 
the  remainder  (Pettenkofer  and  Voit  say  10  ounces)  by  the  lungs.  An 
adult  healthy  tree  of  fair  size  gives  off  an  amount  which  is  enormous  in 
comparison.  The  amount  of  water  exhaled  by  plants  has  been  esti- 
mated by  Hellricgel  to  vary  from  250  to  400  times  the  Aveight  of  the 
drv  orffiinic  matter  formed  during;  the  same  time,  which  means  that 
during  the  growth  of  each  ton  of  green  grass  or  leaves  of  any  kind, 
there  have  been  exhaled  therefrom  many  tons  of  water,  and  that  in  the 
production  of  each  pound  of  dry  matter,  an  average  of  325  pounds  of 
water  has  been  discharged.  The  evaporation  of  water  from  foliage  has, 
among  otTier  important  functions,  that  of  keeping  the  temperature  be- 
low the  point  where  the  vital  processes  would  be  interfered  with. 

The  amount  of  aqueous  vapor  which  a  volume  of  air  will  absorb  and 
retain  depends  on  the  temperature.  For  each  degree  of  temperature,  a 
voliuue  of  air  can  take  up  a  definite  amount  of  vapor,  and  no  more; 
and  when  it  has  taken  up  this  amount  it  is  said  to  be  "  saturated." 
The  higher  the  temperature,  the  greater  the  amount  it  can  hold ;  and 
hence  when  a  volume  of  air  completely  saturated  is  subjected  to  a 
change  in  temperature,  one  of  two  things  will  occur  :  if  the  temperature 
is  increased,  it  can  take  up  more  vapor,  and  hence  is  no  longer  saturated  ; 
if  it  is  diminished,  the  aqueous  vapor  is  in  excess  of  the  amount  re- 
quired for  saturation  at  the  new  temperature,  and  the  excess  will  be 
condensed  and  precipitated  as  moisture.  At  0°  C,  a  volume  of  air 
takes  up  yi-g-  of  its  weight  of  aqueous  vapor  ;  at  15°,  it  takes  up  twice 
as  much;  at  30°,  four  times,  at  45°,  eight  times,  and  at  60°,  sixteen 
times  as  much.  Thus  it  appears  that,  with  each  increase  of  15°  C  in 
temperature,  the  capacity  for  aqueous  vapor  is  doubled.  At  15°  C. 
(59°  F.),  a  cubic  foot  of  air  will  hold  nearly  6  grains  of  water  vapor ; 
at  30°  C  (86°  F.)  it  will  hold  twice  as  much. 

Evaporation  cannot  go  on  when  the  surrounding  air  is  saturated  ; 
therefore,  the  presence  of  a  body  of  water  will  add  nothing  to  a  satu- 
rated atmosphere.  But  plants  and  animals  can  continue  to  give  off 
the  vapor  to  an  already  saturated  atmosphere,  which,  however,  con- 
denses and  deposits  the  excess  at  once,  perhaps  on  the  very  surface 
where  it  is  originated,  as  on  the  leaf  of  a  tree  or  on  the  skin  of  man. 
The  difference   between   evaporation   and   trans])iration,  which   is  the 


A(^IJFJ)IJS    VA/'OfL  277 

proper  Icrin  for  (lie  ;:;iviii^  oil'  oC  \;ipor  Ity  iiiiiiii;ils  ;iii(|  platitH,  \h  that 
i\\(',  OIK!  is  merely  pliysieiil,  while  I  lie  hIIk  r  i-  ;i  vitiil  proee.'^.-i  due  lo  iIk; 
ue.iioii  o("  livine'  cells. 

'V\u'.  r;iie  of  eliiniiwilioii  o("  Wiiler  l)\-  lln'  l)ii(|\-  in  ;i  -lute  oC  rent  de- 
pends upon  the  iiinoiini  of  hiiniidilv  pre.-eni  in  the  ;iir.  I  >etertiiiti;i- 
lions  by  linhncr  :ind  \'on  I  ie\v:i>eiie\v  '  denion-l  i-;ite(|  the  ^.Meat  inlln- 
enec  ol"  Imniidily  in  (his  |>artieMlar.  /\  I  I"/'  ( '.  in  moist  air,  the  daily 
eliminaiion  fell  to  2  Mi  f^rams,  while  in  ilr\-  aii'  at  the  satin-  tetiipcnitiirc 
it  ros(!  toHTI.  The  tale  rises  with  the  teni|»eratiir('  in  both  moist 
and  dry  air,  and  (he  more  promptly,  (he  e-reater  (he  drvncs.s.  'J'lie 
Older  air  contains  coinnKtnly  from  (id  to  To  per  cent,  of  the  amount 
lUHX^ssary  Cor  satnration.  In  some  plaee>  noted  lor  the  dryiicHH  of 
the  air,  tlie  ainoiint  is  miieh  below  ;  in  other.-,  where  (he  op|)osit<!  i.s  the 
ease,  it  is  above. 

lielative  lumiidity  is  tlm  degree  ol"  approach  to  saturation  at  any 
given  tonijKM-ature.  Tliu.s,  "  relative  Inimidity  SO"  means  tliat  at  the 
observed  tem|)eratiii-e,  tlie  air  liolds  but  80  per  cent,  of"  the  amount 
which  it  can  take  U[).  Absolute  humidity  istlieaetiial  weight  of"  moist- 
ure ill  a  given  air  space. 

vV(|ueous  va]ior  exerts  a  most  important  infhienee.  I'y  day,  it  ab- 
sorbs ])art  of  the  sun's  lieat  and  tem])ers  it  ;  by  niglit,  it  acts  as  a  pro- 
t(>cting  blanket  to  the  earth  by  preventing  too  great  loss  of  heat  by 
radiation.  At  night,  the  earth  gives  nj)  ])art  of  the  heat  which  it  has 
absorbed  during  the  day  ;  and  when  the  air  is  very  dry  and  the  sky 
very  clear,  the  temjicrature  falls  nnich  more  than  when  there  is  more 
vapor  ]>reseiit  to  prevent  loss  by  radiation.  In  the  Sahara,  after  the 
hottest  days,  tlie  nights  arc  generally  very  cool,  the  temperature  fall- 
ing sometimes  30  to  40  degrees  C.  in  a  few  hours.  At  high  altitudes 
also,  Avhere  the  blanket  of  vapor  is  thin,  the  fall  in  temperature  at 
night  is  very  marked.  Absence  of  aqueous  vapor  jiermits  the  cooling 
process  to  begin  as  soon  as  the  sun  gets  low,  and  ice  may  form  in  a 
few  hours  where,  during  the  day,  the  sun's  heat  had  been  intolerable. 
This  is  seen  in  the  great  deserts  and  at  high  altitudes. 

It  is  noticed  commonly  that  the  first  frosts  of  autumn  and  those 
which  come  occasionally  in  the  middle  and  later  parts  of  spring  occur 
only  on  very  clear  nights  with  low  humidity. 

An  amount  of  watery  vapor  approaching  saturation  gives  rise  to  dis- 
comfort, whether  the  temperature  be  high  or  low.  The  "  sticky  "  days 
of  summer  and  the  "  raw  "  ones  of  winter  owe  their  disagreeableuess 
to  their  high  relative  humidity.  In  a  hot  saturated  atmosphere,  while 
transpiration  can  proceed,  evaporation  cannot,  and  hence  the  cooling 
influence  of  evaporation  is  missing.  The  sweat  stays  on  the  skin  in 
the  liquid  form  instead  of  passing  into  the  air  as  a  vapor,  and  the  word 
"sticky"  becomes  singularly  appro])riate.  On  the  other  hand,  Mith 
low  humidity  and  high  temperature,  the  sweat  does  not  condense  and 
remain  on  the  skin,  but  piasses  into  the  air,  and  transpiration  is  not 
impeded  in  the  lungs.  Hence  the  great  bearability  of  dry  heat  as 
^  Arcliiv  fiir  Hygiene,  XXIX.,  p.  1. 


278  ATR 

conij);nvcl  with  moist.  Saturation  at  low  temperature  has  as  great,  if 
not  iiTi'utor,  inrtui'iuv  on  bodily  t'oiuiort.  It  docs  not  follow  that  since 
ono  fc't'ls  the  heat  more  acutely  with  hiiih  relative  humidity,  this  condi- 
tion will  enable  one  to  withstand  the  op])()site  discomfort  of  cold. 
Indeed,  the  reverse  is  true.  At  low  tem]ieratures,  saturated  air  causes 
a  cjreater  withdrawal  of  heat  than  drv  air,  and  intensifies  the  sensation 
of  cold  ;  for  moist  air  is  a  much  better  heat  coiuhictor.  Cold  (by  air 
is  much  more  comfortable  than  air  some  degrees  warmer  but  materially 
moist.  In  the  very  cold  climate  of  eastern  Siberia,  the  air  is  so  dry 
that  50°  to  60°  below  zero  F.  is  no  hardshi]"),  provided  one  wears  com- 
]iletely  dry  clothing,  while  with  moist  clothing  one  would  perish  in  a 
very  short  time.  Some  ])arts  of  Siberia  are  both  cold  and  damp,  and 
hence  uninhabitable.  Atmospheric  moisture  has,  thei'efore,  directly 
opposite  effects  ;  it  intensifies  the  effects  of  heat  and  also  those  of  cold. 


DUST  AND  MICRO-ORGANISMS. 

Another  normal  constituent  of  the  atmosphere — one  of  enormous 
importance — is  dust ;  normal,  because  it  is  everywhere  in  the  atmos- 
phere, and  because  a  perfectly  dustless  air  is  an  artificial  product  obtained 
only  with  the  observance  of  great  care.  The  individual  particles  are 
very  small,  but  at  the  same  time  very  variable  in  size,  ranging  from 
those  plainly  discernible  to  the  naked  eye,  to  those  of  extreme  minute- 
ness. 

Dust  is  organic  and  mineral,  and  has  its  origin  in  countless  processes. 
It  includes  ])articles  of  animal  matter,  vegetable  substances  of  every 
kind  including  bacteria  and  moulds,  sea  salt,  matters  swept  from  the 
soil  by  the  action  of  winds,  those  discharged  by  volcanoes,'  others  from 
manufacturing  establishments,  from  chimneys,  and  from  the  millions 
of  meteorites  which  daily  fall  from  iuterj^lanetary  space.  The  ordi- 
nary combustion  of  illuminating  gas  yields  millions  and  millions  of 
particles  of  carbon  for  every  individual  cubic  foot. 

Organic  dust  exists  only  in  the  lower  strata  of  the  atmosphere,  but 
that  of  mineral  origin  is  everywhere.  Micro-organisms  are  very 
abundant  in  the  air  of  inhabited  rooms,  and  in  general  in  that  of  toAvns 
and  cities,  less  abundant  in  the  country,  and  least  at  great  heights  and 
at  sea.  Experiments  have  shown  that  at  an  elevation  above  6,300  feet 
the  air  is  free  from  them.  Pasteur  exposed  a  large  number  of  flasks 
of  broth  at  an  altitude  of  6,000  feet,  and  obtained  a  growth  in  but  one. 
Tyndall  exposed  27  flasks  at  8,000  feet,  and  got  no  growth  whatever. 
Dr.  Fisher-  has  shown  that  on  the  ocean,  120  miles  from  land,  the  air 
is  usually  free  from  organisms,  and  that  at  lesser  distances — 90  miles, 
for  exam])le — it  contains  but  few. 

The  air  of  cities  contains  thousands  in  every  cubic  meter,  against 

^  After  the  preat  eruption  in  Java  in  1883,  a  haze  of  extremely  fine  particles  of 
pumice,  estimated  to  be  from  seven  to  more  tlian  twenty  miles  above  the  earth,  was 
visible  in  all  parts  of  the  world  for  several  months. 

*  2feitschrift  fiir  Hygiene,  I.,  p.  410. 


DUST  AND    MlCllO-OndASISMS. 


279 


Fio.  10. 


less  lli;i,n  .'I  liiiii<li'(>(|  III  llic  sMiiic  \iiliiiiic  (i("  (■(iiMilrv  ;iir.  Il  li;i^  hccii 
('.;i-lcillii,(,(ul  (li;il,  ill  (|(ii.-(|\  |H)|iiil.il((|  jil;iccs,  siicli  ;i^  Loiidoii  and  Man- 
clicslc!!',  Jill  iii(li\  i(lii;il  iiilialcs  in  IIk;  (loiirsc  of"  an  lioiir  ii|)\vai°(l  (>{' 
■  I, 000, 000  of  ^ci'ins  and  spores.  I>iil  tliis  \\\:^u\'i'  i-  ciionnouhlv  in  cxf^iHH 
of  (lie  (i<;iir(!  ^ivMMi  hy  l*'lri;^|^<','  wlio  cshinalcs  llial  in  scvcnfv  ycarH  a 
man  may  inlialc  UT), 000, 000  hadcria,  wliidi,  lie  HSiyn,  is  aLoiil  wli.'it  one 
swiiliovvs  in  'JT)  i'v.  oC  ordinarN-  milk. 

'^riic  nnmlM'rof  Itadiria  in  air  i>  iiiMiiciHcil  vorv  Jjn'^itlv  I)V  drv  winds 
an<l  a(|n('ons  \'a|)oi'.  Tlic  (iiiiiicr,  ^wccpin^'-  (licm  up  from  llic  siiHiu-c, 
inci'cascs  (licir  numlicr  ;  llic  LiKcr,  liy  condensing  on  tlicm  and  on  llie 
dnsl.  parlieles  jo  wliicli  IJuy  adlie|-e,  eauscH  them  (o  fall  to  tlie  ^m-oiiikI. 
Tliey  iire  wnshed  oiilorilie  air  hy  rain,  and  are  killed  hy  lon^'-  expo>iire 
to  l>ri<<;li(,  sunshine.  Moulds,  on  llie  other  hand,  have  heen  oh.served  hy 
Mi(piel  to  iiKirease  i-apidl\'  after  a  rainstorm,  and  to  Im;  mneh  !(«« 
affeoted  by  winds. 

The  a-vei'ai;'(>  nnmher  of  oraanisms  (nimd  at  Montsoiiri.-  in  an  inves- 
tigation which  lasted  six  years  was  A-)^  ])er  eiilne  meter.  The  lowest 
results  were  observed  in  February  and  the 
hi!i;hcst  in  July.  Durin^;  the  same  ])eri()d, 
the  number  in  the  air  at  the  center  ot"  Paris 
was  3,910  ;  the  smallest  figures  were  }ielded 
in  January  and  the  highest  in  INfay. 

All  organisms  are  less  numerous  in  the  air 
at  night,  since  then  there  is  less  mechanical 
disturbance  of  the  earth's  surface. 

While  the  nunxber  of  bacteria  in  outdoor 
nir  may  be  fairly  high,  it  should  be  borne  in 
mind  that  the  majority  of  them  are  of  the 
harmless  varieties,  and  that  the  jiathogeiiic 
kinds  constitute  only  an  infinitesimal  ])ro- 
portion. 

Dust,  as  has  been  said,  is  of  enormous  im- 
portance. M  ithout  it  there  would  be  no  rain, 
no  fog,  no  clouds  ;  the  air  would  be  satu- 
rated with  moisture,  and  every  object  would 
be  continually  wet. 

Dust  is  largely  hygroscopic,  and,  there- 
fore, attracts  the  watery  vapor  of  the  atmos- 
phere, thus  becoming  the  nucleus  for  a  drop 
of  rain  or  particle  of  mist.     Were  it  not  for    ^Xuro/dustto  rSf^anS'fi^.' 
its  presence   in   the   air,  the  aqueous  vapor 

would  condense  without  rain  on  every  tree  and  plant,  ever}-  rock, 
every  dwelling,  every  living  creature,  and,  in  short,  on  every  object  to 
which  air  has  access. 

That  atmospheric  dust  is  necessary  for  the  ]n-odnction  of  rain  and 
fog,  may  be  demonstrated  very  sim]ily  by  condensing  moisture  from  a 
saturated  atmosphere  through  lowering  of  the  temperature,  and  noting 
*  Grundi-ist;  der  Hvijiene,  1897. 


280  AIR. 

what  occurs  when  dust  is  present  or  absent.  For  this  purpose  a  simple 
apparatus,  such  as  is  shown  iu  Fig.  10,  is  all  that  is  required.  This  con- 
sists of  a  large  tlask  fitted  with  a  rubber  stopper,  tlu'ough  which  pass 
two  pieces  of  glass  tubiug,  to  the  free  ends  of  which  pieces  of  rubber 
tubing  with  pinehcocks  are  attached.  The  glass  tubes  project  beyond 
the  shoulder  into  the  body  of  the  flask.  If  we  pour  into  the  flask  an 
amount  of  Arater  rather  more  than  suffieient  to  fill  the  neck  when  tlie 
Hask  is  inverted  with  the  stopper  in  position,  we  have  the  conditions 
necessary  for  complete  saturation  of  the  confined  air  with  watery  vapor. 
If  now  we  withdraw  by  suction  through  one  of  the  rubber  tubes  a 
small  amount  of  the  ct)ntaiued  air,  the  temperature  falls  at  once ;  and 
inasmuch  as  tlie  air  within  is  already  saturated,  and  since  the  lowering 
of  the  temperature  of  a  saturated  atmosphere  is  accompanied  by  con- 
densation of  part  of  its  moisture,  such  a  condensation  occurs  within  the 
flask,  and  is  manifested  by  the  formation  of  a  distinct  haze  which  fills 
the  whole  air  space.  If  next  we  restore  the  original  pressure  by  read- 
mitting sufficient  air  to  abolish  the  partial  vacuum,  the  mist  disappears 
instantly.  The  production  and  dissipation  of  the  mist  cloud  may  be 
repeated  indefinitely  so  long  as  nothing  is  done  to  remove  the  dust  from 
the  air ;  but  if  we  wash  the  air  thoroughly  by  shaking  the  fiask  vigor- 
ously for  a  few  minutes,  and  then  repeat  the  experiment,  no  visible 
mist  is  produced. 

CARBON  MONOXIDE,  ETC. 

Other  matters  found  in  air  include,  under  certain  conditions,  traces 
of  sulphuretted  hydrogen,  sulphurous,  sulphuric,  and  hydrochloric  acids, 
carbon  disulphide  from  rubber  factories,  marsh  gas,  carbon  monoxide 
from  illuminating  gas,  fumes  of  zinc,  arsenic,  and  phosphorus,  organic 
vapors  from  offensive  trades,  and  other  gaseous  and  solid  matters  too 
numerous  to  mention. 

The  most  important  of  these  is  carbon  monoxide,  a  very  powerful 
poison,  often  present  in  the  air  of  mhabited  rooms  from  leaking  gas 
pipes,  imperfect  combustion  of  illuminating  gas,  and  defects  in  heating 
apparatus  fed  with  coal.  It  is  yielded  in  great  abundance  by  burning 
charcoal,  and  is  given  off  in  small  amomits  from  stoves  of  cast  iron, 
which  material  in  a  red-hot  condition  absorbs  it  in  considerable  amounts 
from  burning  coal.  This  was  noticed  first  by  Dr.  Garret,^  of  Chambery, 
who  described  an  outbreak  of  sickness  traced  by  him  to  this  cause. 
Later,  this  property  of  cast  iron  was  established  beyond  a  doubt  by 
others.  Another  by  no  means  insignificant  source  is  burning  tobacco, 
1  gram  of  which,  according  to  Grehant,^  yields  82  cc.  of  the  gas.  Its 
presence  in  the  air  of  rooms  in  which  smoking  is  carried  on  was  illus- 
trated by  Kunkel,'^  in  1888,  before  a  society  of  scientists,  by  exposing 
a  small  amount  of  blood  solution  to  two  puffs  of  tobacco  smoke,  and 

^  Comptes  rendns,  1865,  p.  793. 

'  Annales  d'Hygiene  publiqiie,  1879,  p.  115. 

*  Sitzungsbericht  der  physikalisch-medicinische  Gesellschaft  zu  Wiirzburg,  1888,  p.  89. 


CARJiON  MONOXlDi:,    I'JTC.  281 

(IcmoiiHtniiiii}!,'  (Ii(!  uhsoi'idion  of"  (lie  ^:is  Wy  iiicatiH  «»('  tlif;  HpoctrOHC^^JK!. 
Tlic,  (iiosi  iiii|)<)il;irit,  ,s(»iir<',('  <»('  nil  is  illiMtiiii:i(iii;r  p-is,  wliicli  r/)ntiiin8 
ii,  ill  Viiryiii"!,'  nnioiiiits,  .■iccordiiij.';  to  its  mode  ol"  iii;iiiiif':i<'tiin'.  Under 
ordiiiiiry  (M)iiditioiis,  I  lie  icnkn^'c  oI'^.'ih  IVuin  I  he  iimins  into  (Ik-  soil  ari<l 
tli(!nc,(!  into  iJu^  iitnios|)li(:i(:  is  ((iionnoii-.  I 'ctlciikoli  r  '  nckoncd  that 
in  hiully  jointed  Hyutciins  at  least  ;i  lil'ili  of  the  iinniinl  ont|.iit  is  lost  in 
tli(!  ground,  and  WiisscrCniir'"  ii;is  cnlciiliilcd  the  Miiniial  loss  in  I'arJH 
diK!  to  icnks  as  I  "),()()( ),(»()()  c\\\,\(:  meters.  I>eak;i;;«-  oer-nrs  from  irn- 
pcrfeet  joints,  liuilty  eoeks,  and  corroded  iron  pipes.  I'>e-i<lr>.  that  (hie 
to  k!akag(!,  we  liiixc  to  reckon  with  th:il  due  to  irnperleet  eoinhiistioti. 
WhiU>  an  Ar^Miid  or  otiiei-  liurner  net iiifr  normally  ^Ivch  oil'  no  trar^; 
of  (yirl)on  monoxide,  a  certain  pro|)ortion  of  the  jthh  will  escape  oxida- 
tion and  min^l(!  with  tlu;  air  of  the  room  toc;etlier  with  other  impuri- 
ties, if  the  gas  supply  is  not  properly  reguliited.  The  use  of  j^s 
stoves  is  responsihle  for  moi-e  or  less  contamination  due  to  imperfect 
combustion,  for  when  a  cold  ohject  is  put  into  the  flame,  the  latter  is 
cooled,  and  part  of  its  carbon  inonoxid('  is  given  off  as  such.  Imper- 
fect combnstion  of  kerosene  is  still  another  source  which  should  not  be 
overlooked,  for  a  smoking  lamp  exerts  a  very  decided  influence  on 
the  respirability  of  the  air  of  a  room,  aside  from  the  discomfort  ciiused 
by  the  ])articles  of  soot. 

Less  than  0.25  per  cent,  by  volume  in  the  air  will  cause  poisoning, 
and  but  1  percent,  is  rapidly  fatal  to  animal  life,  owing  to  the  fact  that 
it  unites  very  readily  with  the  hiEmoglobin  of  the  blood  cftrpuscles, 
forming  a  stable  chemical  compound,  carboxyhaemoglobin,  which  will 
neither  take  up  and  carry  ox}'gen  to  the  tissues  nor  jiromote  the  elim- 
ination of  carbon  dioxide.     As  a  consequence,  asjihyxia  occurs. 

In  fatal  cases  of  poisoning,  carbon  monoxide  produces  a  rapid  i)ar- 
enchymatous  degeneration  of  the  liver,  kidneys,  spleen,  and  heart. 

Carbon  monoxide  has  been  proved  by  L.  de  Saint  ]Martin  *  to  be 
present  in  minute  amounts  in  the  l)lood  of  animals  living  in  cities. 
Nicloux  *  has  gone  fiirther,  and  demonstrated  its  existence  in  that  of 
animals  in  the  country,  and,  indeed,  in  about  the  same  amounts  (0.16 
volume  per  cent.).  Nicloux  finds  by  experiment  that  it  is  not  derived 
from  the  air,  but  is  develojied  directly  in  the  system,  and  that  its 
amount  is  diminished  by  bringing  about  slight  asphyxiation.  Potain 
and  Drouin  ■'  have  shown  that,  at  ordinary  temperatures,  it  is  oxidized 
gradually  to  carbon  dioxide. 

Contamination  of  the  air  of  dwellings  with  gas  from  leaking  street 
mains  is  quite  common,  and  fatal  results  are  not  infrequent,  the  gas 
travelling  through  the  soil  lV)r  considerable  distances  and  being  cb-awn 
up  through  cellars  by  the  force  of  aspiration  brought  into  }ilay  by  the 
difference  between  internal  and  external  temperatures.      jNIany  cases  of 

'  Ueber  die  Vergiftiing  niit  Leuchtgas.     Xord  und  Sud,  JanuarT,  1SS4. 

*  Deutsche  YierteljahiWoluift  fiir  otl'entliche  Gesundheitspflege,  X^"!!.,  1885,  p.  309. 

*  Comptes  rendus,  CXXVI.,  p.  1036. 

*  Ibidem,  CXXVI.,   pp.  1526,  1595. 

*  Ibidem,  CXXVI.,  p.  938. 


282  ATR. 

fatal  ]i()isouing  have  been  recorded  in  which  the  gas  was  aspirated 
through  the  soil  for  more  than  a  luuulred  feet.  Such  accidents  are 
naturally  more  likely  to  occur  in  streets  which,  hcini;  well  ]>aved, 
present  an  obstacle  to  the  escape  of  tiie  gas  upward.  Tiic  odorous 
constituents  of  the  gas  serve  a  very  useful  ]nir])ose  in  ])oiutiiig  out  the 
danger,  but  sometimes  they  arc  held  l)ack  by  the  t'artli  and  cannot  per- 
form that  office. 

Dr.  J.  S.  Haldane  has  pointed  out  that  air  vitiated  by  gas  combus- 
tion to  such  an  extent  as  to  show  30  parts  of  CO^  in  10,000  will  con- 
tain about  1  part  of  SO2  per  500,000,  and  that  this  amount  is  suffi- 
cient to  cause  marked  discomfort.  The  air  of  a  room  lighted  with  oil 
was  iu)t  unpleasant,  except  for  the  heat,  when  the  CO^  content  rose  to 
75  ;  but  when  gas  was  burned  it  was  distinctly  unpleasant  when  the 
CO,  rose  to  40  "in  10,000. 


"  SEWER  GAS." 

Another  impurity  is  what  commonly  but  inijiroperly  is  called  ''sewer 
gas."  This  is  simply  sewer  air  which  may  be  more  or  less  foul  by 
reason  of  containing  the  emanations  of  sewage  matters.  Its  chemical 
composition  depends  upon  the  extent  to  which  the  gases  of  decomposi- 
tion are  generated,  and  upon  the  rate  of  ventilation.  It  may  be  almost 
as  pure  as  the  outside  air ;  it  may  be  as  rich  in  carbon  dioxide  as  the 
air  of  badly  ventilated  rooms ;  and  it  may  be  much  worse.  From 
10  to  30  volumes  of  CO^  in  10,000  are  found  quite  commonly.  Dr. 
W.  J.  Russell  found  as  high  as  51  volumes  in  10,000  in  the  air  of  one 
of  the  London  sewers,  and  Letheby  as  high  as  53.2  in  that  of  another, 
while  in  an  nnventilated  sewer  in  Paris  as  high  as  340  volumes  have 
been  reported.  Sulphuretted  hydrogen  and  ammonium  sulphide  are 
ordinarily  present  in  small  amounts  or  mere  traces,  and  may  be  wholly 
al)sent ;  but  in  old  nnventilated  sewers,  they  may  be  present  in  notable 
amounts.  The  highest  recorded,  299  volumes  in  10,000,  was  found  by 
Parent-Dnchatelet  in  an  old  choked  sewer  in  Paris.  Marsh  gas, 
ammonia  and  compound  ammonias,  and  other  gaseous  products  of  de- 
composition of  organic  matter,  may  be  present  in  variable  amounts, 
according  to  circumstances. 

Sewer  air  contains  micro-organisms  and  animal  and  vegetable  debris, 
just  as  does  the  outer  air ;  but,  as  a  matter  of  fact,  the  number  of 
bacteria  is  invariably  small,  and  they  are  often  wholly  absent.  This 
was  shown  first  in  1883  by  Miquel,  whose  results  have  been  corrob- 
orated by  those  of  a  number  of  other  investigators,  including  Carnelly 
and  Haldane,  Laws  and  Andrews,  and  Percy  Frankland.  The  first 
mentioned  conducted  a  most  elaborate  chemical  and  bacteriological  ex- 
amination of  sewer  air,  and  proved  that  from  both  points  of  view  it 
compares  favorably  Avith  the  air  of  schools  and  small  dwellings,  and 
that  l)acteriologically  it  is,  indeed,  far  superior.  It  contains  fewer 
organisms  than  the  air  of  the  streets  above  or  of  any  kind  of  dwelling, 


"si':ivi':n  c-as."  283 

and  HlicJi  iis  Jtrc  pi-csciii.  conic  ciilircly  or  chiefly  f'roin  (lie  oiili  r  nir,  ;iii<l 
not  I'rom  iJic,  s(!\vii<^c. 

LiiWH  iiiid  Andrews  :ii'i-i\'c(|  ;il   Ihc   :-;nnc   conchi^ions  ;iC(ci- ;i  .^irnilnr 
r(!H(';u'cli.      In  cucli  ,s;ini|»lc  ol"  Hcw.'i^c  examined,  /*.  co/l  coifuiuiiUH  Wiw 
fonrxl  in  luinihcrs  varying;-  (Voni  ti(),0()()  (o  j!(»0,0()()  per  ec,  and  eloM'ly 
allied  species  in  even  urcalcr  al  inm  Lincc  ;    Iml  neii  lnr  I  he  one  nor'any<»f 
l,li(^  odiei'S  was    ("oinid    in    I  lie    iii.in\    sani|)le.-^  of  ail'   e.xaniilKtd.      Tlicy 

found,  i'artlier,  lliai   (lie   Ii<i'   of  oipmisins   e.xislini;  in   wjwcr  air 

(icpends  enlii'clv  npoii  llie  niiinlier  |)i-esen1  in  llie  oiilsid*-  air  in  tli<' 
iniinediaie  vicinih',  and  dial  while  scwaLi'c  l»acteria  ar<-  laiyely  of  tin- 
li<piefyini;'  x'ariclics,  such  arc  praci  ic;tll\'  ;il),-cnl   in  the  ;iir. 

The  chief  iinporfancc  of  "  sewer  eas  "  lies  not  in  il-  power  to  pro- 
duce disease,  l»ii(  in  ifscapacilv  for  heina;  die  \  i  hide  for  odors  wlijch 
make  (Ik^  air  (lisaL!,'i"<'eal)le,  hul  not  necessarily  (laii|r('rons  to  health, 
except  that  appetite  and  digestion,  and  hence  general  nutrition,  may  he 
interfered  with. 

As  J.I  matter  of  fact,  sewer  air  lias  served  for  a  long  time  as  a  most 
convenient  scapegoat  in  investigations  of  the  canse  and  s|»read  of  out- 
breaks of  tvph(»id  fever  and  other  infectious  diseases,  and  as  a  most 
useful  aid  in  explaining  obscure  (juestions  of  various  sorts.  Many  be- 
lievers in  the  sewer-air  theory  of  dissemination  of  tyjilioid  \\\rv  hold 
tliat  the  coarser  dust  particles  carry  tiie  germs  on  their  surface,  and 
may  be  blown  about  through  consideral)le  distances  before  the  organisms 
lose  their  vitality  ;  but  the  great  ol)jectiou  to  this  explanation  is  that  in 
sewers  and  cesspools  the  typhoid  bacillus  is  destroyed  sj)ee<lily  by  other 
organisms,  and  that,  e\-en  though  it  be  present  in  an  active  state  in 
licpiid  sewage,  it  is  extremely  unlikely  that  it  will  be  released  therefrom 
into  the  aii'.  No  ordinary  stirring  up  of  the  water  will  throw  the 
germs  into  i\\Q.  air  ;  altliough,  according  to  the  researches  of  Fraid<land,' 
the  bursting  of  gas  bubbles  generated  by  decomposition  will  throw  into 
the  air  traces  of  chemical  salts  which  have  been  mixed  and  dissolved  in 
the  sewage,  and  in  the  same  way  may  throw  out  bacteria  as  well.  But 
it  has  been  shown  by  Niigeli  that  bacteria  cannot  be  given  off  frcnn 
moist  surfaces. 

Another  explanation,  offered  by  Dr.  C.  R.  C.  Tichbourne,'  is 
that  the  disease  germs  are  scattered  into  the  air  by  the  fermenting 
sewage,  and  carrietl  by  a  ndst  formed  when  the  warm  sewer  air, 
saturated  with  moisture,  meets  the  colder  external  air  at  the  jtoints 
where  ventilating  outlets  are  placed.  Then  each  minute  droplet  of 
mist,  carrying  one  or  more  nncrobes,  is  transjiorted  through  longer  or 
shorter  distances  in  the  air,  perhaps  into  dwellings,  and  eventually, 
by  the  inHuence  of  the  heat  of  the  sun  or  by  other  natural  agency, 
becomes  dissipated  as  vapor,  and  leaves  the  org-auisms  suspended  in  the 
atmosphere. 

The  majority  and  the  best  of  the  German  investigators,  as  Fliigge, 

^  Procoodings  of  the  Eoyal  Society,  1879. 

^  Dublin  Journal  of  Medical  Sciences,  July,  1897. 


284  A  IE. 

Rubner,  Gartner,  Soyka,  Pransnitz,  and  others,  maintain  that  sewer 
air  and  sewer  gases  are  iueapable  of  conveying  the  germs  of  typhoid 
fever  and  other  infective  diseases. 

This  whole  question  of  the  distribution  of  diseased  germs  through 
sewer  gas  was  again  brought  j)rominently  to  the  front  by  the  positive 
results  of  the  investigations  reported  by  Horrocks^  in  1907,  and  con- 
tirnied  by  Andrews.* 

Horrocks,  in  his  experiments,  made  use  of  the  B.  prodigiosus,  which, 
because  of  its  distinctive  color,  can  be  easily  recognized  upon  infected 
plates,  and,  by  introducing  this  organism  in  large  quantities  into  various 
])()rtions  of  drainage  systems,  was  able  to  demonstrate  that  the  organ- 
isms were  carried  by  air  currents  in  one  instance  9  feet  above  an  ex- 
perimental running  trap  into  which  they  had  been  introduced.  In 
another  instance  the  typhoid  bacillus,  or  B.  prodigiosus,  which  were 
used  to  infect  slowly  moving  and  quiet  sewage,  were  found  upon  plates 
exposed  in  a  vertical  pipe  11  feet  9  inches  above  the  liquid. 

Finally,  B.  prodigiosus,  introduced  into  actual  drainage  systems, 
were  found  to  penetrate  into  all  parts  which  were  in  open  connection 
with  the  original  seat  of  infection,  even  to  a  height  of  50  feet  above 
the  traps.  The  possible  dangers  of  sewer  gas  as  a  means  of  spread- 
ing infectious  diseases  being  thus  brought  again  into  prominence, 
the  question  was  again  investigated  by  Winslow '"  in  a  report  made 
to  the  Sanitary  Committee  of  the  National  Association  of  Master 
Plumbers. 

Winslow  repeated  very  carefully  the  experiments  of  Horrocks,  and, 
although  he  confirmed  in  the  main  the  results  of  the  English  investi- 
gators as  far  as  their  qualitative  character  was  concerned,  he  proved 
very  conclusively  that  quantitatively  "  the  amount  of  air  infection,  even 
under  extreme  conditions,  is  so  slight  that  one  would  scarcely  expect 
the  general  air  of  sewers  and  house  drains  to  be  appreciably  affected 
under  normal  conditions."  For  instance,  Winslow  found  that  only  48 
out  of  200  liters  of  air  coming  from  house  drainage  systems  contained 
any  organisms  capable  of  developing  at  37°  C.  "  Sewage  bacteria  were 
found  in  the  air  of  the  house  drains  only  four  times  out  of  200  liters, 
and  then  in  the  presence  of  mechanical  spraying  of  sewage  at  the  point 
of  collection.  The  general  air  of  the  house  drainage  system,  aside 
from  this  local  infection,  was,  as  far  as  examined,  free  from  sewage 
organisms.  These  results  accord  well  with  those  obtained  by  Miquel, 
Petri,  Carnelley  and  Haldane,  and  Laws  and  Andrewes  in  street  sewers 
and  with  those  reported  by  Uffelmann  for  drain  air." 

It  is  true  that  some  of  the  gases  given  off  in  the  putrefactive  proc- 
esses which  go  on  in  sewers  are  more  or  less  poisonous,  but  whether 
they  are  capable  of  producing  injurious  effects  depends  very  much  on 

3  Proceedings  of  the  Royal  Society,  Series  B,  Vol.  LXXIX.,  No.  B-531,  p.  255. 

4  Supplement  to  the  Thirty-sixth  Annual  Report  of  the  Local  Government  Board 
containing  the  Report  of  the  Medical  Officer  for  1906-07,  p.  183. 

^  Report  of  the  Sanitary  Committee,  National  Association  of  Master  Plumbers  of 
the  United  States  for  1907,  1908,  and  1909. 


"SEWKIt   (.'AS."  285 

the  amount  iiili.'ikjd  and  on  tin;  dc^rcc!  of  concentration,  fn  any  event 
tlicy  arc  cci"tainly  inca|)al)le  oC  prodiicinj;  any  infective  diKCUHC  in  the 
abHcnce  of  the  Hj)(icili(!  ^cini. 

In  any  vvcll-conslrneled  and  |)i'o|)(!rly  ventilat<;d  .se\V(!r,  no  ^nrat 
amount  of  |»iil  rcliict  ion  will  ^o  on,  sirute  (he  se\va|re  rnafter.s  .soon  panH 
on  and  are  discli.'ir^cd  ;  consc^fjuently  not  nineli  jr.-i-  will  he  evolved, 
and,  with  proper  \ cnlilalion,  \vhatcv(!r  is  (tvoived,  is  soon  dissipafed  in 
the  out(M'  .lir.  <  Xfensivc  f^ase.s  and  odors  Jire  nnuth  inon;  likely  fo  In; 
^iven  oil'  hy  inielean  iinveiitil;itcd  lioii>^c-|»linMl)iiiLr  tli:iii  liv  uell-liuilt 
sewers. 

It  is  asserted  eonunonly  (Jial-  the  inlmlntion  ol".-in;ill  amounts  of  this 
air  will  produce  he;i<la<!he,  ana;niia,  loss  of  ap|ietit<',  sore  throat,  alhu- 
minuria,  diarrluea,  and  other  symptoms,  and  that  it  inny  he  the  ex(;iting 
or  auxiliary  caus(\  of  ty|)lioid  f(!vcr,  measles,  di|)litheria,  scarlet  fever, 
dysentery,  and  other  infective  diseases,  lint  in  the  (^ises  which  are 
ae(!epted  as  proving  the  causal  relation,  inference  has  taken  the  place  of 
proof,  no  oth(>r  means  of  infection  l)ein<!;  ascsertainahlc.  In  not  a  single 
ease  has  the  su])|)osed  relation  been  demonstrated  l)aet<'riologi(%ally. 

In  ausw(!r  to  the  well-known  stubborn  fiict  that  the  workmen  em- 
ployed in  all  the  large  systems  of  sewerage — men  whose  occupatifm 
involves  the  daily  and  constant  inhalation  not  of  traces,  but  of  large 
volumes,  of  sewer  air — are  as  a  class  unusually  healthy  and  strfing,  with 
a  high  mean  age  at  death  and  a  low  death-rate,  it  is  asserted  that  they 
become  immunized  by  daily  contact,  and  thus  escaj)e.  If  we  accept  this 
theory,  however,  we  should  go  farther,  and  say  that  large  doses  are  a 
benefit  in  that  they  confer  immunity,  and  that,  therefore,  all  precau- 
tions against  the  admission  of  sewer  air  to  the  air  of  dwellings  are  mis- 
directed, and  should  be  abandoned. 

The  air  of  properly  constructed  sewers  is  in  constant  motion,  brought 
about  by  differences  in  temperature  and  mechanically  through  influx 
of  sewage.  During  the  colder  months,  the  temperature  within  the 
sewer  is  higher  than  that  of  the  air  above,  and  it  is  influenced  materially 
by  the  fact  that  the  entering  sewage  is  largely  \varm  ;  therefore,  sewer  air 
tends  to  rise  and  escape  through  the  openings  in  the  man-hole  covers. 
Daring  the  warm  season,  the  natural  interchange  is  much  lessened,  since 
then  the  conditions  as  to  temperature  are  reversed.  At  night,  however, 
at  all  seasons,  the  temperature  of  the  air  of  the  sewer  is  higher  than 
that  of  the  atmosphere  above,  and  thus  ventilation  goes  on  by  natural 
laws  the  year  round.  Much  air  is  displaced  by  the  entering  sewage  ; 
in  fact,  disregarding  the  effect  produced  by  the  warmth  of  the  sewage, 
for  every  cubic  foot  of  sewage  which  enters,  a  cubic  foot  of  air  is  forced 
out,  and  as  the  sewage  is  discharged,  more  air  enters  to  take  its 
place. 

Owing  to  the  ]irevailiug  belief  in  the  noxious  character  of  sewer  air, 
it  was  formerly  the  custom  to  place  baskets  of  charcoal  in  the  out- 
let shafts  of  the  man-holes,  but  as  this  material  loses  its  absorptive 
property  with  access  of  moisture,  the  plan  was  abandoned.    It  was  also 


286  AfE. 

regarded  as  an  ;ulvanta2:o  to  comu'ct  tlic  sewer  witli  cliininevs,  which 
act  as  ventilators,  but  in  the  liiiht  of  farther  Unowleduv  and  because 
of  excessive  action,  that  nietiiod  of  ventihition  fell  into  disuse. 

ORGANIC  MATTERS. 

Amono;  other  imjiurities  oiven  off  to  the  air,  the  oroanic  matters 
from  the  jn'oeesses  of  the  body  are,  in  a  Avay,  of  considerable  impor- 
tance. These  include  j)articles  of  ej)itlieb'uni,  the  coiistiluents  of  sweat 
(butyric,  capric,  capronic,  and  caprylic  acids,  lactate,  butyrate,  and 
other  sjdts  of  ammonium),  and  volatile  matters  from  foul  mcniths, 
decayiuii:  ti'cth,  and  the  dit>estive  tract,  and  excrcmentitious  matters 
depositetl  on  unclean  clothing-.  In  addition  to  these,  it  has  been 
asserted  that  other  matters  of  a  poisonous  character  are  given  ofl'  in 
the  process  of  respiration,  which  matters  will  be  referred  to  later  on  in 
the  discussion  of  the  effects  of  impure  air  on  hetdth.  That  the  air  of 
inhabited  confined  s])aees  may  contain  organic  animal  matter,  is  appar- 
ent to  the  senses  when  one  enters  such  an  atmosphere  from  one  not 
thus  contaminated. 

Effects  of  Vitiated  Air. 

The  effects  of  foul  air  on  the  system  are  of  great  im^^ortance,  and 
vaiy  in  degree  within  very  wide  limits.  For  proper  aeration  of  the 
blood,  it  is  necessary  that  the  oxygen  of  the  air  shall  be  present  in  the 
normal  proportion  in  the  free  state,  and  not  in  chemical  union  with 
carbon  as  a  ^vaste  product.  Farther,  it  is  necessary  for  tlie  proj^cr  ex- 
cretion of  the  carbon  dioxide  of  the  blood  that  the  difference  in  the 
tension  of  that  gas  in  the  air  and  of  that  in  the  blood  shall  be  as  wide 
as  possible ;  that  is  to  say,  the  less  the  amount  of  carbon  dioxide  in 
the  inspired  air,  the  greater  the  facility  with  which  the  blood  can  dis- 
ensrao-e  that  which  it  carries  to  the  lungs.  Anv  interference  with  this 
most  important  function  of  the  body  must  have  an  injurious  effect  on 
the  general  health,  and  it  is  accepted  generally  that  impurity  of  the  air 
is,  without  doubt,  the  most  important  of  the  predisposing  causes  of 
disease. 

It  is  well  known  that,  other  conditions  being  equal,  in  ])roportion  as 
a  people  are  drawn  to  employments  indoors,  the  disease-rate  and  death- 
rate  are  increased.  This  is  particularly  true  as  regards  phthisis,  which 
is  preeminently  associated  with  overcrowding. 

Overcrowding  means  the  association  of  two  or  more  jicojile  in  a 
space  so  confined  as  to  preclude  the  adnn'ssion  of  a.  constant  supply  of 
fresh  air  sufficient  in  amount  to  maintain  a  ]iroper  dilution  of  their 
excretoiy  products  and  a  normal  su])])ly  of  free  oxygen.  It  was  recog- 
nized long  ago  as  a  most  important  factor  in  the  ])roduction  of  a  high 
death-rate  among  occupants  of  crowded  jails,  barracks,  and  hospitals; 
and  experience  has  demonstrated  repeatedly  that  increase  in  space 
allowance  is  followed  always  by  decrease  in  sickness-  and  death-rates. 
At  one  time,  for  example,  the  English  army  averaged  11.9  deaths  per 


ICFFKCTS   OF    VITI.\TFI>    MIL  287 

1, ()()()  incii  ;iiiiiii:ill\',  (Voiii  |tlil  lilsis  iilotic  ;  inoif  cflificnt  Icirnick  \«'ri- 
(,iliiii<^)ii  !i-ii(l  iiici-(';is('  (»r  ;iAM'r;i|;c  :iif  s|»;i(:f'  r;iii-((|  iiiiiiii(|i;i(c  iinprovf- 
iiionl.,  ;ui(l  Uic  |tlilliiHis-r;iU!  ('ell  ^rMdiuilly  to  \ /l  [m  i-  I, Odd.  '||ic 
HiUiK!  ^'('iKirMl  I'csnll.  Ii;is  hccii  oltscrxcl  in  the  ;iniil<-  oC  l-'niiicc,  ltii>.-i;i, 
(}(!nn;iny,  ;iii(l   rK'lt;iiiin. 

Wli;i(  is  (rue  of  ovcrci'owdiii;^  ;i|i|ilii'-  nul  ;i|(.iic  to  liiiin.iii  hciiij^^, 
l)ll(,  (()  ;iiiilii;ils  ;is  well,  jiikI  i(.  is  ;i  well- l<  now  n  liicl  tii;il  crowrlcd  hliihlcs 
show  lii<;'li  iiiorlalily  Minoiijjj  cows  iind  horses.  It  has  such  a  n-rnark- 
ilbhi  iiifhic.iicc  on  (■<;•;;:;  |)ro(hicli«»ii  and  }i;fowth  of  lowl-^  that  |»r"a'-lir-al 
poullrynicii  aiH^  cxcccdinnly  carcrul  on  this  point. 

The  ininu'(lia((!  cITccIs  of  inhalation  oC  inipni-c  air  arc  di-t'ornloit  and 
(>p|)i-cssion,  which  may  anionnt  to  headache,  <n//.iness,  rainlne.-.-,  and 
even  naiisc^a.  ('ontinncd  exposnrc  is  likely  (o  hfinji;  ahont  a  j:;radnal 
iinpairnuMil,  ()('  hcahh,  shown  hy  paUor,  lann;nor,  ana-inia,  skin  tronhh-H, 
loss  of  appetite,  and  diniiiiishcd  power  of"  resistance  to  the  excitinj^ 
canses  of  disease,  and  this  is  especially  trne  of  those  wlio.~e  daily  \V(»i-k 
is  carried  on  in  (a'owded  spaces. 

It  is  customary  to  (rite  as  extfcme  cases  of  overcrow(lin<;  antl  its 
eHects,  the  JilacU  Hole  of  Calcutta,  tlu;  shi})  Loiidondrrri/,  and  the 
prison  at  Austerlitz ;  but  the  conditions  that  obtained  in  each  of  these 
instances  were  inost  unusual,  and  the  cases  are  of  historical  rather  than 
sanitary  interest,  since  the  eonrmini;:  of  a  number  of  ])ersons  in  a  s[)ace 
from  which  air  is  ]iractically  excluded  can  have  but  one  f)utconic. 

The  l^lack  Hole  of  Calcutta  is  the  name  a|)plied  to  the  niiliUirv 
])rison  of  Fort  William,  where,  in  June,  175G,  Surajah  Dowlah  con- 
lined  146  persons  over  ni<>;ht  in  a  space  of  less  tiian  5,900  cubic  feet, 
with  two  small  windows  in  one  side.  Within  an  hour,  all  broke  out 
in  a  [)rofuse  sweat,  antl  were  tortured  with  thirst  and  dillicult  breathing ; 
in  three  and  a  half  hours,  a  majority  were  delirious,  and  when  the  place 
was  opened  in  the  morning-,  123  of  the  prisoners  were  found  dead. 

In  the  case  of  the  Loiuloiido-ri/,  which,  in  December,  1.S4.S,  lett  Sligo 
for  Liverpool  and  ran  into  a  storm,  200  steerage  passengers  were  con- 
lined  over  night  in  a  space  18  by  11  by  7  feet,  with  no  means  of  ven- 
tilation. In  the  morning,  when  they  were  released,  it  was  found  that 
over  70  had  expired. 

In  the  other  extreme  case,  that  at  Ansterlitz,  300  ca)itured  soldiers 
were  confined  in  a  small  cellar,  and  within  a  few  hoiu's  all  l)ut  40  were 
dead. 

To  what  one  or  more  conditions  of  impure  air  are  the  ordinary 
effects  due?  We  have  seen  that  COo  is  in  itself  not  an  active  poison, 
and  that  its  action  is  to  interfere  with  the  proper  oxygenation  of  the 
blood  within  the  lungs.  The  aqueous  vapor  of  respiration  and  from 
the  skin,  and  that  produced  in  the  combustion  of  illuminating  material, 
constitutes  an  important  part  of  a  vitiated  atmosphere,  and  is  respon- 
sible for  at  least  a  part  of  the  discomfort  produced  ;  but  it  is  also  true 
that  a  deficiency  in  watery  vajxir  in  the  air  of  well- ventilated  rooms 
has  equal  or  greater  disadvantages,  as  will  appear  in  the  consideration 
of  Ventilation. 


288 


AIR. 


Concerning  the  effect  of  usual  amounts  of  ordinary  dust  in  in- 
habited rooms,  there  is  little  to  be  said.  The  micro-organisms,  most 
of  which  are  non-pathogenic,  vary  in  number  with  eihciency  of  ven- 
tilation. In  pure  air,  the  bacteria  and  moulds  approximate  each  other 
in  number ;  but  in  vitiated  air,  the  bacteria  increase  in  number,  while 
the  moulds  are  much  less  affected.  The  experiments  of  Carnelly, 
Haldane,  and  Anderson  showed  a  progressive  increase  in  both  bacteria 
and  moulds  with  diminished  ventilation.      Thus, 


Character  of  air  space. 

Number  organisms  in  10  L.  air. 

Ratio  of 
moulds  to 

Moulds. 

Bacteria. 

bacteria. 

External  air 

2 

4 

22 

12 

6 

85 
430 
580 

1:3 
1:21 
1:20 
1:48 

2-rooiued  iiouses 

l-roomed  houses 

The  increase  in  bacteria  is  not  due  to  respiration,  though  a  diminu- 
tion in  their  number  might  be  thus  explained  ;  for  the  great  majority 
of  inhaled  bacteria  are  filtered  out  by  the  nose,  and  the  expired  air  is 
almost  completely  free  from  germs,  although  they  may  be  thrown  out 
in  the  act  of  coughing  or  sneezing. 

Investigation  thus  far  has  not  proved  that  the  bacteria  of  infection 
are  commonly  introduced  into  the  system  through  the  medium  of  re- 
spired air. 

As  has  been  mentioned,  it  is  held  by  many  that  the  effects  of  vitiated 
air  are  not  due  to  carbon  dioxide,  but  to  the  organic  matters  and  aqueous 
vapor  given  off  by  the  lungs  and  skin,  and  that  these  are  estimated 
conveniently  by  determining  the  amount  of  carbon  dioxide  with  which 
they  are  discharged.  It  is  said  also  that,  while  considerable  carbon 
dioxide  escapes  even  under  the  most  imperfect  system  of  ventilation,  the 
organic  matters  and  watery  vapor  do  not  so  readily  pass  out,  but  are 
deposited  on  walls,  furniture,  hangings,  and  clothing,  where  they  putrefy 
and  become  offensive.  As  proof  of  this,  is  cited  the  fact  that  a  room  in 
which  a  person  has  slept  without  adequate  ventilation  has  an  unpleasant 
smell  in  the  morning,  and  that  this  persists  even  after  prolonged 
airing. 

Brown-Sequard  and  d' Arson val,  in  1888,  obtained  from  condensa- 
tion of  the  aqueous  vapor  of  men  and  animals  a  liquid  which,  injected 
into  rabbits,  caused  death  with  greater  or  less  rapidity,  according  to  the 
size  of  the  dose.  They  believed  the  toxic  element  to  be  of  the  nature 
of  a  volatile  alkaloid,  and  that  it  was  exhaled  dissolved  in  the  aqueous 
vapor  of  the  breath.  In  the  same  year,  Wurtz,  reporting  a  similar 
research,  claimed  to  have  found  a  toxic  substance. 

Merkel/  in  1892,  claimed  to  have  obtained  positive  results,  and  con- 
cluded that  res])ired  air  from  persons  in  health  contains  a  minute  quan- 
tity of  a  volatile  organic  base,  which  is  poisonous  when  free,  but  innoc- 
'  Arcliiv  fiir  Hygiene,  XV.,  p.  1, 


EFFEVTfi  OF    VITI A '!'/•:  1)   Afll. 


280 


U0U8  after  vxmi-M'.i  witli  uii  swiid.  Dr.  Sivi(;r;i(<» '  ctMcc.U'A  the  ;u|ii(;onH 
vapor  of  llic  hi'cntli  ol"  pcrHoriH  Hiilloriiijr  from  discuses  of  r<:sj)iralioii, 
hoili  willi  iiikI  vvillioiil  Ccv*'!-,  oC  pcrsoiiH  with  no  r(!S|)iratory  (liHwiHO,  but 
willi  f(!V('-r,  ;ui<l  of  [xirsoiis  in  licalUi,  mikI  injcchd  it  into  r;iM)its.  That 
from  thoS(!  vvilh  rcspinitory  diseases  prcKhicrd  fever  and  diminished 
rcHoxcH  litstin^'  iJirce  |(.  six  days;  that  from  eases  of  fever  with  no  rcH- 
pinitory  disease  (laused  iilLh;  or  no  disturbance;  and  that  from  ])crH<)ti8 
in  health  prodiKHid  no  results  wliatever. 

l<'orman('k  ^  coiuilnch'd,  after  nnich  study,  that  no  |)oisonous  substanc;e 
ori<;inates  in  (he  hmj;s  ;  that  \hv.  ammonia  sometimes  found  is  nf)t  a 
])r()(hu!t  of  metaboHsm,  but  of  decomposition  in  ihc  mouth  cavity  (cari- 
ous te(!tli,  etc.)  and  in  the  trachea  and  iun^s  alter  tracheotomy,  and  in 
puhnonary  tuberculosis;  that,  in  the  e.\perim(;nts  wliich  led  U)  the 
theory  of  an  unknown  alkaloid,  ammonia  was  used,  and  mif^ht  have 
caused  the  obstirvcul  effects;  and  that  the  results  of  overcrowding'  (can- 
not be  due  to  any  one  cause. 

Many  other  experimenters,  French,  German,  Italian,  Ameriaui,  and 
Enj>;lish,  working;  alon<>;  the  same  lines,  but  with  extra  precautions  to 
cx(^lude  matters  from  the  nose  and  mouth,  have  failed  to  obtain  toxic 
ctfects  from  the  condensed  vapor ;  others  have  demonstrated  that  the 
lungs  exhale  no  organic  matter  except  in  minute  amounts,  and  that 
these  have  no  poisonous  influence. 

Arloing  pursued  the  subject  further,  in  the  belief  that  the  constitu- 
ents of  the  sweat  are  concerned  in  the  harmfid  effects.  Pie  soaked 
the  underclothes  of  a  man  who  had  spent  a  long  evening  in  dancing, 
and  injected  the  watery  extract  into  dogs  and  rabbits.  From  the  fact 
that  the  animals  showed  various  evidence  of  intoxication  and  died  he 
concluded  that  sweat  is  toxic.  Experiments  in  the  author's  laboratory, 
however,  with  sweat  obtained  directly  from  well-scrubbed  forearms 
and  injected  in  considerable  amounts  into  rabbits  and  other  animals 
yielded  negative  results.  Sweat  vaporized  in  small  confined  spaces 
was  equally  innocent  of  harmful  results  to  men  and  animals  exposed 
thereto.  At  present  the  weight  of  evidence  leads  to  the  con- 
clusion that  the  injurious  action  of  vitiated  air  is  due  to  the  dimi- 
nution of  oxygen  and  to  the  increase  of  carbon  dioxide,  both  of  which 
factors,  alone  or  together,  interfere  with  the  intake  of  oxygen  and  the 
excretion  of  carbon  dioxide  from  the  lungs.  Yet,  dmiinution  in 
oxygen,  which  even  in  very  crowded  rooms  does  not  ]iroceed  very 
far,  is  met  by  increase  in  the  respiratory  function,  which,  however, 
cannot  increase  the  difference  between  the  tension  of  the  carbon  dioxide 
of  the  air  and  of  the  blood.  Not  even  in  very  imperfectly  ventilated 
mines  does  the  oxygen  fall  much  below  20  j)er  cent,  by  volume,  and 
thus  we  see  that  the  whole  range  of  fluctuation  in  the  oxygen  of  pure 
and  of  very  foul  air  is  but  little  more  than  1  volume  per  cent. 

Smith  and  Haldane^  have  shown  that  in  a  leaden  chamber  containing 

^  Archives  Italiennes  de  Bioloijie,  1895. 

'  Avohiv  fiir  Hyiiiene,  XXXVIII.  (1900),  p.  1. 

•■'  Journal  of  Pathology  and  Bacteriology,  I.,  1892. 

19 


290  AfR 

•A\v  which  had  suifered  but  slight  (lii)iiiiiitiiiii  in  oxygen,  but  Avhich 
ODiitained  8S4  ])arts  of  carbon  dioxide  in  10,(K)(>,  two  men  suffered  from 
headache  imnu'thati'ly  on  entering. 

As  a  rule,  vitiated  air  is  associated  witli  higli  temperature  and  satu- 
ration with  aqueous  vapor,  whicli  hitter  interferes  with  evaporation 
from  the  skin.  Less  often  it  is  associated  with  h)\v  tem])erature,  and 
with  this  condition  comes  an  increased  demand  for  oxygen  to  meet 
the  requirements  of  the  oxidation   ])rocesses. 

It  seems  probable  that  where  the  carbon  dioxide  is  not  jircsent  in  any 
great  excess,  and  the  oxygen  is  not  markedly  tleiicient,  the  conclusion 
arrived  at  by  Drs.  Weir  Mitchell,  Billings,  and  Bergey  is  true  ;  namely, 
that  tlie  discomfort  suffered  is  due  largely  and  chiefly  to  heat  and  dis- 
agreeable odors  arising  from  tlie  occupants  in  various  ways  :  from  bad 
breath,  unclean  skin,  imcleau  clothes,  sweat,  and  gases  from  the  bowels. 
Such  may  induce  very  disagreeable  sensations,  amounting  even  to 
nausea,  in  those  who  are  not  habituated  to  such  influences ;  but,  on  the 
other  hand,  those  who  are  accustomed  to  such  air  notice  no  discomfort. 

Disagreeable  smells  do  not  act  directly  as  a  cause  of  speciflc  disease, 
but  appear  to  have  an  influence  on  the  appetite,  and  hence  on  the  gen- 
eral well-being  of  persons  not  accustomed  to  them.  Much  is  due  also 
to  the  imagination  ;  a  disagreeable  smell  from  a  source  known  to  be 
clean  (chemicals,  for  instance)  has  not  ordinarily  as  much  influence 
as  another  of  equally  offensive  character  sup]>osed  to  be  from  filth.  It 
seems  probable  also  that  there  is  much  to  learn  concerning  the  real 
effects  of  disagreeable  smells,  and  that  they  may  be  more  extensive  than 
we  now  commonly  believe  ;  but  in  order  to  determine  this,  we  sliall 
need  methods  which  Avill  reveal  the  nature  of  the  odoriferous  substances 
and  make  their  isolation  possible. 

Other  causes  of  discomfort  may  be  sought  for  in  the  presence  of 
traces  of  carbon  monoxide  from  heating  apparatus  or  incomplete  com- 
bustion of  illuminating  gas,  and  in  excessive  dryness  of  the  air  due  to 
furnace  or  steam  heat. 

It  should  not  be  overlooked  that  impure  air  may  affect  the  vitality 
aud  bactericidal  power  of  the  cells  of  the  air-passages  and  of  the  ali- 
mentary tract,  and  thus  lessen  the  power  to  resist  the  action  of  infective 
material. 

The  Air  as  a  Carrier  of  Infection. 

On  the  agency  of  air  in  spreading  infectious  matter,  nuich  has  been 
said  and  written,  and  much  careful  research  has  been  conducted,  but 
the  conclusions  reached  are  by  no  means  in  agreement  or  conclusive. 
It  is  conceded  generally  that  pathogenic  organisms  in  the  air  are  ad- 
herent to  particles  of  dust  of  various  kinds,  and  that  their  retention  of 
virulence  depends  upon  the  amount  of  hygroscopic  moisture  Avith  which 
they  are  associated.  The  conditions  favorable  to  their  continuance  as 
living  organisms  are  naturally  more  likely  to  oljtaiji  in  indoor  air,  with 
imperfect  ventilation,  than  in  the  outer  air,  where  they  are  diluted 
and  blown  about  and  exposed  to  the  disinfectant  action  of  the  direct 


Tlfh:  Mil   AS   A    dAIUUHIL    OF   I NFF/mON.  291 

r.'iys  (>('  lJi(^  sun.  Iiidnors  or  oiiI<Imoi:-,  the  more  tlii\'  ;iif  |»i'<)l<'clc(|  l»y 
liyi^roscopic,  diisl.  |)il,|•^i(:l(^s,  (Ik;  lonj^cr  llicy  will  i<l;ilii  llif  wunAwvv. 
wliicJi  is  (;,SM(!iil,i;il  (<»  (licir  vialtility.  Il  ;i,|)|t»';ir.-^,  Iod,  tli;ii,  ('..iidilionH 
luiiiij:;  (KjiiiiJ,  (icrliiiii  iiiI(i(i-oi-jr;MiisiiiH  retain  vilalily  lonj^cr  lli;in  miIkth, 
Home  Ixurifjj  bnt  .sli^lilJy,  ollier.4  very  lenaeions  of  life. 

Witli  i'eji;anl  to  tli(!  tnuiHinisHion  <>("  piilmonary  (nln  rcnlo>i-  fliron^li 
the  air,  it  slionld  \n\  said  (liali  while  (here  can  he  no  <lonl)(  (lia(,  (hi.-,  dis- 
(lase.  is  (•,()nn<!e(ed  precMninendy  \vi(li  ovei-er'owdinj^  and  vi(ia(ed  air, 
(here  is  a  ver)'  decided  did'ei'enee  ol'  o|»inioii  as  io  th(!  niediod  of  com- 
vevaiiee,  sonic;  condMidini;-  (ha(  *\\\A,j  and  othcTH  that  InhereuloilH 
inatei-ial,  thrown  in(()  (he  air  in  eon^hin^,  Kj)cukin^,  and  Hncezinji;,  m 
the,   vehicle. 

J>U(;hner  has  Cound  //.  /ii/xrcii/osis  in  an  acli\c  .'-(a(e  in  (he  «his(  of 
U  room  a  year  aCler  (he  dealh  oC  ils  occii|i;inl  Inini  the  disease,  (i. 
C'Ornet'  denions(raie(l  i(s  |»resen(;e  in  more  than  a  third  of  1  17  saiii|»l<'H 
of  (Inst  (!oll(H'-l('d  in  lios|)itals  and  other  |iiil»lic  iii-(  il  nl  inn-^  ;iiid  in  |)rivat<; 
honses  inhahiied  hy  |)hthisical  |)ersons,  and  sn(;ceeded  later  in  prodncinj^ 
the  disease  in  K!  out  of  18  gtiinea-|)igs  exposed  to  air  containing  dust 
from  dried  tuberculous  sputum.  Some  of  the  animals  were  placed  8 
inches  from  a  o^lass  vessel  containinc^  dried  pulverized  sputum  from  an 
advanced  ease;  others  were  i)laced  on  shelves  8  to  28  inches  from  the 
floor  of  a.  room,  on  the  carpet  of  which,  sputum,  mixed  with  dust,  had 
been  spread  and  dried  and,  at  the  end  of  two  days,  stirred  u[)  by 
sweeping ;  others  were  allowed  to  stay  in  the  room  without  disturbance 
of  the  dust. 

Klein  obtained  positive  results  with  g;uinea-})igs  ])laeed  in  (he  venti- 
lating shaft  of  a  consumptives'  hospital ;  but  Hei'on  -  obtained  but  2.7 
per  cent,  of  positive  results  in  74  guinea-pigs  inoculated  with  dust  from 
the  ventilating  shaft  of  the  London  Hospital  for  Diseases  of  the  Chest ; 
and  Kirchner''  got  but  1  positive  result  out  of  16  pigs  inoculated  with 
the  dust  from  a  military  hospital.  Fliigge,  on  the  other  hand,  was 
wholly  unsuccessful  in  inducing  the  disease  in  guinea-pigs  exposed  to 
such  dust ;  and  concluded  that  the  transmission  from  one  person  to 
another  is  chiefly  by  means  of  the  finest  droplets  thrown  into  the  air  in 
sj>eaking,  coughing,  and  sneezing.  From  later  experiments,  conducted 
under  his  supervision  by  Laschtschenko,  Heymann,  Sticher,  and 
Beninde,^  he  concluded  that  in  rooms  in  which  tuberculous  sputum  is 
dried  on  the  floor  or  other  jilaces,  and  where  the  air  is  filled  with  coarse 
dust  through  dry  cleaning  and  air  currents,  or,  as  in  railway  ears,  bv 
continual  mechanical  jarring,  infection  may  arise  ;  and  that,  under  the.se 
conditions,  long-continued  exposure  otters  a  certain  degree  of  probabilitv 
of  infection.  Therefore,  dry  cleaning  is  to  be  avoided  in  rooms  in 
which  consumptives  ai'c  employed  with  others,  and  the  rooms  should 
not  be  occupied  so  long  as  the  air  is  {perceptibly  dusty.  The  great  pos- 
sibility of  infection  through  matters  thrown  ott*  in  coughing  and  snee/-- 

^  Zeitsclirii't  fiir  Hygeine,  V.,  p.  191.  '■'  Tlie  Lancet,  January  G,  1894. 

^  Zeitschrit't  fiir  Hvsiiene  und  Infectionskrankheiteu,  XIX.,  p.  153. 
*  Ibideni,  XXX.,  p.l07. 


292  AIR. 

iug  is  insisted  upon  as  of  paramount  importance.  This  dauo-er  is  to 
be  prevented  bv  requiring  the  jierson  eoughing  to  hold  a  handkerehief 
or  the  hand  before  the  mouth  during  the  aet,  and  by  the  avoidance  on 
the  part  of  others  of  approaching  within  a  meter. 

Answering  Fliigge,  Cornet  '  contends  that  the  number  of  bacilli 
thrown  into  the  air  during  the  act  of  coughing  must  be  extremely 
small.  He  caused  18  consumptives  to  hold  dishes  before  the  mouth 
while  coughing,  and  obtained  2  positive  results  therefrom  on  inoculation 
into  guinea-pigs ;  repeating  the  test  with  1 5  others,  he  got  none ;  but 
Heymann  -  was  more  successful,  for  glass  plates  exposed  in  the  imme- 
diate vicinity  of  coughing  consumptives,  confined  for  an  hour  and 
a  half  in  a  glass  cabinet  of  three  cubic  meters'  capacity,  were  proved 
to  have  become  contaminated  by  the  specific  organism.  The  plates 
were  rubbed  up  with  small  amounts  of  broth,  wdiich  was  then  injected 
intraperitoneally  into  guinea-pigs,  mostly  with  positive  results. 

Experiments  conducted  by  Ivoniger^  confirm  Fliigge  in  his  estimate 
of  the  danger  of  transmission  by  droplets.  In  order  to  give  the  ex- 
pelled droplets  a  character  which  would  admit  of  their  being  traced,  he 
rinsed  his  mouth  with  liquid  rich  in  B.  prodigiosus  or  B.  mycoides,  or 
with  very  dilute  caustic  soda,  and,  in  order  to  trace  them,  he  exposed 
Petri  dishes  and  glass  plates  coated  with  phenolphthalein,  which  agent, 
turning  pink  in  contact  with  an  alkali,  Avould  show  not  only  the 
number  of  droplets,  but  their  size  as  well.  It  was  found  that  no  drop- 
lets are  thrown  out  in  ordinary  exhalation  nor  in  vowel  formation,  but 
with  consonants,  as  t,  k,  and  p,  the  number  is  very  great,  and  is  largely 
dependent  upon  the  amount  of  force  with  which  the  air  under  pressure 
in  the  mouth  cavity  is  released  in  their  formation,  and,  therefore,  upon 
the  manner  of  pronouncing.  Loudness  and  rapidity  of  speech  have 
but  little  influence ;  whispering  m.ay,  indeed,  under  some  conditions, 
cause  a  greater  number  of  droplets  than  loud  speech.  Even  wdth  sub- 
dued speech  and  a  quiet  atmosphere,  it  was  found  that  the  organisms 
expelled  reached  the  most  distant  parts  of  the  room,  which  was  more 
than  20  feet  in  width,  and  in  all  directions.  They  were  found  to 
remain  in  suspension  in  the  air  not  longer  than  an  hour,  and  it  was 
noticed  that  they  fell  upon  the  plates  in  groups,  sometimes  as  many  as 
40  close  together,  which  suggests  that  they  fall  not  as  dry  dust  particles, 
but  that  the  droplets  themselves,  with  their  contained  or  adherent 
organisms,  are  deposited.  In  coughing  and  sneezing,  more  droplets 
are  expelled  than  in  speaking,  and  they  are  projected  to  a  greater  dis- 
tance, because  of  the  greater  force  engaged.  The  precautions  recom- 
mended apply  not  alone  in  tuberculosis,  but  also  in  diphtheria,  wdioop- 
ing-cough,  and  other  diseases  in  which  the  respective  specific  organisms 
are  ff)und  in  the  air-passages. 

Hutchison  *  found  that  bacteria,  sprayed  in  minute   droplets  upon 

^  Berliner  klinische  Wochenschrift,  May  13,  1899. 

*  Zeitschrift  fiir  Hygiene  und  Infectionskiunkheiten,  XXXVIII.  (1901),  p.  21. 
'  Ibidem,  XXXIV.  (1900),  p.  119. 

*  Ibidem,  XXXVI.  (1901),  p.  223. 


Till':  A  in   AS!  A    dAlilLll'Jl    0/-'   ISl'KdTIOS.  293 

ohjccts,  |)(!risli  in  w.  hIioH,  IJiiic,  the  iiuiiii  (iidor  in  I  li<  ir  <l«'Htriic(,ion  hciiif; 
tlio  iiidiKMKic  (»(■  SMiili-^lit.  S|»r;ivc(l  (liiv'clly  into  lli''  iilr,  iii(r-t  of  tlicm 
won;  (omid  (o  li;ivc  liccomc  <lc|)osilc(l  witliin  ;i  IimII'  lioiir,  \\li<-ii  tin;  air 
of  IJk;  room  vviiH  allowc*!  lo  riiniiiii  iindi.sturlx'd,  but  iimiihcrs  of  tlu-tn 
W(!r(\  1<((|)(.  ill  siis|)('iisi()ii  (or  coii^iflcialtlc  iMTiods  hy  slif^lit  iiiiiivoidiiMe 
iiir  (iiiiTciils  ill  IIk'  lower  sIimIii.  I  I<!  hIiowc*!  tlinl,  wifli  fiivoriiig  air 
ciiiT(Mils,  (lie  .sii,s|)(;iidcd  l»;i(;(('ri;i  iu;iy  Ix;  coiidii<-le<l  tliniiifrli  very  nar- 
row or(!vi(!(?s,  us  into  clo.sod  bureau  drawcM's,  iiiid  riom  one  room  U) 
Miiollicr  Ihroiijrji  keyholes  uikI  cnK-ks.  While  tlu;  danger  of  di.swnii- 
iiaiiiij;  bacteria  by  walking  over  an  iiilected  floor  was  fbiin<l  to  bo 
siif^ht,  those  thrown  ii|)  by  ihc;  ehisti<!  rebound  oC  I  lie  boards  failing  t/) 
infect  phites  suHpeiKJed  4  ineluw  above  them,  oi<liiiary  sweejiinj^  wa8 
found  to  (!onta,iniiiat<^  tli(!  atnios|)here  throufj^hoiit  its  whole  extent,  even 
to  iJie  eeilinj:;,  thus  eoiiliniiiiin;  b'lii'^'^^ci's  stalenieiil  w^  1o  the  iindesira- 
bility  of"  dry  clcaiiinii;. 

Closely  similar  residts  were  obtained  by  Kirstein,'  who  concludes 
that  ordinary  air  currents  cannot  detach  livin<jj  or<^anisms  from  surfaces 
upon  which  they  have  been  (Usposited  and  Ixiconie  dried,  but  cona.'dfts 
that,  wiu'u  the  i)actcria,  are  si)rayed  upon  fine  dust  particles,  they  may 
easily  be  borne  about  in  the  air.  Yet  how  sli<^ht  the  dangc^r  of  this 
method  of  infection  is,  so  far  at  least  as  typhoid  fever  is  concerned,  is 
shown  by  the  marked  rapidity  with  which  the  typhoid  or^nisms  die 
when  sent  forth  in  the  form  of  spray.  (^tlier  non-siiore-biiilders, 
sprayed  into  the  air,  retained  their  vitality  for  only  a  eonij)aratively 
short  time,  because  of  the  influence  of  light  and  air  ;  and  lie  believes 
that  the  marked  sensitiveness  of  the  tubercle  bacillus  to  the  influence 
of  light  makes  early  destruction  of  this  organism  most  probable  when 
it  is  thrown  into  the  air  in  minute  droplets,  and  that  thus  may  be  ex- 
plained the  fact  that,  even  in  consumptive  wards,  in  Avhich  there  is, 
without  doubt,  a  constant  discharge  of  bacilli  into  the  air,  attempts  to 
detect  living  organisms  in  the  dust,  etc.,  fail,  excepting  in  those  cases 
in  which  the  sputum  itself  has,  through  lack  of  care,  become  dis- 
seminated. 

Positive  results  of  examination  of  droplets  expelled  by  consumptive 
patients  during  coughing  have  been  recorded  by  Curry,-  Boston,'*  and 
others.  Curry  experimented  with  12  patients,  who  coughed  toward 
plates  suspended  from  1  to  3  feet  distant ;  he  found  the  bacilli  in  the 
larger  droplets  expelled  by  half  the  subjects.  Boston,  observing  fine 
droplets  being  ejected  from  the  month  of  a  patient  with  advanced 
disease  in  each  act  of  coughing,  concluded  that  such  constant  spraying 
at  the  table  and  elsewhere  might  afltbrd  an  explanation  why  patients 
in  the  early  stage  of  the  disease  did  not  do  well  in  the  mstitution  where 
his  observations  were  made,  in  which  every  possible  attention  is  given 
to  ventilation,  light,  and  disinfection  of  sputnra.  By  means  of  a  simple 
device,  the  spray  sent  out  by  50  patients  was  collected,  and  then  sub- 

^  Zeitsclirift  fiir  Hygiene  und  Infeotionski-.inkbeiten,  XXV.  (1900),  p.  123. 

^  Boston  Medical  and  Surgical  Journal,  October  lo.lS9S. 

^  Journal  of  the  American  ^ledical  Association,  Sept.,  14,  1901. 


294  AIR. 

jeeteJ  to  examination  for  the  sjieeifie  organism,  which  was  found  in  76 
per  cent,  of  the  ciises.  The  smallest  number  found  in  any  specimen 
was  4,  and  in  fully  a  third  the  bacilli  were  very  numerous. 

Rayenel's '  exj)eriments  with  tuberculous  cows  haye  proyed  that 
they,  too,  send  forth  the  bacilli  in  great  numbers  in  the  act  of 
coughing. 

Experiments  conducted  at  the  Adirondack  Cottage  Sanitarium  by 
Dr.  I.  H.  Hance,'  for  the  purpose  of  determining  the  degree  of  danger 
of  infection  when  all  possible  sanitary  mciisiu'cs  for  disinfection  of 
sputum  are  enforced,  support  the  view  that  dust  in  the  air  is  of 
secondary  importance,  but  that,  where  carelessness  in  this  regard  ob- 
tains, the  danger  is  a  real  one.  A  complete  examination  was  made  of 
the  group  of  buildings,  some  of  which  had  been  occu])ied  l)y  consump- 
tiyes  for  eleyen  years.  Dust  was  collected  from  j)laces  most  likely  to 
be  infected,  and  with  it  81  guinea-pigs  were  inoculated.  Four  inocu- 
lated with  dust  from  the  infirmary  (a  building  where  all  the  acutely 
sick  are  sent),  and  from  the  main  building  (in  which  are  a  ]iarlor,  sit- 
ting-room and  library),  died  of  other  infections  on  the  third  to  the 
sixth  day.  Five  of  the  ten  inoculated  with  dust  from  the  oldest  cot- 
tage, which  was  occupied  by  a  man  who  had  been  complained  of  for 
promiscuous  spitting,  became  tuberculous.  Those  inoculated  with  the 
dust  from  the  other  buildings  gave  negative  results.  During  eleven 
years,  not  one  of  the  20  to  25  attendants  employed  had  developed  the 
disease. 

As  to  typhoid  fever,  too,  opinions  are  at  variance.  Dr.  John 
Brownlee  reported  before  the  Glasgow  Philosophical  Society  an  ex- 
periment proving  that  the  specific  bacilli  can  live  in  ordinary  dust. 
Buchner  is  of  the  opinion  that  neither  typhoid  nor  other  fevers  can 
thus  be  spread. 

Perhaps  the  most  extensive  research  on  the  subject  of  transmission 
of  this  and  other  diseases  is  that  conducted  by  Dr.  Eduardo  Germano.^ 
In  his  experiments,  he  used  various  kinds  of  dust  and  dirt,  and  from 
his  results,  he  concludes  that  the  typhoid  germ  is  unable  to  withstand 
complete  drying,  and  hence  cannot  be  transmitted  to  man  through  dust 
sufficiently  dry  to  be  disseminated  by  air  currents.  Experiment  showed 
that  the  germ  can  live  for  a  long  time  in  moist  surroundings,  even  in 
an  apparently  dry  condition,  that  is,  when  adherent  to  or  encompassed 
by  matters  which  contain  a  certain  amount  of  moisture,  such  as  cloth- 
ing, particles  of  dirt,  and  fecal  filth.  Most  of  the  bacilli  die  as  drying 
progresses,  but  some  are  more  or  less  resistant,  though  not  necessarily 
dangerous  on  admission  to  air  currents,  since  then  complete  drying  and 
consequent  death  occur.  They  are  dangerous  only  in  case  of  intro- 
duction into  the  system  through  contact  with  the  fingers,  food,  or 
eating  utensils. 

'  Univei-sitv  Medical  Magazine,  November,  1900. 

2  Medical  Record,  December  28,  1895. 

3  Zeitscbrift  fur  Hygiene  und  Infectionskrankbelten,  XXIV.,  p.  403;  XXV.,  p.  439; 
XX\'l.,  pp.  GO  and  273. 


Till':  A I  It    AS   A    CAIUlir.ll    <)l''   INFECTION.  296 

Wii-li  rc^'.'ird  lo  (li|»li(  licil;i,  (  mtiii;iiio  CoiiikI  iIliI  tln'  hiicillijH  witli- 
,s(.iiii<lH  loiij^  (Iryiiif^-  in  nicinlniiiics,  lis^iics,  ,iii<l  dii-t,  even  when  tin; 
(Ir-yiii^  |)r()c,(ssH  in  jiHsislcd  l»y  Hiilpliiiric!  iirid  ;  mimI  tlmt  ItH  rcHiKJarw*!  Ih 
}jjrc;ii(!i'  juKiordiii^  !,(»  (lie  jiiiioiiiil  o("  cnvt'lopinj^-  inulcr'i;il  wliirli  n-fanls 
()xi(l;i(i(ni.  VVIicii  (•(»ni|»l('lcl\'  div,  il  |)i<scrv<'S  ils  vinilciic*'  ti|i  (<»  fli«; 
l.iiiu^  il,  (lies.  Ilcncc  liis  Ixlid"  I  li;i(  I  lii-  <li.sc;iH(:  '":'}'  !»<• 'Ii.s.-(iiiiii;it((l  liv 
ail'  (Mirrciils. 

Willi  regard  lo  iiiiciiinoiiia,  erysipelas,  and  ol  lier  .-t  r('|)l(»coceiis  infee- 
tioiis,  (ilcrniano  finds  llial  llie  resisliuu'c  oC  llie  orjranisni  lo  llie  dryinj^ 
|)fo('('SS  is  always  liii;li,  lliontili  il.  varies  willi  llie  rnctlMtd  (ollowed  and 
iJic  nal.in'e  o("  I  lie  enschtpini;'  nialerial,  and  may  persisl,  a  innnhei-  of 
nionllis.  '^Fransinission  ihionnli  (he  ;nr  is  exlrcnu;ly  prol»ai>l<'.  I  lie 
diploeoe(^i,  in  ti^(!ii(!raJ,  hear  diyiiit;'  loi-  a,  lon<r  time  ;  .some  \arieli«;H  live 
loii«;er  wlien  dricul  than  il"  moist,  and  some  j)ossess  hut  lillle,  resistaner; ; 
but  the  ni|)idity  ol"  tin;  diyiui;' procv'ss  willi  medium  tern |)(;nitii re  does 
not  affect  tlio  rc^sult.  He  found  that  llie  cholera  or<;anism  retiiin.s  it« 
virulence  only  so  lonii^  as  it  remains  moist,  and  dies  (|uicUly  on  drying, 
|)arti(Uilafly  if  the  j)ro(U'Ss  is  hastened.  He  eoncluded  that  dissendna- 
tion  by  air  is  most  hi<>;hly  im|)robal)le. 

(Tcrmano's  work  with  the  plague  bacillus  confirms  the  results  an- 
nounced by  Kitasato  and  Wilm.  This  or<ranisin  does  not  withstiind 
dryino;,  but  lives  a  louii;  time  in  a  moist  (condition.  It  remains  active 
fairly  lonuj  when  dried  on  cloth,  because  then  complete  dryinjr  requires 
a  long  time,  and  thus  may  be  explained  the  danger  of  infection  recog- 
nized to  exist  in  infected  clothing. 

Germano's  cxjieriments  with  the  diplococcus  of  epidemic  cerebro- 
spinal meningitis  agree  in  results  with  those  of  Jiiger,  who  found  the 
organism  in  an  active  condition  in  a  handkerchief  six  weeks  after  use 
by  a  patient  sick  with  the  disease.  Germauo  shows  that  it  belongs  to 
the  class  of  bacteria  which  oppose  the  greatest  possible  resistance  to 
drying,  whether  the  process  is  slow  or  quick,  and  whether  assisted  by 
the  action  of  sul])huric  acid  ;  and  concludes  that  it  may  M'ithout  diffi- 
culty enter  the  air  in  the  form  of  dust,  and  thus  spread  the  infection. 
This  view  is  su]>ported  by  Buchanan,'  who  argues  from  the  fact  that, 
of  60  cases  which  came  under  his  observation,  57  were  in  men  who 
followed  occu[iati(^ns  in  which  they  were  exposed  to  dust,  the  specific 
organisms  are  thus  conveyed. 

Dr.  Max  Neisser,'  working  in  the  same  line  as  Germauo,  with  au 
apparatus  of  his  own  design,  which  maintains  a  constant  aspiration 
current  of  dusty  infected  air,  disagrees  as  to  the  pueumococcus,  inas- 
much as,  while  mice,  inoculated  with  infected  dust,  dial  from  the  in- 
fectiou  without  exception,  24  others,  inoculated  with  the  dust  af\er 
it  had  beeu  sent  through  the  apparatus  in  a  current  of  air,  gave  abso- 
lutely negative  results.  His  experiments  with  various  organisms  led 
him  to  the  conclusion  that  dust  infection  is  impossible  with  the  organ- 
isms of  diphtheria,  typhoitl  fever,  cholera,  plague,  and  pneumonia,  but 

1  Britisli  ■NFedioal  Jouni;i1,  Soptomlvr  14.  1901. 

^  Zeitsoiuil't  lur  Hygiene  uiul  Infeotiimskrankheiten,  XXVI.,  p.  175. 


296 


ATR. 


possible  witli  Siaphylococcus  pyogenes  aureus,  J?,  pyocyaneus,  B.  an- 
thracis,   B.   tuberculosis,  and   ineninoxieoccu.s. 

Neisser's  conclusion.^,  .'^o  far  a.^^  t])cy  relate  to  diphtheria,  are  opposed 
to  the  results  obtained  by  Kichardiere  and  Tollemer/  who  made  a  series 
of  examinations  of  the  air  of  diphtheria  wards  of  the  Hoj^ital  Trons- 
seau.  In  one  set  of  experiments,  the  wards  had  not  been  disinfected 
for  several  weeks ;  and  in  another,  the  examinations  were  made  after 
disinfection  had  been  carried  out.  The  results  showed  that  active 
diphtheria  bacilli  were  present  in  the  air  which  had  not  undergone 
disinfection.  The  bacteriological  tests  were  controlled  by  inoculation 
cxpenmcuts  with  animals. 

A\'ith  rcg-ard  to  the  possibility  of  spreading  cholera  germs  through 
the  agency  of  moving  air,  Dr.  N.  William  ^  has  reported  that,  while 
that  means  has  been  regarded  as  most  favorable,  in  actual  experiment 
it  foils.  Mixed  with  dry  dust,  the  germs  live  but  a  short  time,  and 
perish  more  quickly  when  a  current  of  air  is  conducted  through  the 
dust.  AVheu  the  dust  is  distributed  through  large  volumes  of  air,  the 
germs  die  rapidly,  and  when  the  impregnated  dust  is  let  fall  upon  a 
suitable  culture,  only  a  very  small  proportion  of  living  organisms  can 
be  found.  In  other  words,  cholera  germs,  adherent  to  du.st  particles 
floating  in  and  moved  about  by  air,  do  not  retain  their  activity  for  any 
length  of  time  nor  through  any  considerable  distance. 

The  experiments  of  Honsell  ^  indicate  that  the  cholera  organism  finds 
no  favoring  conditions  for  its  passage  into  the  air  from  its  situation  in 
privy  vaults. 

The  subject  of  danger  of  cholera  infection  by  dust  from  baled  rags 
was  considered  thoroughly  at  the  Dresden  Cholera  Conference,  and  it 
was  found  impossible  then  to  quote  a  single  case  in  which  infection 
could  be  traced  to  this  source. 

According  to  Dr.  E.  W.  Hope,*  atmospheric  dust  is  largely  respon- 
sible for  the  spread  of  infantile  diarrhoea  in  cities  and  large  towns, 
where,  from  unavoidable  causes,  the  air  becomes  more  or  less  laden 
with  filth.  He  presents  evidence  of  the  association  of  rainfall  and 
its  attendant  cleansing  of  the  atmosphere  with  diminished  mortality 
from  choleraic  diarrhoea,  as  follows  : 


Average  rainfall 

Annual  average  of  deaths 

Period. 

June  to 

Conditions. 

from  diarrhoea  during 

September. 

third  quarter  of  year. 

6  years 

13.8  inches 

Average  wet  sum- 
mers. 

373 

14     " 

10.9      " 

Average  dry  sum- 
mers. 

573 

Extreme  years. 

1891 

16.0      " 

Wettest  .summer. 

203 

1895 

7.7      " 

Driest  summer. 

819 

1  Gazette  des  Maladies  infantiles,  No.  10,  1899. 

^  Zeitschrift  fiir  Hygiene  and  Infectionskrankheiten,  XV.  (1893),  p.  166. 
^  Arbeiten  aus  dera  patholog-anatomischen  Institut  zu  Tiibingen,  1896. 
♦  Public  Health,  .July,  1899. 


EXAMINATION    OF  A  I II.  297 

Influence  of  Fog. 

Dust  ;ui(l  nioisliin!  (,();^( oilier  in  llif  I'liin  nC  lo^'  ;ifr<'t  tlic  lic'ilfli  of 
\',iY\!\\  (ioiiiinnnilics  in  ii,  in.-irkcd  decree.  In  ;i  still  iiir  nearly  or  coni- 
pUiLoly  sjitiiraidd  willi  a(|M('()iis  vjipor  and  rontaiiiin^  ordinary  dnst  and 
smoko,  a  fail  in  l(!ni|)('ia(iir('  <;iiihoh  (3a(!li  particle  of  diiHt  and  Koot  U) 
heoomc  tlu;  nn(!!(!ii,s  of  a,  niiinilc!  dropK^f  of  f.ondc.nHcd  inoJHtnn!.  TlH^ci 
countloHH  droplets  in  a  slati;  of  snspcnsion  form  a  inon-  or  JesK  d('tiH(! 
I)laiik(^t  of  fo^,  wliicJi  impedes  dispersion  of  the  impurities  jrivr-n  off 
by  natural  pro(;css{!S  and  as  products  of  (;ond)Ustion.  Wliile  r»rdinary 
country  and  seiishon^  fo^s  ai'c;  not  known  to  cxort  d(!let(Tions  eU'ectw, 
in  smoky  cities,   lik(!    London,   tlu;  easi^   is  fpiit(!  diff(;r<!nt. 

It  is  a  \vell-re('.(»^nized  fai^t  that,  duriufr  |)eriods  of  heavy  fo^s  in 
mauul;icturin<ij  c(Miters,  the  morbidity  and  mortality  from  nvspiratory 
disease  are  increased  very  greatly,  and  that,  as  the  atinos])iierc  clears,  a 
sharp  de(!linG  follows.  In  London,  for  example,  the  usual  death-rate 
from  all  causes  has  been  known  to  Ixicome  almost  doubled  diu'ing  a 
fortnight  of  coutimied  dense,  smoky  fog,  and  then  to  return  t^)  its 
normal  figure  with  the  advent  of  clear  weather,  the  increase  being  due 
particularly  to  bronchitis  and  other  affections  of  the  respiratory  tract, 
attributed  to  the  irritating  influence  of  the  finely  divided  particles  of 
soot  and  the  acids  which  accompany  them. 

During  the  prevalence  of  thick  fogs,  the  air  being  necessarily  in  a 
stagnant  condition,  it  has  been  observed  that  the  carbon  dioxide  content 
increases  progressively.  During  one  such  period  following  bright 
weather,  the  air  of  London  acquired,  in  four  days,  three  and  a  half 
times  its  normal  content  of  this  gas. 

The  importance  of  smoke,  both  as  a  promoter  of  disease  and  on  ac- 
count of  its  corrosive  and  disfiguring  action  on  buildings,  and  also  on 
account  of  the  obstruction  of  light,  has  led  to  much  legislation  and  to 
the  exercise  of  inventive  genius  for  devising  means  for  the  prevention 
of  its  discharge  in  objectionable  amounts  into  the  atmos])here  of  cities. 
Many  patents  have  been  granted  for  smoke-consuming  devices,  the 
majority  of  which  have  been  found  to  work  unsatisfactorily.  The 
most  effective  invention,  which  gives  promise  of  solving  the  problem 
most  completely,  is  one  which  has  been  brought  to  the  attention  of  the 
Department  of  State  by  Consul  General  Mason. ^  This  process  consists 
in  distributing  heated  and  slightly  compressed  air  through  hollow  gmte 
bars  to  the  whole  lower  surfoce  of  the  furnace.  Not  only  is  practically 
perfect  combustion  attained,  but  immense  saving  of  expense  is  possible, 
since  what  are  ordinarily  unsalable  low-grade  coals  can  be  employed  to 
greatest  advantage. 

Examination  of  Air. 

For  all  practical  purposes,  the  examination  of  air  may  be  restricted 
to  the   determination   of  the  amounts  of  aqueous   vapor  and   carbon 
dioxide.     The  essential  element,  oxygen,  fluctuates   within   such  veiy 
1  Consular  Keports,  1899,  p.  491. 


298 


ATR 


narrow  limits  that  its  estimation  is  a  matter  of  purely  scientific  interest, 
and,  moreover,  tlie  process  is  one  which  demands  a  much  higher 
degree  of  juanipuiative  skill  than  is  possessed  by  those  to  whom  the 
task  of  making  sanitary  examinations  ordinarily  falls.  The  chief  con- 
stituent, nitrogen,  is  practically  constant  in  amount,  and  its  determina- 
tion would  serve  no  useful  purpose.  Whatever  is  the  cause  of  the 
deleterious  effects  of  an  atmosphere  vitiated  by  res])iration,  whether  it 
Ik'  carbon  dioxide  or  the  organic  matters  given  olf  by  the  body,  this  at 
least  is  certain,  tiiat  the  amount  of  carbon  dioxide  serves  as  an  index 
of  impurity,  and  that  the  tunount  of  aqueous  vapor  is  of  considerable 
sanitary  importance.  In  s])ecial  cases,  it  is  important  to  look  for  that 
most  dangerous  contamination,  carbon  monoxide,  which,  coining  even 
in  very  small  amounts  from  leaking  gas  ])ipes  and  other  sources,  exerts 
a  decidedly  deleterious  influence.  In  the  minds  of  many,  the  test  for 
ozone  is  also  of  importance. 

In  addition  to  chemical  analysis,  the  determination  of  the  amount 
of  dust  and  the  number  and  varieties  of  micro-organisms  present  may 
be  of  interest  and  importance. 

Determination  of  Aqueous  Vapor. — As  has  been  stated  above,  a 
volume  of  air  at  a  given  temperature  can  hold  a  definite  amount  of 
moisture,  and  no  more,  and  when  this  amount  is  present  the  air  is  said 

Fig.  11. 


Apparatus  for  direct  determination  of  moisture. 

to  be  saturated.  The  amount  which  a  volume  of  air  contains  consti- 
tutes its  absolute  humidity,  and  the  difllerence  between  this  and  the 
amount  which  it  is  possible  for  it  to  hold  is  known  as  its  saturation 
deficiency.  The  ratio  which  its  absolute  humidity  bears  to  its  possible 
content  is  known  as  its  relative  humidity. 

Direct  Determination  of  Moisture  by  Weighing. — Prepare  two  wide- 
mouthed  flasks  of  about   150  cc.   capacity  in   the  following  manner: 


F.XAMINATION   OF  Mil. 


2(>0 


Provide;  (iMc.li  vvilJi  w  \'\\r\\[\y  liMin^  i-iiMxr  sloppci-  willi  (wo  jHTforatioiiH, 
tliroii^li  wlii<'li  ;i,r(!  iiiHcrle^d  two  piece-  oC  <^\:\-r    liihin^   hciil.  at  a   right 

angl(!.        One   of    (Ji(!M(!   numlldH    In    llie    liolldlil    of    I  he    |l;i.-|<,    ;i|ul   HrTVCH    OH 

ail  inliit  ;  tlu;  o(Ji(!i'  cxIcikIs  only  a  short  (h'slunc*;  helow  th(!  hlo|»|»cr, 
and  S(!i"V((S  as  an  onllel.  I' ill  (he  fhisks  wi(h  Kni;dl  pi<'cc.s  (»r  |iurnie«; 
wlii(;h  have  Ixen  lie.iled  lo  ;i  lii^jli  lenipeiiil  nie  over  ;i  |'>nn-eti  hnrncr, 
(h'oj)ped  while  hot  into  eoiieenlraled  snl|»hiirie,  acid,  I'enioveti  llie|-c(roin, 
and  (jnicl<ly  drained.  Tlu;  two  llasks  (hns  (llle<l,  and  wi(li  .-(op|)er.s 
(ij2,'h(ly  ins(!r(('(l,  arc  (hen  (o  he  (ronnee(ed  hy  means  of"  a  short  |>iee,(;  of 
rnhhcr  tnhinu;,  (he  inh'l  o("  one  joinin}^  (he  oii(le(  of  the  (tthcr.  Tlicy 
arc;  then  wei<;lied.  The  ll;isl<  willi  the  free  onllct  tuh(;  Ih  MOW  t()  be 
<;onn('e(,('d  wi(h  :in  ;is|>ira,(or,  hy  means  of  which  from  20  to  '>()  lit<;r.s 
of  air  ar(!  drawn  (hronnh.  As  (he  air  conu^s  in  contact  \vi(h  th(!  jinmico 
satnra(cd  wi(li  snlphuric  acid,  its  mois(nrc  is  ahsorhcd  and  retained.  >\t 
the!  cxj)iration  of  the  aspiradng  procicss,  the  flasks  are  diseoimectod  from 
the  aspirator  and  again  wcij^hed.  Tiic  increa.se  in  weight  repre.sents  the 
amonnt  of  moistnre  in  the  vohnne  of"  air  used. 
The  a[)paratu8  is  shown  in  J*'i<;'.  !  I .  Know- 
ing the  tc^mperatnre  of  the  air,  one  can  then 
easily  determine  the  relative  humidity  by  refer- 
ence to  the  tabk^  beh)w,  which  shows  the  maxi- 
mum humidity  possibleat  different  temperatures. 

TAnr.K  OF  MAXIMUM  WATER  CAPACITY  FOR 
TEN   LITERS  OF  AIR. 


Fio.  12. 


Tempera- 
ture centi- 
grade. 

Corre- 
sponding 
degrees  F. 

Grams. 

Tempera- 
ture centi- 
grade. 

Corre- 
sponding 
degrees  K. 

Grams. 

—10 

14.Q 

0.021 

13 

55.4 

0.113 

—  8 

17.6 

0.027 

14 

57.2 

0.120 

—  6 

21.2 

0.032 

15 

59.0 

0.128 

—  4 

24^8 

0.038 

16 

60.8 

0.136 

—  2 

28.4 

0.044 

17 

62.6 

0.145 

0 

32.0 

0.049 

18 

64.4 

0.151 

1 

33.8 

0.052 

19 

66.2 

0.162 

2 

35.fi 

0.056 

20 

68.0 

0.172 

3 

37.4 

0.060 

21 

69.8 

0.182 

4 

39.2 

0.064 

22 

71.6 

0.193 

5 

41.0 

0.068 

23 

73.4 

0.204 

6 

42.8 

0.073 

24 

75.2 

0.215 

7 

44.6 

0.077 

25 

77.0 

0.229 

8 

46.4 

0.081 

26 

78.8 

0.242 

9 

48.2 

0.088 

27 

80.6 

0.256 

10 

50.0 

0.094 

28 

82.4 

0.270 

11 

51.8 

0.100 

29 

84.2 

0.286 

12 

53.6 

0.106 

30 

86.0 

0.301 

Determination  of  Relative  Humidity  by  the 
wet  and  dry  Thermometer  Bulbs.  This  instru- 
ment, which  is  kno\vi\  also  as  the  psychrom- 
eter,  consists  of  a  pair  of  accurate  thermoni- 
eters  on  an  upright  support.  The  bulb  (^f  one 
is  free  ;  that  of   the  other  is  covered  with    a 


rsychrometor. 


300 


AIE. 


layer  of  muslin  kept  moistened  by  means  of  a  piece  of  wickiug  which 
dips  into  a  small  vessel  of  water  beneath.  (See  Fig.  12.)  In  a  satu- 
rated atmosphere,  no  evaporation  can  occur  from  the  wet  nuislin  ;  but 
in  one  not  saturated,  the  process  goes  on  with  varying  rapidity.  Evap- 
oration is  a  process  which  requires  heat  and  causes  a  lowering  of  the 
temperature  of  the  moist  surface ;  the  more  rapid  its  rate,  the  greater 
the  abstraction  of  heat.  The  drier  the  atmos])here,  the  greater  the  rate 
of  evaporation,  and,  therefore,  the  greater  the  fall  in  temperature.  If 
the  instrument  is  placed  in  a  saturated  atmosphere,  the  two  thermom- 
eters will  give  the  same  readings ;  but  in  one  not  saturated,  the  wet 
thermometer  will  fall  gradually  until  the  temperature  of  the  surface  of 
its  bulb  is  nearly  as  low  as  that  of  the  dew-point ;  that  is,  falls  to  that 
point  at  which  air  at  the  indicated  temperature  is  so  saturated  that  a 
farther  lowering  would  be  followed  by  condensation  of  moisture.  As 
a  matter  of  fact,  the  wet  thermometer  does  not  fall  so  far  in  a  quiet 
air,  since  its  bulb  becomes  surrounded  by  a  layer  of  stagnant  saturated 
air,  and  receives  more  or  less  heat  from  the  surrounding  warmer 
atmosphere.  Again,  in  a  saturated  atmosphere,  the  wet  thermometer 
may  stand  slightly  higher  than  the  dry  one,  owing  to  the  fact  that  its 
covering  protects  it  from  loss  of  heat  by  radiation. 

GLAISHEE'S  TABLE. 


Reading  of 

Reading  of 

Reading  of 

dry  bulb 

Factor. 

dry  bulb 

Factor. 

dry  bulb 

Factor. 

thermometer. 

thermometer. 

thermometer. 

10 

8.78 

41 

2.26 

71 

1.76 

11 

8.78 

42 

2.23 

72 

1.75 

12 

8.78 

43 

2.20 

73 

1.74 

13 

8.77 

44 

2.18 

74 

1.73 

14 

8.76 

45 

2.16 

75 

1.72 

15 

8.75 

46 

2.14 

76 

1.71 

16 

8.70 

47 

2.12 

77 

1.70 

17 

8.62 

48 

2.10 

78 

1.69 

18 

8.50 

49 

2.08 

79 

1.69 

19 

8.34 

50 

2.06 

80 

1.68 

20 

8.14 

51 

2.04 

81 

1.68 

21 

7.88 

52 

2.02 

82 

1.67 

22 

7.60 

53 

2.00 

83 

1.67 

23 

7.28 

54 

1.98 

84 

1.66 

24 

6.92 

55 

1.96 

85 

1.65 

25 

6.53 

56 

1.94 

86 

1.65 

26 

6.08 

57 

1.92 

87 

1.64 

27 

5.61 

58 

1.90 

88 

1.64 

28 

5.12 

59 

1.89 

89 

1.63 

29 

4.63 

60 

1.88 

90 

1.63 

30 

4.15 

61 

1.87 

91 

1.62 

31 

3.60 

62 

1.86 

92 

1.62 

32 

3.32 

63 

1.85 

93 

1.61 

33 

3.01 

64 

1.83 

94 

1.60 

34 

2.77 

65 

1.82 

95 

1.60 

35 

2.60 

66 

1.81 

96 

1.59 

36 

2.50 

67 

1.80 

97 

1.59 

37 

2.42 

68 

1.79 

98 

1.58 

38 

2.36 

69 

1.78 

99 

1.58 

39 

2.32 

70 

1.77 

100 

1.57 

40 

2.29 

EXAMINATION   OF  A  1 11. 


:;oi 


V\)V  llio  piirpoHC!  To?-  wliicli  il  is  inlcndid,  tlic  iii-fnirrKTit  is  cxpoHr-*! 
until  Uk!  WcI.  llici'Kioiiictcr  (■<';i,-;cs  to  full,  ;iii<l  tli'ii  iIm-  rciulltij^  ol'  \uA\i 
i,s  n()t(!<l.  I^'roiii  llic,s(!  (I;tl;i,  willi  llic  ashi:-t;i ik-c  i,\'  ( i hiJHlicr'M  fiurtorH 
(,s(!(!  i;i,l)I()  on  |);i|i;c  .'>00),  tJic  (|c\v-|»oiiit  is  cMsily  <',;il(Miliit«'(l  in  llic  f'ollow- 
\\\\r  ni;inn(^r  :  MMlli|)ly  tli<'  (lill'crcnct!  in  llic  two  rcjulin^s  hy  tlir- liictor 
oppo.sitd  tlu;  (i<i;inc  in  (lie  tiiMc  corn'Sporidin^  to  the  t<'in|)(!r;itiirr-  of  flic 
dry  bull),  ;ind  sul)(iu('l   the  product  from  this  tcni})eriitiin;. 


'I'ABLE  OF 

tp:nsk)N.s. 

Toinpora- 

tiiro. 

Fahi'onliolt. 

Corrn- 
Hpoiidiiig 
dogrecs  (!. 

'rciisioii 

ill  iiicli(!S()f 
iiiert'uiy. 

Tension 
in  mm. 

Tempera- 
lure. 
Fahrenheit. 

Corre- 
Hpoiiding 
degreeit  < :. 

Tension 

In  incheHoC 

mercury. 

0.374 

Teniilon 
In  mm. 

1° 

—17.2° 

O.OIC. 

1.17 

51° 

10.6° 

9.50 

2 

— 1().7 

O.OIS 

1.22 

62 

11.1 

0.388 

9.86 

3 

—  Ki.l 

0.05 

1.27 

53 

11.7 

0.403 

10.24 

4 

— 15.(; 

0.052 

1.32 

54 

12.2 

0.418 

10.62 

5 

—15.0 

0.051 

1.37 

55 

12.8 

0.433 

11.00 

6 

—  14.4 

0.057 

1.45 

56 

13.3 

0.449 

11.40 

7 

—13.9 

0.060 

1.52 

57 

13.9 

0.465 

11.81 

8 

—  13.3 

0.002 

1.57 

58 

14.4 

0.482 

12.24 

9 

—  1 2.8 

0.0()5 

1.65 

59 

15.0 

0.500 

12.70 

10 

—  12.2 

o.O(;s 

1.73 

60 

15.6 

0.518 

1.3.16 

11 

—  11.7 

0.071 

1.80 

61 

16.1 

0.537 

13.64 

12 

—  11.1 

0.074 

1.88 

62 

16.7 

0.556 

14.12 

13 

—10.6 

0.078 

1.98 

63 

17.2 

0.576 

14.63 

14 

—10.0 

0.082 

2.08 

64 

17.8 

0.596 

15.14 

15 

—  9.4 

0.086 

2.18 

65 

18.3 

0.617 

15.67 

16 

—  8.9 

0.090 

2.28 

66 

18.9 

0.639 

16.23 

17 

—  8.3 

0.094 

2.38 

67 

19.4 

0.661 

16.79 

18 

—  7.8 

0.09S 

2.49 

68 

20.0 

0.684 

17.37 

19 

—  7.2 

0.103 

2.62 

69 

20.6 

0.708 

17.98 

20 

—  6.7 

0.108 

2.74 

70 

21.1 

0.7.33 

18.62 

21 

—  6.1 

0.113 

2.87 

71 

21.7 

0.759 

19.28 

22 

—  5.6 

0.118 

3.00 

72 

22.2 

0.785 

19.94 

23 

—  5.0 

0.123 

3.12 

73 

22!8 

0.812 

20.62 

24 

—  4.4 

0.129 

3.28 

74 

23.3 

0.840 

21.34 

25 

—  3.9 

0.135 

3.43 

75 

23.9 

0.868 

22.05 

26 

—  3.3 

0.141 

3.58 

76 

24.4 

0.897 

22.78 

27 

—  2.8 

0.147 

3.73 

77 

25.0 

0.927 

23..55 

28 

2.2 

0.153 

3.89 

78 

25.6 

0.958 

24..33 

29 

—  1.7 

0.160 

4.06 

79 

26.1 

0.990 

25.15 

30 

—  1.1 

0.167 

4.24 

80 

26.7 

1.023 

25.98 

31 

—  0.6 

0.174 

4.41 

81 

27.2 

1.057 

26.85 

32 

—  0.0 

0.181 

4.60 

82 

27.8 

1.092 

27.74 

33 

+   0.6 

0.188 

4.78 

83 

28.3 

1.128 

28.65 

34 

1.1 

0.196 

4.98 

84 

28.9 

1.165 

29.59 

35 

1.7 

0.204 

5.18 

85 

29.4 

1.203 

30.55 

36 

2  2 

0.212 

5.38 

86 

30.0 

1.242 

31.55 

37 

2^8 

0.220 

5.58 

87 

.  30.6 

1.282 

33.56 

38 

3.3 

0.229 

5.82 

88 

31.1 

1.323 

33.60 

39 

3.9 

0.238 

6.04 

89 

31.7 

1.366 

34.69 

40 

4.4 

0.247 

6.27 

90 

32.2 

1.410 

35.81 

41 

5.0 

0.257 

6.53 

91 

32.8 

1.455 

36.95 

42 

5.6 

0.267 

6.78 

92 

33.3 

1.501 

38.12 

43 

6.1 

0.277 

7.04 

93 

33.9 

1.548 

39.31 

44 

6.7 

0.2SS 

7.32 

94 

34.4 

1.596 

40.53 

45 

7.2 

0.299 

7.59 

95 

35.0 

1.646 

41.80 

46 

7.8 

0.311 

7.90 

96 

35.6 

1.697 

43.09 

47 

8.3 

0.323 

8.20 

97 

36.1 

1.749 

44.42 

48 

8.9 

0.335 

8.51 

98 

36.7 

1.802 

45.77 

49 

9.4 

0.348 

8.84 

99 

37.2 

1.856 

47.14 

50 

10.0 

0.361 

9.17 

1      100 

37.8 

1.911 

48.54 

302 


AIR 


Havino;  now  (U'tmniiu'd  tlu-  d^'W-poiiit,  the  next  step  is  to  ascertain 
the  ehistic  tension  ot"  the  vapor  ])resent  in  the  air,  that  is,  the  tension 
of  the  dew-point,  and  the  tension  of  that  neeessarv  for  satnration  at  the 
temperature  of  the  dry  bnlh,  whieh  data  ean  l)e  obtained  by  reference 
to  the  table  ou  page  25o. 

From  these  several  data  the  relative  hiiinidity  is  calculated  as  fol- 
lows :  Divide  the  tension  of  the  dew-point  by  that  of  saturation  at  the 
actual  tempei'ature,  and  multiply  by  100. 

Example  : 

Keading  i)f  dry  hulb  =  67° 
Keading  of  wet  bulb  =^-  (52° 
Dew  point  =  ()7— (5X1-80)  =  67—9  =-  58° 

Relative  Jiuiuidity      =  ^""^^^  X  100  =  72.92  per  cent. 


Fig.  13. 


INIore  accurate  determination  may  be  made  by  emj^loyins;  the 
"  Avhirled  "  or  "  sling  "  thermometers.  These  are  fastened  to  a  string 
of  such  a  leugth  that  the  distance  from  the  bidbs  to  the  held  end  is 
exactly  a  meter.  In  use,  they  are  whirled  in  a  horizontal  plane  100 
times  at  the   rate   of  one   revolution   per   second.     By  their   use,  the 

errors  mentioned  as  likely  to  occur  when  tlie 
observations  are  made  in  still  air  are  elimi- 
nated. For  all  practical  purposes,  the  use  of 
the  thei'mometers  in  the  ordinary  way  gives 
sufficiently  accurate  results. 

In  making  determinations  out  of  doors 
when  the  temperature  is  below  the  freezing- 
point,  the  wick  may  be  dispensed  with,  and 
the  bulb  is  then  wetted  by  dipping  it  into 
Avater,  the  excess  being  removed  by  means 
of  filter-paper  or  common  blotting-paper,  or 
water  may  be  applied  Avith  a  camel's-hair 
pencil.  Below  the  freezing-jxjint,  however, 
the  relative  humidity  is  of  little  hygienic 
interest,  since  the  amount  of  moisture  Avhich 
air  then  can  contain  is  l)nt  slight. 

A  very  convenient  instrument  for  quick 
approximate  determinations  without  the 
necessity  of  tables  and  computation  is 
known  as  the  hygrophant  of  Winlock  and 
Huddleston.  It  consists  of  a  jiair  of  ther- 
mometers and  a  cylinder,  upon  which  is 
inscribed  a  series  of  22  coknnns  of  figures 
numl)ered  from  1  to  22,  any  one  of  which 
may,  by  a  turn  of  a  knob,  be  brought  into 
apposition  with  a  fixed  scale  on  the  casing.  (See  Fig,  13.)  To  ascer- 
tain the  relative  humidity,  note  the  difference  in  the  readings  of  the 
thermometers,  turn  the  cylinder,  until  the  column  having  at  its  top 
the  luuid^er  corresponding  to  the  difference  appears  opposite  the  scale, 


Hygrophant. 


EXAMINA'I'IOM    Oh'  A//L 


and   rc.'ul   i\u:  (i<<'iii'('H  upposilc   tlic   ihiiiiImi'  <-oir<-|i<)ii<liii^ 
jxM'iiiiii'd  (>(■  IJk'  wcl  bull). 
P].\;iiii|)l(',  : 


liciidiiiKof  (Irv  l)iill.       72° 
Hi-.uWuir  (.r  w<"l,  l.ull.       m° 

I)i(IiT<Ml(C  12° 


to    llic    tctii 


Tlio  cylinder  is  tiinict!  iinlil  ciijiiinii   !'_!  ;i|)|)c;irs.      Oppnsil*-   '10  nC  die 
H(!iii(!,  lli(!    I'ciidin^    is     Mi;   mid  tliis  is  ;ippri),\iin;itcl\-  flx'  |»cr<Tiit;ij_'c  uC 


sjitn ration  present. 

Determination  of  Carbon  Dioxide. 


•l"'or  the  eolleetioii  of  .'-:iMip](!H 


Fi(,.  14. 


of  air  for  this  deleniiinnl  ion,  it  is  well  to  pi'o\'ide  ;i  nnniher  of  hottlen 
of  about  a  gallon  eiipneity.  These  sIkuiIiI,  (ii>l  oC  ;ill,  be  Mi<';i-ni'e(| 
very  e:i.re('ully.  This  may  be  done  by  lillinL;  llnni  with  iee  water  and 
noting'  the,  number  of  ee.  recpiired,  oi'  by  dclciniinintr  by  nKsm.s  of"  plat- 
i'orni  senJes  sensitive  to  o  i;'r:n)is  the  dillerenee  between  llnir  wei^rjits 
empty  a,nd  lllled.  It-  is  well  to  plnee  ;i  distinii'uishinLr  number  and  tho 
tlj>;ures  deuolinj:;  its  eapa('ity  on  eneh  but  lie,  eiiher  on  ;i  l;d)el,  or,  belter, 
by  means  of  ;v  wi'itinu,' diamond.  When  used,  the  bottle  shonid  be 
perfectly  clean  and  dry. 

When  it  is  neecssary  to  (imploy  tli(;  same  bottle  a_L;ain,  lim<;  beinjj^  an 
ol)jcct,  the  drying  process  is  hastened  very  Jiuicli  by  wasliing  first  witli 
water,  then  with  a  little  alcohol  to  remove  the  small  amount  of"  water 
which  will  not  drain  away,  and,  tin;dly,  \vith  a  little  ether  for  the  re- 
moval of  the  I'csiduuni  of"  alcohol.  The  small  amount  of  adherent  ether 
may  then  be  removed  by  blowing  a  current  of  air 
into  the  bottle  by  means  of  a  bellows.  A  number 
of  tightly  fitting  rubber  caps  should  be  provided 
in  place  of  corks  or  rubber  stopiiers,  though  if 
these  are  not  at  hand,  the  latter  may  be  used  ;  but 
note  should  be  made  of  the  volume  of  air  which 
they  displace  when  they  are  inserted. 

Solutions  Required. —  1.  Solution  OF  Bat{iu:m 
IIvDRATK. — Dissolve  about  4.o  grams  of  liarium 
hydrate  and  0.5  of  barium  chloride  in  a  liter  of 
distilled  water  which  ju-eviously  has  been  boiled, 
in  order  to  ex]iel  any  carbon  dioxide  which  it  may 
contain.  It  is  well  to  prepare  an  amount  suf- 
ficient for  future  needs,  say  4  liters,  and  to  keep 
it  in  a  bottle  such  as  is  shown  in  Fig.  14.  This 
is  provided  with  a  rubber  stopper  with  two  per- 
forations, through  one  of  which  a  bent  tube,  reach- 
ing to  the  bottom,  and  intended  for  withdrawal 
of  the  reagent,  is  inserted.  Through  the  <ithcr 
is  carried  a  tube  extending  only  into  the  neck, 
and  communicating  at  its  outer  extremitv  with 
a  U-tube  filled  with  pieces  of  ]>umice  soaked  while  hot  in  a  strong 
solution  of  caustic  potash.       The   delivery   tube  carries  at  it*  outer 


Bottle   for  V>arium 
hydrate. 


304  AIR. 

end  a  piece  of  closely  fitting  rubber  tubing,  which  is  kept  closed  by 
means  of  a  pinehcock. 

In  withdrawing  the  reagent  for  use,  a  100  cc.  pipette  is  inserted 
into  the  free  end  of  the  rubber  tube,  suction  is  applied,  and  the 
pinehcock  is  opened.  AVhen  the  pipette  is  filled  to  the  mark,  the 
pressure  is  removed  trom  the  })inclicock  and  the  ])ipette  released.  As 
the  reagent  is  withdrawn,  air  fiows  in  through  the  other  opening,  and 
is  robbed  of  its  carbon  dioxide  by  contact  with  the  caustic  potash  with 
which  the  pumice  has  been  charged.  This  reagent  is  used  for  the 
absorption  of  the  carbon  dioxide  contained  in  the  sample  of  air  under 
examination.     The  reaction  is  expressed  by  the  following  formula : 

BaO^H, +CO,=BaC03+H20. 

The  function  of  the  barium  chloride  is  explained  below. 

2.  Standard  Solution  of  Oxalic  Acid. — Dissolve  2.808  grams 
of  pure  oxalic  acid  in  a  liter  of  distilled  water.     One  cc.  of  this  solu- 
tion is  equivalent  to  0.5  cc.  of  carbon  dioxide ;  that  is  to  say,  will 
neutralize  the  same  amount  of  barium   hydrate  as  will  combine  with 
carbon  dioxide  to  form  barium  carbonate. 

3.  Solution  of  Phenolphthalein. — Dissolve  0.5  gram  of 
pheuolphthalein  in  100  cc.  of  alcohol.  This  solution  is  used  as  an 
"  indicator  "  of  alkalinity. 

Process  of  Analysis. — The  process  of  analysis  depends  upon  the  fact 
that  when  a  volume  of  the  barium  hydrate  solution  is  brought  into 
contact  with  carbon  dioxide,  its  alkalinity  is  diminished  by  the  forma- 
tion of  barium  carbonate,  which  is  a  neutral  body.  The  greater  the 
amount  of  carbon  dioxide  to  which  it  is  exposed,  the  greater  will  be  the 
reduction  of  its  alkaline  strength.  A  preliminary  determination  of 
the  amount  of  oxalic  acid  solution  which  100  cc.  of  the  reagent  will 
neutralize  is  made  by  titrating  25  cc.  contained  in  an  Erlenmeyer  flask 
and  colored  by  means  of  a  few  drops  of  the  phenolphthalein  solution, 
and  multiplying  the  result  by  4.  After  the  reagent  has  been  sub- 
jected to  the  influence  of  the  gas  in  the  air  sample,  a  similar  determin- 
ation is  made.  The  difference  between  the  two  results,  divided  by  2, 
indicates  the  number  of  cc.  of  carbon  dioxide  jjresent  in  the  amount 
of  air  employed. 

The  sample  of  air  is  obtained  in  the  following  manner  :  One  of  the 
bottles  above  mentioned  is  placed  in  the  situation  from  which  the  air 
is  to  be  obtained,  and  its  air  content  is  displaced  by  means  of  a  bellows 
provided  at  its  outlet  with  a  rubber  tube  of  sufficient  length  to  reach 
nearly  or  quite  to  the  bottom.  A  half  minute's  pumping  is  sufficient 
to  insure  that  the  original  air  is  replaced  by  that  under  observation. 
One  is  sometimes  admonished  to  be  careful  not  to  breathe  in  the  direc- 
tion of  the  mouth  of  the  bottle,  but  this  is  an  unnecessary  precaution, 
since  the  current  issuing  from  the  bottle  is  much  too  powerful  to  admit 
of  the  entrance  of  any  air  except  that  propelled  by  the  bellows.  A 
much  more  and  very  necessary  precaution  to  be  observed  is  that  the 
operator  shall  not  allow  his  breath  to  reach  the  inlet  holes  of  the  bel- 


I'lXAMIiS'A'I'ION   OF  Alii.  305 

loWH.  Art(!ra  li.'ilf  nilniifc's  |)iiiii|»iii^,  llic  riildxir  r;i[»  is  Mflixcd,  jiiid 
the  l)()ttl(;  iiiiiy  lluin  he  (•,:i,n'i('<|  to  \\\<',  l;il»(ii;itiii-y,  or,  l»(lt<'i-,  (lie  trciit- 
iiKiiil.  <»('  tlic  (;<>iil;i:iiic<l  ;iir  iii;iy  lir  piocccdcd  wiili  on  iIh'  -jioI.  Aii- 
oLlici'  iiU',tJ)<»<l  ol'  c-olhicliii^'  (li(!  s;iiiij»l(;  is  ollcii  1 1  coiiiinciKlcd  in  |)l;ic«' 
of  tlio  OIK!  <l(!Hcril)(!(l.  It  coiiHi.stH  ifi  filling  (Ih'  Ix.iilc  with  wat<r  ;iri(l 
(unptyin^'  it  wh(!r(!  th(!  uir  is  to  \)v,  taken.  lU'  this  jji-occi^s,  \\\v.  hpatx; 
originally  o(H;n])ir(l  Wy  wafer  is  (ilh-d  with  aii-,  hiit  the  method  is  f;hjec- 
tionabhi  in  that  I. Ik;  water  cannol  (hain  a\v;iy  eoni|)l'  tdy,  and  that  that 
whic.li  reinainM  S(M'V(!S  to  dihile,  slij^htly  it  is  lrii«;,  the  eharj^*;  of  l*ariniii 
hy<h'at{!  next  to  be  intnxhiec'd,  an<l  Ihns  brings  in  an  error  u(  th(r  very 
<)nts(!t. 

Next,  100  cc  of  the  harinni  hych'afe  sohition  aic  intro(hicc'<l  hy 
drawing  aside  the  edge  of  the  rnhher  ea|)an<l  insertinLS  iiil'>  tiieopcJiing 
so  made,  the  point  of  the  I11I(m|  |)ipette,  and  allowing  its  (contents  to 
(h)W  nnaided  into  the  hotth'.  'i'he  heginner  will  often  in(;Iine  inadver- 
tently to  gain  time,  and  assist  the  emptying  of  the  |)ipette,  by  blowing 
into  it,  tiuireby  vitiating  his  resnlts  with  the  imj)nritie.s  of  his  own 
respiration.  As  soon  as  the  pipette  is  emptied,  it  is  withdrawn  and  the 
edge  of  the  cap  is  re|)laeed.  The  bottle  is  tlien  shaken  thoronghly  for 
about  ten  minutes,  eai'e  being  observed  not  to  wet  the  eaj),  since  in  that 
event  some  of  the  reagent  may  escape  by  capillary  attraction.  At  the 
end  of  that  time  it  may  be  assumed  that  all  of  the  contained  carbon 
dioxide  has  been  brought  into  contact  with  and  absorbed  by  the  barium 
hydrate,  which  is  then  to  be  ])oured  quickly  from  tlie  bottle  through  a 
fairly  large  funnel  into  a  glass-stoppered  bottle  of  rather  moiv-  than 
100  cc.  capacity.  The  solution,  which  is  now  more  or  less  turbid  from 
the  presence  of  barium  carbonate,  is  allowed  to  stand  until,  through 
settling  of  this  substance,  the  supernatant  liquid  is  clear.  Three 
successive  portions  of  25  cc.  each  are  next  to  be  withdrawn  by  means 
of  a  jiipette  of  the  proper  size,  and,  after  addition  of  the  indicator, 
titrated  in  Erlenmeyer  flasks  with  the  standard  oxalic  acid  solution 
until  the  pink  color  caused  by  the  former  is  made  to  disappear.  So 
long  as  any  color  remains,  one  knows  that  barium  still  exists  in  the 
form  of  hydrate,  and  that  the  contents  of  the  flask  are  still  alkaline, 
for  phenolphthalein  gives  a  pink  tinge  only  in  the  presence  of  the 
alkalies.  When  the  pink  color  disappears,  the  process  is  finished,  and 
the  reading  of  the  burette  is  noted.  The  three  portions  of  25  cc.  each  are 
titrated  in  turn,  and  the  mean  of  the  results  is  multi])lied  by  4.  The 
dittereuce  between  this  product  and  the  figure  olitained  in  the  pre- 
liminary test  of  the  strength  of  the  reagent,  divided  by  2,  indicates 
the  number  of  cc.  of  carbon  dioxide  in  the  volmne  of  air  taken  for 
analysis. 

In  filling  the  25  cc.  pipette  from  the  bottle  containing  the  used 
reagent,  great  care  should  be  observed  not  to  stir  up  the  sediment  of 
barium  carbonate.  To  perform  the  operation  properly,  it  is  necessarj' 
to  insert  the  point  of  the  pipette  well  below  the  surface,  and  to  fiU  it 
up  to  the  mark,  or  just  beyond  it,  by  one  iiuiuterrupted  act  of  suction. 
If  one  stops  to  regain  breiith,  part  of  the  liquid  already  within  the 
20 


306  AIR. 

pipette  will  eseupe  downward  duriuij  the  interval  with  snfficient  force 
to  .stir  up  the  sediment.  When  the  pii)ette  is  filled,  the  point  of  the 
tongue  should  be  api)lied  to  its  U})i)er  end,  and  the  tip  should  then  be 
withdrawn  from  the  buttle.  Then  bv  iilacinp-  the  end  of  the  forelinu'er 
over  the  opennig-  of  the  tip  of  the  pipette,  the  escape  of  its  contents  is 
prevented,  while  the  forefinger  of  the  other  hand  is  replacing  the  point 
of  the  tongue.  The  reason  for  such  careful  avoidance  of  stirring  up 
the  stHlimcnt  is  that  the  presence  of  barium  carbonate  introduces  a 
slight  eri-or  in  the  titration.  The  slight  excess  of  oxalic  acid  present 
when  the  eoh)r  t)f  the  ])hein)l])hthalein  is  discharged  attacks  the  sus- 
pended barium  carbonate,  forming  barium  oxalate  and  setting  free  the 
combined  carbon  dioxide.     Thus  : 

II^C^O^  +  IkCOj  =  BaCjO^  +  H,0  -|-  CO,. 

The  free  carbon  dioxide  then  attacks  more  of  the  carbonate  and  forms 
barium  bicarbonate,  ^\■hich,  being  soluble  and  of  alkaline  reaction, 
causes  the  pink  color  to  reappear. 

/OH 

co/ 

>Ba  =BaH,(C03)2. 

co/ 

^OH 

The  reason  for  adding  barium  chloride  in  making  the  barium 
hydrate  solution  is  that  most  barium  hydrate  contains,  in  addition  to 
small  amounts  of  carbonate,  traces  either  of  caustic  soda  or  of  caustic 
potash.  When  either  of  these  snbstances  is  brought  into  contact  with 
barium  chloride,  mutual  decomposition  occurs,  and  we  have  as  results 
barium  hydrate  and  sodium  (or  potassium)  chloride.  If  the  impurity 
Mere  disregarded,  it  would  cause  errors,  as  shown  below.  The  barium 
hvdrate  solution  when  titrated  with  oxalic  acid  would  behave  according 
to  the  following  formula: 

BaO^H,,  +  BaCOs  +  2NaOH  +  2H,C,0,  =  BaCp^  +  BaCOj  +  l^^atCfl^  -\-  4H,0 
(Barium         (Barium  (Sodium  (Oxalic  (Barium  (Sodium 

hydrate)       carbonate)       hydrate)  acid)  oxalate)  oxalate) 

In  practice  a  very  slight  excess  of  oxalic  acid  is  also  jiresent,  and 
the  reaction  then  proceeds  still  farther.  The  sodium  oxalate  attacks 
the  barium  carbonate,  forming  barium  oxalate  and  sodium  carbonate. 

Thus 

Na.CjO,  +  BaCOg  =  BaC.O^  +  Na^COg. 

Next,  the  sodium  carbonate  neutralizes  the  traces  of  free  oxalic  acid, 
and  any  surplus  causes  a  reappearance  of  the  pink  color  and  neces- 
sitates farther  addition  of  oxalic  acid.  This  causes  the  formation  of 
more  sodium  oxalate,  which  in  its  turn  attacks  another  portion  of  the 
barium  carbonate,  with  the  same  results  as  before ;  and  so  the  cycle 
continues  until  the  last  trace  of  suspended  carbonate  is  decomposed. 
If  the  hydrate  contains  no  impurities,  the  addition  of  chloride  is 
unnecessary. 


ICXAMINATION   OF  Mil.  307 

Corrections. —  In  (i^iirin^j  (lie  rcsiills  o("  the  dch  riniii.'ition,  ciil.-iin 
(•,(>r'r(!(;(,i()iiH  ;i,f(!  iicccwsMry.  I''ir.sl,  tlic  soliiinc  uC  llic.  Ii;ii-iiiiii  liydnito 
ii,S(!(l  (100  cc.)  iiiiisl,  l)(!  .Mill»tr;ii'l((|  riom  iIm'  <;i|);icily  (»f  tlu!  bottle,  kImco 
i(,.s  iii(;f()<lu<d,i()ii  <lis|»Ia(!CH  iiii  ('(jikiI  \mIiimi(  <ir;iii  ■;  and  luixt,  allowatuji'M 
imi.st  Ik!  iiia<l(!  lui'  any  (Icpai'lMrc  lidin  .-laiiil.inl  ti  in|»cra(un:  aii<l  haro- 
nu',tri(!  prcsHni'c,  since,  llie  eapaeily  of  lln'  .sample  IhiHIc  Jh  njckoned  fur 
air  at  0°  (J.  and  7(10  nun.  |H'essnre.  In  order  to  make  (lie  neeessary 
eori'iictions  for  t(!mpera(iir(!  and  |>ressnre,  tlu;  tliermonieter  an<l  haroni- 
c't(!r  slionld  bo  noled  at  the  time  o("  fakin<r  tin;  sample. 

Ill  cUitci'mininj^  the  amount  of  corret-lion,  we  are  guided  by  two 
])hy.sical  hiws  :  that  for  each  decree  of  temperature,  air  oxpatidH  a  (!on- 
.stant  fraction  of  its  own  vohimc!  (Law  of  (yharlesj;  and  that  \\\i'.  vol- 
nnu!  of  a.  f:;as  is  invei'sely  proportionate;  to  the  pi-essiire  (Law  of  I'oylej. 
l\>r  CJUih  d(;t!;i'e(;  <'enti,a;ra(l(!  aho\'e  oi-  below  0"  ('.,  air  expand-  or  fori- 
tracts  0.00o(5()  bS  of  its  volinne  ;  and  this  ligiire  is  known  as  the  <;o- 
eflieicnt  of  expansion  for  eenlinradc?  (U^grces.  For  each  dej^rec  Fahren- 
heit above  or  below  '-Vl^ ,  air  expands  or  contracts  O.t)02t).'>r)  of  itH 
vohnue  ;  and  tliis  is  known  as  the  coeilieieiit  of  cx[)ansi(»n  for  I'^ahren- 
heit  degrees.  Thus,  1  liter  ol'  air,  limited  to  40°  C,  will  expand  to 
1  +(40  X  0.00;5()(J4<S),  which  equals  1.146r)92  liters;  or  heated  tf> 
104°  F.  (104°  F.  =  40°  C),  it  will  expand  to  1  +  (72  X  0.002030), 
which  equals  1.14(545)2,  as  before.  Again,  the  same  volume  cooled  to 
— 15°  C,  will  contract  to  1  —  (15  X  0.00.30(348),  or  945  cc. ;  or  cooled 
to  5°  F.  (5°  F.  =  15°C.),  it  will  become  1  —(27  X  0.002030)  or  945 
CO.,  SIS  before.  So  au  apparent  volume  of  1,000  cc.  at  any  tem])crature 
above  freezing  is  iu  reality  a  smaller  volume  expanded  to  that  size ; 
and  at  any  temperature  below,  is  a  larger  volume  Ijrought  to  that  size 
by  contraction. 

To  correct  volume  for  temperature,  we  must  divide  the  apparent 
volume  by  1  plus  the  ])roduct  of  0.0030648  times  the  number  of 
degrees  away  from  0°  C,  or  in  case  of  temperatures  below-  freezing, 
by  1  minus  that  amount.  If  the  Fahrenheit  scale  is  used,  the  appro- 
priate coefficient  and  factors  must  be  substituted.  Thus  we  may  employ 
a  set  of  formula)  as  follows  : 


For  tomporatiiros  al)ove  0°  C V- 

P'ov  temperatures  lielow  0°  C V- 

For  temperatures  above  32°  F.    .    .    .   F  = 


1  +  0.003G648./i°  C. 

V 

1  —  0.0036648.«°  C. 

V 

1  +  0.002036  (<°F.- 


Tr 

For  temperatures  below  32°  F.   .    .    .  T"^^ 


-0.002036  (32  — <°  F.) 

In  the  above,  T^  ^  correct  volume. 
!''=  apparent  volume. 

Inasnnich  as  volume  is  inversely  proportionate  to  pressure,  the  ti'ue 
volume  at  any  observed  ]irossure  is  obtained  by  multiplying  the 
apptirent  volume  by  the  barometric  pressure  expressed  iu  millimeters 


308  AIR. 

or  inches,  and  dividing  the  product  by  7(50  or  by  29.92,  as  the  case 
may  be.     AA\^  may   use,  theu,  this  formula : 

760 

Applying  it,  we  find  that  an  apparent  volume  of  1,000  cc.  at  750  mm. 
becomes 

1,000  X  750      oQ^ 

-^ ~ =98/  cc. 

760 

or  usiug  the  other  scale,  the  barometer  standing  at  29.53  inches  (29.53 
in.,  750  mm.),  it  becomes 

1,000X29.53^33.^^^ 
29.92 

If  the  barometer  reads  higher  than  the  standard  pressure,  the  true 
volume  will  be  grciiter  than  the  apparent.  Thus,  suppose  the  pressure 
to  be  30.22  inches,  then  1,000  cc.  "will  represent 

MOiX  3022^1  010  cc. 
29.92  ' 

Instead  of  going  through  two  separate  calculations,  we  may  make 
both  corrections  at  once  by  means  of  one  formula  which  is  a  combina- 
tion of  the  two  kinds  already  used.  For  temperatures  above  0°  C. 
the  correct  volume  is  obtained  by  means  of  the  folloAving  : 

V^. ^'X^ 


(1  +  0.0036648.<°)  760 

By  changing  the  plus  sign  to  minus,  the  formula  is  adapted  to  tem- 
peratures below  freezing.  If  the  Fahrenheit  thermometer  is  used,  and 
the  barometric  pressure  is  expressed  in  inches,  the  formula  is  as  fol- 
lows : 

r= V'XB       _. 

[1  +  0.002036  {t°F.  -  32)]  29.92 

and  if  the  temperature  is  below  32°,  it  must  be  changed  to 


V=- 


V'XB 


[1  —  0.002036  (32  —  t°  F.)]  29.92 
In  these  formulae  : 

V  =  correct  volume. 

V  =  apparent  volume. 

B    =  barometric  pressure. 
t°    =  temperature. 

In  order  to  avoid  the  tedious  process  of  multiplication  and  division 
which  the  working  of  these  formulae  involves,  recourse  may  be  had  to 
the  admirable  tables  of  Dr.  Walter  Hesse,^  wherein  can  be  found  the 
correction  to  be  made  for  all  temperatures  between  —  2°  and  30°  C 
and  for  all  pressures  between  680  and  770  mm.,  by  simple  reference 
to  the  proper  column. 

^  Tabellen  zur  Reduction  eines  Gasvolumens  auf  0°  und  760  mm.    Brunswick,  1879. 


EXAMINATION   OF  A  1 11.  300 

l^'or  iill  priU'-l.if'ul  purposes,  tlic  ♦•(icnicicnfs  of  cxpiiii-ion  rnav  l»c 
Hh()r(,(iiic(l  (o  0.00.'>()()  jiiid  OMiVl,  lliiis  !ivoi(liii|r  miicli  (i;.'iiiiiiM^  wliich 
luis  V(!iy  \\\\\{\   iii(Iiicii('(!  oil  (lie  cud  results. 

Example  of  Method  of  Reckoning  CO,^. — (Jjipjicity  of  K;ini[)lc  l)ottIe, 
.*},S8r)  (!(;.  25  (;<!.  of  Iwiriiini  liydruU;  solution  r(!(jiiirc  21  c^;.  of"  Hbmdard 
solution  of"  oxalic  acid,  licncc  100  (!c.  =  H4  cc.  Af"t<;r  contact,  25  cc. 
rc(jnir(!  17.2  cc.  ;    100  v.r..  nujiiii'i;  (JH.H  cc. 

J)in"(!r(^ncc  in  oxalic  acid  i-c(jiiircd     -  Hi  —  08.8        15.2  cc. 

1  cc.  of  oxalic  aciid  solution  0.5  cc.  of  i'A),  ;  Ik  iicc,  15.2  cc.  7,0 
cc.  of  CO,. 

The  ail"  in  \\\v.  hotllc  conlain<'d,  tlicrcrorc,  7. (J  cc.  of  COg. 

Determiuation  of  volinnc  of  air  taken  : 

Capacity  of  hottle  =3,885 

Amount  of  haiiiini  Holution      =:     100 
Appari'iit  volume  of  air  =3,785 

Observed  barometric  pressure  ^^  29.60  inches. 
Observed  temperature  =  65°  V. 

y 3,785  X  29.60 112,036 _  112,036 

""  [1  H-  (0.002036  X  33) ]  X  29.92  "  1.067188  X  29.92  ~    31.93  ~ 
3,509  cc.  ^=  actual  air  vohime  examined. 

Then  3,500  cc.  of  air  contain  7.6  cc.  of  COg.      It  being  customary  to 
express  results  in  parts  per  10,000,  this  rate  is  determined  as  follows  : 

3,509  :  7.6  =  10,000  -.x    a:  =  21 .66. 

Hence  the  air  contains  21.66  volumes  of  CO,  in  10,000. 

Determination  of  CO,  by  Wolpert's  Method. — This  process  is  designed 
for  what  may  be  called  roughly  approximate  work  in  testing  the  air 
of  school  rooms  and  similarly  crowded  spaces.  It  requires  no  chemical 
training  on  the  part  of  the  operator,  and  for  practical  purposes  gives 
fairly  satisfactory  results,  indicating  that  the  air  is  good,  fair,  poor,  or 
very  bad.  The  apparatus  consists  of  a  graduated  glass  cylinder 
with  a  movable  piston  reaching  to  the  bottom  and  kept  in  proper 
position  by  a  metallic  cap,  throngh  the  center  of  which  the  shaft  pro- 
trudes. The  shaft  is  a  glass  tube  of  narrow  caliber,  open  at  l)oth  ends. 
The  reagent  used  is  a  standard  solution  of  alkali,  colored  with  phenol- 
phthalein. 

In  making  a  test,  the  piston  is  removed  and  2  cc.  of  the  solution  are 
introduced  into  the  cylinder  by  means  of  a  pipette.  The  piston  is  re- 
placed and  pressed  down  until  all  air  is  expelled  through  the  shaft  and 
the  liquid  appears  within  the  bore.  The  piston  is  then  drawn  up  until 
its  lower  edge  is  opposite  the  first  mark,  and  in  the  process  the  space 
so  made  is  filled  with  air  which  enters  through  the  shaft.  The  appara- 
tus is  now  shaken  vigorously  for  one  minute.  If  the  liquid  becomes 
colorless,  it  is  proof  that  the  air  of  the  room  is  bad.  If,  on  the  other 
hand,  the  color  persists,  the  piston  is  raised  to  the  next  graduation, 
and  the  shaking  is  renewed  for  another  minute.  If  the  reagent  still 
retains  color,  the  piston  is  raised  further  and  more  air  is  admitted. 
The  process  is  continued  until  repeated  additions  of  air  and  renewed 


310 


AIR. 


Fig.  15. 


fJ^ 


shakings  cause  the  color  to  be  discharged.  At  this  point,  the  reading 
of  the  scide  indicates  the  character  of  the  air.  The  greater  the  amount 
of  air  required  lor  coni[)lete  decok)rization,  the  less  the  relative  amount 
of  impurity.     The  apparatus  is  shown  in  Fig.  15. 

Determination  by  Fitz's  Method. — A  modification  of  tliis  ])rocess,  giv- 
ing results  wliu'li  arc  in  close  agreement  with  ])arallel   analyses  by  the 
Pettenkofcr  method  above  described,  has  been  devist'd  by  Dr.  G.  W. 
Fitz.'     The  apparatus  is  very  sim])le,  and  consists  of  a  small  cylinder 
of  glass  with  a  rounded  bottom,  and  a  smaller  open  one 
which  slips  into  the  other  through  a  collar  of  rubber  tubing 
which   makes  a  tight  joint.      As   the   inner  cylinder    is 
drawn    out,  air   enters   through   its   upper  end,  and  its 
amount   is  measured   by   the  graduations  on    the    outer 
tube,  the  lower  margin   of  the  inner  tube  serving  as  an 
index.      (See  Fig.  16.) 

The  reagent  used   is   a   1    per  cent,    solution   of  lime 
water  made  in  the  following  manner.     About  95  cc.  of 
water  containing  a  few  drops  of  phenolphthalein  solu- 
tion are  neutralized    by  the  addition,  drop  by  drop,  of 
lime  water,  which  causes  a  pink  color  that  at  first  dis- 
appears on  shaking.     As  soon  as  a  faint  tinge  persists, 
the  complete  neutralization  of  the  carbon  dioxide  of  the 
water  is  evident.    One  cc.  of  saturated  lime  water  is  next 
added,  and  the  whole  is  then  made  up  to 
100  cc.     The  solution  should  be  made  as 
needed,  since  it  retains  its  full   strength 
but  about  twelve  hours. 

In  making  a  test,  10  cc.  are  introduced 
into  the  outer  cylinder  ;  the  inner  one  is 
inserted  as  far  as  it  will  go  and  then 
raised  to  the  10  cc,  mark  on  the  scale, 
which  means  the  presence  of  20  cc.  of 
air,  since  the  tube  itself  contains  10  cc. 
The  apparatus  is  then  closed  by  applying 
the  end  of  the  forefinger,  and  shaken 
vigorously  thirty  times.  If  the  pink 
color  persists,  the  inner  cylinder  is  pushed 
to  the  bottom  and  then  di-awn  up  again, 
and  the  operation  is  repeated  uuIjI  the 
color  disappears.  At  this  point,  the 
amount  of  air  used  is  noted,  and  by 
reference  to  a  table,  the  number  of  parts 
per  10,000  is  ascertained.^  Dr.  Fitz 
asserts  that,  in  the  hands  of  an  ordinarily 
careful  man,  the  process  is  accurate  within  1  part  of  CO2  in  10,000. 


^ilH 


-5i 


Fig.  16. 


Wol7)ert's  air 
tester. 


Fitz's  air  tester. 


'  .Journal  of  the  Ma.ssaelnisetts  Association  of  Boards  of  Health  IX.,  p.  5. 
^  The  apjjaratiis  and  complete  directions  for  use  are  obtainable  of  the  Knott  ApjDa- 
i-atus  Company,  Boston. 


EXAMINATION   OF  A  I II.  311 

Tliis  is  siil>sl:i,iiii:ilc(l  by  rroCcssor  L.  I'.  I\  liniinill ,'  of  f  lie  WoniCHtcT 
r(»ly(,('('liiiic.  I  iislil-nlc,  wlio  li;is  (■iii|)l(iy(<l  tlxr  |(f<)cc.-,H  liiiiiHcIf  and 
coiii-rollcd  il.s  use.  by  oihcrH  vvilJi  |t!uallcl  aii.-ilyHcs  by  ihc  I'l-llrrikoli.T 
iiu^lJiod. 

Determination  of  Carbon  Monoxide. — \\\\\\c  a  iKinibfi-  <A'  yvitc- 
('HH(!H  li:iV(!  b('(wi  (l(!vis('(l  for  IIk-  (Iclcction  aii<l  tlctcniiiiiat  ion  <i('  carli'in 
monoxide,  iioiu^  has  been  (lis(^()vcn!d  as  yet  lliai  is  wholly  sil  isradory 
for  oilier  iJiaii  (|iiali(al  ivd  work.  Tlic  /^aM  iiiiiy  be  i\vU'rUi\  rjiialita- 
t.iv(!ly  by  (•x|)osin<;'  \va(<'r  coiilaiiiiiijr  a  small  arnoiml  of  frcsli  nortiiiil 
blood  lo  the  air  iiiidcr  cxiiiiiiiialioii,  and  then  cxatniniiijr  flif  Kaiiur 
with  iJu!  S|)cciroscd|»c.  If  no  carbon  monoxide  i-  [H'c-cnt  in  llie  air, 
ilio  eliaracieristie  absorption  bands  of  oxylia-nioL^dobin,  shown  by  the 
si)oe,iroseo|)e,  are  ehan<;'e(l  to  a  sinujle  ban<l  in  the  space  belween  on  iho 
a,ddilion  ol'  a.  redncinti;  ai;'ent,  sneh  as  ammoniimi  ~iil  |iliid<-.  If,  how- 
ever, i.he  _t>;as  is  |)resen(,  no  ehaii,i;'e  oecnrs. 

The  test  is  a-pi)lied  in  (he  ibilowinn;  manner:  A  few  dro])s  of  blood 
well  dilnlcd  with  waier  are  exi)ose(l  to  the  air  in  a  Jar,  and  bron<rht 
into  inlimalc  eontax-t  by  vin'orous  shakinir.  A  few  (lro|)s  of  ammoninni 
snlphide  are  next  added,  and  the  mixtnre  is  again  well  shaken.  If  on 
s])eetroseopie  examination  but  a  single  band  is  observed,  the  absencx; 
of  the  gas  in  anionnt  cqnal  to  3  parts  }wr  10,000  may  be  inferrwl,  for 
this  is  the  limit  of  delicacy  claimed.  If,  however,  the  clianieteristic 
two  bands  of  oxyh;emoglobin  aj)pear,  the  ])resencc  of  the  impin-ity  to 
that  extent  is  proved,  since  otherwise  the  reagent  would  have  exerted 
its  normal  effect. 

The  following  ]irocess,  devised  by  Fodor,"  is  said  to  be  of  snffir-ient 
delicacy  to  detect  1  ]iart  in  20,000.  Fresh  defibrinated  blood  is  mixed 
with  10  volumes  of  water  and  introduced  into  a  large  jar  containing 
the  suspected  air.  After  being  allowed  to  stand  for  about  an  hour 
without  shaking,  it  is  transferred  to  a  small  flask  provided  with  a  rulv 
bcr  sto])per  carrying  two  glass  tubes,  one  of  which  dips  Ix'ueath  the 
surface  and  connects  at  its  outer  end  with  a  potash  i>ull)  containing 
]ialladium  chloride  solution.  The  other  tube  serves  as  an  outlet,  and 
is  connected  with  a  series  of  three  potash  bnlbs  containing  respectively 
lead  acetate  solution,  dilute  sulphuric  acid,  and  palladium  chloride  so 
diluted  that  it  has  a  bright-yellow  color.  The  terminal  bull)  is  con- 
nected with  an  aspirator,  wdiich,  when  set  in  action,  draws  a  current 
of  air  through  the  live  ditierent  pieces.  The  flask  containing  the  blood 
is  heated  on  a  water-bath  for  fifteen  to  thirty  minutes  with  occasioual 
shaking,  and  meanwhile  a  slow  current  of  air  is  drawn  through  the 
api^aratus.  AVhen  the  blood  begins  to  change  color,  the  carboxyha^no- 
globin  decomposes  and  yields  its  CO,  which  reduces  the  ])al]adium 
contained  in  the  terminal  bulb.  The  chloride  of  palladium  in  the  first 
bulb  is  used  for  removing  any  traces  of  the  gas  and  of  other  re<lucing 
agents  in  the  aspirated  air.  At  the  close  of  the  operati<in,  if  the 
blood  contained  CO,  the  palladium  chloride  in  the  terminal  bulb  shows 

'  TiOCO  citato,  p.  8. 

^  Deutsche  Vierteljabi-ssclu-ift  fiir  ofl'ontliche  Gesundlieitspflege,  Vo'.  12. 


312  Am. 

a  precipitate  of  reduced  palladium  and  the  liquid  has  a  somewhat 
darker  tint.  The  lead  acetate  and  dilute  sulphuric  acid  serve  to  remove 
auy  traces  of  sulphuretted  hydrogen  and  aumionia,  both  of  which  sub- 
stances will  cause  precipitation  of  the  palladium. 

Other  qualitative  tests  of  greater  or  less  delicacy  include  the  following  : 

1.  Mix  o  cc.  of  exposed  blood  solution  and  15  cc.  of  a  1  per  cent, 
solution  of  tannic  acid.  The  resulting  precipitate,  which  settles  very 
slowly,  has  a  brownish-red  color,  if  CO  was  present  in  the  air ;  other- 
wise it  is  grayish-brown. 

2.  Mix  10  cc.  of  the  blood  solution  with  5  cc.  of  a  20  per  cent, 
solution  of  potassium  ferrocyanide  and  1  cc.  of  acetic  acid  (1  part  of 
glacial  acetic  acid  to  2  of  water).  A  reddish-brown  preci})itate  is  in- 
dicative of  the  presence  of  the  gas,  and  one  of  grayish-brown  shows  its 
absence. 

3.  Bring  together  on  a  porcelain  plate  1  drop  each  of  exposed  defi- 
brinated  blood  and  sodium  hydrate  solution  of  a  specific  gravity  of 
1.300.  With  CO  blood,  the  color  is  bright  red,  while  with  normal 
blood  it  is  brownish  or  blackish. 

4.  In  place  of  the  above  reagent,  use  a  mixture  of  1  part  of  the  same 
with  3  of  calcium  chloride  solution.  CO  blood  gives  a  carmine,  and 
normal  blood  a  light-brown  or  brownish-red,  color. 

5.  Draw  air  through  a  tube  containing  a  solution  of  cuprous  chlo- 
ride, which,  in  the  presence  of  CO,  deposits  a  characteristic  precipitate, 
which,  according  Berthelot,  is  CU2CI2CO.2H2O. 

Quantitative  Determination. — Nicloux  ^  has  devised  a  colorimetric 
method  for  which  he  claims  great  accuracy.  It  is  based  upon  the  fact 
that,  by  the  action  of  carbon  monoxide  on  iodic  acid,  definite  amounts 
of  iodine  are  set  free.  He  combines  this  with  an  alkali,  acidulates  and 
shakes  out  with  chlorform  or  carbon  disulphide,  and  then  compares 
the  color  with  solutions  containing  known  amounts  of  iodine.  From 
the  amount  of  iodine,  the  amount  of  CO  which  caused  its  liberation 
may  be  reckoned. 

Gautier^  allows  the  liberated  iodine  to  act  upon  copper  foil,  and 
determines  the  amount  of  CO  from  the  increase  in  weight.  He  also 
determines  the  COj  produced  by  the  action  of  iodine  pentoxide  on 
CO  ;  the  result  indicates  volume  for  volume.  Potain  and  Drouin  ^ 
recommend  a  colorimetric  method  by  means  of  dilute  palladium 
chloride  solution. 

Determination  of  Ozone. — The  allotropic  form  of  oxygen  acts 
upon  potassium  iodide  in  the  presence  of  moisture  and  converts  it  to 
hydrate,  with  liberation  of  iodine,  according  to  the  following  formula  : 

2KI  +  H^O  +  O3  =  2K0H  +  O^  +  I^. 

This  reaction  is  the  basis  of  most  of  the  processes  which  have  been 
proprtsed  for  qualitative  and  quantitative  determination,  none  of  which 
may  be  regarded  as  of  value,  since  there  are  many  sources  of  error  to 

»  Comptes  rendus,  CXXVI.,  p.  746. 

■'  Ibidem,  CXXVI,.  pp.  871,  931,  973.  3  Ibidem,  p.  938. 


EXAMINATION  (>l'    Mil.  '513 

be  t<lk(!ii    iiil.o   !M'-(;oiiii(,  sources    iiii|»<):--il)lc  (o   clIiiiinMlc   .-ind    u\    itiijior- 
t,;i,n(!(!  iinpoHsiMc  to  (•otiipiilc 

'V\\v.  |)r(;H(;ii(!('  (»("  ozone  in  llie  ;iii'  i-  -n|>|io-e(|  [o  he  'lemon-t  r;ife<l 
when,  on  exposure  oC  |i;i|per  s!itnr;ite(|  with  hIjutIi  pii^te  coiiljiiiiiii^ 
polassimri  iodide,  ;i  Line  cdlor  e:i':i<ln;dly  develops,  owiii^'-  (o  llie  ;ietion 
of  tll(!  Iil)(!ritle(l  iodine  on  llii'  >l;iicli.  (  ^n;i  nt  it;il  ive  de|erniiii;il  ion-  are 
lliiidc  l>y  con  I  purine-  ihc  lint,  willi  a  standard  scale,  the  depth  of  nAov 
Ix'int;' (l(!|)('ndenl  upon  the  anionnl  oC  i(»dine  liheraled,  and  this  iipf»ri 
th(^  aiiioiinf  of  ozone  |)resent.  Thi'  |>ap(;r.s  arc  prej)ar(;d  in  the  follow- 
ing iiiiimicr  :  l^'roni  2.5  to  10  j^ranis  of  starch  arc;  taken,  acconJiiig  to 
the  recoinnicndat.ions  followed,  and,  after  trituration  with  a  Hrnall 
atnoiint  of  ('(»ld  water,  are  hoiled  for  ahont  ten  rninute.s  in  ahoiit 
200  vc.  of  water,  and  llltered.  ( )ne  ^rani  of  jxitassiuni  iodidf;  in  soln- 
tjon  is  next  added  t^i-aduall}'  with  constant  stirrinL"-.  Strips  of  wtout 
liltor-paper,  wet  with  distilled  water,  ar(!  soaked  in  the  starch  prepa- 
ration until  they  are  thoroughly  iuipre<j^iiated  faliout  two  to  four 
hours),  then  removed  with  the  aid  of  forceps,  spread  flat,  and  dried 
in  the  dai'k.  When  used,  th(\y  are  hunjr  up  out  (»f  the  direct  .sun- 
lioht  and  exposed  for  a.  definite  time,  then  removed,  moi.stene<l  with 
water,  and  coni])ar(Ml  with  the  scale.  The  objections  to  tlie  process 
are  that  a  nuniher  of  other  substances  wdiich  may  be  in  tin;  air, 
such  as  cei'tain  volatile  orsj^anic  acids,  chlorine,  nitrous  acid,  and  hycb'o- 
gen  peroxide,  cause  this  same  cliemical  reaction;  that  the  blue  color  is 
destroyed  by  other  substances,  as  sulphuretted  hydrogen  and  sul|)hur- 
ous  acid  ;  and  that  light,  moisture,  heat,  and  wind  exert  very  decided 
modifying  influences.  Thns,  wind  brings  more  air  into  contact,  sun- 
light bleaches  the  color,  moisture  hastens  the  bluing,  and  heat  dissi- 
pates the  free  iodine. 

In  order  to  differentiate  between  ozone  and  nitrous  acid,  it  has 
been  proposed  to  use  neutral  litmus  (violet)  paper  instead  of  ordi- 
nary filter-paper  in  making  the  strips.  The  KOH  formed  in  the 
reaction  will  change  the  violet  to  blue,  while  nitrous  acid,  chlorine, 
and  organic  acids  will  convert  it  to  red,  or  bleach  it,  or  leave  it 
unchanged. 

In  spite  of  the  fallacies  mentioned,  the  weight  of  evidence  thus  far 
obtained  in  ozonimetry  shows  that  the  reaction  with  starch  is  most 
marked  in  pure  air  at  the  seashore  and  at  great  heights,  and  that  but 
little  reaction  occurs  indoors. 

Determination  of  Dust. — Dust  is  determined  quantitatively  in 
two  ways,  and  the  results  are  expressed  in  terms  of  weight  or  of 
number.  In  order  to  ascertain  the  iccight  of  the  dust  contained  in 
a  given  volume  of  air,  a  chloride  of  calcium  tube,  containing  \\ev- 
fectly  dry  absorbent  cotton  or  glass  wool,  is  weighed  accurately, 
and  then  attached  to  a  water  suction-pump  with  an  air-meter  between. 
A  large  amount  of  air,  say  500  liters,  is  then  drawn  through  as 
quickly  as  possible.  When  a  sufHeient  amount  has  passe<l,  the  tul>e  is 
detached  and  placed  either  in  a  drying-oven  or  in  a  desiccator  over 
sulphuric  acid,  and  kept  until  it  ceases  to  lose  weight  (moisture).     The 


314  AIR. 

lU't  ineron.^e  in  ^vt'i^■llt  represents  the  amount  of  dust  in  the  vohnne  of 
air  aspirated. 

To  determine  the  nuniher  of  dust  partieh\>^  in  a  oiven  volume,  the 
method  of  Aitkin  is  employed.  The  ajiparatns  inelndes  a  shallow 
metallic  box  with  ^lass  top  and  bottom  etched  in  squares.  Into  this 
box,  containing  air  which  has  been  freed  from  dust  by  iiltration  through 
cotton,  and  is  kept  saturated  with  moisture  by  means  of  wet  iilter- 
paiHU",  a  small  measured  amount  of  the  air  under  examination  is  in- 
troduced. By  causing  the  formation  of  a  partial  vacuum,  each  par- 
ticle of  dust  becomes  coated  with  condensed  moisture  and  hence  tends 
to  fall  upon  the  etched  squares  of  the  bottom.  The  number  deposited 
is  counted  with  the  aid  of  a  magnifying  glass.  The  number  of  ])ar- 
ticles  varies,  according  to  Aitkin's  observations,  from  8,000  to  100,000 
per  cubic  inch  in  the  country,  and  irom  1,000,000  to  50,000,000  in 
cities. 

Bacteriological  Examination. — The  method  which  involves  the 
least  trouble  and  requires  a  minimum  of  apjiaratus,  and  which  for  all 
practical  purposes  gives  greatest  satisfaction,  consists  in  exposing 
gelatin  plates  or  Petri  dishes  for  a  definite  period,  and  then  covering 
them  and  letting  the  colonies  develop.  After  the  ])roper  interval,  the 
nnnil)er  of  growths  may  be  counted,  and  the  indi^'idual  species  isolated 
and  studied.  This  method  is  very  useful  for  comj^arative  work,  the 
results  being  given  as  the  number  of  colonies  M'hich  develop  after  a 
given  exposure. 

For  more  accurate  quantitative  work,  Petri  ^  devised  a  process  of  sand 
filtration.  A  glass  tube,  9  by  1.6  cm.,  serves  to  carry  two  small  filters, 
which  are  arranged  in  the  following  manner :  Two  small  tightly 
fitting  diaphragms  of  fine  wire  gauze  are  inserted  into  the  tube  at  a 
point  midAvay  between  the  ends.  Into  one  side,  a  quantity  of  fine 
quartz  sand  is  packed,  and  upon  it,  to  keep  it  in  place,  another  dia- 
phragm is  driven.  Above  this,  the  space  is  filled  with  a  cotton  plug.. 
The  tube  is  now  reversed  and  a  second  filter  of  sand  is  made  in  the 
same  way.  After  complete  sterilization,  the  cotton  plug  in  one  end  gives 
way  to  a  rubber  stopper  with  a  single  perforation,  through  which  passes 
a  glass  tube  connected  with  an  aspirating  pump.  The  other  cotton 
plug  is  removed  and  the  process  of  suction  begun.  When  a  sufficient 
amount  has  been  drawn  through,  the  two  filters  are  removed,  each  by 
itself,  and  mixed  with  the  nutrient  gelatin  from  which  plates  are  next 
to  be  made.  The  first  filter  should  contain  all  of  the  organisms,  the 
second  serving  as  a  control. 

Ficker  suggested  an  improvement  in  the  construction  of  the 
filters,  substituting  for  sand,  which  to  a  certain  extent,  masks  the 
colonies,  powdered  glass,  which  has  not  this  disadvantage.  A  still 
better  material  is  fine  sugar,  the  use  of  which  was  suggested  first 
by  Sedgwick.  The  advantage  of  this  is  that  it  is  dissolved  in  the 
liquefied  gelatin,  and  thus  disappears  from  view,  and,  therefore, 
neither  masks  the  colonies  nor  can  be  mistaken  for  them  in  counting. 
^Zeitschiift  fiir  Hygiene,  III.,  p.  1. 


EXAMINATION   OF  A  III.  '515 

Sc(l|jJwi('l<',M  inclliod  of  collccl  iii^--  <)r}_';iiii-iii~  ;iii<l  nl  it:iiiiiii;_'  (■llllll^^s  JH 
OlK!  wllic'll,  on  I, lie  wliulc,  Ir  pi'd'cinlilc  In  ;ili\'  oIIk  |-  ||i;it  |i;is  |»ccil  HII^- 
|i;(!.Mi,(!(l.  I  lis  ii|)|);ir:iliis,  Is  now  II  iis  I  he  ;i(-iol)iii-(ii|)c,  i-  ;i  ^|;ihh  f  illx' ;iliuiit 
14  inclics  ill  l(!ii;4lli,  ,sli;i|)('(l  like  ;i  li\<li()iiiilii- ;iii<l  'i|icii  at/ hotji  cikIh. 
'V\\i\  iiiiri'ow  |)<»rl-ioii,  wliirli  is  iMlhcr  less  tli;iii  linll'  llic  Iciij/^tli  of 
ilu;  (iilxi,  li;is  Mil  iiil('rii;il  (liiiiiiclcr  of  <)._!  inch  ;  tlic  l>r<i;i<lcr  port  ion  lia.s 
MM  iiilxM'iiiil  (liiiiiiclcr  of  I.S  inches,  ;iiiil  ;il  lis  (irr-  end  is  <Miii.sl,ric,t<'(|  for 
nil  iiKth  to  ;iJ)()ii(.  h.'ill"  its  si/e.  Iiilu  I  he  niilcr  einl  of  \\u'.  narrow  j»or- 
lioii,  M  (li:i|)hr;i|;iii  coiiHlHtinfi:;  o("  ;i  roll  oC  line  wire  jraii/x;  is  inH(;rt<-(l  to 
•iXvX.  MS  M-  pliii;;  (or  Ihe  siit^'iir  filler.  The  tAvoo|ieii  ends  miv  sloppfil  witli 
coKoii,  Mild  the  M|)pMrn,(iis  is  then  s(erili/,e<|.  The  plii}r  m(  the  lar|;ffr 
end  is  next-  i'enio\'ed  ;iiid  the  siiii;ar,  siiHieienl  in  nnioimt  to  (ill  the  small 
iiilx!  above  its  eoiitniiuid  di!iplirM<;in,  is  int  rodiievd.  The  pint:  '^  replaced, 
and  then  (he  wIioKms  steriii/cul  Mt  120°  C.  for  several  hour-.  In  ii-e,  the 
apparatus  is  lu>ld  in  m-  vertical  position  Nvitli  tli<'  narrow  portion  down, 
the  pln<2;s  are  removed,  and  m  measured  volume  of"  air  is  drawn  through 
by  means  of  an  as|)iratiiiLi;  ap|)arafiis  connected  hy  a  riilthcr  tube  to  the 
lower  end.  When  the  desired  aiuoiint  of  air  has  been  asj)irated,  the 
suj>;Mr  with  the  bacteria  which  it  has  arrested  is  brou<rht,  by  proper 
manipulation,  into  the  broad  part,  into  which,  by  means  of  a  bent 
funnel,  a  siiflicient  amount  of  liquefied  nutrient  ^(ilatin  is  introduced. 
The  plug  is  replaced,  and  the  tube  is  then  rolled  and  chilled  on  ice,  and 
set  aside  for  the  development  of  colonies.  After  the  jn'ojxr  interval, 
the  count  is  made  in  the  usual  manner. 

The  methods  above  tj^iven  have  generally  superseded  that  of  Hesse, 
who  was  a  pioneer  in  this  branch  of  investigation.  His  a})paratus  con- 
sists of  a  glass  tube,  28  inches  long  and  about  1|  wide,  su]iported  in  a 
liori/ontal  position  upon  a  wooden  tripod.  One  end  is  covered  with  two 
rubber  caps,  the  inner  of  which  has  a  single  perforation ;  the  other  end 
is  closed  with  a  rubber  stop))er  \\\\\\  an  outlet  tube  of  glass  plugired  at 
each  end  with  cotton  and  connected  with  a  pair  of  aspirating  flasks  of 
a  liter  capacity.  The  tube  is  sterilized  and  charged  Avith  50  cc.  of 
gelatin,  which  is  allowed  to  solidifv  before  use.  In  conducting  the 
operation,  the  outer  cap  is  removed,  thus  exposing  the  inner  jierforated 
one,  and  a  current  of  air  is  drawni  slowly  thr(iugh  by  the  action  of  the 
aspirating  flask,  which,  filled  with  water,  emj^ties  itself  into  the  other. 
By  reversing  the  flasks,  any  number  of  liters  of  air  may  be  drawn 
through.  In  its  passage,  the  air  dejiosits  its  bacteria  on  the  gelatin. 
The  process  has  many  disadvantages,  and  can  make  no  great  claim  to 
accuracy. 


CHAPTKK    III. 
THE   SOIL. 

Notwithstanding  the  constant  and  necessarily  intimate  relation 
of  all  life  to  the  soil  npon  wbieli  we  build  our  habitations,  from 
\vhieh  we  derive  in  such  great  part  our  supply  of  drinking-water, 
into  which  we  cast  vast  quantities  of  organic  filth,  and  to  which  we 
consign  our  dead,  the  subject  of  the  sanitary  importance  of  the  soil 
has  not  until  within  comparatively  recent  years  received  the  attention 
which  it  merits.  That  the  soil  exerts  important  influences  on  the 
public  health,  was  recognized  long  before  the  time  of  Hippocrates, 
and  extensive  researches  on  the  subject  figure  among  the  earliest 
investigations  of  the  modern  hygienist,  but  by  far  the  greatest  part 
of  the  attention  paid  to  the  study  of  the  soil  has  been  due  to  con- 
siderations of  public  wailth  rather  than  of  public  health.  With 
the  gradual  development,  however,  of  a  more  accurate  knowledge 
of  the  causes  of  disease,  has  come  an  increasing  interest  in  the  rela- 
tions of  the  soil  to  those  causes,  and  what  has  hitherto  been  a 
rather  neglected  field  of  exploration  now  bids  fair  to  be  well  and 
thoroughly  tilled. 

That  portion  of  the  earth's  crust  in  which  we  as  hygienists  are 
interested  includes  the  superficial  layer,  known  as  tilth  or  arable  soil, 
which  is  the  result  of  the  disintegration  of  rocks  and  decay  of  animal 
and  vegetable  life,  and  the  subsoil,  which  lies  directly  beneath.  The 
former  varies  from  a  few  inches  to  several  feet  in  depth  ;  the  latter 
extends  few  or  many  feet  downward  to  the  hardpan  or  other  imper- 
meable stratum. 

Soil  is  a  mixture  of  sand,  clay,  and  other  mineral  substances,  with 
humus,  or  organic  matter,  and  living  organisms ;  and  it  is  classified 
according  as  one  or  another  of  its  constituents  predominates.  The 
usual  classification  of  soils  includes  sands,  clays,  loams,  marls,  humus, 
and  peats. 

Sandy  soils  consist  almost  wholly,  or  at  least  more  than  four-fifths, 
of  pure  sand  of  any  kind. 

Clays  are  stiff  soils  consisting  chiefly  of  silicate  of  aluminum  and 
other  very  finely  divided  mineral  matters.  Clay  exists  in  particles  of 
the  smallest  possible  size,  is  very  cohesive,  possesses  a  high  degree  of 
plasticity,  and  plays  a  very  important  part  in  determining  the  fertility 
of  soils,  their  texture,  and  their  capacity  for  holding  water.  Its  plas- 
ticity is  due  to  the  presence  of  a  small  proportion  of  hydrated  silicate, 
and  is  modified  very  greatly  by  the  addition  of  less  than  a  hundredth 
part  of  caustic  lime.  It  is  exceedingly  impermeable  to  water,  and 
when  wet  dries  with  great  slowness. 
316 


77//';  SOIL. 


317 


/yoam.s- iinMiiixlnrcH  of  wind,  (;l:iy,  ;iii<l  Ihiiiiiih  ;  li(!n<;('  tlicir  propcr- 
lics  p:u-(;ik(;  «»(■  iJic  (tlmruclfi-istlcs  oC  (licsc  Mihslaiiccs  acconliiipr  to  the 
cxiciil,  lo  wliicli  (•;ic.li  is  |>ivsciil.  Win  n  :-;in<l  |)i<(|<.iiiiiiai<'H,  tlu*y  are 
(l(!Miji,'ii:itc.(l  iis  Ill/Id  ;  :iihI  wIicii  <'l:iy  |.iv\  :iil.-,,  tli<y  ;irc  known  ;ih  hrt/vi/. 
'I'li(:,s(>  t('rniH,  li(»W(!V(r,  li.i\«'  no  r<  rcirncc  lo  wci^lil,  l>iit  lo  llic  i-m-c  or 
(liirKtnlty  vvilli  vvliicli  tlicy  iirc  \\oil((l  in  I  lie  procc.sH<!,s  of  aj^rirnlf  un; ; 
and,  IndiHid,  those  soils  which  aiv  I  he  li^ditcst  in  this  sense  an-  the 
hcavic^st  in  aclnal  \\ci<;lil.  Since  loani.s  e^»n.siHt  of  varying  pro|)ortioiiH 
of  (he,  chief  conslitneiils,  il  is  ol.vioiis  that  the  word  loam  may  have 
hnt  littU' si,<;ni(icMnee  without  some  (pialifying  term,  and  tliey  are,  there- 
fore, (hvi(h'd  inio  fi\'e  classes,  as  follows: 

1.  llwivy  clay  loatii,  (•(.ntaiiiiiiK 10-2o  per  cent,  of  Hand. 

2.  (Hay  loam,  coiilaiiiiiifi; 25-40 

3.  tjoaiii,  cotilaiiiiii;^ 40-00 

4.  Sandy  loam,  ('onlainiii^' (50-75 

5.  !jfj;iil  sandy    loam,  mntainiiif^ 75-!(0 

Mixtures  eontainino-  less  than  10  or  mon;  than  !J()  jicr  cent,  of  sand  arc 
chissed,  rcsj)eetivcly,  as  clay  or  sand. 

3f(irh  are  mixtures  of  ("hiy,  sand,  and  amor])lious  eah-ium  carl)f)nate 
in  various  pi'oportious,  and  contain,  often,  ])otash  or  phospjiate.s  from 
the  fannii  and  flora  of  the  scji.  From  their  content  of  carbonate  of 
calcium  they  arc  known  often  as  lime  soils,  and  according  as  one  or 
another  constituent  ])rc(h)minates  they  are  desi_i2;nated  as  clay  marl,  s:and 
marl,  and  shell  marl.      All  contain  varyino;  amounts  of  humus. 

Ham.us  is  a  term  used  to  designate  the  entire  product  of  vegetable 
decomposition  in  the  various  intermediate  stages  of  the  process.  It  is 
the  essential  element  of  vegetable  mould,  and  is  necessarily  of  most 
complex  composition — so  complex,  indeed,  that  it  cannot  definitely  be 
determined.  It  is  composed  of  a  great  number  of  closely  related 
definite  chemical  compounds,  chief  among  which  are  ulmin  and  ulmic 
acid,  which  are  supposed  to  characterize  brown  humus ;  humiu,  and 
humic  acid,  which  dominate  dark,  or  black  humus  ;  and  crenic  and 
apocrenic  acids.  Its  principal  characteristic  is  its  high  percentage 
of  nitrogen,  especially  marked  in  some  of  our  prairie  soils  and  in  the 
"black  soil"  found  in  the  provinces  of  the  Ural  Mountains,  which, 
according  to  Von  Hensen,^  contains  as  much  as  from  5  to  12  per  cent, 
of  organic  matter.  Its  complete  decay  is  most  rapid  in  warm  well- 
drained  soils  permeable  to  air,  and  in  such  soils  the  amount  of  humus 
present  at  any  one  time  will  be  relatively  small,  while  in  soils  which 
are  damp,  not  w^ell  ventilated,  and,  for  months  at  a  time,  frozen,  its 
accumulation  is  favored.  While  its  ultimate  products  of  decay  are  of 
the  greatest  importance  to  vegetable  growth,  it  does  not  follow  that  its 
complete  absence  renders  a  soil  necessarily  sterile,  or  even  poor, 
provided  the  necessary  nitrogen  is  supplied  in  the  form  of  nitrates. 
But  its  presence  is  necessary  to  the  growth  and  life  processes  of  the  soil 
bacteria,  without  whose  assistance  many  plants  would  fail  to  thrive. 

Peat,  muck,  and  humus  soils  contain  large  amounts  of  humus,  but  diifer 
'  Zeitscbrift  fiir  wissenschaftliclie  Zoologie,  XXVIII.,  p.  360. 


318  THE  SOIL. 

accorclino-  to  tlio  ooiulitions  iiiulcr  which  they  arc  fornicd.  Feat  and 
muck  result  tVom  the  iiioDinplete  decay  of  vegetable  matter  iiuder  water  ; 
the  lornier  term  ;ii)plie.s  to  that  which  is  compact  and  iibrous  ;  the  latter 
is  less  compact,  not  fibrous,  and,  when  dry,  easily  reduced  to  powder. 
They  contain  but  a  small  amount  of  mineral  matter.  JIainus  i<:oi/s  are 
soils  which  coutaiu  large  percentages  of  vegetable  mould  with  ordinary 
soil  constituents. 

The  cxj)ression  rockij  soil  applies  to  any  kind  of  soil  containing 
masses  of  rock. 

Gravellij  soils  are  those  which  contain  notal)le  amounts  of  gravel, 
which  consists  of  small  fragments  of  rock  more  or  less  worn  by  the 
action  of  water,  and  larger  and  coarser  than  sand. 

Alkaline  or  salt  soih  are  soils  which  contain  considerable  amounts 
of  st)luble  salts,  especially  carbonate  and  sulphate  of  sodium  and  salts 
of  calcium. 

Constituents  of  the  Soil. — The  chief  constituent  of  the  soil  is  silica, 
Avhich,  it  is  estimated,  forms  about  two-thirds  of  the  entire  earth's  crust. 
Next  in  abundance  is  aluminum,  chieiiy  in  the  form  of  clay  (silicate  of 
aluminum).  Lime  and  magnesia  are  large  constituents,  existing  chictiy 
as  carbonates  in  the  form  of  limestone.  Both  are  indispensable  to  the 
growth  of  plants,  and  lime  exerts  a  marked  influence  on  the  physical 
condition  of  the  soil  and  upon  the  processes  of  nitrification.  Although 
its  principal  combination  is  carbonate,  it  exists  also  largely  as  phos- 
phate and  sulphate. 

Iron  is  universally  present,  and  is  of  very  great  importance  to  vege- 
tation, although  but  a  small  amount  is  needed.  The  red  and  yellow 
colors  of  soils  are  due  to  the  presence  of  iron  compounds.  Manganese 
stands  second  to  iron  in  abundance  among  the  heavy  metals,  but  is  of 
much  less  importance.  It  is  a  constituent  of  many  plants,  notably  of 
tea.  Chlorine  is  not  a  large  constituent ;  it  occurs  chiefly  in  combina- 
tion with  sodium,  potassium,  and  magnesium.  Its  total  amount  in 
ordinary  unpolluted  soil  seldom  exceeds  yTj-g-Q-o  P^^'^  of  the  whole.  Sul- 
phur occurs  as  sulphides  and  sulphates,  the  latter  usually  in  combina- 
tion with  calcium.  It  is  very  necessary  to  vegetable  growth,  as  it  is  an 
essential  element  of  vegetable  albumin.  Phosphorus  in  the  form  of 
phosphates  of  lime,  magnesia,  iron,  and  alumina,  is  another  essential 
element,  widely  distributed  in  small  amounts.  So(huni  and  potassium 
are  present,  chiefly  in  the  form  of  insoluble  silicates  and  partly  as 
chlorides.     Their  total  in  combination  seldom  exceeds  4  per  cent. 

Nitrogen  exists  in  soils  in  three  distinct  forms  :  proteids,  ammonia 
and  its  salts,  and  nitric  acid  and  nitrates.  In  average  soils,  the  total 
nitrogen  is  not  large  in  amount — considerably  less  than  1  per  cent. — 
but  in  some  exceptionally  rich  humus  soils  4,  b,  and  even  6  per  cent, 
are  found.  In  the  organic  combinations  (proteids)  it  is  not  available  as 
plant  food,  consequently  these  must  be  broken  U])  into  simpler  forms 
in  order  to  be  of  direct  use.  In  their  decomposition,  the  second  form, 
ammonia,  is  produced,  i>ut  not  all  the  ammonia  of  the  soil  is  from  this 
source,  for  some  is  brought  into  it  from  the  air  by  raiu.     And  in  the 


Till':  SOI!.. 


riio 


HC!(!(Hi<l  Conn,  ;ils(>,  il,  ;i|>|K:irs  In  he  iiol,  :iv;iil;il>l('  wr.  pl.-iiil  IVtod,  hiil,  <'Vcii, 
."iccordilin-  (o  |',()i|cli;ii'(|;i(  ;iii<l  ^  'lor'/,'  scciris  to  ;i('t  :i.-  ;iii  ciictp'l  ic  jjoIhoII 
when  ;il),Morl)C(l  l)\'  phiiil  rool.s  IVoiii  :-^oliil  ions  of  0. 1  (oO.Ol  JXM*  (M;tit. 
,str(!n^(li.  So  il.  is  |ii(ilt;il»lc  lli;il  coniplclc  o.\i<l:ilion  to  tlic  tJiinI  form 
Ih  ncncMSJiry  lor  I  lie  ;ili-(ii|il  ion  of  any  (orni  of  nil  ro|_.cii.  Am  hocmi  ;ih 
ili(!  unmionia,  is  oxidized  in  its  Inrn  to  niliic  aeid,  tliis  latter  coinMtieH 
with  so(huMi,  |)o(assiinn,  or  caleiinn,  and  the  resnHiiifr  nilrateH  are  then 
rwidy  lor  ahsorplion. 

All  of  i,h(!S(!  ehanj^cs  (Voin  lla;  <'oMi|)le.\  |)roleid  fo  the  simple  nitrate 
ai'c  earried  aloni;'  hy  dilTci'cnt.  groups  ol"  niiero-or^anisins,  hnl  nr»  ^reat 
aecuintilation  o("  th<'  end  products  occurs,  heean-e,  while  \ cjrfitatioii  is 
lloiirishiiiti;,  ilu^y  are  removed  as  fast  as  lornie*!,  an<l  whin  it  has  (^'i.sed, 
tluiy  ar(!  washed  down  into  tlu;  suhsoil  hy  the  lain  and  melting  snow. 

'rh(>  amount  of  oi-yanic  matter  in  soils  varies  widely  according  U) 
(arenmsta.n(^(!S,  hut  tlu;  amount  necessary  (or  veu-etation  is  (piite  small, 
althou,i;'h  certain  croj)s,  as  tohacco  and  wheat,  riipiire  niiich  more  than 
others,  as  oais  and  rye.  'I'he  soils  richest  in  orj^anic  matter  are  the 
peats  and  uuicks  ;  next  couk.'  the  very  rich  humus  soils,  whieli  may 
yli^ld  more  than  a  loiirth  of  their  weij^ht.  l^^'om  10  to  1  ">  jK-r  a-nt. 
denotes  unusual  richness,  and  al)out  (!  per  cent,  may  he  regarded  as  a 
fair  amount  for  a  productive  soil. 

Physical  Properties  of  Soils. — Pore-volume. — Ju  all  soils,  no  mat- 
tor  how  closely  the  individual  particles  are  ])acked,  there  must  exist  a 
greater  or  less  amount  of  interstitial  space,  which  may  \ni  filleil  with 
water  or  aii",  or  hoth  together.  The  sum  total  of  these  interstitial 
spaces  is  known  as  the  ^w/'o.s////  i)v  pore-volume,  and  is  expressed  in  per- 
centage of  the  volume  of  the  soil.  Its  amount  depends  not  uj)on  the 
size  of  the  soil  particles,  hut  U])on  their  uniformity  or  lack  of  uniform- 
ity of  size,  and  u[)on  their  arrangement.      If  Ave  have,  for  instance,  a 


Fi(i.  17. 


Via.  18. 


v^ery  coarse  S(mI,  ct>nsisting  of  particles  of  uniform  size  as  large  as  peas, 
and  another  of  uniform  particles  the  size  of  small  shot,  we  shall  find, 
on  determining  their  porc-vohime,  that  it  is  practically  the  siime  in 
each  case,  and  is  probably  not  far  from  a  third  of  the  whole.  Packed 
in  the  most  solid  manner  ]iossible,  which  is  that  in  which  each  sphere 
rests  on  three  beneath  it  (arranged  like  the  familiar  pyramid  of  mar- 
bles), helps  support  three  in  the  layer  above  it,  and  comes  in  contact 
with  others  at  six  equidistant  points  along  its  equator,  as  in  Fisr.  17, 
the  volume  of  interstitial  space  will  equal  25.95  per  cent,  of  the  whole. 
Packed  as  loosely  as  possible,  so  that  each  rests  upon  but  one,  sup- 
^  Deutsche  medicinisclie  Wochenschrift,  ISSG. 


320  THE  SOIL. 

ports  another,  and  comes  in  contact  Avith  but  four  of  its  neighbors  in 
the  same  layer  as  itself,  as  in  Fig.  18,  the  volume  of  the  interstices 
will  be  47.64  per  ceut.^  Thus  a  soil  composed  of  spherical  grains  of 
uniform  size  ■would  have,  regardless  of  the  coai'seness  of  the  grains, 
a  pore-volume  of  not  less  than   25.95   per  cent. 

That  the  size  of  the  individual  grains  makes  no  difference,  may  easily 
be  demonstrated  in  a  practical  manner.  If  we  take  two  cylindrical 
glass  vessels  of  the  same  size,  lill  them  to  the  same  height  with  water, 
and  then  add  to  the  one  a  measure  of  large  shot  and  to  the  other  an 
equal  measure  of  nuich  finer  shot,  and  secure  as  solid  packing  as  pos- 
sible by  gentle  tapping,  it  will  be  found  that  the  water  in  each  cylin- 
der has  risen  to  practically  the  same  height ;  that  is,  that  the  actual 
volume  of  each  is  about  the  same.  There  will  be,  perhaps,  some  slight 
diiFerence  one  way  or  the  other,  owing  to  the  impossibility  of  securing 
absolute  uniformity  of  packing,  and  to  the  error  due  to  the  inequality 
of  the  spaces  along  the  circumference  of  the  cylinders.  But  in  nature 
we  do  not  deal  with  perfect  spheres  or  with  soils  made  up  of  particles 
all  of  the  same  size,  but  with  soils  composed  of  angular  pieces  of 
varying  size.  The  greater  the  variation  in  size  of  tlie  particles,  the 
greater  the  possibility  of  variation  from  the  limits  of  pore-volume  as 
given  above.  With  varying  size,  the  small  particles  may  fall  into  the 
spaces  made  by  the  larger  ones,  and  the  spaces  between  the  new  comers 
may  be  trespassed  upon  by  still  smaller  grains,  and  so  on  until  the 
interstitial  space  has  been  reduced  to  a  minimum. 

To  illustrate  this  diminution  in  a  practical  way,  fill  a  large  beaker 
with  marbles,  then  pour  into  it,  from  a  graduate,  sufficient  water  to 
displace  all  of  the  air  in  the  interstices,  and  note  the  amount  of  water 
required,  which  is  the  pore-volume  of  the  mass.  Next,  pour  out  the 
water  as  completely  as  possible  and  run  on  to  the  surface  of  the 
marbles  a  quantity  of  coarse  sand  or  shot,  and  shake  the  vessel  gently 
in  all  directions  so  as  to  favor  their  descent  into  the  spaces  below. 
When  all  have  penetrated  that  can,  pour  in  water  again  until  it  ap- 
pears at  the  surface,  and  note  the  amount  required ;  this  is  smaller 
than  before,  on  account  of  diminished  air  spaces.  Now  pour  off  the 
water  a  second  time,  add  still  finer  shot,  and  repeat  the  operation  as 
before.  So  long  as  new  matter  can  be  added,  so  long  Avill  the  pore- 
volume  show  a  diminution. 

Irregularity  of  size  and  shape  of  the  particles  may  also  have  an  in- 
fluence in  the  other  direction,  and  cause  the  formation  of  large  spaces 
and  increased  pore-volume. 

All  soils,  even  the  most  compact  rocks,  have  a  certain  amount  of 
pore-volume,  and  some  apparently  compact  masses,  such  as  sandstone, 
have  as  much  as  30  per  cent.  In  soils  which  are  cemented  into  homo- 
geneous masses,  the  pore-volume  sinks  to  a  minimum,  but  in  ordinary 
soils  it  amounts  to  about  40  per  cent. 

Permeability  of  Soils. — The  permeability  of  a  soil  to  air  depends 
not,  as  it  might  appear,  upon  the  amount  of  its  pore-volume,  but  upon 
'  Soyka,  Der  Boden,  Leipzig,  1887. 


Till':  SOIL. 


'VI I 


tli<!  ,siz(!  of  \\\v.  iii<livi<lii;il  sp.'Krcs.  In  (iicl,  ;i  soil  tA'  \\\'^\\  itorc-voliiiiirf 
may  b(!  iilinosl;  iMi|)<Tiiic;il)l<'  loiiii'  in  coniiciri.-on  with  one  (tf  i<',s.s  jK)f(t- 
voliimc,  !is  will  Ix'  shown  ;  nnd  I  lie  |»orc-\olninc  is  of  itself  no  iiicaHuro 
what0V(!r  of  ixTincnhiliiy,  wliieli  diniinl-lic-  in  ;in  cxt  r;ioi<liiiiirv  rlc^ec 
with  (Hininiil  ion  in  the  si/c  oC  llw  soil  ));ii(icl(s.  'Ilic  jficntcr  tlie  iniin- 
bor  of"  the  iii<IIvi(ln;il  s|)a(rcs,  (he  ^i-calcr  (he  iniinhr-r  of"  ;in}f|cs  :\\u\  llu; 
^i'(!iit(',r  the.  (Viction  o("  the  cnlcrint:;  ;iir;  :in(i,  conversely,  tlict  less  the 
iiiMulxM-,  ;iM(l  (!oiise({ii(Mitly  the  lar^ci"  the  si/e  of  tlic  .spac-es,  the  ](!S.s  the 
ninnlxT  of  angles  and  the  less  tlie  olwti'nel  ion.  A  Heries  of  cxperimentH 
(•,on(ln(d('(l  veiy  cMrcifulIy  hy  I'cnk  '  wilh  (lilTei-enl  kinds  of  .soil  in 
cylindc^rs  of  (mjiimI  hei^lil,  lhi'(»ii<^li  which  iiir  \\;is  forced  niid(.'r  the  Kanic 
(legi'ee  of  preHSure,  yielded  the  following  interesting  results  : 


Nature  of  soil. 

Diumctur  of  grains. 

I'ore- 
volunie  f. 

I'rcfwure 

iu  ;nm.  of 

water. 

Amount  of 

air  in 
liters  per 
minute. 

0.001.33 
0.112 
1.280 
6.910 
15.540 

liatio. 

Fine  Hiiiul 

McdiuiTi  siiiid      .    .    . 
(loiirse  Hiiiid     .    .    .    . 
Fine  gravel     .... 
Medium  gravel  .    .    . 

Less  llnin  •'  iriiri. 
\  U)  1   nun. 

1  to  2  nun. 

2  to  4  mm. 
4  to  7  mm. 

55.5 
55.5 
37.9 
37.9 
37.9 

20 
20 
20 
20 
20 

1 

84 

961 

5,195 

11,684 

Thus  it  is  seen  that  a  fine  sand  with  a  pore-volume  f)f  o').5  ])er  cent, 
permitted  the  passage  of  but  1  volume  of  air,  while  a  gravel  of 
medium  coarseness  with  much  lower  porosity  permitted  the  pas.sage  of 
11,684  times  as  much  in  the  same  unit  of  time.  Renk  showed,  fai'ther, 
that  with  soils  of  the  finer  textures,  permeability  to  air  is  dircctlv  pro- 
portionate to  pressure,  but  that  this  is  not  true  of  those  of  coarser  grain. 


Nature  of  soil. 

Size  of  grain. 

Height 

of 
column. 

Units 

of 

pressure. 

Ratio  of 

volume  of  air 

passed. 

Fine  sand 

Medium  sand 

Coarse  sand 

Fine  gravel 

Medium  gravel 

Less  than  J  mm. 
^  to  1  mm. 

1  to  2  mm. 

2  to  4  mm. 
4  lo  7  mm. 

0.50  m. 
0.50  m. 

2.00  in. 

0.50  m. 

2.00  m. 

0.50  m. 

2.00  m. 

2.00  m. 

1 

1.5 

1 

2 

3 

1 

2 

3.6 

1 

2 

3 
1 
2 

3 

1 
2 

4 

1 
2 

3 
1 
2 
3 

1 
1.5 

1 
2 

3 

1 

•7 

.3.6 

1 

1.91 

2.78 

1 

2 

2.9 

1 

l.ir 

2.30 

1 

1.77 

2.42 

1 

1.65 

2.19 

21 


1  Zeitschrift  fiir  Biologic,  XY.,  p.  205, 


322 


THE  SOIL. 


The  abscuce  of  any  ('oniu'ction  ht'tworii  pdri'-voluiiK'  and  piTincabil- 
ity  lias  been  shown  also  by  von  \\\']itsc-hko\vsky,'  iVoni  whose  results 
the  lollowino-  table  has  been  'eonstrueted  : 


Nature  of  soil. 


Fine  sand 
Mediiim  sand 
Coarse  sand  . 
Fine  e-ravel  . 


Pore-volume  •fe. 


41.87 
40.64 
o7.38 
35.47 


Pressure 
iu  luiu. 
of  water. 


50 
50 
50 
50 


Amount  of  air 

in  liters 
per  minute. 


0.0058 

0.8990 

7.399 

33.651  '^ 


Katio. 


1 

155 
1,276 

5,802 


Since  permeability  diminishes  with  fineness  of  texture,  it  follows  that 
clay  and  similar  soils  possess  this  property  in  the  smallest  degree,  and 
that  when  these  are  mixed  with  sandy  soils  they  must  necessarily  lessen 
it  to  a  very  marked  extent.  But  clays  and  loams  may  occur  in  very 
open  crumbly  form,  that  is,  in  loose  fragments  of  varjang  size,  each 
consisting  of  myriads  of  small  particles  held  together  by  the  aid  of 
moisture ;  and  such  soils  show  a  high  permeability,  due  to  their  large 
interstitial  spaces. 

The  degree  of  permeability  to  air  is  influenced  very  greatly  by  the 
amount  of  contained  moisture,  the  maximum  mfluence  being  exerted 
by  decided  wetness.  This  is  due  to  the  fact  that  the  greater  the 
amount  of  water  present  in  the  mterstices,  the  greater  the  diminution 
m  the  space  available  for  the  passage  of  air  and  the  greater  the 
obstruction  to  its  movement.  Thus  the  complete  occlusion  of  the 
interstices  by  Avater  is  equivalent  to  absolute  impermeability,  except 
when  the  pressure  of  air  is  sufficient  to  displace  the  water  and  move  it 
along. 

In  the  case  of  soils  that  are  only  partially  wet,  the  diminution  in 
permeability  varies  according  as  the  moisture  enters  from  above  by 
rain  or  from  below  by  capillary  attraction  from  the  water  iu  the  sub- 
soil. This  is  owing  to  the  fact  that  when  the  soil  is  wetted  from 
above  by  rain,  the  superficial  interstices  are  occluded  more  or  less 
completely,  and  the  air  in  those  below  is  restrained  in  its  movement ; 
while  when  the  moisture  is  derived  by  capillary  attraction^  the  air  is 
displaced  upward,  and  the  superficial  interstices  are  more  or  less  com- 
pletely open.  The  action  of  downward  and  upward  moistening  has 
been  investigated  by  Renk,''  whose  results,  in  part,  are  given  in  the 
following  table  : 

'  Beitrag  zur  Kenntniss  der  Pernieabilitiit  des  Bodens  fiir  Luft :  Arcliiv  fiir  Hygiene, 
II.,  p.  483. 

^  The  height  of  the  cohinin  of  matei-ial  in  tin's  experiment  was  three-fourths  of  a 
meter,  instead  of  a  half,  as  in  the  case  of  the  three  others.  With  an  equal  height  the 
result  would  have  been  much  larger, 

^  Loco  citato. 


'/'///•;  son. 


<)9<> 


Naturoofdoll. 


M(!(liiini  \s,\-A\n;\ 

CoiiiW!  H.'ind 
IMcdiiiiii  siiikI  . 

l''iiu!  Siiiid      .    . 


■M.\) 
'M.'.) 
Wl.'.) 

-li.r, 

55.5 
55.5 


;il)Hcii 
IVdni 
from 

JlllMCIl 

from 

from 

.'iliHcn 

fi 

frurii 

!ll)HCII 

from 
from 

!lI).S('ll 

froin 
from 
ahscn 
from 
from 


t, 

;iliov<; 
Im;1ow 
I, 

illlOVC 

liclow 
!, 

!il)ovi; 
liclow 


I, 

!ll)()V(r 

Ik.Iovv 
t 

IlllOVO 

l)(;loW 

t, 

:ii)ovo 

below 


I'roMturo, 


20 

20 

20 

'10 

'10 

'10 

40 

'10 

40 

150 

150 

150 

150 

150 

150 

150 

150 

150 


Itatio  of  fttr 

pflMKXl. 

15.54 
14.«3 
1."..70 
14.04 
i:'..l« 
12.55 
2.:« 

i.tn 

1.71 
0.57 
0.11 
0.00 
0.04 
O.O.'i 
0.00 
0.01 
0.00 
0.00 


l\'niu';il)ilitv  is  Icssciu'd  also  Wy  iVcczino;  temperatures,  by  reason  of 
the  iiuit  tliat  tlic  contaiiu'd  nioistiiix!  c'.\|)aii(ls  about  one-eleventh  of  its 
vobune  as  it  IVee/cs,  and  so  occupies  that  nui(;h  more  s[)aee  in  the  int<.'r- 
stices.  Moreover,  when  frozen,  the  moisture  is  in  a  fixed  rather  than 
a  movable  condition,  and  causes  tlic  production  of  a  compact  ma.ss 
more  or  less  resembling;  stone.  The  finer  the  grain,  the  more  solid  the 
])ro(hu't,  and  the  o;reater  the  diminution  of  peruu^ability.  Reid<  '  deter- 
mined the  diminution  in  the  permeability  of  soils  of  different  grain  size 
due  to  freezing,  as  follows  : 


Nature  of  soil. 


Medium  gravel 
Fine  gravel  .  . 
Coarse  sand  .  . 
Medium  sand  . 


Source 
of  moisture. 


from  above 

"  below 

"  above 

"  below 

"  above 

"  below^ 

"  above 

"  below 

"  above 

"  below 


Permeability. 


Moist. 


14.63 

13.70 

13.16 

12.55 

1.91 

1.71 

0.11 

0.00 

0.23 

0.00 


Frozen. 


13.87 

12.20 

12.54 

10.18 

1.64 

1.27 

0.07 

0.00 

0.00 

0.00 


Diniinuti/>n. 


5.2% 
10.9 

5.4 
19.0 
14.1 
25.7 
36.4 

100. 


The  degree  of  permeability  of  soil  to  water,  like  that  of  permeability 
to  air,  is  governed  by  the  textui'e  rather  than  by  ]i(^re-voIume,  as  i.^ 
shown  by  the  following  results  obtained  by  von  Welitsehkowsky,"  who 
determined  the  rates  at  Avhich  water  Avould  pass  through  columns  of 
soil  of  differing  fineness  packed  in  cylinders  of  equal  diameter.     Each 

'  Boitnio-  7,nv  Kenntniss  der  Permeabilitiit  des  Bodens  fiir  Luft :  Archiv  fiir  Hvgiene, 

II.,  p.  -I8;i 

•'  Kxperiiuontolle   Untei-sucliung  iiber  die   Permeabilitiit  des   Bodens   fiir   Wasser, 

.Vn-luv  fiir  llyo-ioiie,  II.,  p.  499. 


324 


THE  SOIL. 


specimen  M'as  first  completely  saturated  and  then  kept  so  during  each 
experiment,  the  M'ater  supplied  being  kept  at  constant  level. 


Height  of  column  of  soil. 

25  cm. 

50  cm. 

Height  of  water  column  above  soil  surface. 

20  cm.      1      50  cm. 

20  cm.      1      50  cm. 

"  Nature  of  soil  and  size  of  grain. 

Amount  of  water  discharged  in  liters  per  min. 

Fine  sand,  less  than  J  mm 

Medium  i^and  j^  to  1  mm 

0.00024 
0.175 
1.767 
8.570 
14.909 

0.00059 
0.435 
4.014 
16.190 

0.00014 
0.123 
1.351 
7.465 

12.872 

0.00028 
0.237 

2.422 

Fine  gravel,  2  to  4  mm 

Medium  gravel,  4  to  7  mm 

11.705 

Comparing  these  results  with  those  obtained  by  the  .same  investi- 
gator in  his  experiments  on  permeability  to  air,  it  will  be  noticed  tliat 
the  total  pore-volume  has  here  even  less  significance. 


Nature  of  soil. 


Height. 


Pleasure. 


Pore- 
volume  ^. 


Batio  of  permeability. 


To  air. 


To  water. 


Fine  sand  .  . 
Medium  sand 
Coarse  sand  . 


50  cm. 
50  cm. 
50  cm. 


50  cm. 
50  cm. 
50  cm. 


41.87 
40.64 
37.38 


1 

155 
1,276 


1 

846 
8,650 


Capacity  for  Water,  and  Water-retaining  Capacity. 

If  to  a  volume  of  any  soil  packed  into  a  cylinder  of  glass  or  metal 
we  add  w^ater  in  such  a  way  that  all  of  the  air  in  the  interstices  is  dis- 
placed, the  soil  is  then  saturated  and  the  amount  of  the  contained 
water  represents  the  total  "  water  capacity,"  which,  it  is  seen,  equals 
the  pore-volume.  The  "water-retaining  capacity/'  is  quite  another 
thing,  and  depends  upon  the  structure  and  composition  of  the  soil, 
and,  in  a  minor  degree,  upon  other  considerations.  If  for  the  imper- 
vious bottom  we  substitute  one  of  wire  gauze  or  coarse  cloth,  the  con- 
tained water  will  begin  to  drain  away,  owing  to  the  force  of  gravity, 
and  the  flow  will  by  degrees  become  less  and  less,  and  finally  cease. 
Then  the  interstices,  which  originally  were  filled  with  air  alone  and 
next  with  water,  are  filled  in  part  with  the  one  and  in  part  with  the 
other. 

By  comparing  the  original  weight  of  the  volume  of  soil  with  its 
weight  in  its  now  wet  condition,  its  power  to  retain  water  is  easily  de- 
termined. This  power  is  the  result  of  tw^o  forces  acting  in  opposition 
to  the  force  of  gravity  ;  namely,  surface  attraction  of  solids  for  liquids, 
and  capillary  attraction.  The  water  which  is  simply  adherent  to  the 
surfaces  of  the  soil  grains  is  known  as  hygroscopic  water,  while  that 
which  is  held  in  the  capillary  spaces  is  called  capillary  water ;  and  it  is 
the  latter  which,  in  any  but  the  coarsest  soils,  constitutes  by  far  the 
larger  part  of  the  retained  moisture. 

Not  all  of  the  interstices  of  a  soil  form  capillary  spaces,  but  only 
those  of    which  the  boundary  walls  are   separated  only  by  intervals 


CAPAdlTY   FOU    WATKIl,    AND    WATEn-llKTAIMSd    CAI'ACITY     '525 

wlilc.li  roinc  williiii  llic  liiiiils  ol"  (•:i|)ill;iry  inaf^iiiliid*'.  TIiiih,  a  (!OiirHC 
Koil  may  coiiliiiii  (;oiii))aiiitiv(;ly  lew  .sucli  HpaccH,  while  oik;  of"  u  fine 
tcxtuH!  may  liav(!  ils  particlcw  ko  cIoHcIy  a|)|>r()xiriiut<!(l  that  all  of  ite 
inktrsliliul  .spaces  ai'e  capillary.  It  followH,  flierefore,  lliat  eorrijKict 
Hoil.s  |)()SS((SK  ^reatef  relaiiiin^  power  lliaii  tliose  with  larj.'e  iiiU-r- 
stic/CH  whi<!h  |)(!rmit  rapid  |>er(rolalioii,  ;iii<l  tli:ii  wlnn  llie  t<-xtiir(r  i.s  ho 
fine  that  all  tlu^  spa(!(W  arc  ca[)illaiy,  the  iiia.xiiiiiiin  retaining;  power  in 
attaiiK^d. 

The  iiifhieiiee  oC  soil  (<'.\tiire  on  eapatiity  lor  holdiiij^  wat<'r  may  he 
seen  in  the  lollowiiig  table  of  some  of"  the  re-siills  ohtjiiiie<l  \)y  II«»f'- 
maiiii  :  ' 


Diameter  of  grain 
in  mm. 

Pore-volumo  per 
1,000  cc. 

Amount  of  con- 
tained water  in  cc. 

Amount  of  con- 
Ulned  air  in  cc. 

Percent,  of  pore- 

▼olume  OIlea  with 

water. 

5 
3 
2 
1 

0.5 
less  than  0.5 

431 
41.S 
410 
400 
413 
413 

55 

77 

98 

150 

270 

347 

379 
341 

312 

250 

143 

66 

12.7 
1S.4 
23.9 
37.5 
65.4 
84.0 

The  watei'-retaiiiing  capacity  of  soils  is  determined  very  largely  also 
by  the  amounts  of  oi'ganic  matter  present ;  a  soil  rich  in  orgjinie  matter 
will,  other  conditions  being  the  same,  show  more  water  than  another 
of  less  richness.  The  extreme  influence  is  observed  in  the  case  of 
humus,  w^iich  can  hold  ten  times  its  weight  of  water.  In  view  of  this 
influence  of  oi'ganic  matter,  it  is  very  clear  that  one  way  to  help  keep 
a  soil  dry  is  to  avoid  discharging  tilth  into  it,  and  thus  keep  it  clean. 

For  the  purpose  of  illustrating  the  influence  of  very  fine  soil  par- 
ticles (clay)  and  of  organic  matter  (humus),  the  following  results  of  an 
investigation  by  Woltf  -  may  be  quoted.  He  packed  soils  of  varying 
clay  and  humus  content  into  a  metallic  vessel  with  a  permeable  bottom, 
saturated  them  completely  Avith  water,  then  superimposed  a  column  of 
water  of  equal  cross-section  and  8  cm.  high,  and  observed  the  time 
required  for  the  added  water  to  be  delivered  below  : 


"Nature  of  soil. 

Percenta 
Per  cent. 

je  of  clay. 
Ratio. 

Percentage 

of 

humus. 

Time  rt 
Hours. 

'quired. 
Ratio. 

Very  fine  sandy  loam     .... 
Very  fine  shandy  loam      ... 
Black,  rich,  chalky  loam    .    .    . 
Very  fine  sandy  loam      .... 

Very  olnyey  soil 

Soil  with  considerable  clay   .    . 

15.74 
15.96 
18.17 
25.93 
42.56 
29.76 

1. 

1.+ 
1.15 
1.64 
2.70 
1.89 

0.88 
1.40 
6.87 
0.92 
0.66 
2.19 

20.3 

25.8 
31.0 

75.8 
133.0 
188.0 

1. 

1.27 

1.52 

3.73 

6.-55 

9.26 

It  Avill  be  observed  that  the  soil  which  permitted  the  passage  of  the 
water  in  the  shortest  time  was  poorest  in  clay  and  almost  so  in  humus, 

'  Archiv  fiir  Hygiene,  I.,    p.  273. 

-  Anleitving  zur  chemischen  Untersnchimg  landwirthschaftlich  wichtiger  Stofl'e,  1S75. 


326  THE  SOIL. 

and  that  the  one  ■which  required  tlie  lonoest  time  combined  a  consid- 
erable amount  of  chiy,  not  the  highest,  witii  a  high  percentage  of  hunins, 
also  not  the  highest.  The  highest  percentage  of  clay  was  associated 
with  the  lowest  amoimt  of  hunuis,  and  the  highest  of  humus  with  a  low 
content  of  clay  ;  but  these  two  soils  (Nos.  5  and  3)  were  bt)th  less 
imjiermeable  than  that  (No.  6)  which  contained  less  clay  than  the  one 
and  less  humus  than  the  other.  It  is  to  be  noted,  however,  in  the  case 
of  the  soil  V\'ith  the  highest  proportion  of  clay  and  lowest  of  humus, 
that  it  contained  12.8  per  cent,  of  chalk  as  against  2.28  per  cent,  in 
the  most  impermeable,  and  that  this  substance,  as  has  been  mentioned, 
has  a  very  great  iuiiueuce  in  diminishing  the  degree  of  plasticity  of 
clays. 

Soil  Temperature. 

The  sources  of  heat  in  the  soil  are  three  in  nund)er ;  namely,  the 
sun's  rays,  chemical  changes,  and  the  original  heat  of  the  earth's  inte- 
rior. The  principal  source  is  the  sun.  The  heat  derived  from  cheniical 
changes  is  not  great,  and,  indeed,  is  not  even  worthy  of  consideration, 
except  in  soils  very  rich  in  organic  matter  ;  and  here  the  changes 
occur  only  in  the  presence  of  comparatively  high  temperature  due 
to  the  action  of  the  sun.  The  third  source  is  constant  and  of  much 
importance. 

The  soil  temperature  is  influenced  by  a  number  of  conditions, 
including  exposure,  atmospheric  temperature,  color,  compactness,  com- 
position, and  moisture.  Naturally,  the  surfaces  exposed  to  the  greatest 
amount  of  sunshine  get  more  heat  than  others.  The  nearer  the  angle 
of  incidence  of  the  sun's  rays  approaches  a  right  angle,  that  is,  the 
more  perpendicularly  the  rays  strike,  the  greater  the  amount  of  heat 
received. 

The  rapidity  with  which  soils  are  aiFected  in  either  direction  by 
changes  in  atmospheric  temperature  varies  widely,  but  with  any  soil  it 
is  only  in  the  very  uj^permost  layers,  the  very  surface  in  fact,  that  any 
immediate  corresponding  rise  or  fall  is  obsers^ed.  Great  sudden  changes 
affect  the  soil  below  the  surface  very  slowly,  and  in  the  deeper  layers 
the  maximum  and  minimum  temperatures  occur  much  later  than  in  the 
atmosphere  above.  The  annual  variation  diminishes  as  the  distance 
from  the  surface  increases ;  at  fifteen  feet  the  amplitude  is,  as  a  rule, 
less  than  10  degrees  F.,  and  between  fifty  and  eighty  feet  the  tempera- 
ture is  constant  the  year  round. 

The  color  of  a  soil  exerts  an  important  influence  in  the  determination 
of  its  temperature.  As  is  well  known,  a  black  surface  exposed  to 
the  sun  absorljs  the  heat  rays  more  than  a  white  one.  A  common 
illustration  of  this  fact  is  the  greater  rapidity  'with  which  snow  melts 
when  its  surface  is  dotted  over  with  dirt  and  soot  than  when  it  is 
clean  and  white,  owing  to  the  absorption  of  heat  by  the  dark  particles 
and  its  communication  by  conduction  to  the  snow  beneath  and  about. 
In  the  same  way,  soot  and  cinders  Avork  their  way  downward  into  the 
ice    on    a    pond.      Another    illustration    is    the    greater    feeling    of 


SOIL  Ti'iMi'i'niA'nriU':.  '.vil 

wiirnilJi  coiiCcn'cd  l>y  hhick  clotlics  lliiiii  \)\  \\lii(<'  in  tlic  ljri;.f|il  -iiri- 
sliiiic. 

So,  oilier  <',oii(lil,ions  l)ciii<^  I  lie  siiiiic,  u  (l;irU  s<iil  is  wiiiiiicr  tli:tii  ;i 
liji;lit  one,  wliicli  rcllecls  IIk'  licni.  r;iys  iiislx'Jid  of  aW.-'fwhiii;^  tlicm. 
OI),S(!i'va(J<»ii  lias  sliown  a  (linrrcncc  of  more  tli.-m  25  dc^n-c,-  V.  in  ilic 
i(!iri|)('raliir<!  o("  l)lacl<  and  white  sands  cxpoH'd  side  by  side  f<»  tlnr 
direct  rays  of  the  snn,  hiif  (lu;  wlii(e  sand  hy  reas(»n  of  refleelin^  \\\i' 
Ileal,  rays  will  a|»|><'ar  Id  he  inneli  liotler  lh;in  il   i-ealiy  is. 

'V\\v.  indiK'iK^e  of  conipac.l.ness  on  soil  tciii|)eraliire  varies  with  the 
season.  Aecordinn-  to  Kino-,'  ihc  general  tendeiic\'  of  rollinjr  ilic  hind 
is  (()  inak(!  il.  wanner  during  hri;;lil,  sunny  weather,  hut  in  elondv  or 
cold  weather  it  lends  to  pronioti!  (;ooliii<^.  \\v  has  observed  that,  at 
tluMlepth  oC  1.5  inches  helow  the  siirCaee,  a  rolled  fi(!ld  may  have  a 
toinjK'raturc  U)  (lc!<i;rees  l*\  hitiher  than  a  similar  soil  not  roll(;d,  and  at 
double  the  distance  he  has  noted  a,  din'cicnec  o("  (1.5  dc^rocs.  Tlii.s  i.s 
duo  chiedy  to  the  (act  that  a  compael  soil  is  a  better  eoiidiietftr  of  hejit 
than  one  (lontainino-  lari;(!  interstic(!S  tilled  with  air. 

The  chai'aeter  of  the  mineral  and  organic  constitiKjiits  of  the  soil  and 
tlu^  atnonnt  of  its  content  of  water  exert  the  very  great<ist  inHuen(Hj 
upon  its  temperatnrc.  Rocks,  sands,  and  mineral  substancres  in  gen- 
eral are  better  beat  (V)nduct()rs  than  watcM*,  organic  matter,  and  air,  and 
they  dilTer  also  one  I'rom  another  in  conductivity.  Organic  matt<^'r  is 
a  particnlarly  poor  conductor  of  heat,  and  hence  the  greater  the  amount 
of  hiinius  a  soil  contains,  the  slower  its  response  to  the  action  of 
the  snn. 

The  great  influence  of  moisture  on  soil  tcm])erature  is  due  to  the 
high  specific  heat  of  water,  and  to  the  loss  of  lieat  which  accompanies 
the  process  of  eva]ioration.  The  specific  heat  of  ordinaiy  dry  soils 
varies  from  a  fifth  to  a  fourth  of  that  of  water,  although  in  exceptional 
cases  it  may  amount  to  nearly  a  half ;  and  the  wetter  the  soil  is,  the 
higher  will  be  the  specific  heat  of  the  mass,  that  is,  the  greater  the 
nnmber  of  heat  nnits  necessary  to  warm  a  given  weight  1  degree. 
Thus  it  happens  that  a  light-colored  dry  soil  may,  in  spite  of  the  great 
influence  of  color,  attain  a  much  greater  degree  of  warmth  than  a  dark 
one  which  is  damp.  The  different  soil  constituents  have  different 
specific  heats,  ranging  from  about  0.16  for  certain  sands  and  clavs,  to 
about  0.44  for  dry  humus,  that  of  water  being  unit}\  Thus,  to  raise 
the  temperature  of  100  pounds  of  water  1  degree  will  require  100 
units  of  heat,  while  to  perform  the  same  office  f^r  equal  weights  of  drv 
sand,  wa^athered  porphyry,  weathered  granite,  and  humus,  will  require 
respectively  16,  20,  30,  and  44  units.  Therefore,  the  same  amount  of 
heat  necessary  to  raise  a  given  weight  of  water  1  degree  will  raise  the 
equivalent  weights  of  these  substances  respectively  6.67,  5.00,  3.33, 
and  2.27  degrees. 

But  although  the  high  specific  heat  of  water  is  of  importance  in 
determining  soil  temperatures,  the  chief  influence  of  moisture  in  this 
direction  is  due  to  the  great  loss  of  heat  which  accompanies  the  process 
'  The  Soil,  New  York,  1S9S. 


328  THE  SOIL. 

of  evaporation,  for  the  change  from  the  liquid  to  the  gaseous  form  is 
aecomplishecl  only  at  the  expense  of  heat.  The  greater  the  amount  of 
water  evaporated  from  a  given  soil,  therefore,  the  greater  the  expendi- 
ture of  heat  and  the  greater  the  lowering  of  the  soil  temperature. 
Conversely,  the  drier  the  soil,  the  less  the  evaporation,  and  the  greater 
its  warmtii.  A\'atcr  does  not,  however,  always  tend  to  produce  haver- 
ing of  the  temperature,  for,  in  point  of  fact,  it  may  and  often  does 
have  the  opposite  eifect.  In  the  spring,  for  instance,  when  the  frost 
is  not  vet  out  of  the  ground  and  when  the  interstices  are  filled  Avith 
cold  water  derived  from  the  melting  ice  and  snow,  the  warmei-  rain 
hastens  the  removal  of  frost,  and,  as  it  sinks  into  the  soil,  displaces 
downward  the  colder  water  and  consequently  raises  the  temperature. 

Changes  in  the  Character  of  Soils  Due  to  Chemical  and 
Biological  Agencies. 

Chemical  action  is  constantly  at  work  in  the  soil,  not  alone  on  the 
organic  constituents,  but  upon  the  mineral  matters  as  well.  The 
changes  Avhich  occur  in  the  latter  are  of  importance  to  the  hygienist 
almost  solely  in  so  far  as  they  affect  the  quality  of  the  drinking-water. 
Complicated  processes  involving  the  decomposition  of  organic  matters 
give  rise  to  quantities  of  carbon  dioxide  which,  being  taken  into  solu- 
tion by  the  w^ater  in  the  interstices,  assists  in  the  production  of  still 
more  complicated  processes  which  engage  the  mineral  constituents. 

The  changes  which,  from  a  public  health  point  of  view,  are  of  the 
greatest  interest  are  those  which  are  in  progress  in  the  process  known 
as  the  "  self-purification  "  of  soils,  in  which  the  complex  organic  mat- 
ters are  broken  up  and  reduced  to  simple  chemical  substances  through 
the  intervention  of  bacterial  life.  In  the  end,  the  carbon  is  oxidized 
to  CO2,  and  the  nitrogen  either  is  set  free,  or  is  combined  with  hydro- 
gen in  the  form  of  ammonia,  or  is  oxidized  to  nitric  acid  and  nitrates. 

The  process  requires  the  presence  of  atmospheric  air  and  of  moist- 
ure not  in  excess,  and  is  favored  by  temperatures  between  53°  and  131  ° 
F.,  the  most  favorable  being  98°.  It  proceeds  most  vigorously  and 
perfectly  nearest  the  surface,  and  virtually  ceases  at  a  depth  of  more 
than  three  feet,  little  or  no  action  occurring  in  the  subsoil  beyond  that 
depth.  If  too  much  organic  filth  and  its  attendant  moisture  are  pres- 
ent, the  soil  becomes  boggy  and  the  changes  cannot  proceed. 

An  influence  of  very  great  importance  in  its  effects  on  the  physical 
and  chemical  characteristics  of  soils  is  that  exerted  by  earth  worms, 
which  live  chiefly  on  half-decayed  leaves,  which  they  drag  into  their 
burrows  to  be  used  as  food  and  as  linings  and  plugs  for  the  burrows  as 
well.  According  to  Charles  Darwin,^  their  castings  contain  0.018  per 
cent,  of  ammonia,  and  the  humus  acids,  which  have  been  proved  to 
play  a  very  important  part  in  the  disintegration  of  various  kinds  of 
rocks,  appear  to  be  generated  within  their  bodies.  They  swallow 
earth  both  in  the  process  of  excavating  their  burrows  and  for  the 
^  The  Formation  of  Vegetable  Mould  through  the  Action  of  Wonns. 


SOIL-A  III. 


.'}29 


nutriment  wliicli  it  tii;iy  conlnin,  ;in(l  (;xcrt  :in  iniport.'int  riir'(;li;iiii<'al 
uctioii  on  tii(!  soil  ;^i;iiiis,  r((lucin<^  tlicir  si/c  liv  ;itlrili'in  williin  llicir 
gizzards.  Artcr  (illinn-  iIicimscKc-  uilli  i-.w\\\,  lli<  y  -(mn  conif  to  tlx; 
snrfiMM!  ("or  (Ik^  purposi;  of  ('ni|)tyin<^  I  licnis«tlvr's. 

"  In  iniiny  |);U'ts  ol"  I^jij^Iund  a.  wcifflit  of  more  th.iii  10  ton-  of"  dry 
earth  anniiuiiy  passes  tin-oii^li  the  bodies  of"  worms,  and  i.-^  bronjrlit  to 
tlic  Hurfiuic  on  each  aere  <»f"  land,  so  (hat  the  whohi  Htij>erlieial  Ix-d  of 
vegetal)h!  monUl  passes  tin-onnh  iheir  hochcs  in  the  (jourse  of  every  few 
y(!ars."  I^^-om  various  data,  l)ar\vin  eai(;uhitcd  that  th(!  {xistin^, 
spn^ad  out  uniformly,  woidd  f"orm,  in  the  course  of"  ten  yj^rs,  a  layer 
varyiiifj^  f'l-om  O.S,''),  in  (he  eas(!  of  a  very  jxtor  soil,  to  2,2  inches  in 
ordinarily  rich  soils,  'iheir  mechanical  action  and  that  of  ants,  moleH, 
and  other  burrowing  animals  have  much  to  do  with  keeiiiug  soils  open 
and  friable. 

Soil-air. 

The  air  in  the  int(M'stices  of  the  soil  differs  from  that  of  the  atmos- 
])here  mainly  in  its  i-iehness  in  carbon  dioxide,  which  arises  l"rom  the 
decomposition  of  organic  matters.  It  is  also  poorer  in  oxygen,  but  by 
no  means  always  in  a  corresponding  degree,  and  it  is  usually  quite 
humid  by  reason  of  the  presence  of  soil  moisture. 

The  amount  of  carbon  dioxide  varies  very  widely  in  different  soils 
and  at  different  de])ths  of  the  same  soil,  and  it  fluctuates  very  consider- 
ably also  under  differing  conditions  at  any  given  point  in  the  same  soil. 
Other  conditions  being  the  same,  the  amount  is  most  marked  in  .soils 
rich  in  organic  matter  undergoing  decomposition-changes.  In  soils 
poor  in  this  respect,  the  amount  may  be  no  greater  than  in  the  atmos- 
phere. Pettenkofer,  for  instance,  found  in  the  air  of  desert  .«and, 
which  was  devoid  of  organic  matter,  the  same  amount  as  was  present 
in  the  air  immediately  abov^e  it. 

In  ordinary  soils,  the  amount  increases  with  the  distance  from  the 
surface,  as  has  been  shown  by  Fodor,Mvho  made  a  great  number  of 
analyses  of  air  at  different  depths  at  a  number  of  places,  the  ob.serva- 
tions  extending  over  several  years.  The  average  amounts  found  at 
depths  of  1,  2,  3,  and  4  meters,  expressed  in  parts  per  1,000,  were 
as  follows  : 


Depth  in  meters. 

1                       2 

3 

4 

Station  1 

4.8 
13.7 
18.1      1 

6.6 
14.3 
28.4 

20.  i 

28  7 

Station  2 

Station  3 

36  5 

The  influence  of  season  also  was  shown  by  him  to  be  very  considerable, 
the  highest  amounts  occurring  during  the  hot  months,  and  the  lowest 
in  winter.  The  averages  bv  months  are  presented  in  the  following 
table : 

^  Boden  und  Wasser,  Braunschweig,  1SS2. 


330 


THE  SOIL. 


Mouth. 


Jamiarv  . 
Febniarv  . 
March  ."  . 
April  .  . 
May  .  .  . 
June .  .  . 
July  .  .  . 
August .  . 
September 
October  . 
November 
December 


Depth  iu  meters. 


6.5 

6.8 

7.0 

9.9 

11.5 

14.5 

15.8 

12.8 

10.9 

9.8 

8.4 

8.1 


12.6 
12.2 
11.8 
14.9 
IG.l 
21.5 
22.8 
20.7 
19.3 
15.0 
13.8 
12.6 


25.0 

24.8 
24.7 
25.2 
27.2 
29.2 
35.9 
32.6 
31.4 
29.4 
26.5 
25.8 


Fig.  19. 


These  results  are  only  such  ns  might  be  expected  when  we  consider 
that  decomposition  of  organic  matters  proceeds  most  vigorously  within 
certain  limits  of  high  temperature. 

Fluctuations  in  the  amount  present  at  any  given  point  arc  due  to  a 
number  of  conditions  which  include  rainfall,  the  action  of  the  wind, 
the  rise  aud  fall  of  the  subsoil-water,  and  differences  in  atmospheric 
pressure  and  temperature. 

Rainfall,  by  tilling  the  superficial  interstices  of  the  soil  with  water, 
interferes  with  the  natural  process  of  soil  ventilation  and  causes  an 
immediate  accumulation  of  carbon  dioxide,  which, 
however,  is  shortly  followed  by  a  diminution  due 
to  absorption  of  the  gas  by  the  water,  which 
thus  acquires  an  increase  in  its  power  of  attacking 
and  dissolving  the  mineral  constituents  of  the  soil. 
Inasmuch  as  the  bulk  of  the  absorbed  rainfall  is 
held  by  the  upper  strata  of  the  soil,  its  influence  is 
more  marked  there  than  at  greater  depths.  As  it 
sinks  downward,  however,  in  very  \vet  weather,  it 
drives  the  air  before  it,  and  causes  its  escape  at 
points  where  its  egress  is  not  obstructed. 

The  action  of  wind  is  exerted  in  two  ways:  by 
perflation  and  by  aspiration.    By  blowing  strongly 
across  the  surface  of  the  soil,  it  aspirates  the  air  in 
the  upper  layers  and  causes  an  upward  movement 
in  the  air  below,  or  it  may  suck  it  out  at  one  mo- 
ment and  take  its  place  the  next.     Again,  it  may 
blow  with  such  force  against  the  surface  as  to  drive 
the  contained  air  downward  before  it,  so  that  the 
interstices  become  filled  with  ordinary  atmospheric 
air.     The  action  is  more  marked  in  soils  of  ordi- 
nary coarseness  of  texture  than  in  very  open  soils 
with  large  interstices,  which  permit  freer  movement 
in  the  upper  strata.      This  may  readily  be  demonstrated  by  means  of  a 
simple  experiment  with  the  apparatus  shown  in  Fig.  19.     Here  we  have 
a  glass  cylinder,  inside  which  is  a  glass  tube  extending  from  the  bottom 


Apparatus  to  show  action 
of  wind  on  soil  air. 


SOIL- A  in.  •'!•"' 1 

and  l)Oiit  ovor  at  ilio  top  ho  uh  (o  foi'in  a  U,  info  wliirli  an  anion iil  of 
wat(!r  snirKricnl,  lo  (<'ftii  a  sc-il  rri;iy  Ix-  inl rodncfd.  If  ii<»\v  \v«-  fill  the 
intorveninji;  s|);i,c,c  up  (o  the  (op  willi  siiikI,  ;iii(I  iIkh  direct  a^riinHt  tlio 
Hnrfiiec  of  IIk!  lallci'  ;\.  einTcnt  oCair  by  nicMn.s  of  ;i  IjcIIowh  or  liy  l)Io\v- 
\\\\f  sliiirply  tln-on<:;li  a  tnlx;  of  p;lass  or  other  niafx-rial,  the  whole  volume 
of  air  in  tiie  inters! ic.(!,4  is  set  in  motion,  wliieh  is  comniiinicati-d  to  the 
!iir  within  tlu;  enc^loscd  t.nhe,  so  that  the  water  in  the  U-shaped  dcpn-K- 
sion  is  eansed  to  oscill.ilc.  If  \\\v.  water  complet<!ly  fillH  thr;  short  le^ 
oj"  the  U,  it  may  l)(^  (oreed  over  and  eansed  to  drij).  If,  howev('r, 
insti'iid  of  em|)loyin<i;  s;iiid,  we  (ill  the  cylinder  with  (-(cirse  ^^ravi;!, 
the  oseilhilion  ol"  the  water  will  he  either  less  notieeahle  or  entirely 
absent,  the  air  which  enters  at  one  point  on  the  Hnrlliee  ecunmuni- 
catinfjj  its  motion  only  to  tliiit    Immediately  adjac^ent  in  the  upper  part. 

The  rise  and  (iill  of  the  wsiter  in  {\\v.  snhsnil  assist  in  the;  prodnetion 
of  vnriMlions  in  the  iimonnl  of  eai'hon  dioxide;  on  the  on(>  hand,  hy 
its  rise,  foreinn;  (lie  rich  soil  :iir  iipwiird  :ind  <iii(w;iril,  :incl,  oti  the 
other  hand,  by  its  fall,  dr;iwin<;-  the  soil-:iir  downward  and  e^m.-in^ 
its  place  in  the  upper  strata  to  he  lilled  with  atmospheric  air  with 
low  (V)ntent  of  the  eas. 

J)ilferen(X!s  in  temperatni'e  and  harometrie  ])ressnre  have  also  Ix-en 
mentioned  as  excrtin*^  influence  on  the  motion  of  the  f^ronnd  air.  In 
sprino;  and  summer,  the  ground  air  is  colder  and  denser;  and  in 
autunm  and  winter,  it  is  warmer  and  lighter  than  the  air  above.  Hence 
in  the  former,  it  tenets  to  remain  stationary  or  to  siid-c ;  while  in  the 
latter,  it  rises  and  jningles  witli  the  atmosphere,  which,  under  proper 
conditions,  replaces  it.  Again,  these  changes  may  occur  in  both 
directions  within  the  same  space  in  twenty-four  hours.  For  instance, 
at  evening  and  at  night  the  atmospheric  air,  l^eing  colder,  enters  the 
soil ;  while  by  day,  being  warmer,  its  direction  is  reversed,  and  air  is 
drawn  up  from  below. 

Movement  due  to  temperature  differences  is  almost  constant,  since  it 
is  only  rarely  that  the  temperatures  of  the  air  and  soil  are  in  agree- 
ment. The  influence  of  barometric  pressure-changes  is  not  very  great ; 
with  fall  in  pressure,  the  tendency  is  toward  upward  movement,  and 
with  rise,  toward  downward  movement ;  but  Fodor  found  from  the 
study  of  a  large  number  of  observations  that  the  actual  observable 
changes  were  insigniflcant. 

A¥ith  the  various  influences  at  work  causing  movement  of  the  soil- 
air  in  all  directions,  it  is  plain  that  the  soil,  especially  if  highly 
permeable,  is  endowed  with  a  sort  of  respiratory  function  which  keeps 
it  moi'e  or  less  well  ventilated. 

Formerly,  it  was  believed  by  Pettenkofer  and  others  of  the  "  Munich 
School  "  that  the  amount  of  carbon  dioxide  in  soil-air  might  serve  as 
an  index  of  the  amount  of  impurity  and  of  the  rate  at  which  the  latter 
is  decomposing,  and  tliat  comparison  of  the  amounts  obtainable  from 
different  soils  would  serve  to  indicate  their  relative  cleanliness.  But 
such  is  not  the  case  with  soils  equally  permeable,  owing  io  the  influence 
exerted  on  soil  ventilation  bv  so  manv  varvinjr  and  conflicting  causes. 


332  THE  SOIL. 

Indeed,  it  has  been  proved  by  Fodor  that  a  permeable  soil  extensively 
contaminated  by  org;anic  filth  may  yield  less  of  this  index  of  impurity 
than  one  far  cleaner,  but  less  susceptible  to  ventilating  influences. 

Soil-water. 

The  moisture  contained  in  the  soil  may  be  designated  in  three  dif- 
ferent ways,  according  to  its  position  and  the  forces  by  which  it  is 
lu'ld  in  ]>lace ;  namely,  hvgrosco])ic,  ca}iillary,  and  gravitation. 

Hygroscopic  water  is  that  which  adheres  to  the  surfaces  of  the  soil 
particles  in  the  presence  of  air.  A  certain  amount  of  moisture  is  con- 
densed upon  the  surface  of  most  solid  substances  exposed  to  ordinary 
dampness,  and  it  adheres  with  great  tenacity.  The  amount  of  water 
so  obtained  differs,  other  conditions  being  the  same,  according  to  the 
nature  of  the  soil,  some  soil  constituents  surpassing  others  in  their 
powder  to  attract  it.  Thus,  soils  rich  in  organic  matter  (humus)  have  a 
greater  degree  of  hygroscopicity  than  others  in  which  this  constituent 
is  present  to  a  lesser  extent.  In  some  soils,  the  amount  of  hygroscopic 
M'ater  is  very  marked  by  reason  of  the  large  amount  of  organic  matter, 
and  because  also  of  the  large  surface  area  presented  by  the  soil  particles. 
Some  idea  of  the  tenacity  with  w^hich  this  moisture  is  retained  may  be 
derived  from  the  fact  that  air-dried  soils  w'hich  appear  to  be  quite 
dry — the  dust  of  country  roads,  for  instance — may  yield  as  much  as  a 
tenth  of  their  weight  of  w^ater  on  complete  drying  by  ordinary  labora- 
tory methods.  Both  the  moisture  absorbed  from  the  air  and  the  water 
held  on  the  soil  grains  by  surface  attraction  after  a  condition  of 
decided  wetness  has  been  changed  by  the  draining  away  of  the  rest, 
may  be  termed  hygroscopic. 

The  capillary  moisture  is  that  which  is  held  within  those  spaces 
which  have  been  spoken  of  as  capillary  in  their  nature.  Under 
ordinary  conditions,  these  are  intermingled  with  spaces  which  may  not 
be  so  designated  and  wdiich  contain  air,  and  so  the  capillary  moisture 
does  not  ordinarily  equal  the  pore-volume.  The  water  in  the  capillary 
spaces  may  be  that  which  is  retained  after  thorough  wetting  from  above, 
or  it  may  have  crept  upward  or  laterally  from  points  completely  satu- 
rated. Capillary  movement  occurs  in  all  directions,  but  it  is  most 
marked  from  below  upward  to  points  wdiere  water  is  being  withdrawn 
by  evaporation  or  by  the  demands  of  growing  vegetation. 

The  height  to  which  water  may  rise  by  virtue  of  this  force  depends 
upon  the  diameter  of  the  spaces ;  the  smaller  the  diameter,  the  greater 
the  rise.  Jurin's  law  of  capillary  movement  is,  that  the  height  of 
ascent  of  one  and  the  same  liquid  in  a  capillary  tube  is  inversely  as 
the  diameter  of  the  tube.  Thus,  water  will  ascend  ten  times  as  high 
in  a  tube  having  a  diameter  of  0.1  mm.  as  it  will  in  another  with  a 
diameter  of  1.0  mm.  It  follows,  therefore,  that  capillary  movement 
is  most  marked  in  soils  of  fine  texture. 

Capillary  movement  is  influenced  materially  also  by  temperature 
and  by  the  nature  of  substances  held  in  solution.     It  diminishes  as  the 


SOIL- WATER.  o''"3 

tcmi)(!nitiir(!  riHdH,  and  iiKToaHii.s  uh  tlic  l<iii|)i  i.iiinv  (iills,  sr*  fliat  (^K)Iiiij^ 
a  Hoil  iiiiiformly  will  (^•UIS(•  iiutrcMscd  ciiiillmy  iiiovciiiciit,  and  lir-Jitiii^ 
ii  will  (laiisc,  a-  (all.  I>iil  vvilli  iincvrn  Iciiipcraliircs,  flu;  motion  will  !«; 
didrnMil,  acc.ordiiijr  as  (Ik;  (cMipcraiMrds  vary.  'I'hns,  if  (lie  lower  |»art 
of  a  colnnui  o("  soil  Ix;  <',oolcd,  the  surface  f<'nsion  of  its  contained 
waier  will  l)e  iiuu-eased  ai,  lliai  point,  and  water  will  he  ;itlr;ieted  from 
\\w.  |)ar(,s  above,  }z;ravil,y  assisting  ;  wlier(;as,  if  it  he  heated,  its  con- 
tained water  will  he  attracted  npwanl. 

In  satnra((Ml  soils,  motion  of  the  water  in  any  direction  is  in(lnenr-ed 
very  greatly  by  tem|)eraliM'e,  becanse  of  tlu;  elfeet  of  heat  in  chan^in^ 
the  viscosity  of  water.  The  higher  Ihe  tompcralnre,  the  ^rcat<;r  tho 
diminntion  in  viscosity  and  the  freer  the  movement. 

'V\\v,  indnencc  of  dissolved  snbstances  dc|)eiid.-  ii|Min  thiir  natnre, 
Konu^  favorinir,  and  others  retarding;,  movement.  'V\h'.  rate  is  increased 
by  the  presenile  of  nitrates,  and  is  diminished  by  common  salt  and 
snlphatc  of  calcinm  ;  bnt  the  favoring;  infln<'nee  of  the  prcHenw  of 
nitrates  is  connteraeted  most  markedly  by  or<i;ani(;  snbst^in(!cs  prodiiWKl 
in  the  d(>com]>osition  of  matters  of  vc^;ctable  ori<rin,  for  a  minute  trace 
of  these  completely  neutralizes  the  effect  of  such  amounts  of  the 
former  as  are  commonly  present  in  cultivated  soil. 

It  is    self-evident    that   anything    tending   to    the    diminution    of 
capillarity  of  a  soil  diminishes  the  rate  of  capillary  flow.      When  the 
soil  is  Avorked  in  such  a  way,  therefore,  as  to  produce  an  o]:»en,  crumbly 
condition  in  place  of  one  of  compactness,  the  rate  of  ca|)illary  move- 
ment within  it  is  diminished  very  greatly. 

We  come  now  to  the  third  division,  which  has  been  designated  as 
gravitation-water.  This  is  the  water  which  has  drained  away  thrr>ugh 
the  soil  by  the  force  of  gravity  and  accumulated  in  the  sul)sr)il  over  an 
impermeable  stratum  which  has  arrested  its  farther  downward  journey. 
This  is  what  is  commonly  known  as  ground-water,  or  subsoil-water. 
Its  zone  extends  from  tlie  surface  of  the  impermeable  barrier  upward 
to  that  point  where  the  interstices  of  the  soil  cease  to  be  completely 
filled  with  water,  but  are  filled  partly  with  air.  This  point  is  knf»wn 
as  the  ground- water  level.  The  zone  above  it,  through  which  water  is 
moved  in  the  capillary  spaces,  is  known  as  that  of  the  capillaiy  soil- 
water,  and  extends  as  far  as  the  water  is  moved  through  that  force. 
Above  this,  at  and  near  the  surface,  is  the  zone  of  eva]>oration,  from 
which  water  is  evaporated  into  the  atmosphere. 

The  impermeable  stratum  beneath  the  subsoil-water  may  be  either 
very  fine  sand,  compact  clay,  or  rock.  It  may  be  thin  or  thick,  accord- 
ing to  circumstances.  Behnv  it,  there  may  be  a  succession  of  alter- 
nating permeable  and  impermeable  strata,  so  that  in  driving  deep  wells 
a  variety  of  strata  are  pierced,  and  waters  of  varying  composition  may 
be  secured.  Dense  clay  is  practiciilly  impermeable  to  water,  but  at 
the  same  time  it  can  communicate  its  moisture  to  surfaces  with  which 
it  comes  in  immediate  contact,  a  fact  which  renders  necessary  the  in- 
terposition of  damp-proof  material  in  the  foundations  of  houses  built 
upon  it. 


ti 


334  THE  SOIL. 

Rocks  vary  greatly  in  impermeability  ;  the  densest  of  them  contain 
very  small  amounts  of  moisture  in  their  pores,  while  others  are  so 
porous  that  they  may  contain  as  much  as  a  third  of  their  volume  of 
water.  Auaiu,  most  rock  de})osits  arc  more  or  less  fissured  and 
seamed,  and  thus  permit  to  a  greater  or  less  degree  the  passage  of 
M'ater  at  these  points. 

The  water-bearing  stratum  is  usually  gravel  or  sand,  but  may 
l)e  porous  or  fissured  rock.  Its  depth  is  exceedingly  variable, 
dejK'nding  upon  local  geological  conditions,  and  at  two  jwints  not 
widely  separated,  it  may   be  respectively  slight  and  considerable. 

The  ground-water  is  in  constant  motion  both  laterally  and  vertically. 
Its  lateral  movement,  whatever  its  rate,  depends  u})on  the  configuration 
of  the  impermeable  layer  below,  and  not  upon  that  of  the  surfiicc  of 
the  land.  Generally  speaking,  the  direction  of  the  movement  is  toward 
the  nearest  large  body  of  water,  be  this  the  sea,  a  lake,  or  a  river ; 
but  it  is  not  often  possible  to  determine,  except  in  a  general  way,  from 
surface  observations,  whether  at  any  given  point  the  flow  is  in  one 
direction  or  another.  This  is  especially  true  when  the  water-bearing 
stratum  is  thin  and  underlaid  by  an  impermeable  stratum  of  very  irreg- 
ular conformation. 

The  rate  of  movement  is  also  exceedingly  variable ;  it  may  be  fast, 
or  slow^,  or  hardly  perceptible.  In  Munich,  for  instance,  according 
to  Pettenkofer,  it  amounts  to  about  fifteen  feet  daily,  while  at 
Berlin,  it  is  only  very  slight,  and  at  times  is  wanting.  It  is 
influenced  by  the  configuration  of  the  subsurface,  by  the  perme- 
ability of  the  subsoil,  by  the  amount  of  the  accession  of  moisture 
from  rainfall  and  melting  snow,  by  the  obstacles  interposed  by  the 
roots  of  trees  and  other  plants,  by  others  at  its  outfall,  and  by  the 
withdrawal  of  moisture  by  the  needs  of  vegetation  and  of  communities 
of  men. 

The  rise  and  fidl  of  the  ground-water — that  is,  its  vertical  move- 
ment— depend  chiefly  upon  the  amount  of  rainfall  ;  and,  on  the  other 
hand,  upon  the  rate  of  withdrawal  by  evaporation,  vegetation,  and 
Avater  supply  of  communities,  and  upon  the  freedom  of,  or  obstacles  to, 
the  outflow. 

The  effect  of  rainfall  is  generally  not  immediately  perceptible,  for 
so  much  time  intervenes  between  heavy  falls  and  penetration  that  a 
falling  of  the  ground-water  level  may  continue  to  be  observed  for  a 
long  time  after  a  period  of  great  wetness  ;  but  when  the  level  rises,  it 
is  a  proof  that  additions  have  been  received  from  above,  though  per- 
hapvS  the  accession  has  travelled  through  a  long  distance  in  the  soil. 
When  the  level  falls,  it  is  a  sign  that  the  upper  strata  have  become  dry 
through  evaporation,  and  that  capillary  attraction  has  carried  moisture 
upward  to  replace  the  loss. 

The  rise  and  fall  of  the  ground- water  level  may  be  determined  by 
measuring  from  day  to  day  the  distance  between  the  surface  of  the  soil 
and  the  height  of  the  water  in  a  number  of  wells  in  a  given  locality. 
This  may  readily  be  done  by  means  of  a  tape-measure  or  chain  to  which 


SOIL-WATKIl.  "•>■> 

is  jit(,:i(;li(Ml  ;i  nxl  Ix-uriiip;  ;i,  iiiiiiilxr  oC  sliiillow  rrict:illic  riips  wliicli  Jirc, 
I()Wci"<'<l  into  the  \v;ilci\  'I'lic  <list!iiicc  hctwccii  tlic  |i<tiiit  on  (Ik;  <;li;iill 
;ii  iJic  nidlllh  (if  Ihc  well  :ilnl  Mk'  II  |  t|  nil  n<  >  - 1  fillt  ill  uliidi  Wutf.T  Ih 
found    indic.'ilcs    \\\r    |iositiuii    of    tin-    \v;ilcr-lcvcl    uilli    i'i:-|ii<t    to    fli<; 

HMI'lilcc. 

By  i-<wnovin^  oI»sI,!I(;Ich  Io  I  lie  oiitliill  (»('  flic  nii(lci}^roiiii<l  I'ivcr  an  it 
H()iucUni{!S  is  CM  I  led,  ;tnd  l>y  cfciilina;  mw  onlliUls  by  dilcliiti^  rnon;  or 
less  dc(!|)ly,  ;ic(;(»rdin<;'  lo  iiidi\  idii.d  conditioiiH,  by  Hiiildn^  drainage 
wells,  or  l»y  liiyiiit;  <li;iiii  lili'  Ixncitli  (lie  snrliuK!  at,  siieli  depths  as  may 
a|)|)e:i-i-  to  lie  :idvisal)le,  I  lie  iesci  oC  the  ground-water  may  he  eoti- 
siderahly  lowei-ed,  and  I  lie  soil  (lierchy  remlcicd  <<ii  i(-)ioinlin^ly  drier, 
and  also,  hy  reason  of  the  inlln(!n<!o  of  water  on  .^oil  t<;m|)r;raturc, 
warmer. 

Sources  of  Soil-water. — 'V\\v.  ])rinei|)al  source;  of  soil-water,  it  in 
hardly  necessarv  to  saN',  is  the  rainfall,  hut  hy  no  means  all  of  the 
water  precipitated  iVoiii  lli<;  alniosplicic  during  a  storm  j)enetrat<.'«  t^j 
the  subsoil.  Lij^ht  I'alns  may  be  wholly  lost  by  evaj)oration,  and 
heavicM'  ones,  especially  durin<>;  acitive  V(!g(;tation,  may  penetrate  but 
very  slightly  beneatli  the  sin-face.  In  early  sprin*;  and  in  au- 
tumn, the  anioimt  which  percolates  downward  is  natni-ally  much 
larger  in  |)roportion.  A  by  no  means  insignificant  amount  of  nioLst- 
ure  is  that  derived  by  absor|)tion  and  condensation  from  a  moist  atmos- 
phere. In  periods  of  drought,  this  power  of  dry  soil  to  absorb  water 
from  lumiid  air  is  of  the  greatest  value  to  vegetation.  The  amount 
absorbed  tlillcrs  aticording  to  the;  nature  and  hygroscopic ity  of  the 
soil  elements.  Thus,  a  soil  rich  in  humus  will  attract  more  water 
than  another  composed  wholly  of  sand.  Condensation  of  water 
occurs  when  the  surface  is  cold  and  in  contact  with  moist  air.  This 
contlensatiou  may  occur  from  above  or  from  the  rising  moist  soil  air 
just  below. 

A  third  source  of  moisture,  of  no  great  importance,  is  the  breaking 
up  of  organic  matter  into  its  constituent  elements,  in  which  process 
the  hydrogen  is  in  great  part  ultimately  released  in  combination  with 
oxygen  as  water.  Another  and  exceedingly  important  source  of  soil 
moisture,  important  not  because  of  the  amount,  but  because  of  the 
(piality  of  the  water,  aud  because  of  its  possible  effect  on  the  supply  of 
drinking-water  and  on  public  health,  is  the  waste  waters  incident  to 
human  life,  which  in  so  great  a  })ro}iortion  of  communities  are  dis- 
charged directly  into  the  soil,  where,  being  out  of  sight,  they  are  equally 
out  of  mind. 

Loss  of  Soil  Moisture  by  Evaporation. — The  amount  of  water 
which  a  soil  loses  by  evaporation  is  infiuenced  by  a  number  of  fictoi-s, 
which  include  the  water  content  of  the  soil,  the  height  of  the  jiermeable 
layer,  the  composition  and  structure  of  the  soil,  and  the  character  of 
its  surface,  and,  particularly,  whether  it  is  covered.  In  other  woixls, 
the  rapidity  of  the  process  is  projxn-tional  to  the  combined  area  of  sur- 
faces exposed,  and  to  the  facility  for  replacing  the  loss  by  withdrawals 
from  below. 


336  THE  SOIL. 

Influence  of  Vegetation  on  Soil  Moisture. — The  amount  of  water 
in  soils  is  iutlueneed  greatly  by  growing  vegctatiou,  which  requires  a 
vast  supply  for  the  proper  inaiutenance  of  its  fuuctions.  It  withdraws 
it  by  absorption  by  the  roots,  which  extend  down^^•ard  to  surprising 
depths,  the  roots  of  wheat,  for  instance,  attaining  sometimes  a  length 
of  eight  feet  and  more.  From  the  roots,  the  water  passes  into  the  cir- 
culatiou  of  the  plant,  assists  in  the  various  physiological  processes,  and 
then,  for  the  most  part,  is  given  off  from  the  leaves  into  the  atmos- 
phere. It  has  been  calculated  by  Pettenkofer  that  an  oak  evaporates 
more  than  eight  times  the  rainfall,  and  that  the  Euealyptus  globulus  is 
even  more  active.  The  difference  between  the  rainfall's  contribution 
and  the  amount  exhaled  represents  the  amount  which  has  been  with- 
drawn by  the  roots  from  the  capillary  spaces  and  from  the  water-table 
itself.  As  the  water  in  the  capillaries  is  relinquished  by  them,  more 
comes  up  from  below  to  take  its  place.  Thus  it  is  that  a  plant  or  tree 
acts  during  the  growing  season  as  a  constantly  working  suction  appara- 
tus tending  to  dry  the  ground,  and  so  may  be  explained,  in  part  at 
least,  the  condition  of  wetness  that  is  acquired  by  some  lands  after 
removal  of  trees. 

All  growing  crops  withdraw  enormous  amounts  of  water,  and  after 
the  grow'th  becomes  well  advanced,  it  is  the  capillary  water  upon  which 
dependence  is  placed,  for  the  rainfall  penetrates  but  a  short  distance 
into  cultivated  land,  and  most  of  it  is  lost  by  evaporation.  Were  it 
not  for  the  capillary  water  supply,  no  crops  could  be  raised,  except 
under  most  extraordinary  conditions  of  weather  and  by  artificial  irri- 
gation, since  but  a  short  period  of  drought  would  suffice  to  produce 
wilting.  According  to  Stockbridge,^  "  The  quantity  of  water  thus 
required  and  evaporated  by  different  agricultural  plants  during  the 
period  of  growth  has  been  found  to  be  as  follows  : 

1  acre  of  wheat  exhales 409,832  pounds  of  water. 

1     "     "    clover  exhales 1,096,234         "      "       " 

1     "     "    sunflowers  exhales 12,585,994         "      "       " 

1     "     "    cabbage  exhales 5,049,194        "      "       " 

1     "     "    grape-vines  exhales 730,733         ''      "       " 

1     "     "    hops  exhales 4,445,021         "      "       " 

But  the  influence  of  vegetation  on  the  water  content  of  the  soil  is 
not  limited  simply  to  its  withdrawal  and  evaporation  into  the  atmos- 
phere, for  it  acts  in  the  other  direction  to  impede  surface  flow  and  sub- 
surface drainage.  This  is  seen  more  particularly  in  the  case  of  trees 
and  forests.  The  forest  cover  keeps  the  soil  granular  and  ])romotes 
downward  percolation  ;  the  tree  roots,  penetrating  in  all  directions, 
present  an  effective  obstacle  to  rapid  lateral  movement  through  the  soil. 
Removal  of  forests  and  clearing  away  the  surface  of  the  forest  litter 
promote  sudden  and  destructive  freshets  in  the  springtime  and  drought 
when,  later  in  the  year,  the  water  is  needed.  The  ill  effects  of  deforest- 
ation are  noticed  particularly  in  parts  of  Maine  and  in  the  Adiron- 
dacks,  where  streams  that  formerly  ran  full  the  year  round  are  raging 
'  Kocks  and  Soils,  New  York,  1888. 


SOIL-  \VA  'I'Kll.  ''''7 

tfMTcnls  wlict)  i\\r.  wiiifcr's  hiiovvk  ;ir(!  iiu'lliii^  iiiid  Imi  idsij^riilir-unt 
brooks  or  wliolly  dry  during'  IIk;  siiiniiicr  iihmiI  li-:.  It,  lian  hfcn  hUit«,-d 
hy  M;ij(»i'  Itnyiiiond,  of  (Ik;  If.  S.  MiiHlnccrs,  tli;i(,  in  foroHt  urcjUH,  four- 
IHlli.s  of  tli(!  r;iiiil;ill  arc  savcid,  wlillf  in  '■|(;iic(|  l.mil  ihc  saiiic  amount 
i,M  lost  hy  (ivapor'atioii  and  siirCacc  llnw. 

Other  Effects  of  Vegetation  Upon  the  Soil.-  In  addiiion   U)  it« 

inlliiciicc  on  (lie  nioNcnicnt  of  soil-wald-  and  on  il-  amount,  vegeta- 
tion is  an  im|)orl;inl  fador  in  llic  ddi  i  ininal  ion  oC  soil  temjMjruturc 
and  of  tli(!  amoimt  of  mineral  matter  availalde  lor  siie(;e(;dinjf  jrrowtliH. 
TIk!  dee|)ly  peneti'at  ino;  roots  hrinjji;  to  the  tissues  of  tin;  ^rowin^  plantH 
a  lar^'c^  ainouni  ol"  mineral  m;illiis  iVuin  llic  -nh.-oil.  ( )ii  th(;  d<yitli 
and  d(u;ay  of  the  plant,  these  matters  are  relnrned  to  the  soil  at  itw 
siirfacio,  whore  thoy  are  avaihiblc;  for  reabs(»r|)tion  as  plant  food. 

The  efl'ec^t  of  ve<i;etation  on  soil  tem|)(!i'atin"e  is  of  nineh  im|M»rtance 
in  both  hot  and  eold  climates.  A  bari'en  soil  or  one  from  whieli  veg- 
etation has  been  strij)pe(l  absorbs  the  heat  rays  of  the  sun  more  raj)- 
idly  and  becomes  niueh  hotter  than  one  which  is  protected  by  growth 
of  any  kind.  The  air  al)ove  the  soil  becomes  hotter,  too,  because  of 
greater  Jieat  radiation,  and  the  dilTerencc  in  tlie  surface  tem])erature  of 
bare  ground  and  that  covered  by  grass  or  other  vegetation  is  further 
increased  by  the  cooling  effect  of  evaporation  of  moisture  from  the 
leaves.  Herbage  acts  as  a  protection  against  excessive  heating  in  hot 
climates,  and  as  a  blanket  to  prevent  loss  of  heat  in  cold  ones.  In 
summer,  the  areas  covered  by  vegetation  are  cooler  than  those  which 
are  un})rote(!ted  against  the  direct  rays  of  the  sun,  and  in  winter,  they 
are  warmer  because  of  the  obstacle  to  heat  loss. 

Trees  obstruct  the  sun's  rays  and  impede  wind  currents,  and  thus 
the  soil  is  cooler  and  at  the  same  time  suffers  less  loss  of  moisture  by 
evaj)oration.  Tlie  obstruction  of  the  wind  currents  deprives  the  soil 
air  of  one  of  the  influences  having  to  do  with  its  movement,  and  thus 
interferes  with  soil  respiration.  The  obstacle  opposed  by  trees  to  the 
motion  of  air  is  so  great  that,  in  the  intericn-  of  a  ])iece  of  woods,  the 
air  may  be  quite  calm  while  a  gale  is  blowing  outside.  In  winter,  the 
obstruction  of  the  sun's  rays  aids  in  the  consei'vation  of  the  soil  heat 
by  preventing  the  accumulated  snow  from  melting,  and  thus  keeps  the 
surface  protected  by  a  blanket. 

In  cold  cHiTiates  the  influence  of  trees  may  be  at  the  same  time  per- 
nicious and  beneiicial ;  that  is  to  say,  pernicious,  in  that  the  ground  is 
colder  and  moister  tlian  it  Mould  be  had  the  sun's  rays  free  access, 
and  beneficial,  in  that  the  trees  aflbrd  protection  against  wind.  The 
judicious  removal  of  trees  will  often  render  a  climate  more  equable. 
In  hot  climates,  as  in  cold,  trees  should  be  removed  ouly  in  case  of 
necessity  and  after  due  consideration  of  the  probable  results.  The 
hottest  spots  in  hot  countries  are  those  deprived  of  the  beneficial  influ- 
ences of  vegetation. 

It  may  not  be  out  of  place  here  to  meutiou  the  supposed  agency  of 
woodland  in  pi'oteeting  communities  from  "  malarial  exhalations  "  from 
swamp  localities.     That  the  interposition  of  a  belt  of  trees  has  been 
22 


338  THE  SOIL. 

followed  in  a  number  of  instances  by  decided  improvement  in  public 
health  so  far  as  malaria  is  concerned,  cannot  well  be  denied  ;  but  the 
innn-ovenu'iit  is  not  owino;  to  the  fancied  property  of  leaves  to  con- 
dense ujion  their  surfaces  tiie  malarial  poison,  but  to  the  I'act  that  the 
win^ied  bearers  of  this  poison,  blown  along  by  the  wind,  are  tiltered 
out  of  the  air  by  the  leaves,  or  themselves  seek  the  ])rotection  thus 
afforded  against  farther  involuntary  movements,  and  attach  themselves 
to  the  lec\\ard  side  of  leaves  and  trunks. 

Pollution  of  the  Soil. 

The  soil  receives  polluting  matters  of  infinite  variety  and  in  widely 
differing  amounts,  but  their  nature  and  their  amount  are  of  less 
importance  relatively  than  their  point  of  entrance.  Some  of  these 
})ollutions  are  unavoidable,  and  these,  indeed,  are  the  ones  concerning 
which  we  may  give  ourselves  the  least  concern  ;  others  are  avoidable, 
though  not  always,  or  even  usually,  without  the  incurring  of  expense. 

The  unavoidable  pollutions  include  the  urine  and  droppings  of 
animals,  the  carcasses  of  such  as  have  died  and  have  escaped  the 
notice  of  other  animals  that  act  as  scavengers,  and  vegetable  matters 
of  every  conceivable  kind  in  various  stages  of  decay.  Excepting 
under  very  uiuisual  conditions,  such,  for  instance,  as  may  exist  in 
time  of  war  or  flood  or  epidemics,  when  large  numbers  of  horses,  cattle, 
and  other  animals  are  killed  or  die,  these,  lying  at  or  near  the  surface, 
are  of  comparative  unimportance,  since,  exposed  to  natural  processes  of 
purification,  they  are  resolved  into  simple  innocuous  substances,  which 
are  absorbed  by  plant  life  or  washed  downward  into  the  soil. 

The  avoidable  pollutions  are  mainly  those  which  man  deposits 
beneath  the  surface,  and  these  are  first,  and  of  minor  importance,  the 
bodies  of  the  dead,  and  second,  of  vast  importance,  the  excreta  and 
other  organic  filth  that  constitute  sewage.  The  temporary  storage  of 
filth  in  water-tight  receptacles  built  under  ground  can,  of  course,  do 
no  harm  to  the  surrounding  soil,  but  it  is  not  into  such  that  man  usu- 
ally chooses  to  deposit  his  waste.  Water-tight  cesspools  gradually 
become  filled  and  then  require  to  be  emptied,  while  those  with  pervious 
bottoms  permit  the  escape  of  the  contents  downward,  require  no 
thought  or  care,  and  are,  therefore,  a  source  of  contentment  and  of 
saving  of  expenditure.  The  filth  thus  introduced  is,  however,  below 
the  zone  of  bacterial  activity  of  the  beneficent  kind,  and  becomes  stored 
up  in  the  subsoil  or  is  washed  away  gradually  by  the  ground-water, 
which  thereby  is  made  unfit  for  human  consumption.  Organic  matters 
deposited  in  the  upper  strata  of  the  soil  are  resolved  into  their  con- 
stituent elements  with  greater  or  lesser  rapidity  according  to  local  con- 
ditions of  distance  from  the  surface,  temperature,  degree  of  moisture, 
and  permeability  to  air,  the  process  advancing  most  rapidly  in  a  well- 
ventilated,  moderately  dry  soil  near  the  surface,  and  most  unfavorably 
in  wet,  compact  soils,  far  from  the  surface. 

The  influence  of  the  physical   condition  of  the  soil   is  observed  fre- 


rofjjf'i'ioN  OF  'I'lii':  SOIL.  '■','■'>'■) 

(|ii(!iitly  ill  (lie  ex liiiiii.il  ii»ii  of  Ixtdifs  (or  one  (•;iii.sc  or  ;iii(ii Ikt  ;i('t<'r  Vary- 
ing |)(!ri(»(ls  o("  iiilcriiiciil .  'Tims,  in  o|)cii  noils,  Ijodic^  miiy  <li)^:t|>jHjiir 
nlmoHt-    coiilplclcly     ill     I  lie    coiirsi'    oC   w     few    y^'JlPH,    while    ill    htill"    wet 

(iiiiyH  Iriicy  limy  he  IoiiikI  even  \i\\v.v  Ivvcnly  iiiwi  iimih;  ycurh  lo  Ix;  |tiitri<l 
MiiiHHOH,  still  iiii(lrri;(»iiiL!,'  :i,  iiiosi  ^riMlii.'il  |)r()C('ss  of  (lisiii(4"^-r;ilioii. 
Ill(li!(!(l,  il,  is  s(:i(('<l  lliiil  ill  cxciiAiit  iii;^;  ;iii  ;iiMiciil  cliiircliyiirfl  in  Lon- 
don, tlu!  soil  of  wliicli  w.'is  il  wet  cliiy,  hoWics  were  rciiio\i(|  tint  -lio\v<<l, 
ii('t(ir  two  (!(!iiiiiri('S  of  inlcfrmcnt,  no  m:it,<jri;illy  (jill'crfnt  ;i|)|M;ir;uic<' 
from  i\\\\i  oCoilicrs  wliicli  li.-id  hccii  buried  not  over  ii  seon;  of"  ycarh. 
Ivec-eiitly,  Dr.  A.  IMcdel  '  li;id  uii  opporliinily  (o  eoiiipare  tli(!  ix-HuItrt 
o("  (leco!ii|M)si(ion  proceed in^r  in  Ixtdies  hiiricd  for  ;il)oni  t lie  same  |K;rio<l 
in  s(»ils  (lint  wen;  I'especiiveiy  loose,  well-<li;il ncd,  iiinl  w ell-vciitllaUjd, 
;uid  (U)iu|)aet,  wet,  and  iiiiperiiieal)]((  to  air.  in  tliclirst  instance;,  tin; 
remains  W(!re,  iiiirly  dry  aii<l  (jiiite  inoneiisi\('  to  tlu;  sense;  of  sniell  ;  in 
tlic;  other,  they  wein;  a,  slimy,  loatlisonu!  mass  of  rottenness,  which  pive 
out  siieh  a,  lioi-riMe  stench  that  the;  ci'owd  of  Idlei's  that  lia<l  ;_ralh(red 
was  (|nic;Uly  dissipated,  whih;  those;  whose  duty  (;om|)elled  them  to 
remain  wein;  made;  unpleasautly  si(;k,  and  could  not  rid  themselves  of 
the  smell,  whi(;h  (;luni:;  to  them  until  s(;veral  days  had  claj)scd. 

In  the  de(;om[)<).sition  of  organic  substances  in  the  soil,  no  otlensive 
emanations  are  noticed,  if  a  snbstiintial  layer  of  earth  i.s  intor)w.sed 
between  tliem  and  the  atmosj)hcre.  Just  as  it  has  ))ower  to  retain 
water  in  its  intersti(;es  and  on  the  surface  of  its  constituent  particles, 
so  has  the  soil  tlu;  faculty  of  absorbing  gases  and  vapors,  a  jiro])erty 
which  cannot  have  escaped  the  notice  of  any  person  acquainted  with 
the  common  earth-ch)set.  The  soil  acts  in  this  respect  like  charcoal, 
and  can  take  up  not  only  odors,  but  also  coloring  matters  and  other 
substances. 

Perhaps  the  most  striking  illustration  of  the  affinity  of  .soil  for 
odors  is  the  fact  that  illuminating  gas  from  leaking  street  mains  has 
in  its  journey  through  the  soil  been  known  to  be  divested  of  its  odor- 
ous constituents  to  such  an  extent  that,  being  drawn  into  houses  with 
the  soil-air,  its  presence  escaped  observation  until  the  production  of 
poisonous  effects  drew  attention  to  the  existence  of  an  unusual  condi- 
tion of  the  air. 

A  like  retaining  action  is  manifested  in  a  less  marked  degree 
toward  substances  in  solution,'  which  are  held  back  by  surface  attrac- 
tion, a.  fact  which  has  been  noted  repeatedly  by  hygienists  and  agri- 
cultural chemists.  This  is  more  noticeable  in  soils  of  fine  grain,  since 
such  present  a  far  greater  area  of  grain  surface.  Hoffmann^  filled  two 
cylinders  of  equal  si>ce  with  sand  of  different  degrees  of  fineness,  but 
Avith  the  same  total  jiore-volume,  and  to  each  was  added  from  above 
an  equal  volume  of  solution  of  common  salt,  and  then  daily,  for  ten 
days,  an  equal  volume  of  distilled  water.     The  drainage  of  each  day 

*  IMiinohonor  modioinislio  Woohonschril't,  June  6,  1899. 
''  Se'o  page  341  for  an  unusually  striking  example. 

''  Uebor  das  Eindvingen  von  ^'eruureinigungeu  m  Bodeu  und  Grundwasser.  Arohiv 
fiir  Hygiene,  XL,  p.  145. 


340  THE  SOIL. 

was  tested  as  to  its  omitent  of  salt,  aiul  it  was  found  tliat,  whereas 
that  from  the  eoarser  sand  yielded  salt  on  the  second  day  and  gave  the 
higliest  results  on  the  third,  from  which  time  the  yield  progressively 
dwindled,  that  from  the  finer  showed  no  trace  until  the  sixth  day,  and 
its  maximum  on  the  seventh.  Repetition  of  the  exjieriment  in  the 
same  way  in  all  particulars  yielded  identical  results.  Thus  it  is  shown 
that  j)ollution  travels  more  quickly  in  coarse  soils  than  in  fine. 

In  the  decom[)osition  of  proteid  substances  in  the  soil,  basic  sub- 
stances are  believed  by  some  to  be  formed,  which  may  be  tidveu  into 
the  system,  and  so  affect  the  resistance  of  the  body  to  disease  as  to 
favor  infection.     This,  however,  is  purely  hypothetical. 

As  has  been  remarked,  the  presence  of  bacteria  is  essential  for  the 
resolution  of  organic  matters  in  the  soil.  This  has  beeii  illustrated  in 
a  striking  manner  by  Duclaux,^  who  treated  sterile  soil  with  sterile 
organic  matters,  such  as  milk,  sugar,  and  starch  paste,  and  then  planted 
therein  peas  and  beans.  Although  the  resulting  plants  were  well  cared 
for,  they  did  not  thrive,  but  remained  as  thin  and  weak  as  though 
growing  in  distilled  Avater.  The  organic  matters  in  the  soil  were 
of  no  value  in  their  growth,  for  they  could  not  be  absorbed  as  such, 
but  only  after  decomposition.  The  addition  of  a  little  unsterilized 
earth  sufficed,  however,  to  start  the  required  j)i"ocess,  and  then  the 
growth  improved  at  once. 

Bacteria  of  the  Soil. 

The  bacteria  of  the  soil  are  found  almost  wholly  in  the  superficial 
layers,  and  below  a  depth  of  twelve  feet  their  number  is  I'clatively  few. 
As  they  need  organic  matter  for  their  growth  and  multiplication,  it 
may  be  inferred  that  the  greater  the  amount  present,  the  greater  will  be 
their  number.  Thus,  they  are  far  more  numerous  in  rich  garden  soil 
than  in  ordinary  sand  and  clays. 

The  conditions  most  favorable  to  their  develojjment  are,  in  addition 
to  the  presence  of  the  organic  pabulum,  moisture  and  certain  limits  of 
temperature.  Dryness  and  extremes  of  heat  and  cold  are  all  unfavor- 
able ;  saturation  with  water  may  or  may  not  be,  according  to  the  vari- 
ety, for  there  are  some  that  in  a  wet  rich  soil  can  go  on  decomposing 
organic  matters. 

In  ordinarily  rich  soil,  the  number  of  bacteria  ranges  from  hundred 
thousands  to  millions  per  cubic  centimeter  in  the  surface  layers,  below 
which  they  diminish  in  number  very  rapidly,  until,  at  ten  to  twelve 
feet  below  the  surface,  the  soil  is  practically  sterile,  except  for  those 
that  have  been  washed  down  or  carried  by  burrowdng  animals,  or,  as 
above  stated,  deposited  by  man  in  organic  filth. 

The  soil  bacteria  are  maiidy  of  the  beneficent  varieties,  the  sap- 
ropliytes  which  perform  only  useful  offices,  including  the  numerous 
varieties  of  the  nitrifying  organisms.  While  different  species  of  path- 
ogenic bacteria  have  been   found   in   the  soil,  and  although  certain  of 

'  Comptes  rend  us,  C. 


p.A('r/':nfA  or  the  sou..  f*>n 

iJicMi,  the  l>;icilli  <.('  ici;iiiiis  ;iii<l  <>C  iii;i  IIl' ii;i  iil  fi(lciii;i,  ;irf  yvxy  ^i'm'V- 
iiJIy  |>r<\sciil.,  (Jiis  cImss  of  oi'Hiiiiisnis  I'iihIs,  ;is  ;i  rule,  I  he  (■(»ii(|i(iuiiH 
|)i'(!S(Wi(,  ill  tlic,  soil  iindiA'ornhIc  lo  (l('Vclo|»iiir'ii(. 

In  tlio  first  pliuic,  (lie  (ciiiiirniliirf  i~  loo  low,  (•x<'c|)lin^  in  tin-  wry 
npiMU'inoHt  liiycrs  in  \\;irni  \vcalii<r;  nml,  riiitlicrniorc,  tlic  patlio^cnir 
kinds  ciinnot  thi-ivr  in  I  lir  |>r(!scnc(!  of  I  Ih'  i  hoi monsly  rnirncroiiH  h:i|>- 
ropliyics,  vviiiciii,  in  sonic  ninnncr  not.  as  yet  satisfiU'torily  explained, 
hi-injr  al)onl,  llieii-  deslrncfion.  This  action  lias  heen  deinon>t rated 
repoatodly  by  Ko(^li  and  ollieis,  wIk)  showed  that  anthrax  haeilli  and 
otiier  |)atho<2;eni(^  varieties  can  ^row  in  sterili/e(|,  hnt,  not  in  nnsteril- 
i/ed,  soil. 

Klein'  insists  that.  |)athoiz;enie,  or<z;anisnis  in  hnried  bodies  eannot 
maintain  vitality  in  tlu;  presence  ol'  />'.  r'tddnris  Kporof/ciics,  which  is 
always  present  in  deeoniposinji;  bodies,  and  that,  in  most  cases,  a  month 
is  sunicient  time  t(»  insnre  destru(!tion.  He  buried  (i;ninea-pip;s  con- 
tainiiiin'  varions  kinds  of  micro-organisms  within  the  abdominal  cavity, 
and  at  dilTerenl  times  exhnmed  them  and  made  search  for  livinj^  speci- 
mens. He  fonnd  that  />.  prodii/ioKiix  lived  4  weeks,  bnt  not  0  ;  Siaph- 
yloeoceun  ((.ui'ciis,  abont  the  same;  iSp.  cholene,  19,  but  not  28  days; 
B.  fi/pJiosii.s  and  />,  (liplifherlfe,  not  lonjrcr  than  2  M-eeks  ;  B.  pe.sfifi,  17, 
but  not  21  days,  and  />.  lii,h('rcu!osi.s,  not  7  weeks. 

It  is  believed  that,  in  the  dee])er  layers,  away  from  tlie  saprojiliytes, 
the  spores  of  pathogenic  species  may  tind  a  lodgement  favorable  to 
storage,  but  not  to  development,  and  that  there  they  may  remain  with 
dormant  vitality. 

Many  examinations  of  graveyard  soils  and  of  bits  of  coffins  have 
been  made  by  Dr.  E.  H.  Wilson,  of  Brooklyn,  to  determine^  if  jiossible, 
the  presence  of  pathogenic  bacteria  as  well  as  the  number  of  bacteria 
as  compared  with  those  in  other  kinds  of  soils.  He  found  no  more 
bacteria  than  in  others,  and  no  pathogenic  kinds  whatever. 

There  is  one  kind  of  soil  that  has  been  found  again  and  again  to 
have  a  destructive  action  on  pathogenic  bacteria,  and  that  is  l^eat, 
which  kills  them  very  quickly,  probably  through  the  contained  organic 
acids. 

The  soil  acts  as  a  very  good  filter,  and  holds  back  most  of  the 
organisms,  but  by  the  aid  of  flowing  ground-water  or  water  entering 
from  above,  they  may  be  carried  through  considerable  distances.  Thus, 
Drs.  Abba,  Orlandi,  and  Rondelli,-  experimenting  on  the  filtration 
capacity  of  the  soil  about  the  filter  galleries  of  the  Turin  water  supply, 
found  that  cultures  of  Jficrococcus  prodir/iosus,  poured  with  large  vol- 
umes of  liquid  into  the  ground  at  various  points,  made  their  appearance 
200  meters  away  in  42  hours,  and  12  and  27.5  metei's  away  in  7  houi^s. 
In  these  experiments  the  property  of  the  soil  for  holding  back  sulv 
stances  in  solution  was  manifested  in  a  remarkable  degree,  methvl-eosin 
and  uranin,  substances  which  impart  intense  red  and  green  coloration 
to  water,  and  which  were  added  with  the  cultures,  not  appearing  until 

*  Twenty-eighth  Annual  Report  of  the  Local  Government  Board,  Supplement 

*  Zeitschrift  fiir  Hygiene  und  Int'eotionskrankheiten,  XXI.,  p.  66. 


342  THE  SOIL. 

long  after  the  (M'oanisnis  liad  j)assi'(l  throiio-li.  In  the  instanee  in  Avliieli 
tlu'v  appeared  in  42  hours,  the  e()h>rinii;  agents  eoukl  not  be  detected 
until  after  75  hours  had  elapsed. 

The  relation  of  the  soil  to  the  various  pathogenic  bacteria  will  bo 
discussed  farther  under  separate  headings. 

Soil  and  Disease. 

The  influence  of  the  soil  on  health  and  disease  is  admitted  very 
generally,  but  is  little  understood.  We  know  that  certain  soil  condi- 
tions favor  the  occurrence  of  certain  diseases,  but  why  this  is  so  remains 
a  problem  for  future  research  to  solve. 

Our  notions  concerning  the  causal  relation  of  the  soil  are  probably 
greatly  in  error  with  respect  to  certain  diseases,  being  doubtless  exag- 
gerated as  regards  some,  and  equally  undeveloped  with  others.  Com- 
position, permeability,  temperature,  moisture,  evaporation,  soil-air,  and 
fluctuations  of  the  level  of  the  subsoil-water,  all  are  supposed  to  bear 
important  relations  to  many  of  the  diseases  of  mankind  and  of  animal 
life  in  general. 

Such  evidence  as  bears  on  the  relation  of  the  soil  to  diseases  is  given 
in  general  terms  below. 

Soil  Dampness  and  Disease  in  General. — It  has  long  been  univer- 
sally noticed  that  dampness  in  and  near  the  surface  of  the  soil  injuri- 
ously affects  the  health  of  those  dwelling  nearby.  It  causes  coldness 
of  the  soil  and  dampness  of  the  atmosphere  immediately  above,  and 
appears  to  conduce  more  particularly  to  rheumatism,  neuralgias,  and 
diseases  of  the  respiratory  tract.  It  has  been  noticed  by  many  who 
have  investigated  the  subject,  that  the  general  health  of  those  dwelling 
over  damp  soils  is  much  inferior  to  that  of  those  more  favorably  cir- 
cumstanced in  that  regard,  and  instances  of  improvement  on  renioval 
from  damp  to  dry  localities  are  too  commonly  known  to  need  illus- 
tration. 

It  is  generally  agreed  that  a  soil  in  which  the  ground-water  level  is 
high,  five  to  ten  feet,  for  instance,  from  the  surface,  is  not  favorable  to 
health  ;  and  that  a  deep  level,  fifteen  feet  and  more,  is  unobjectionable 
on  the  score  of  dampness.  This  being  admitted,  it  might  reasonably 
be  inferred  that  artificial  lowering  of  the  ground-water  will  be  fol- 
lowed by  increase  in  salubrity,  and,  as  a  matter  of  fact,  that  is  precisely 
what  does  occur.  But  it  should  be  stated,  in  order  to  be  historically 
accurate  and  in  all  fairness,  that  while  increased  healthfulness  is  a  con- 
sequence, as  a  rule  it  is  not  the  object  sought,  for,  as  a  general  thing, 
soil  drainage,  especially  on  a  large  scale,  has  been  carried  out  to  meet 
the  demands  of  successful  agriculture  rather  than  in  consequence  of 
solicitude  for  public  health. 

The  methods  employed  may  be  stated  generally  as  increasing  the 
outlet  and  removing  obstructions  to  the  outfall.  Ditching  and  the 
construction  of  underground  channelways  by  means  of  drain  tile 
or   rubble   and  fieldstones   are  the  most   common   methods   of  drain- 


,S'0//,    AM)   DISEASE.  -"'l:^, 

ilijj^.  Soiiicl  iincs,  (li';iiii;iiic  wells  ;ii'('  (lri\r'ii  ;il  iiitci-\;il-  (lowii  f  lifoii<.'|i 
tli(!  irii|>(!nii(;;il)lc  sli';iliiiii  iiilo  ;iii  ojkii  iih-'iil,  inlo  wliidi  tli(\'  flicn 
(lr;iiii. 

'V\\v.  (liniciill  ics  ill  tlic  \\;i\'  nC  di'.iiiiiiijj;  cxlcii-ivc  ;irr';is  of  iiiilic;ill  liv 
itiid  :ii;ri(Mil(iir;illy  (iii|ir()(|ii('l  i\'c  ImihI  li(!  cliicfly  in  llic  i;irl<  of  itnli- 
vidiiMJ  <',()(")|)('r;iii(tii.  SiictJi  iin(l('r<:il<iiiji;.s  iiiiiHt  iic(;('s,s;irily  Im*  'virricd 
on  ill  il  Hyslcinniic.  iiuimicr,  ;iii(l  fiiinhl,  ;il\v;iy.s  (u  lie  nii'lcr  (Ik-  dircctidn 
of  souu;  c(!ii(r;d  niilliorily — iiiiiiiiiM|>;il,  sliilc,  or  ii;itioii;il. 

By  inOcins  of  iindcr-iiniiii.'iuc,  I  hoiisniids  ;iiid  t  lioii-.-md-  of  ;icrc,-  in 
various  |)iirfs  of  (liis  country,  iiot;il»ly  in  Illinois  ;ind  Indiana,  and 
vast;  annis  of  land  in  IOnt;hiiid  and  on  the  conlincnf,  have  l>c(!n  rtoii- 
vertdd  from  imlidallliy,  nialarions,  and  inoicor  li  ~~  iinprodnctive  tracts, 
into  healthy  and  ridily  |»rodn(;liv(!  (uxinliy  ;  hut  (lie  scheme  is  not 
always  snceessfnl  in  iclicNiiii;  a  loc^ality  of  disease,  especially  of  malaria, 
as  has  been  |)rov('(l  in  parls  of   Ilaly,  Ansd'alia,  and  elsewhere. 

Soil  and  Pulmonary  Tuberculosis. — There  is  an  nndouhled  eon- 
nection  between  this  disease  and  soil  dampness,  which  is  most  manifest 
when  one  investii>;ates  the  prevalence  of  the  disease  over  the  same  soil 
before  and  wWer  soil  draina,^e,  by  which  it  will  always  be  found  to  be 
diminished.      Why  this  is  so  we  can  only  (conjecture. 

We  know  that  dampness  is  one  of  a  possibly  considerable  nuinber 
of  factors  in  producing  predisposition  to  the  disease.  We  know  that, 
other  conditions  beinti;  the  same,  the  disease  is  far  more  common  on  low 
damp  soils  than  on  elevated  dry  ones.  We  know  also  that  the  disease 
is  comparatively  rare  in  some  parts  of  the  earth  where  the  soil  is 
exceptionally  dry. 

The  distribution  of  the  disease  and  its  relation  to  soil  dampness  were 
first  brought  to  public  notice  by  Dr.  Henry  I.  Bowditch,'  of  Boston, 
at  the  annual  meeting  of  the  Massachusetts  Medical  Societv,  in  1X62, 
who  submitted  two  propositions,  the  results  of  most  extensive  investi- 
gation, which  w^ere,  iu  substance,  that  dampness  of  the  soil,  whether 
inherent  or  acquired  by  reason  of  proximity  of  bodies  of  water,  is  an 
exciting  cause  of  consumption,  which  disease  can  be  checked  in  its 
course  or  even  prevented  by  proper  attention  to  soil  conditions. 
Shortly  afterward,  similar  conclusions  were  promulgated  in  England 
by  Dr.  Buchanan,  who  had  been  making  observations  along  the  same 
line,  not  knowing  that  Dr.  Bowditch  was  similarly  engaged.  The.se 
propositions  were  accepted  by  the  profession,  and  have  been  maintained 
ever  since. 

Typhoid  Fever. — It  is  believed  quite  generally  that  this  disease  is 
connected  in  some  way  with  soil  conditions  as  well  as  ^^•ith  drinking- 
water.  Indeed,  there  are  some  authorities  who  regard  the  soil  a.s  of 
infinitely  greater  importance  in  the  causation  of  epidemics  of  this 
disease  and  of  cholera  than  ilriuking-water,  which  to  their  minds  has 
absolutely  no  influeuce  one  wav  or  another.  The  Pettenkofer  theoiy 
of  the  cause  of  these  outbreaks  attributes  it  to  the  soil,  from  which  the 

^  Topographical  Distribution  and   Local  Origin  of  Cousuuiption  iu  Massachusetts. 

Transactions,  1862. 


344  THE  SOIL. 

exciting-  cause  is  tlistrilnited   by  tlio  groniul  air,  wliicli,    as   lias  been 
stated,  is  in  constant  movement. 

According  to  the  distinguished  originator  of  the  soil  theory,  the  un- 
known poison  is  introduced  into  the  soil,  where,  under  proper  condi- 
tions of  organic  filth,  and  other  influences,  a  species  of  fermentation 
occurs,  the  end  product  of  which  is  the  exciting  cause,  which  is  then 
capable  of  inducing  the  disease  in  those  by  whom  it  is  inhaled.  All 
important  in  this  process  is  the  vertical  movement  of  the  ground-water, 
and  it  is  certainly  true  that  over  a  long  period  of  years  of  observation 
at  jNIunich,  there  was  a  most  remarkable  coincidence  between  epidemics 
of  typhoid  fever  and  fluctuations  in  the  ground-water  level. 

The  condition  most  favorable  to  high  morbidity  was  demonstrated 
to  be  a  rapid  fall  after  an  unusually  high  level.  The  highest  death- 
rates  during  the  time  covered  occurred  during  the  years  of  lowest  level, 
and  the  lowest  rates  in  the  years  of  the  highest  level.  A  similar 
coincidence  has  been  noticed  elsewhere,  but  by  no  means  in  all  or  even 
a  majority  of  the  localities  where  investigations  have  been  made. 

The  theory  had,  for  a  time,  many  adherents,  and  the  controversy 
between  the  soil-theorists  and  the  "water-fanatics,"  as  Pettenkofer 
called  them,  was  carried  on  at  times  with  exceeding  bitterness.  But 
within  the  past  d('cade,  the  w^ater  theory  has  been  so  thoroughly  proved 
as  the  chief,  if  not  the  sole  cause  of  extensive  outbreaks,  that  interest 
in  the  theory  has  fallen  oif,  and  its  supporters  are  now  few  in  number. 
Pettenkofer  ^  himself,  however,  was  to  the  end  as  uncompromising  as  in 
the  beginning,  and  found  no  difliculty  in  applying  it  to  the  great  epi- 
demic of  cholera  in  Hamburg,  in  1892. 

The  contention  that  the  extraordinary  endemicity  that  prevailed  so 
long  at  Munich  was  due  to  the  filthiness  of  the  subsoil,  which  was 
honeycombed  with  cesspools,  cannot  lightly  be  brushed  aside,  for  it  is 
a  fact  that,  with  discontinuance  of  these  abominations,  and  with  a 
system  of  improved  sewerage,  the  typhoid  fever  rate  fell  from  its  posi- 
tion as  a  leader  down  among  the  lowest  known.  Nor  was  this  fall  due, 
as  has  been  claimed,  to  change  in  the  water  sujjply,  for  the  great  ei)i- 
deniics  had  ceased,  and  the  fall  had  long  continued,  before  the  water 
supply  was  changed. 

Experiment  has  shown  that  the  typhoid  organism  may  retain  its 
vitality  in  the  soil  for  considerable  periods  under  favoring  conditions 
of  warmth  and  moisture.  Robertson  ^  removed  sods  from  several 
places  in  a  field,  and  wet  the  exposed  soil  with  diluted  typhoid  cultures, 
one  at  the  surface,  one  at  a  depth  of  nine  inches,  and  a  third  at  eighteen 
inches.  After  130  days,  the  bacilli  on  the  surface  had  multiplied,  and 
where  they  had  been  placed  eighteen  inches  below,  they  could  also  be 
found  in  the  surface  layer.  Later  on,  in  the  winter,  no  results  could 
be  obtained  ;  but  in  the  spring,  he  moistened  the  patches  with  sterile 
bouillon  in  very  dilute  condition,  and  afterward  succeeded  in  obtain- 
ing growths. 

^  Miincliener  medicinische  Woclicnsclirift,  May  2,  1899. 
'  British  Medical  Joumal,  Jan.  8,  1898. 


,S'0//.   AND    DfSfCASE.  .".15 

Tlii.s  posirivc  I'f'siill  ;i('(^or<ls  willi  llif  \'i(\\-  of  (^M-niiano,'  who  foiiiid 
tliMt  lyplioid  l)!ic,illi  will  live  (or  inonllis  wln-ii  iiicoiri|»I<'f<'ly  'Irv  ;  l»iit, 
juicordiiijj;'  lo  I*'li"iji,'^<',  llicy  do  not  :-iiiviv(!  ('((niplclc  dryiiit^  \<>]\^£i-r  tliaii 
fifl,(!('ii  diiys.  In  iiir-dricd  condition  llicy  appear  to  liavr-  uriiinpain-d 
vilality  ("or  sonic  days,  accoi'din;^  lo  I.rownicc,^  who  <h-icd  and  stcrili/,<'d 
ordinary  soil  and  (lien  infected  it  vvidi  a  liiotli  cidtnre  oC  typhoid  and 
kept  it  at  !)H"  V.  Cor  a  day.  It  was  then  leCt  exposed  to  tliC!  air  Cor  a 
week,  (hii-in^  which  time  it  hc^eanu!  snlliciently  dry  lo  \u'.  easily  scat- 
tci-(«l  l)V  the  hreath.  ( 'MJtnres  Croni  this  ^ave  positive  results.  l>rit 
it  sliould  l)c  reinend)cred  that  air-dried  soil  r-ontains  fronsidf^rahle 
liyfrr()S(;()pic  water;  conse(|nenlly  his  hacilli  were  donhtlcsH  fairly 
well  sM|>plIcd  with  the  necessary  moisture.  OC  moi-c  importaiK!0,  aji- 
parently,  (han  the  (piestiou  of  moisture — Cor  all  soils  j)tissess  some — \H 
the  nature  oC  the  contained  organic  matter.  hi.  Sidney  Martin'''  has 
shown  that  nnp(tllntcd  (vire;in)  soils  arc  inimical  to  the  typhoid  hacillu.s, 
refi:;ardlcss  of  the  anionnt  of  their  contained  organic  matt<'r  of  vegetiible 
origin,  while  s|)ecimens  containing  polluting  material  of  animal  origin 
favor  its  existence.  Such,  after  sterilization,  were  j)lanted  successfully, 
and  it  was  learned  that,  in  the  presence  of  moisture,  differences  in  tem- 
perature had  hut  little  influence.  Thus,  the  organi.sni  thrived  alxiut 
equally  well  when  specimens  were  kept  at  98°  F.,  at  ordinary  room 
tem])erature,  and  as  low  as  .37°  F.  By  no  means  the  least  interesting 
ohs(>rvation  made  was  with  regard  to  the  duration  of  viability  of  the 
baciUus.  In  one  of  the  sterilized  polluted  soils,  the  organism  was  still 
active  at  the  expiration  of  456  days ;  and  even  then,  after  thorough 
drying  and  pulverization,  active  growth  could  be  obtained.  In  com- 
jmny  with  various  species  of  bacteria,  among  which  the  predominant 
kinds  were  members  of  the  B.  coll  group,  it  was  recovered  after  50 
days'  exposure  to  temperatures  ranging  between  37°  and  61°  F. 

Later  experiments,''  in  which  the  tyjihoid  organism  was  planted  with 
different  soil  bacteria,  proved  that  various  species  from  a  particular  soil 
had  the  power  of  coniplotcly  exterminating  it  within  a  short  time,  while 
others  had  no  influence  whatever.  Therefore,  it  would  apjiear,  whether 
or  not  the  typhoid  organism  can  exist  in  a  given  soil,  will  depend  upon 
the  kinds  of  soil  bacteria  present,  as  well  as  upon  special  conditions  of 
temperature  and  dampness.  Dr.  Martin  found  the  period  of  vitality 
iu  unsterilized  soils  to  be  about  12  days,  but  in  no  case  did  the  organism 
appear  to  multiply.  An  experiment  conducted  by  Levy  and  Kayser  ^ 
to  determine  the  duration  of  infectivity  of  this  organism  yielded  most 
interesting  results.  The  feces  of  a  typhoid  patient  were  discharged 
into  a  cemented  vault,  remained  therein  5  months,  and  were  then  spread 
on  a  clay  soil,  from  which,  after  15  days  of  winter  weather,  the  specific 
organism   was   isolated.      Thev  came  to  the  natural    conclusion  that 

'  Zeitsclirift  fiir  Hvsjiene  uiid  Infectionskranklieiten,  XXIV.,  p.  403. 

^  Public  Health,  January,  1899,  p.  272. 

=*  Report  of  Local  Governnient  Board,  1898,  London,  1899. 

*  Ibidem,  1900,  London,  1901. 

» Centmlblatt  fiir  Bakteriologie,  etc.,  March  20,  1903,  Abth.  I.,  XXXIII.,  p.  4S9. 


346  THE  SOIL. 

typhoid  stools  ought  always  to  be  disinfected  before  being  discharged 
into  a  privy  vault. 

Tlio  etfect  of  toniperature  changes  due  to  the  presence  of  animal  ex- 
creta mixed  with  the  soil  is  shown  by  Gaertner '  to  be  considerable. 
He  introduced  cultures  of  various  organisms  in  wire  baskets  into  the 
interior. of  compost  heajis  of  various  comjiosition,  Mhich  became  heated 
tt)  ditterent  extents,  and  observed  that  the  bacilli  of  ty]ih()id  and 
eholera  were  the  least  resistant  of  all.  With  rapid  and  marked  heat- 
ing, their  life  was  short ;  but  it  appears  probable  that  in  the  absence 
of  heat,  even  with  the  given  surroundings,  they  may  live  through 
the  winter.  ITnder  the  ordinary  heating  that  occurred  in  the  comjjost, 
these  two  organisms  were  destroyed  in  a  week,  while  the  bacillus  of 
tuberculosis  remained  virulent  a  number  of  months. 

But  aside  from  what  we  glean  from  scientific  research  with  the  spe- 
cific org-anisms,  we  know  from  experience  that  there  are  many  places 
with  polluted  soils  where  t}'phoid  fever  was  unknown  imtil  the  impor- 
tation of  a  single  case  from  Avithout,  and  that,  afterward,  sporadic;  cases, 
for  which  no  convincing  explanation  is  afforded,  have  occurred  at 
varying  intervals.  And  in  country  districts,  whose  inhabitants  are 
not  given  to  travelling  much  beyond  the  confines  of  their  farms,  it  is 
noticed  frequently  that  single  cases  occur  in  the  same  household  at 
intervals  of  a  year  or  longer. 

In  such  cases,  it  seems  hardly  reasonable  to  say  that  the  original 
case  has  left  nothing  as  the  exciting  cause  for  later  attacks,  and  that 
fresh  introductions  of  the  specific  organism  must  have  occurred  from 
some  unknown  source,  for  it  is  not  unlikely  that  the  variety  of  condi- 
tions that  affect  the  viability  of  the  organism  may,  in  some  cases,  act 
to  keep  it  alive,  and,  on  occasions,  stimulate  it  into  a  condition  of  aug- 
mented activity. 

Cholera. — Concerning  the  relation  of  this  disease  to  the  soil,  there 
is  but  little  to  be  said.  Prior  to  the  discovery  of  the  specific  organism, 
the  soil  theory  of  the  origin  of  epidemic  outbreaks  had  considerable 
vogue ;  but  now  it  is  known  that,  even  in  times  of  greatest  prevalence 
of  the  disease,  the  organism  has  never  been  found  under  natural  con- 
ditions in  the  soil.  It  can  be  kept  alive  under  certain  favorable  con- 
ditions of  moisture  and  heat  for  varying  periods ;  but  under  natural 
conditions  it  is  one  of  the  least  resistant  bacteria  and  quickly  dies.  We 
have  no  evidence  whatever  that  cholera  is  a  soil  disease. 

Bubonic  Plague. — This  has  been  regarded  as  a  soil  disease;  and  it 
has  been  believed,  from  the  fact  that  rats  have  been  conspicuous  as  vic- 
tims of  it  in  the  early  stages  of  its  devastating  outbreaks,  that  these 
animals  have  acquired  the  infection  in  the  soil,  and  have  brought  it 
to  the  surfiice,  and  thus  acted  as  its  carriers.  But  rats  are  notorious  as 
frequenters  of  ])laces  where  filth  of  all  kinds  accumulates,  and  it  is 
not  strange  that  where  they  and  filth  al)Ound,  they  become  diseased,  if 
the  infectiv^e  agent  is  present. 

The  whole  question  of  etiology  of  plague  has  been  cleared  up  by  the 

*  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXVIIL,  p.  1. 


SOIL    AND    DIShlASE.  347 

diHCOVory  tlijit  flciiH,  mikI  especially  l.lie  eonniKiii  i;il  fle;i  ( f'ufr.r  /in/fiduM, 
(J(r<U(yplvjillim  fascial  lis)  o("  h-opie.'il  eliiii;il(;s,  ;ie,l  as  an  iiiN-ririerlint*' 
lioHt  (or  tlio  bacillus  of  |ilaijiie.  'Ilni-;  (he  rcfciprocal  fraiiHfcr  of  ihe 
H|)(H!i(i(;  <)ri;aiilsin  helvveeii  man  ;iii<l  ral-,  lo^eflier  willi  oilier  rorleiith, 
HUcli  as  ^roiiiid  .scjiiirrels,  has  hecii  (leiiioiislraled  rej)cal.e(lly. 

Diphtheria.— All  lioii<^''li  Ihere  is  no  pcoof  lliiil  liie  hacillii-  f)('  (lipli- 
(lieria  is  Coiind  even  as  an  oeeasioiial  lodt^ci-  in  the  s(»il,  fhere  \>  ;i  ^en- 
VX',\\  a{;Teeinenl  lli;il  a  elo^e  conneelinn  e\i-t-  l)ehv('(;ll  Hoil  (laiiipiic-s  and 
the  |)r('valence  of  this  disease.  Il  is  line  ihal experiment  has  dem»»ri- 
slralcd  the  \ial)ilil\'  oC  IIk;  orLcanistii  in  moisi,  soils  lor  linnU-d  periodn, 
l)U(.  ir  has  ne\('r  heen  I'onnd  in  soils  olliei-  lli;in  lliose  in  wliieh  it  wa8 
doposilcd  inlcntionallw  'The  eonimon  helief  i>  ||i;il  ;i  nioi<t.  soil  i.s  iin 
inva,rial)le  e()n<M)niilanl,  ol'  iiiinsnnl  pi'e\alenee,  ;ind  lii.il  in  tiinrw  of 
(lompai'alivc  freedom  from  (Ik^  disease,  IIk;  soil  is  dry  and  the  level  of 
\\\o  <>;roun(l-\vaier  low.  "As  Ioiiij:  ^''^  •'"•  ^'•''  i>^  well  washed  hy  the 
wiutcr's  hiji'h  tide  ;iiid  aflerwai'ds  dried  and  aT'rahd  dni-inL*"  llu;  sumnior'H 
low  tide,  all  o'oes  well:  hut  so  soon  as  lliese  salnlary  mov(!ni(;nts  arc 
arrested  or  their  order  distnrbed,  (li|)litlieri;i  prevails,  reaehit)j^  its 
jionic  of  prevalence  when  stat;iia(ion  at  a  relatively  hiixh  lewl  is  most 
complete."^ 

Accordinii;  to  Dr.  S.  M.  Copeman,^  there  appears  to  he  no  direct 
relation  between  epidemics  and  rise  or  fall  of  the  fjronnd-water,  "  pro- 
vided that  the  strnetur(>  and  atmosphere  of  the  houses  are  not  affecte<l. 
Many  districts,  which,  nsnally  dry,  are  liable  to  oeca.sional  floods,  are 
remarkably  free  from  the  disease,  so  that  it  ap]iear.s  that  a  persistent 
impregnation  of  the  soil  with  moistnre  is  of  more  importance  than 
flnctnations  in  the  hei<>;ht  of  the  gronnd-water,  ]iarticnlar1y  if  these 
have  any  considerable  rang-e." 

0)>posed  to  the  views  above  expressed  are  the  conclnsions  based  on 
a  most  eareful  and  extensive  investigation  Iw  T)\\  Arthin'  Newsliolme,^ 
of  epidemics  of  diphtheria  in  all  civilized  conntries  and  their  incident 
conditions  of  rainfall  and  soil  moisture.  Dr.  Newsholme's  eminence 
as  a,  skilful  interpreter  of  the  value  of  statistics,  and  the  fact  that  no 
such  exhaustive  iuqniry  into  this  question  has  ever  before  been  made, 
entitle  his  conclusions  to  more  than  ordinary  weight.  Admitting  that 
personal  infection  is  the  chief  means  by  wdiich  dij^htheria  is  spread  from 
town  to  town,  and  from  country  to  countrv,  he  summarizes  his  obser- 
vations on  the  relation  between  rainfall  and  ground-water  and  the  origin 
of  epidemic  diphtheria  as  follows  : 

"  1.  An  epidemic  of  iliphtheria  never  originates,  in  the  towns  and 
countries  in  which  I  have  been  able  to  collect  facts,  when  thei'e  has 
been  a  series  of  years  in  which  each  year's  rainfall  is  above  the  average 
amount. 

"  2.  An  epidemic  of  diphtheria  never  originates  or  continues  in  a 
wet  year  (/.  c,  a  year  in  which  the  total  annual  rainfall  is  materially 

*  Notter  and  Firth,  Treatise  on  Tlypiene,  189(>,  p.  463. 

^  Stevenson  and  ^tnrpliy.  Treatise" on  Hygiene,  1802,  Vol.  I.,  p.  338. 

3  The  Origin  and  Spread  of  randeniic  l>iphtheria,  Loudon,  189S. 


348  THE  SOIL. 

above  the  average  amount),  uiiles?^  this  wet  year  follows  on  two  or 
more  drv  years  imnxediately  preceding-  it. 

"  3.  The  epidemics  of  dij)htheria,  for  which  accurate  data  are  avail- 
able, have  all  originated  in  dry  years  (/.  c,  years  in  Mhich  the  total 
annual  rainfall  is  materially  below  the  average  anionnt). 

"  4.  The  greatest  and  most  extensive  epidemics  of  diphtheria  have 
occurred  when  there  have  been  four  or  five  consecutive  dry  years,  the 
epidemic  sometimes  starting  near  the  beginning  of  this  series,  at  other 
times  not  until  near  its  end. 

"5.  Dry  years  imply  low  ground-water,  and  we  find,  therefore,  in 
the  years  of  epidemic  diphtheria  that  the  ground- water  is  exceptionally 
low.  The  exact  variations  in  the  ground-water  which  most  favor  epi- 
demic (hphtheria  cannot,  with  the  data  to  hand,  as  yet  be  stated  ;  but 
it  is  probable  that  when  this  is  cleared  up  it  will  become  clear  why  in 
exceptional  years  which  have  a  deficient  rainfall  epidemic  diphtheria  is 
either  absent  or  but  slight." 

It  has  often  been  pointed  out  that  local  soil  conditions  causing 
dampness  of  habitations  even  in  dry  years,  such  dampness,  for  instance, 
as  obtains  in  houses  built  over  wet  impervious  clays,  conduce  to  out- 
breaks of  diphtheria  in  the  dwellers  therein  ;  but,  as  is  well  known,  such 
dampness  acts  as  a  very  important  depressant  of'  the  vital  forces,  and 
prepares  the  mucous  membranes  of  the  respiratory  tract  for  the  favor- 
able reception  of  specific  organisms  of  various  kinds. 

Malaria. — It  has  ever  been  held  that  the  most  intimate  relation 
exists  between  the  soil  and  malaria,  especially  prominent  in  districts 
abounding  in  marsh  lauds.  It  has  been  noticed  repeatedly  that  in 
malarious  countries  the  upturning  and  excavation  of  wet  or  damp  soil 
are  commonly  followed  by  the  occurrence  of  the  disease  among  the 
laborers  so  engaged ;  that  infection  is  more  common  among  those  who 
go  about  at  night,  and  especially  among  those  who  sleep  out-of-doors ; 
and  that  the  draining  of  marsh  lands  is  often  followed  by  the  disap- 
pearance of  the  disease.  All  of  these  facts  are  compatible  with  the 
theory  of  transmission  by  mosquitoes,  and  it  is  now  accepted  generally 
that  malaria  is  connected  with  soil  conditions  only  in  so  far  as  the 
latter  permit  the  breeding  of  the  specific  mosquitoes.  (See  Chapter 
XII.) 

Yellow  Fever. — There  is  no  evidence  of  connection  between  the 
soil  and  outbreaks  of  yellow  fever,  although  for  many  years  such  a 
relation  was  assumed  to  exist.  The  work  of  American  investigators 
has  proved  this  disease,  also,  to  be  mosquito-borne. 

Tetanus  and  Malignant  (Edema. — It  is  well  known  that  the 
organisms  of  these  two  diseases  are  found  very  commonly  in  most 
garden  soils,  in  road  dust,  and  in  soil  in  general  which  has  been  en- 
riched by  the  addition  of  decomposing  organic  matter.  But  in  spite 
of  the  fact  that  opportunity  for  infection  through  abrasions,  cuts,  and 
wounds  of  the  hands,  feet,  and  other  parts  is  a  matter  of  daily  occur- 
rence with  a  large  proportion  of  the  people,  these  diseases  are  compara- 
tively uncommon.     They  are  noticed  most  commonly  in  cases  of  severe 


SOI  I J   Ai\l)   niS/'JASK 


MU 


injiiricH,  hiicIi  jis  ('ompoiiiid  (nK^tiircH,  and    in  Hlinllcrinfr  wounds  diif  to 
((xplo.sive.s.      A('r.()vd\\\y^  to  .some  uiilliorilics  inoculation  ol  bporcH  uloiw, 

i.S  witllOUl,  ('(Ircl, 

Am  nniisnal  luiinlKT  of  (!aH(;.s  of  t(l;uins  is  notinr-d  in  varioiiH  local- 
ilics  in  (his  connlry  aflcr  (jvcry  annii;il  cclchrafion  of  I  Mdc|icndcnc<; 
Day,  diK;  (liiiclly  to  wonnds  (taiiscd  hy  cannon-crackers  and  Idank  c;ir- 
lridfi,(!S  lired  in  toy  pistols. 

In  ilic  followinfjj  <ai)lc'  is  a:i\-cn  (lie  nnmlxr  oC  cases  of  Iclann--  that 
hav(!  ()(H',un-(!d  in  th(!  United  States  in  the  years  IDO.'J  to  ItHO  inchi- 
sivo,  together  witli  IIk!  |)rohahl(;  Hoiirec;  of"  th(!  iid'eetion  : 


Year. 


1904 
1905 
19()(i 
1907 
1908 
1909 
1910 


ISIllliU 
ciii-lridxi;. 


3(;;i 

74 

or) 

54 

52 

5« 

i;K) 

C4 


OillMt, 

criLclicr. 


17 

18 
17 
17 

8 


Cannon. 

Firearms. 

Powder, 
etc. 

27 

Total. 

5 

•} 

415 

5 

1 

7 

105 

4 

5 

K', 

104 

1 

7 

10 

89 

(i 

4 

.S 

73 

4 

.'5 

6 

76 

1 

4 

G 

150 

5 

1 

72 

Examinations  of  cannon-crackers  by  Dr.  Harold  Walker  and  of  blank 
cartridges  by  Dr.  JI.  G.  AVells  for  tetanns  organisms  have  yielded 
negative  results,  and  it  is  ])robablc  that  infection  is  due  to  organi.sms 
ab'cady  on  the  liand  of  the  celebrant  when  the  accident  occurs. 

Anthrax. — The  bacillus  of  anthrax  has  been  found  in  the  soil  of 
pastures  in  which  infected  animals  have  lieen  confined,  and  it  Avas  thought 
at  one  time  that,  following  the  burying  of  animals  dead  with  the  disease, 
the  soil  could  be  infected  thoroughly  through  s])ore  formation,  the  sj)ores 
being  brought  to  the  surface  by  earthworms,  there  to  be  the  cause  of 
fresh  infections.  Now,  however,  this  view  is  regarded  as  untenable, 
since  the  spores  are  not  formed  within  the  puti'cfying  carcass,  and 
the  bacillus  itself  is  soon  destroyed  in  the  process  of  decomposition 
of  the  tissues.  Thus  wlien  a  body  is  buried,  the  organisms  are 
soon  rendered  incapable  of  reproduction  or  of  continuing  their  own 
existence. 

The  the(My  that  the  spores  are  brought  to  the  surface  by  burrowing 
earthworms,  was  demolished  by  Koch,"  whose  conclusions  were  based 
upon  direct  experiment,  and  was  abandoned  by  Pasteur  himself,  who 
first  sugo-ested  it  because  of  finding  spores  in  the  superficial  layer  of  soil 
at  a  s}>ot  where,  two  years  previously,  a  coav,  dead  of  the  disease,  had 
been  buried  at  a  depth  of  over  two  meters,  a  depth  not  ordinarily 
reached  by  earthworms  in  their  burrowing. 

Therefore,  it  seems  most  likely  that  fresh  outbreaks   among  cattle 

grazing  on  fields  where  others  have  died  and  have  been  buried  are  due 

not  to  the   buried   organisms,  but  to  those  which   in  one  way  or  an- 

1  The  Joninal  of  the  American  Medioal  Association,  Sept.  8,  1910,  p.  S65. 
-  Mittlieikuigeu  aus  dem  kaiserlicheu  Gesundheitsamte,  ISSl. 


350  THE  SOIL. 

other,  from  the  blood  or  dejecta  of  former  oases,  have  beeu  de])osited 
on  the  surface. 

Tlie  question  as  to  wlietlier  pathogenic  micro-organisms  can  be  brought 
to  the  snrlace  by  vegetables  and  deiH)sited  upon  their  stems  and  leaves 
in  the  })rocess  of  growth  has  been  investigated  recently  by  llendinger 
and  Nouri.'  These  observers  used  in  their  experiments  B.  jirodigiosus, 
B.  anthraeis,  B.  typhosus,  and  B.  choleras. 

In  the  first  experiment  a  large  box  was  filled  Avith  earth  with  fur- 
rows dejnvssed  10  or  12  centimeters  below  the  ordinary  level.  The 
box  was  untler  observation  from  August  to  December,  was  open,  but 
it  was  not  exposed  to  sun  or  rain.  Radishes,  potatoes,  peas,  and  beans 
planted  in  the  box  were  irrigated  every  second  day  in  the  furrows  with 
water  contaminated  with  cultures  of  typhoid,  cholera,  anthrax,  and  B. 
prodigiosus.  From  time  to  time  the  whole  surface  of  the;  box  was 
sprinkled,  without  especial  care,  with  tap  water.  When  the  plant  had 
grown  sufficiently,  specimens  of  the  stems  and  leaves  were  taken  at  a 
height  of  from  2  to  20  centimeters  and  tested  for  the  above-named 
organisms.  B.  prodigiosus  alone  was  found,  and  that  upon  only  one  of 
ten  leaves. 

In  the  second  experiment  wheat  grains  and  radish  seeds  were  planted 
2  centimeters  deep.  Immediately  after  planting,  the  soil  was  watered 
with  cultures  of  the  same  organisms.  After  the  plants  had  grown 
sufficiently,  cultures  were  again  made  from  the  leaves  and  stems,  and 
the  bacillus  of  anthrax  was  found  twice  out  of  eight  times  and  the 
Bacillus  prodigiosus  four  out  of  ten  times. 

In  the  third  experiment  peas  and  beans  were  soaked  in  the  above 
cultures  and  then  planted  5  centimeters  deep.  B.  prodigiosus  was  found 
twice  out  of  six  times  and  bacillus  of  anthrax  once  out  of  six  times 
on  the  leaves  and  stems. 

In  the  fourth  experiment,  wheat,  radish  seeds,  peas,  and  beans  were 
placed  in  wet  absorbent  cotton  and  later  were  moistened  with  the  above- 
named  cultures.  Bacillus  of  anthrax  was  found  on  the  leaves  25  days 
after  inoculation  and  B.  ^jrodigiosus  30  days  after  inoculation.  No 
typhoid  bacilli  or  cholera  bacilli  were  found,  although  they  persisted  in 
the  wet  cotton. 

In  the  foregoing  experiments  it  is  apparent  that  typhoid  and  cholera 
organisms  do  not  tend  to  appear  on  the  stems  and  leaves  of  plants  if 
the  soil  in  which  those  plants  are  j)laced  is  artificially  infected.  If  they 
have  any  tendency  to  be  present  on  the  leaves,  they  are  apparently 
killed  off  by  exposure  to  air  and  light.  These  experiments,  however, 
would  seem  to  show  tliat  animals  might  be  infected  with  anthrax  by 
eating  vegetable  matter  growing  from  polluted  soils. 

Uncinariasis. — The  disease  which  stands  forth  pre-eminently  as  a 
true  soil-disease,  concerning  whose  etiology  there  is  no  dispute,  is  un- 
cinariasis or  hook-worm  disease,  known  also  as  ankylostomiasis,  miners' 
ausemia,  brickmakers'  disease,  Egy})tian  chlorosis,  and  St.  Gothard 
tunnel  disease.  It  was  first  brought  to  public  notice  in  1879  by  Per_ 
1  Compt.  rend.  Soc.  de  biol.,  Par.,  1910,  LXVJIL,  105-107. 


,S'0//.   ANI>    n/Sh'ASK  .">'>! 

roiK'.ilo,  wlio  invcHl.i};:i.l((l  (lie  ('|ti<iciiii<'.  wliicli  occ^iirrcd  .'Urionjr  tlir-  \v«»il<- 
nujn  <;iig;in(:(|  in  diiviri}^  IIk;  SI.  (lolliMrd  liiiinci,  :iii<l  <lisr;(»v('r«'<l  lli«; 
caUHO  <)("  I-Ik;  profoiliid  uii!i;[iii;i.  to  \><'  IIk;  |>;ir;i  ili  A  hIciiIohIoiiiuiii  ihioih- 
rude,  wliioli  is  ;i  worm  iilxml  linlf  .m  imli  in  l<  ii^tli,  wliicli  allaclics 
itsciir,  ,soni(!(-iin(!S  in  ciKH-itiKiis  iniinlx  r.-,  Id  llif  \  illi  ul'  the  ii|i|mt  |i<)r-li<»ri 
of  (lio  HtiiJill  itilcsliiK!,  tliroii^li  which  ;i  coii.sl.inl,  (h;iin  is  made  <»ii  lh<j 
blood.  Not  milil  r('(r(!iii  years,  howffvcr,  has  1  he  diseases  al(ract<'<l  (ho 
jitteiition  that  its  iiii|)()rtaiu',(Mlcs(3rv('s,  allhoiiii;h  it  has  Irmjr  Ijccu  known 
to  bo  vory  pnivah-iit  in  J>ra/il,  K^y|>l,  India,  and  varions  parts  of 
Europe,  and  os|)(!eialIy  in  mining  districts  and  brickfields,  whence  lh(! 
names  '' miiuM-s'  aiia'tnia"  and  "  brielvinaUers'  disease."  In  1 1K)0,  Dr. 
Bailey  K.  Ashlord  '  mad(;  known  its  presence!  in  (he  West  Indies  and 
brought  it  to  notice  as  i\\v.  (-aiise  o("  \\u:  ti-npic;d  ana'tnia,  which,  in 
Porto  liieo,  causes  o;r(;at  mis(!ry  and  an  enormous  d(ath-rat<;;  and  in 
1902,  Dr.  (Jharles  Wardell  Stilc^s-  announcied  thai,  in  some  j)ftrts  of 
the  Soutb,  it.  is  (lie  most  (common  disease  of"  man,  and  (hat  it  is  more 
prevalent  on  the  farms  and  planfations  of  the  sand  district  (han  in  the 
mining  districts.  Stiles  discovered  that,  in  this  country,  it  is  due  U) 
a  species  of  ankylostomuni,  not  before  described  and  not  found  in  the 
Old  World,  which  differs  in  some  imj)ortant  res[)ects  from  An/:i/fo.s(o- 
muni  duodiiude  {^Unciiiaria  daodcmdis),  but  produces  the  same  eflecLs. 
This  parasite  he  named  Uncinaria  Americana.  Shortly  after  this 
announcement  by  Stiles,  Harris  ^  reported  that  a  study  of  malaria  in 
Southern  Georgia  and  Florida,  in  a  region  where  profound  atuemia  is 
most  common,  proved  that,  insfead  of  malaria,  he  had  to  deal  \vi(h 
uncinariasis,  the  sufferers  showing  generally  no  malaria  jtarasites,  but 
being  almost  invariably  infested  with  hook-worms.  In  I'JOo,  Ashford 
and  King*  declared  uncinariasis  to  be  the  great  scourge  of  fully  90  per 
cent,  of  the  agricultural  laboring  classes  (about  600,000  jx-rsons)  of 
Porto  Rico.  As  an  indication  of  its  jn-evalenee  in  the  South,  the  ex- 
perience of  Dr.  L.  M.  Warfield  '^  is  of  great  interest.  He  examined 
60  boys,  inmates  of  an  orphanage  near  Savannah,  and  found  that  no 
fewer  than  48  were  infested.  Dr.  Claude  A,  Smith,®  speaking  of 
its  prevalence  in  the  Smith,  says  :  "  It  seems  as  though  the  entire 
country  was  literally  saturated  with  it.  It  is  found  on  the  highlands 
as  well  as  on  the  lowlands,  and  on  the  mountains  as  well  as  on  the 
seaboard." 

Within  recent  years  the  disease  has  been  found  to  exist  in  many 
parts  of  Europe  (England,  Belghnii,  Hungary,  Germany),  where  its 
presence  never  before  was  suspected,  but  the  victims  have  been  chiefly 
miners,  and  the  disease  has  been  regarded  as  peculiar  to  coal-mining 
and  other  underground  occupations.  The  fact  that  this  is  no  more  the 
case  in  Europe  than  in  tins  country  is  shown  by  the  observations  of 

'  New  York  Medical  Journal,  April  14,  1900. 

2  Public  Health  Reports,  October  24,  1902. 

'  American  Medicine,  November  15, 1902. 

*  Ibidem,  September  5,  1903. 

^  Ibidem,  January  9,  1904. 

•^  Journal  of  the  American  Medical  Association,  August  27,  1904. 


352  THE  SOIL. 

the  Drs.  Ibcrer/  who  exaniinod  large  numbers  of  peasant  lads,  who 
never  had  ANorked  in  the  mines,  but  \\\\o,  nevertheless,  yielded  in  many 
instances  large  numbers  of  the  parasites,  which  fact  leads  to  the  con- 
clusion that  the  disease  is  endemic  on  the  farms.  Many  of  these 
young  men  after  an  absence  of  3  years,  during  which  time  they  were 
doing  military  service,  were  found  to  be  still  infested  ;  but  they  had, 
nevertheless,  suti'ered  in  no  way  in  consequence.  Of  the  miners  ex- 
amined, no  less  than  94  per  cent,  yielded  the  parasites,  and  yet  no 
more  than  one-fourth  were  even  temporarily  incapacitated. 

So  long  ago  as  1895  the  disease  was  declared  by  ThornhilP  to  be 
far  more  serious  in  India,  Assam,  and  Ceylon  than  cholera,  on  account 
of  the  vast  number  of  people  affected  and  the  aggregate  direct  and  in- 
direct mortality.  He  called  attention  to  the  fact  that,  instead  of  uncin- 
ariasis, ana?mia,  debility,  dropsy,  malarial  cachexia,  and  diarrhoea  were 
given  as  diagnoses.  This  is  of  especial  interest  when  we  read  that,  in 
the  district  studied  by  him,  Harris  has  shown  that  most  cases  of  malaria 
prove  to  be  uncinariasis.  The  disease  is  essentially  one  of  the  poor, 
and  its  spread  is  due  to  the  habit  of  discharging  feces  upon  the  surface 
of  the  ground.  The  eggs  of  the  parasite  are  produced  in  great  numbers 
and  escape  with  the  feces.  Deposited  on  moist  soil,  they  hatch  in 
about  24  hours,  and  the  embryos,  after  twice  shedding  their  skin,  are 
ready  in  from  4  to  5  weeks  to  infest  man.  Baker  ^  accounts  for  the 
prevalence  of  the  disease  by  the  habits  of  the  people  where  it  is  most 
common.  They  live  without  regard  to  ordinary  sanitation ;  they  are 
dirty  in  their  habits  ;  they  discharge  their  feces  wherever  they  happen 
to  be ;  they  eat  with  dirty  hands,  and  often  eat  the  dirt  itself.  Ash- 
ford  and  King  say  that,  in  the  parts  of  Porto  Rico  where  the  disease 
prevails,  there  are  practically  no  privy  vaults,  and  a  bit  of  soil  as  large 
as  a  ]iea  may  contain  as  many  as  50  larvae. 

While  it  is  generally  accepted  that  the  chief  portal  of  infection  is 
the  mouth,  to  which  the  parasites  are  conveyed  on  food  contaminated 
by  dirty  fingers  or  by  dirty  dishes,  or  on  unwashed  vegetables  or  fruits 
likely  to  be  spattered  with  mud,  or  perhaps  in  muddy  water,  there 
appears  to  be  ground  for  the  belief  that  a  large  jiroportion  of  cases  are 
due  to  infection  of  the  skin.  The  first  to  assert  that  the  parasites  can 
reach  the  intestine  through  the  skin  was  Looss,*  who  rubbed  the  larvae 
into  the  backs  of  puppies  and  later  found  that  the  animals  contained 
the  parasites  within  their  intestines. 

Boycott  and  Haldane^  believe  that  infection  can  occur  through  the 
skin,  and  Smith  ^  appears  to  have  proved  it.  He  bound  some  earth 
containing  4-day-old  larvae  to  a  man's  wrist  and  allowed  it  to  remain 
in  contact  for  1  hour.      Almost  at  once  the  spot  began  to  itch  and 

1  Miincliener  mediciniscbe  Wochenschrift,  1903,  No.  22,  p.  992. 
'  Indian  Medical  Gazette,  September,  1895,  p.  339. 
3  British  Medical  Journal,  March  28,  1903. 

*  Centralblatt  fur  Bakteriologie,  etc.,   1.  Abt.  XXIX.,  p.  733;  XXXIII.,  Orig., 
p.  330. 

»  .Joui'nal  of  Tropical  Hygiene,  January  1,  1903. 

^  Journal  of  the  American  Medical  Association,  August  27,  1904. 


SOIIj   AJSD    JJJ,SJ'JA,SK  .'i.O.'i 

tiii^Io.  'I^Ik;  Htools,  wlii<!li  wc.ra  ox.'irriincid  at  tli<;  time  witli  n<■^^•lfiv(: 
r(!8iiI(;M,  W(!r(M!X!uniii(:(l  iwi<'(!  cacli  week  tlicr(!an(;r  and  coiitiinn-d  U)  \k; 
lioriruil  until  tlu;  middle  of"  IIk;  s(;v(!ntli  week,  when  f%rjrs  Ix-p-m  to 
appear.  In  a  j)ri(>r  communication  '  Ik;  asscifcd  that  ^ronnd-iteli  is  the 
most  common  disease  in  tlic  SdulJi,  due  lo  I  lie  habit  of  ^oinj^  barefoot; 
and  Wai'licihP  stat(;s  that  of  tix;  l-S  boys  in  whom  he  fonnd  the  para- 
site!, hi  f^av(!  a  history  of"  i^ronnd-itch.  \\  arhcld  sn/.'-^resL-,  lio\v(;v(;r, 
that.  th('  way  in  vvhi<-h  the  patients  with  ^ronnd-itch  beeorru;  inf'eeled 
internally  is  very  simple  :  that  tli(;y  scratch  their  i'cet  and  break  the 
vesicles  and  thus  ^ci,  |||(.  embryos  on  thc^ir  finders,  by  which  they  arc 
conv(!y(!d  to  tJu;  mouth.  J>nt,  howciver  it  lia])j)ens,  the  infectiii}^ 
material  comes  from  tin;  soil.  Nicholson  and  ]{an kin,'' also,  are  of  the 
opinion  that  t:;roun(l-itc.h  is  the  most  imjxtrtant  factor  in  the  transmis- 
sion of  uncmiariasis.  Thiiy  have  noted  that  where  there  is  no  ground- 
iteh  there  is  little  or  no  uncinariasis,  and  that  where  one  is  c<jmnion, 
the  other  is  also.  Nearly  every  one;  of  a  large  number  of  cases  studied 
by  them  gave  a  history  of  ground-itch. 

Out  of  148  southern-bred  recruits  examined  at  Fort  Slocum,  N.  Y., 
up  to  November  17,  1909,  there  were  115  infected  with  hookworm. 
At  Jefferson  Barracks,  Mo.,  all  southern-bred  recruits  enlisted  were 
examined  for  hookworm  and  10  out  of  14(S  were  found  to  l)e  iiifecte<l.< 
The  j)rincii)al  mcastu'c  of  prophylaxis  is,  naturally,  the  discontinu- 
ance of  the  practice  of  polluting  the  surface  of  the  ground  ;  but  it  is 
difficult  in  all  countries  to  persuade  those  who  have  never  been  accus- 
tomed thereto  to  use  latrines  of  any  kind.  In  a  privy-vault,  the 
embryos,  which  cannot  live  without  air,  will  speedily  die.  They  are 
destroyed  also  by  freezing  and  by  com])lete  drying,  but  soil  wliicli  is 
apparently  dry  ofteu  contains  considerable  moisture.  Other  preventive 
measures,  which  are  so  obvious  as  hardly  to  need  mention,  include  the 
wearing  of  shoes,  the  observance  of  personal  cleanliness,  especially  of 
the  hands,  and  discouragement  of  the  habit  of  dirt-eating. 

The  worms  can  be  largely,  if  not  absolutely,  eliminated  by  treat- 
ment with  thymol  in  proper  doses.^ 

Goitre. — The  various  theories  connecting  individual  constituents  of 
the  soil  with  goitre  have  now  been  well-nigh  universally  abandoned, 
since  no  one  of  them  has  been  found  to  hold  good  in  different  localities 
having  the  same  general  soil  characteristics.  Thus,  the  magnesian 
limestone  theory,  which  in  some  quarters  is  still  in  favor,  can  hardly 
stand  in  the  face  of  the  tact  that,  in  some  vast  tracts  of  such  formation, 
as  in  parts  of  New^  Zealand,  for  instance,  the  disease  is  practically 
unknown.  Similarly,  the  metallic  sulphides  escape  conviction,  for  in 
districts  where  they  abound  extensively,  the  tlisease  may  be  absent,  and 
in  others  where  they  are  unknown  it  may  prevail. 

*  Journal  of  the  American  Medical  Association,  September  19,  1903. 
^  Loc.  cit. 

3  Medical  News,  November  19,  1904. 

*  Report  of  the  Surgeon-General  of  the  U.  S.  A.,  1910. 

°  Details  of  treatment  may  be  obtained  bv  consulting  articles  on  the  subject  br  Pr. 
C.  Wardell  Stiles,  of  the  Public  Health  and  Marine  Hospital  Service,  Washington,  D.  C. 

23 


354  THE  SOIL. 

Epidemic  Diarrhoea. — The  i;iv:it  ])rc'valen('e  of  dinrrlKral  diseases, 
espirially  anioiig  very  yimng  eliiklreii,  tluring  tlie  hotter  months  of  the 
year,  lias  long  engaged  the  attention  of  sanitarians  as  a  treniendons 
factor  in  the  ahvays  high  death-rate  of  the  iirst  age  ])eriods ;  but  be- 
yond the  observanee  of  a  few  ct)ineidences,  no  conneetion  has  been 
proved  to  exist  between  it  and  the  soil. 

In  the  investigation  of  milk  sujiplies  in  single  cases  and  in  groujw 
of  cases  in  single  households  and  in  institutions,  various  very  virulent 
organisms,  including  B.  enterit'idi.s  sporogefiies,  have  been  found,  and 
it  is  not  unlikely  that  the  infective  agent,  whatever  its  origin,  owes 
much  of  its  dissemination  to  being  blown  about  in  the  dust  of  the  air. 
Observations  made  by  Drs.  Hope,  Newsholme,  and  others  indicate  that 
in  rainy  summers,  when  the  dust  is  kept  down,  the  incidence  of  diar- 
rhoea falls  notably,  and  in  unusually  dry  summers  it  shows  a  corre- 
sponding rise. 

Examination  of  Soils. 

The  complete  examination  of  a  soil  includes  chemical,  physical,  and 
bacteriological  determinations,  but  inasmucli  as  the  chemical  analysis, 
beyond  the  estimation  of  water  and  organic  matter,  is  of  no  especial 
interest  to  the  sanitarian,  though  of  great  importance  to  the  agricul- 
tural chemist,  we  shall,  with  the  exceptions  noted,  confine  ourselves  to 
the  processes  involved  in  the  physical  and  bacteriological  tests. 

In  taking  samples,  a  place  should  be  selected  which  fairly  represents 
the  locality,  and  under  some  circumstances  a  number  of  specimens 
should  be  obtained.  These  may  or  may  not  be  mixed  and  treated 
as  one.  About  two  pounds  of  the  soil  may  be  broken  up  by  being 
passed  through  a  coarse  sieve,  then  spread  out  and  left  for  one  or 
several  days  exposed  to  the  air,  and  to  that  extent  dried.  To  deter- 
mine the  relative  proportion  of  the  grains  of  different  sizes,  a  weighed 
amount  of  the  sample  is  now  passed  through  a  series  of  sieves  of  vary- 
ing coarseness,  made  of  metal  or  porcelain  with  circular  open  spaces, 
which  in  each  sieve  are  of  uniform  diameter.  Those  used  by  the 
German  scientists  have  openings  respectively  ^,  1,  2,  4,  and  7  mm.  in 
diameter,  by  means  of  which  a  specimen  is  separated  into  grains  of  less 
than  J,  from  ^  to  1,  from  1  to  2,  from  2  to  4,  from  4  to  7,  and  over  7 
mm.  in  diameter.  Other  sized  openings  may  be  used,  but  these  fulfil 
all  requirements.  The  specimen  is  passed  first  through  the  coarsest  of 
the  set,  and  then,  in  order,  down  to  the  finest.  If  the  particles  adhere 
firmly,  the  separation  is  done  best  with  the  assistance  of  water ;  and 
should  it  be  necessary,  a  pestle  covered  at  the  working  end  with  rub- 
ber may  also  be  employed.  The  separate  parts  are  then  dried  and 
weighed,  and  their  respective  amounts  expressed  in  percentages  of  the 
whole. 

The  finest  particles,  that  is,  those  of  less  than  ^  mm.,  may  be  separated 
still  further  by  the  process  of  washing  in  an  elutriating  a])paratus,  of 
which  there  are  several  kinds,  none  of  which,  however,  gives  results 
that  are  more   than  approximately  accurate,    since  so   many  different 


EXAM  [NATION   OF  SOILS. 


350 


lor(!(!H  juid  ('(HiditioiiH  conic  info  pl.'iy  fo  iriflticrKM;  flic  |tr<)cc:--.  W'ifli 
sorrx!,  (Jic  scp.'inition  is  clVccilctl  by  cunHiiij;  flic  [KirliclcH  lohclllc  <i<»wii- 
Wiird  (liroii^li  ;i  voIiimk!  of  w.'iicr,  llic  licuvic.'-t  ouch  rcicliiiifr  fllicrjrct- 
icully,  bill,  not  wliolly  in  priK^ticcj  llu;  hofloni  firsf,  ;in<l  llic  lij/lMxiHt 
Hcttlitif^  out,  liisi  or  I'cniuinin^  ;i  lonj;  tinic  in  Hiispcnsion. 

An  iij)j)iiriitnK  of  lliis  sort  in  sliown  in  Fig.  20,  wliich  rcrjuirc-  im) 
exj)ijui;iti()n.  Anotlicr,  known  as  Knop'H  KJlt  cylinder,  is  ^jiown  in 
Fif^.  21.  This  is  a  cylinder  carrying  lateral  tiihcH  fitted  with  stopcocks, 
sit.natcd  at  c(jnal  distances  (10  cm.)  apart,  'riie  s:iniplc  is  placr-(|  in 
th(!  cylinder,  which  is  then  fill(!d  with  wat(;r  and  well  shaken.  After  a 
given  time  the  u|)p(!r  stopcock  is  o|)encd  and  the  wat<T  above  it  is  drawn 
of!'.      TluMi    after   the   la])S(!  of  another   intijrval,  the  second  is  ojM;ned, 


Fio.  20. 


10 

=-|2(? 

JO 

40 


Fiu.  '21. 


ilB=6- 


6i=^=^ 


ts^ 


Apparatus  for  separation  of  fine  particles  of  soil. 


Knop's  silt  cylinder. 


JJ 


and  next,  in  the  same  way,  the  third.  The  process  is  repeated  until 
the  wash  water  conies  away  clear,  then  the  lowest  tube  is  opened,  and 
the  rest  of  the  water  above  the  remaining  material  drawn  off.  The 
different  portions  may  then  be  collected,  dried,  and  weighed,  and  their 
relative  proportions  expressed  as  before  in  percentages.  Or  the  residue 
may  be  dried  and  weighed  and  the  remainder  estimated  by  difference. 

By  another  method,  the  washing  is  carried  out  by  means  of  an  up- 
ward flow  of  M'ater  in  a  conical  vessel,  at  the  bottom  of  which  the 
sample  is  placed.  The  water,  delivered  through  a  tube  reaching  to 
near  the  bottom  of  the  vessel,  carries  the  lighter  finer  particles  upward 
and  out  through  the  exit  tube  near  the  top.  Such  an  apparatus,  known 
as  Schultz's,  is  shown  in  Fig.  22. 

Pore -volume. — The  pore-volume  is  determined  very  simply  by 
adding  to  a  volume  of  water  in  a  graduated  evlinder  a  known  volume 


356 


THE  SOIL. 


)r  soil 


rises. 


in   the 
Ii;    for 


ilrv   state, 
instauce, 


the  water 
u})    to    the 


Fig.  22. 


Schultz's  elutriating  apparatus. 


and  noting  the  height  to  which 
to  a  liter  jar  containing  water 
500  cc.  mark,  we  add  500  cc.  of  dried  soil 
in  as  nearly  as  possible  its  natural  state  of 
compactness,  and  observe  that  the  level  of 
the  water  is  in  consequence  raised  to  the 
850  cc.  mark,  it  follows  that  the  increase, 
350  cc,  rej)resents  the  actual  bulk  of  the 
soil  grains,  and  that  the  difference  between 
this  and  the  volume  occupied  originally  by 
the  sample  (500  cc),  that  is  to  say,  150  cc, 
represents  the  amount  of  interstitial  space 
filled  with  air.  Then,  since  500  cc  of  soil 
contains  150  cc  of  air  space,  it  follows 
that  the  pore-volume  of  the  sample  is  x 
in  the  equation  500  :  150  :  :  100  :  x,  or  30 
per  cent. 

In  order  to  approximate  more  closely  the 
natural  condition  of  compactness,  the  sample 
may  be  taken  from  the  soil  by  means  of  a 
metallic  cylinder  with  a  cutting  edge.  It 
is  then  dried  in  order  to  expel  the  contained 
water,  which  otherwise  would  constitute  a 
source  of  error,  and  is  then  added  to  the  water  in  the  liter  jar  as  before. 
Permeability  to  Air. — Permeability  to  air  may  be  determined  by 
forcing  measured  volumes  of  air  under  constant  pressure  through  a 
cylinder  closely  packed  with  the  sample,  and  noting  the  amount  which 
is  delivered  during  any  given  unit  of  time.  In  making  comparison 
tests  between  different  soils,  the  same  conditions  must  be  observed  in 
every  case ;  that  is  to  say,  the  length  of  the  column  of  soil  in  the  cyl- 
inder, the  pressure  employed,  and  the  unit  of  time.  A  still  farther 
condition  which  should  be  observed,  but  which  is  commonly  disre- 
garded, is  the  temperature  of  the  air,  for,  as  is  the  case  with  liquids, 
the  viscosity  of  gases  varies  with  changes  in  temperature,  though  not 
in  the  same  direction.  The  viscosity  of  liquids  is  increased  with  dimin- 
ished temperature,  whereas  in  the  case  of  gases  the  reverse  is  true. 
Disregard  of  this  fact  leads  to  important  degrees  of  error. 

The  apparatus  for  this  determination,  shown  in  Fig.  23,  comprises 
a  gas-holder  {A),  a  gas-meter  [B),  and  a  cylinder  (C)  provided  with  a 
manometer  (i)).  For  the  purpose  of  keeping  the  soil  in  position, 
tightly  fitting  perforated  disks  [E  and  F)  of  metallic  gauze  are  intro- 
duced into  the  cylinder  at  both  ends  of  the  column  of  soil. 

In  the  preparation  of  the  cylinder,  the  disk  F  is  first  introduced,  and 
then  the  soil  is  added  a  little  at  a  time,  and  made  as  compact  as  pos- 
sible by  striking  the  lower  end  of  the  cylinder  downward  with  reason- 
able force  against  the  table.  When  the  desired  length  of  column  has 
been  reached,  the  disk  E  is  introduced,  between  which  and  the  inlet 
end  ( G)  an  air  space  of  sufficient  size  is  left  to  insure  uniform  pressure 


EXAMINATION   OF  SOILS. 


357 


;i^;iiiisl,  <Jio  cnfin-  siirf;u;c  oC  flic  disk.  'V\\v.  iiil<;l,  ('(id  in  <-l(tsff!  \ty 
(iKtiuis  <»r  :i  tij^lilly  (Kliii^  iiihltci-  ,sl<>|>|»<r  having  two  |icr-(orali()(is,  <»n«; 
of  wliicli  (i!irri(!H  tlic  iiilcl  liihc  (Vom  llic  ji;:iH-rnctcr,  ami  fli<;  olhfr  the 
inaiioniclc'r  in<li(%'i,l,iii^  (lie  prcssiiic  <'iii|tloyc(l. 

Tlic  prcssiin^  is  ohlaincd  by  (ii(;a,iis  ol"  a  (miIiimiii  dC  water  foiniiiiiiii- 
caiiiijji;  vvilli  llic  cliainlxT  of  ilic  f^as-lioldcr,  \vlii«"li  is  cDiinccl*'*!  hy  a 
rublu!!-  tube  vvilli  tlic  iiilct  of"  tli(;  nic.ti-r ;  and  it  is  regulated  by  u  wrew 


Fkj.  2;{. 


Apparatus  for  determination  of  permeability  of  soil  to  air. 


pinclicock  on  the  outlet  tube  of  the  latter.  The  foree  is  apjilied.  the 
reading:  of  the  meter  is  noted,  and  at  the  expiration  of  the  unit  of  time, 
one,  five,  or  whatever  number  of  minutes  it  may  be,  the  reading  of  the 
meter  is  taken  again. 

Permeability  to  Water. — The  permeability  of  a  soil  to  water  is 
expressed  in  terms  indicating  the  auKnint  of  water  which  will  pass 
from  above  downward  through  a  column  of  saturated  soil  durinor  anv 


358 


THE  SOIL. 


given  unit  of  time  under  a  given  pressure.  The  apparatus  for  this 
determination,  shown  in  Fig.  24,  consists  of  a  metallic  cylinder  (tI) 
with  a  perforated  or  gauze  bottom  on  which  the  sample  of  soil  is  packed 
closely,  and  another  cylinder  (/>),  likewise  of  metal,  provided  with  a 
number  of  outlet  tubes  (c),  at  regular  intervals,  preferably  of  5  or 
10  cm.  The  lower  end  of  B  fits  tightly  into  the  up]ier  end  of  ^t,  and 
the  joint  is  made  impervious  to  water  by  means  of  adhesive  plaster, 
sealing-wax,  or  other  suitable  material.  The  soil  within  the  lower 
cylinder  is  kept  in  place,  and  its  surface  kept  intact,  by  means  of  a 


FiQ.  24. 


Apparatus  for  determination  of  permeability  of  soil  to  water. 

superimposed  disk  of  gauze  or  coarse  cloth.  The  outlet  tubes,  provided 
with  cocks,  serve  to  maintain  a  constant  level,  and,  therefore,  a  constant 
pressure  of  water  as  desired.  Water  is  admitted  in  a  constant  stream 
to  the  cylinder  through  its  upper  end,  by  means  of  a  rubber  tube  con- 
nected with  a  water  faucet.  If  it  be  desired  to  employ  the  highest 
pressure  obtainable  with  the  apparatus,  all  the  corks  of  the  outlet  tubes, 
except  the  upper  one,  are  kept  in  place.  In  this  case,  the  pressure 
would  be  expressed  by  the  distance  l)etween  the  top  of  the  soil  under 
investigation   and  the   uppermost  outlet,  through  which   the   excess  of 


EX  AM /NAT/ON   Oh'  SOILS.  S-Of) 

water  from  (he  faiu'ct  is  ;ill<»\v(<l  lo  <.'-c;i[)c,  hy  \v;iy  of"  ;i  nihlxc  liihr- 
loJuHn^  to  ;i  ,siiil<.  Siinihiily,  ;iiiy  ollici-  lici^lil,  ;in<l  [(rcsHUic  riiav  1»«- 
oni|)I(»y<'(l  hy  iciii(>viii<^  tlic  cork  of  I  lie  corrcHpoiMlin^  oiillft,  wliirh 
iJniH  Ix^cotiK'H  (Jic,  (•(lliiciil,.  WliJilf'Vcr-  llic  licij.rlit,  iii:iiii(:iiiM(l,  if.  \h 
n(!<!(!ssiiry  to  l<('<'|)  llic  delivery  end  of  (he  inlcf.  tiihe  helow  (lir-  siirfiwx; 
of  the  W!ii(!r 

'^riio  process  is  iis  loilovvs  :  n;iviii<i;  (ilioscii  llu;  |ir(!s,siire  iiti'l  ridjii-fefl 
tlic  wusic  i\\\n\  to  tlie  proper  oiillel,  (Ik;  wjitx-r  Ih  allowed  to  iiiii  in  ;iiid 
f'oi'cc  its  Wiiy  down  lliroiit;li  the  soil  until  the  latter  heeoines  s:tliiralc(J. 
In  ord(^r  to  iiisnic  eompletc  saturation,  it  is  hest,,  Jiowever,  to  irnrtxTHC 
tJie  soil  cylinder,  in  order  that,  all  the  air  rriav  llierehv  lie  displaced 
upward.  When  this  has  been  a(^M)in|)lished  aixl  water  he^ins  to  run 
or  diip  throni;;li  the  ^anz(!  bottom,  the  time  is  not(rd,  and  tli(;  disr-har^'cfi 
wat(M"  is  rcceivecl  in  a  suitable  j^radnate.  At,  tlu;  expiration  of  th<;  unit 
of  time,  \\w  lattcir  is  removed  and  its  (;ontonts  measured.  The  experi- 
ment may  be  repcjitod  as  oClen  as  tnayseem  advisable,  ami  the  effects 
of  varyinii;  ))ressures  may  also  be  determined. 

Water  Capacity. — The  ))ower  to  hold  water  is  determined  bv 
moans  of  a  metallic;  cylinder  of  known  (capacity  with  a  ^auze  bottom. 
This  is  weighed,  thou  filled  with  the  dried  sam[)le,  and  again  w(;ighed. 
The  soil  next  is  saturated  completely  by  immersion  of  the  cylinder 
in  water,  and  then  it  is  allowed  to  drain  as  long  as  water  continues  to 
escape.  When  th(>  water  ceases  to  <lrain  away,  the  cylinder  is  wiped 
(hy  outside,  and  the  weight  of  the  whole  is  taken  ag:uu.  The  increase 
in  weight  is  the  amount  of  water  retained,  and  it  may  be  stated  in 
percentiige  of  the  pore-volume,  which  should  have  been  determined 
previously. 

Capillarity. — The  height  to  which  water  W'ill  rise  in  a  column  of 
soil  by  capillary  attraction  is  determined  by  packing  the  sample  tightly 
into  a  graduated  glass  tube,  the  lower  open  end  of  which  is  covered 
with  coarse  linen  tied  securely  on,  so  as  not  to  slip.  The  tube  is  sup- 
ported wn'th  its  cloth-covered  end  resting  in  a  shallow  dish  tilled  with 
water,  which  is  kept  at  constant  level.  The  height  to  which  the  water 
rises  through  the  column  of  soil  is  noted  from  time  to  time,  until  ascent 
ceases.  The  change  in  the  color  of  the  soil,  due  to  Avetting,  indicates 
the  progress  of  the  action. 

Moisture. — The  amount  of  moisture  in  a  soil  is  determine<l  most 
accurately  by  taking  a  sample  in  its  natural  condition,  by  means  of  a 
brass  cylinder  with  a  cutting  edge,  Aveighing  a  portion  of  it,  and  then 
drying  it  in  an  air  bath  at  105°  C.  until  it  ceases  to  lose  weight. 
The  difl^erence  between  the  original  and  final  weighings  represents  the 
amount  of  water  in  the  given  weight  of  soil.  If  it  is  desired  to  know 
the  amount  of  water  which  the  same  soil  will  absorb  from  a  saturated 
atmosphere,  the  thoroughly  dry  sample  may  next  be  placed  with  a  dish 
of  Avater  under  a  bell-glass.  The  confined  air  will  become  saturated 
with  aqueous  vapor  in  a  short  time,  and  this  will  be  abs<M-lied  by  the 
soil  up  to  the  limit  of  its  capacity,  which  is  shown  when  its  weight  no 
longer  continues  to  increase. 


360  THE  SOIL. 

The  hygroscopic  moisture  of  a  soil  may  be  determined  roughly  by 
air-drving  a  sample  aud  theu  taking  a  known  weight  of  it  and  heating 
it  iu  an  air-bath  at  105°  C. ;  or  by  exposing  it  to  a  dry  atmosphere  in 
a  bell-glass  containing  an  open  dish  of  concentrated  sulphuric  acid, 
until  it  ceases  to  lose  weight. 

Organic  and  Volatile  Matters. — Since  it  is  impossible  to  deter- 
mine bv  ordinary  processes  the  exact  amount  of  organic  matter  present 
in  any  soil,  it  is  necessary  to  designate  the  diminution  in  weight  which 
occurs  on  subjecting  a  sample  to  such  a  heat  as  will  burn  off  the 
organic  matter,  and  which  represents  other  losses  than  the  latter,  as 
"  loss  on  ignition  "  or  "  organic  and  other  volatile  matter."  For  this 
determination,  the  soil  which  was  used  for  the  estimation  of  moisture, 
or  another  sample,  thoroughly  dried,  may  be  placed  in  a  platinum  dish 
and  heated  over  a  Bunsen  flame  at  no  higher  temperature  than  is  suffi- 
cient to  keep  the  dish  at  a  dull-red  heat.  When  all  the  organic  matter 
has  been  destroyed,  the  residue  is  allowed  to  cool,  and  is  then  moistened 
with  a  little  saturated  solution  of  carbonate  of  ammonium,  in  order  to 
restore  the  carbon  dioxide  that  belongs  to  the  inorganic  constituents,  then 
dried  and  gently  ignited  to  expel  the  excess  of  ammonia,  and  finally 
weighed.  The  loss  represents  organic  matter,  ammonium  salts,  nitrates, 
water  of  crystallization,  etc. 

Determination  of  CO2  in  Soil  Air. — The  analysis  of  soil  air  is 
conducted  upon  the  same  principles  as  that  of  ordinary  air,  but  the 
method  employed  is  necessarily  different  so  far  as  the  obtaining  and 
handling  of  the  sample  are  concerned.  The  reagents  are  the  same  as 
required  in  the  analysis  of  atmospheric  air ;  the  apparatus,  however,  is 
quite  different.  It  consists  of  a  number  of  sections  of  water-pipe 
with  screw  joints,  one  having  a  pointed  foot,  above  which  are  a  number 
of  perforations  within  a  limited  area ;  an  absorption  tube,  in  which  the 
barium  hydrate  solution  is  held  and  through  which  the  air  is  drawn, 
and  an  aspirator.     (See  Fig.  25.) 

The  section  with  the  pointed  end  is  driven  into  the  soil,  and  the  pipe  is 
lengthened  by  the  addition  of  the  other  sections,  so  that  any  desired  depth 
may  be  reached,  and  thus  the  air  of  any  stratum  may  be  withdrawn.  The 
upper  extremity  is  connected  by  a  rubber  tube  with  the  inlet  tube  of 
the  absorption  apparatus,  which  latter  may  be  a  plain  glass  tube  about 
an  inch  in  diameter  with  a  bend  of  about  130  degrees  near  one  end. 
Better,  however,  is  the  apparatus  shown  in  the  illustration.  Here  the 
short  leg  of  the  bent  tube  is  a  large  bulb,  and  the  long  leg  is  a  series 
of  small  bulbs,  the  communications  between  which  are  of  small  diame- 
ter. In  either  case  the  inlet  tube  passes  through  a  tightly  fitting 
rubber  stopper  and  extends  to  a  point  just  beyond  the  bend.  The 
other  end  of  this  apparatus  is  connected  by  means  of  a  rubber  tube  with 
the  inlet  of  the  aspirator.  Any  form  of  aspirator  may  be  used,  but 
preferably  one  of  a  capacity  of  about  twenty  liters.  A  measured 
amount  of  the  dilute  solution  of  barium  hydrate,  sufficient  to  occupy 
the  greater  part  of  the  long  leg,  is  introduced  into  the  absorption  appa- 
ratus, and  the  connections  throughout  are  tested  to  prove  the  absence 


EXAMINATION   OF  SOILS. 


361 


of  l(!,'iks.  WIk'Ii  IJic  oiidcl  cock  ()('  I  lie  Mspir.'ilor  i-  dprricd,  flic  r-watK* 
of  (,li(!  coniiiirKul  vv.'ilcr  c.rcMlcs  a  jiarlial  \;iciiinii,  wliicli  i^  nlir-vc*!  t>y 
Hiiciion  of  air  froiri  flic  soil  iitid  f lir(»ii;^li  flu;  wlndc  apparatii-.  As  flic 
air  cincrtrcs  froin  flic  iiilcf,  fiihc  oC  flic  al)S(irj)lioii  apparafiis,  if  j)aHH(*( 
upward  in  flu;  foriri  of  hiihhics  fliroii^li  flic  rca^n-iif,  to  uliicli  if  ^ivcH 
uj)  its  (ionldiif,  of  (X)^.  'flic  reason  lor  iirereiiin;/  tlie  Liilhed  fiihc  Ih 
tliJit;  (!a(!li  l)iil)l)l('  of  air  in  ils  jiassa^c  froiii  one  hull)  fo  flic  ucxf  ahovc 
is  nc(;ossarily  l)ron<^lif,  info  niorf;  infiniale  and  iiroJon^r'-'i  cf^niixcA  wifli 
ilic  rcajj:;cnf,  flian  is  flic  cas(;  when    flic   |ilaiii  iiciil   fiihe  is  eriiploycd,  for 

Fki.  2r>. 


-■6 


-0' 


01 


w>. 


^^^q,^°^ 


,c:^'-^' 


'?f*^' 


Apparatus  for  determination  of  CO3  in  soil  air. 


here  the  air  bubbles  pass  quickly  aloug  the  upper  inner  surface  of  the 
tube,  and  are  not  so  exposed  to  the  reagent  as  to  lose  all  the  contained 
COj.  For  this  reason,  it  is  necessaiy  to  dra^v  the  air  through  a  second, 
and,  perhaps,  a  series  of  such  tubes,  but  one  bulbed  tube  as  pictured 
above  is  sufficient. 

The  water  from  the  aspirator  is  measured  carefully,  and  its  amount 
indicates  the  volume  of  air  that  has  been  sucked  up  (^ut  of  the  soil  to 
take  its  ]>lace.  When  the  desired  amount  has  been  acted  upon,  the 
stopcock  of  the  aspirator  is  closed,  and  the  reagent  in  the  absorj)tion 


362  THE  SOIL. 

tube  is  transferred  quickly  to  a  glass-stoppered  bottle  of  suitable  size. 
From  this  point,  the  determination  is  the  same  as  described  in  the  chapter 
on  Air. 

Bacteriological  Examination  of  Soil. 

The  bacteriological  examination  of  the  soil  requires  necessarily  an 
intimate  acqnaiutiince  with  bacteriological  technique,  a  subject  beyond 
the  scope  of  tliis  work.  It  may  be  stated  brieily  that  many  of  the 
organisms  that  inhabit  the  soil  )nay  be  isolated  by  adding  small  por- 
tions of  the  sifted  .sample  to  liqueticd  gelatin  and  then  plating,  or  by 
sprinkling  over  the  surface  of  a  nutrient  medium,  or  by  shaking  with 
distilled  water  and  transferring  thence  to  the  proper  media. 

The  many  anaerobic  forms  require,  of  course,  the  special  treatment 
of  their  class,  and  some  of  them  may  be  grown  on  ordinary  culture 
media  ;  but  many  of  the  saprophytes,  notably  the  nitrifying  organisms, 
cannot  be  isolated  by  the  ordinary  methods.  For  the  details  involved 
in  the  separation  and  identification  of  the  numerous  varieties  of  soil 
organisms,  the  reader  is  referred  to  the  standard  works  on  bacteriology. 


Oil  A  VT\:\l    I  V. 
WATER. 

A.R8()liii'rioi,^'  pure  wnicf,  tlint  is,  tlic  siil)>t;iiK;(!  (•(»rn|)f»s('(l  wliolly  oC 
hydrojrcn  ;iii(l  uxyircii,  ;iii(l  rcin'csciilcd  liv  tlic  Hyinhiil  11./),  is  never 
fniiiid  ill  luiiiii'c,  ;ui<l  is  never  se(!n,  exeej)!  in  -iniill  iiinoiints  us  a  lahora- 
tory  (^iii'iosily.  In  llie  hrond  sense,  liowever,  the  word  jmrr  ■,]s  ;i]t|tii<-d 
to  water  e.oiiN'eys  llie  idea  of  iVeedoiii  (Voni  liiirinriil  iii*rredieiils  ;iiid  of 
wholesoineiiess  jukI  siii(;il»ilil  y  ("or  driid<iiiL''  .'ind  for  llie  |)re|);ii';ilion  of 
food.  In  nature,  all  water  contains  more  or  less  (»f  {gaseous  and  solid 
siibstan('.(\s  in  solution  and  sns])ension,  and  sf)  lon^  as  tliese  aiv'  not 
present  in  sneli  ainoiuits  as  to  alleet  llie  (|ii:dily  injuriously,  and  s<»  lonj^ 
as  they  iuv  not  intrinsically  dan<^erous  to  health,  the  adjective  is  w»m- 
monly  held  to  ho  appropriate.  But  in  the  sense  that  purity  involves 
the  limitation  of  tlio  amount  of  (contained  suhstanccs  of  a  liarmlcss 
nature,  it  becomes  a.  dillicult  (jueslion  where  to  draw  the  liiu;  where 
water  ceases  to  be  ])ure,  and  what  term  to  iqiply  as  an  antonym.  In 
the  sense  that  it  involves  complete  absence  of  matters  intrinsi«dly 
dan2:erous,  the  line  can  be  sharjily  drawn,  and  water  which  fails  to 
satisfy  the  requirements  of  the  term  may  be  designatc^d  indifferently  as 
impure,  polluted,  or  contaniinated. 

In  the  classic  reports  of  the  State  Board  of  Health  of  Massachusetts 
on  public  water  supplies,  waters  are  classed  as  "  normal  "  or  "  polluted  " 
according  as  they  are  or  are  not  free  from  direct  or  indirect  pollution 
by  the  waste  products  of  human  life  and  industry.  Under  this  classi- 
fication it  follows,  naturally,  that  normal  waters  must  vary  veiy  widely 
in  appearance,  composition,  and  general  character,  and  that  a  normal 
water  is  not  necessarily  suitable  for  drinking,  although  incapable  of 
causing  specific  disease.  The  nature  and  amount  of  the  dissolved 
matters  cannot  but  have  considerable  influence  in  modifying  the  prop- 
erties and  eftects  of  a  w^ater. 

Waters  may  be  classified  accoi'ding  to  source  as  follows  : 

1.  Rain  and  snow. 

2.  Surface-water  (rivers,  ponds,  basins,  etc.). 

3.  Ground-water  (also  known  as  subsoil-water). 

4.  Artesian  or  deep  well-water. 

RAIN. 

Rain  is  the  original  source  of  all  natural  waters  of  whatever  class. 
It  results  frouT  condensation  of  the  aqueous  vapor  of  the  atmos]ihere, 
and  in  its  descent  to  the  earth  it  takes  up  gaseous  and  suspended  mat- 
ters from  the  atmosphere,  which  to  that  extent  becomes  thereby  pu ri- 
ses 


364  WATER. 

fied.  In  the  oj-ien  country,  nftor  the  air  has  been  washed  for  a  while, 
the  colleeted  rain  is  very  clean,  and  is,  in  fact,  the  purest  form  of  nat- 
ural water.  If  its  fall  is  accompanied  by  wind  from  dusty  localities, 
it  cannot  be  obtained  in  so  clean  a  condition  within  so  short  a  time,  on 
account  of  the  greater  amount  of  suspended  matters  to  be  M'ashcd  down. 
Near  the  sea,  it  contains  more  or  less  salt ;  and  iu  cities  and  large  towns, 
it  mav  have  a  slightly  acid  reaction. 

In  its  passage  downward  through  the  atmosphere,  rain  absorbs  con- 
siderable air,  or,  more  properly,  constituents  of  air ;  that  is,  oxygen,  nitro- 
gen, carbon  dioxide,  and  ammonia  compounds.  Since  each  gas  has  its 
own  coefficient  of  solubility  in  water,  and  as  air  is  a  mixture  and  not 
a  chemical  union  of  gases,  it  follows  that  water  will  absorb  the  con- 
stituents of  air  separately  and  according  to  their  respective  solubilities. 
So  it  happens  that  the  absorbed  air  has  a  very  different  composition 
from  that  of  atmospheric  air,  being  much  richer  in  oxygen  and  poorer 
in  nitrogen,  its  oxygen  content  being  35  instead  of  21  per  cent.  On 
reaching  the  earth,  some  of  the  rain  is  evaporated,  some  sinks  into 
the  soil,  and  some  runs  over  the  surface  to  streams  or  other  bodies 
of  water.  The  amount  that  sinks  into  the  soil  depends  upon  the 
permeability  of  the  latter  to  water.  Thus,  a  sandy  or  gravelly  soil  will 
take  up  more  of  the  rainfall  than  a  close-grained  clay.  The  amount 
which  is  returned  to  the  atmosphere  by  evaporation  is  surprisingly 
large.  It  has  been  reckoned  by  Dalton  that  in  the  whole  of  England 
and  Wales,  about  50  per  cent,  of  the  total  annual  rainfall  is  lost  by 
evaporation.  In  the  watershed  of  the  Rhine,  the  loss  is  reckoned  at 
50  per  cent.  ;  in  that  of  the  Rhone,  at  42  ;  of  the  Seine,  at  67,  and 
of  the  Garonne,  at  35. 

SURFACE-WATERS. 

Surface-waters  are  collections  of  water  running  along  or  stored  upon 
the  earth's  surface  iu  contact  with  the  atmosphere.  Under  this  head 
are  included  rivers  and  smaller  streams,  ponds,  lakes,  and  impounding 
basins.  They  vary  according  to  the  different  characters  of  the  areas 
which  they  have  drained  or  traversed,  or  in  which  they  are  stored. 
Thus,  a  water  that  has  flowed  over  a  rocky  soil  is  more  likely  to  be 
free  from  organic  impurity  than  one  that  has  flowed  over  loamy  soil  or 
has  vStood  in  swamps  ;  and  one  that  has  flowed  through  sandstone  bot- 
toms is  more  likely  to  contain  mineral  impurities  than  one  that  has 
flowed  over  the  virgin  soil  of  a  forest. 

Surface-water  means  something  more  than  the  rain  of  the  district 
plus  the  impurities  of  whatever  character,  organic  and  mineral,  which 
it  has  collected.  Rivers  and  lakes,  for  example,  are  made  up  of  rain 
that  has  run  over  the  surface  of  the  ground,  dissolving  in  its  course 
small  amounts  of  easily  soluble  matters,  and  of  water  that  has  come  up 
from  the  soil  below  through  springs,  or  that  has  trickled  in  from  the 
upper  layers  of  the  soil ;  and  these  latter  contribute  matters  which  may 
be  of  very  widely  different  character  from  those  obtainable  along  the 


alio  UNI)  WA  THUS.  305 

Hurfiicc;,  iKHJordiiij;'  (<»(lic  ^'foIojjicMl  cliMf.-irlcr  u("  tlif  soil  s(r;il;i  tli.il  liuvc 
l)C(!n  iu;t(!(l  ii|)(»ii. 

A  riv(!i'  Mijiy  l;il<c  i(s  (iri;^iii  in  ;i  s|»iiii;j,  ;in<l  (•<iii.'-i.-t  for  sofiic  fiiii<"  of 
^roiind-wiiicr  mKhic,  hut  iisiiiilly  it  is  not,  loiijr  before  it,  n'C(!iv<'s  ;i<t<!h- 
Hi(»iis  of  siirfjuM'-w.'ilcr  :iii(l  soon  ;i(!(|iiii"('S  tlu;  cliMnictcrislics  <»f  flic  latter. 
Aii,';iiii,  some  hikes  :in<l  ponds  .'ire  fed  almost  wholly  l»y  springs  at  tlieir 
bottoms  a n<l  sides;  bnt  e\'en  so,  llieir  \v:ilers  soon  clianj^t-  in  eharartor 
and  a('(|iiii"(!  (lie  various  forms  of  ;i(|n.itic  lif*-. 

Snrf:i(^c-\vaters  may  contain  mneli  or  litlle  or  r)o  orp'inie  matter, 
uecordinu:;  U)  eirciimslanees.  'I'lu'y  may  Ix;  eolored  or  colorless;  tlicy 
may  be  rich  or  poor  in  nilnernl  snbstaiKics.  Those  which  <'om(!  largely 
from  the.  eionnd  will  naturally  poHscsH  largely  the  charafttcristics  of 
ground-water,  :ind  those  free  irom  a(r(;<!ssioiis  from  this  sourer-  will 
approximate  more  nearly  the  charactei"  of  rain,  "^riie  (jn:ilitv  of  snrfiiee- 
waters  is  inllueneed  by  the  seasons,  by  drought  and  rainfall,  by  vege- 
tation, by  rate  of  movement,  and  by  other  conditions. 


GROUND-WATERS. 

Ground-water  is  that  which  penetrates  the  soil,  sinks  to  varirms 
de{)ths,  according  to  the  nature  of  the  soil,  and  aecumulat<'S  on  some 
more  or  less  impervious  stratum.  It  is  not  exposed  to  light  and  the 
atmosphere,  like  surface-water.  It  varies  widely  in  ebaracter  accord- 
ing to  the  nature  of  the  soil  over  wdiieli  it  has  once  flowed  and  through 
which  it  has  percolated.  It  enters  with  more  or  less  air  and  CO2  in 
solution,  and  comes  in  contact  with  the  soil  air  in  the  interstices, 
Avhich  is  much  richer  than  atmospheric  air  in  this  gas.  With  the 
assistance  of  the  CO2  Nvhich  it  has  brought,  and  that  which  it  farther 
acquires  in  the  interstices,  it  dissolves  various  mineral  constituents  of 
the  soil.  That  which  penetrates  very  deeply  has  its  solv^ent  power 
increased  by  increased  temperature  and  pressure.  As  it  enters  the 
soil,  it  brings  with  it  whatever  organic  matters  it  may  have  dissolved 
out  of  the  surface  layers,  and  in  its  descent  it  may  lose  them  entirely 
through  the  actiou  of  the  saprophytic  bacteria  of  the  soil,  or  it  may 
acquire  still  more  if  the  soil  be  polluted  and  so  permeable  as  to  ]x^rmit 
rapid  passage  downward.  It  passes  slowly  or  rapidly  through  the 
interstices  until  it  reaches  an  impermeable  stratum,  over  which  it 
accumulates,  filling  the  interstices  completely.  The  soil  at  this  point 
is  said  to  be  saturated,  and  the  upper  limit  of  saturation  is  known  as 
the  ground-water  level,  or  water  table.  Between  this  and  the  surface, 
the  water  is  in  contact  with  the  air  of  the  interstices,  and  is  known  as 
capillary  moisture.  The  water  table  is  by  no  means  necessarily  hori- 
zontal, but  follows  in  a  general  way  the  contour  of  the  surface  of  the 
soil,  and  often  it  is  much  more  irregular,  and,  by  reason  of  local  geo- 
logical conditions,  even  quite  diti^erent  from  what  the  surface  formation 
would  indicate.  Thus,  at  one  point  in  a  level  stretch  of  country,  the 
table  may  be  quite  near  the  surface,  and  at  another,  a  short  distance 


366 


WATER. 


away,  it  uiav  be  situated  much  more  deeply,  owing  to  abrupt  changes 
of  level  of  the  imj)ei-meable  stratum. 

Irregularity  of  the  surface  of  the  water  table  is  due  largely  also  to 
the  rainfall,  wliicli,  coining  at  frequent  intervals,  falls  upon  surfaces  of 
differing  permeability,  so  that  while  one  part  is  still  draining  its  water 
downward,  another  has  completed  the  process  and  is  ready  for  more. 
When  drought  occurs,  however,  the  level  becomes  more  and  more  uni- 
form until  it  may  become  quite  horizontal.  With  return  of  rainfall, 
the  level  rises,  and  irregularity  of  the  surface  of  the  water  table  is 
again  produced.  The  level  at  any  point  is  influenced  also  by  the 
amount  of  water  withdrawn  from  the  soil  by  the  demands  made  upon 
wells.  When  the  amount  of  percolation  is  exceeded  by  the  amount  of 
withdrawal,  the  level  falls  ;  when  the  conditions  are  reversed,  the  level 
rises. 

The  water  table  in  its  irregular  course  touches  the  surface  of  the 
ground   here  and  there,  and  gives  rise  to  springs  which  may  flow  the 

Fig.  26. 


Outcropping  of  water  table. 

year  round  regardless  of  drought,  or  may  dry  up  completely  with  fall 
of  the  level.  Similarly,  all  permanent  ponds  are  outcroppings  of  the 
water  table,  ,and  the  beds  of  rivers  as  well,  but  the  level  of  the  table 
in  the  near  vicinity  is  almost  invariably  higher  than  the  surface  of 
these  bodies.  Sometimes,  however,  the  water  level  is  so  near  the  sur- 
face that,  without  emerging  in  the  form  of  springs,  it  extends  in  a  broad 
sheet  just  at  or  below  it  and  pauses  marshy  conditions.  In  Fig.  26 
the  manner  in  which  the  water  table  crops  out  in  springs  and  feeds 
lakes  and  other  bodies  of  water  is  shown. 

By  some,  the  water  table  is  spoken  of  as  an  underground  river,  a 
term  which  is  very  misleading,  in  that  it  suggests  a  body  of  water 
rather  than  a  condition  of  saturation  of  the  soil.  There  are,  to  be  sure, 
in  some  localities,  especially  in  limestone  districts,  bodies  of  water  flow- 
ing between  impermeable  strata,  and  instances  are  known  of  disap- 
pearance of  streams  into  fissures  of  rocks  and  emergence  at  a  distance 
elsewhere,  but  these  streams  are  not  a  part  of  the  water  table  as  gen- 
erally understood  and  may  not  properly  be  classc^d  as  ground-water. 

In  most  cases,  and  except  where  the  water  lies  in  deep  depressions 


J'lnSKJAI.   ANI>   ailKMKJAI.   (IIAIIACTICIUSTICS   O/'    WATIH:.    'MM 

or  |)()(;I«!iH  wilJi  no  si(l(!  oiitN^tH,  lli<:  j^ronn(l-wat,<'r  in  in  fioriHfant  l;it<T;il 
motion  in  (Jk;  (liiccfion  of  IIk;  oniraii,  and  this  is  <roniirionly  llic  ncajfht 
lar^c  body  of"  vvalcf,  cillicr  ii  lake,  or  a.  riv(;r,  or  (li<;  sea.  in  ifs  rinwani 
cour.sc  ov(;r  an  irregular  inijM'rviou.s  sfralnrn,  lli«t  niovcrn(;nt  in  at  tirrifh 
iiidiniid  iipwanl  and  at  times  downward,  hut  ever  in  the  Hamc  j^oricral 
direction  lat(;rally. 

The  rat(!  of"  movement  is  dctcrniincd  hy  a  niuidjcr  of  iiilhienees, 
ainonjr  whieh  the;  most  elleefivi!  an;  th(r  {\v\i^ri'r.  of  permeahilit v,  the 
inclination,  and  th(!  harometric  pressure.  The  (h-j^ree  ol"  jx-rmeahihly, 
de|)endent  n|)on  the  eoarscnesH  of  the  Hoil  particles,  is  of  very  ^reat 
importance,  the  more.  ra|)i<l  fh)W  occnrrin^;  through  the  s(»ils  of"  e«)arser 
text-lire.  'I'he  inclination,  or,  in  other  words,  the  infhiencc;  of"  conlonr 
in  promoting;  oi-  |)reventinj^  the  assistance  of  gravity,  has  a  very 
decided  (ifl'ect. 

The  barometric  |»ressui-e  alTects  the  rate  of"  movemenl  Ihr-oii^rl,  its 
efreets  on  the  air  in  the  interstices  above  the  water  level.  While  this 
air  is  itself"  in  constant  movement,  it  cannot  move  (piickly  hecansf!  of 
the  great  amount  of  f"ri(!tion  created.  Lessenwl  pressure  above  the 
ground  causes  tiie  soil  air  to  expand,  and  as  this  occurs,  the  tendency 
is  along  the  lines  of  least  resistan(;e,  namely,  upward  and,  under  cer- 
tain conditions,  laterally,  so  that  the  water  in  the  interstices  is  assist<.'d 
in  its  flow,  lint  the  influence  of  diminished  harometric  pressure  is 
felt  almost  at  once  at  the  outfalls,  because  of  lessened  back  pressure  ou 
the  water.  This  influence  may  be  measured  by  noting  the  fluctuations 
iu  the  water  levels  in  wells  which  rise  as  the  baromet<'r  falls,  and  fall 
as  it  rises.  Thus,  resistance  is  removed  at  the  outfall,  and  coinci- 
dently  the  water  is  being  jnished  along  by  the  expansive  force  of  the 
air  in  the  interstices.  With  increased  barometric  pressure,  these  condi- 
tions are  reversed  and  the  flow  becomes  less  rapid. 

The  rate  of  movement  being  so  dependent  upon  local  conditions,  it 
follows  that  it  varies  widely  in  diif'erent  soils.  In  some  places  it  is  so  slow 
as  to  be  almost  unmeasurable  ;  iu  others  it  is  extremely  rapid  ;  and  even 
within  a  restricted  area,  it  may  be  exceedingly  variable  at  different 
points.  At  Budajicst,  for  example,  Fodor  ^  determined  the  rate  of 
movement  at  five  difierent  points  to  be  95,  125,  190,  209,  and  210 
feet  daily.  The  average  of  these  figures,  167.6,  re])resents  unusually 
rapid  How.  At  Munich,  the  daily  rate  of  flow  toward  the  Isar  has  been 
calculated  by  Pettenkofer  as  a  trifle  more  than  15  feet. 

Physical  and  Chemical  Characteristics  of  "Water. 

At  the  standard  barometric  jn'essure,  760  mm.  or  29.922  iuche.<5, 
water  boils  at  100°  C.  or  212°  F.  With  lower  pressures,  it  boils  at 
correspondingly  lower  temperatures  ;  on  very  high  land,  for  example, 
it  boils  at  such  \ow  temperatures  that  meat  and  vegetal^les  cannot  be 
thoroughly  cooked  in  it.  Evaporation  occurs  at  all  temperatures, 
even  below  the  freezing-point. 

^  Boden  und  Wasser.     Brunswick,  1SS2. 


368  WATER. 

Water  has  its  niaxiinum  density  at  4°  C,  above  and  below  which 
point  it  expands.  At  0°  C.  it  freezes,  and  in  doing  so,  it  expands  to 
the  extent  of  about  'J  per  cent,  of  its  volume,  and  thus  acquires  a 
specific  gravity  less  than  that  of  unfrozen  water,  in  which,  therefore,  it 
fioats.  As  the  surface  freezes,  it  gives  out  heat  to  the  layer  ininiedi- 
att?ly  beneath  and  thereby  causes  a  retardation  of  the  process.  As  this 
layer  becomes  cooled,  the  ice  formation  continues,  and  thus  the  growth 
in  thickness  of  the  ice  cover  proceeds  downward.  Its  specific  heat  is 
high,  and  is  taken  as  the  standard  of  comparison.  As  a  conductor  of 
heat  it  stands  very  low. 

Water  is  the  most  universal  solvent  known,  there  being  but  few  sub- 
stances which  are  not  acted  upon  by  it  to  some  extent.  It  takes  up 
all  known  gases,  and  its  solvent  power  for  them  is  greater  according  as 
the  temperature  is  depressed  and  the  pressure  increased.  In  the  case 
of  substances  other  than  gases,  Avith  few  exceptions  its  solvent  power 
is  increased  with  increased  temperature. 

Appearance. — Pure  water  is  clear,  and,  in  proportion  as  it  contains 
dissolved  air  and  carbon  dioxide,  is  bright  and  sparkling.  Brilliancy 
of  appearance  is,  however,  by  no  means  conclusive  evidence  of  purity, 
some  extensively  contaminated  waters  showing  remarkable  brightness. 
Turbidity  of  water  is  due  to  organic  and  mineral  matters  in  suspen- 
sion ;  the  organic  matters  may  be  ordinary  dead  vegetable  and  animal 
substances  or  microscopic  living  plants  and  animals. 

Some  public  supplies  derived  from  rivers  are  distinctly  muddy  in 
appearance.  The  slight  degrees  of  turbidity  designated  as  milkiness  and 
opaleseence  are  due  commonly  to  very  minute  clay  particles,  which  may 
remain  in  suspension  for  a  long  time,  even  when  the  vessel  con- 
taining; the  water  is  allowed  to  stand  undisturbed.  Sewage  matters 
also  may  give  these  same  appearances.  Turbidity  due  to  clay  may  be 
removed  readily  by  the  addition  of  various  substances,  as  lime,  alum, 
and  sulphuric  acid,  which  cause  the  particles  to  agglutinate  and  settle 
out.  Water  which  is  apparently  clear  when  viewed  in  an  ordinary 
glass  vessel  may  be  seen  to  have  decided  turbidity  when  viewed  through 
a  depth  of  a  foot  or  two  against  a  pure  white  surface. 

Some  ground-waters  which  are  quite  clear  when  drawn  may  acquire 
a  turbid  appearance  on  standing,  due  to  the  presence  of  compounds  of 
iron  which  undergo  changes  in  composition  and  become  precipitated. 
In  such  cases,  the  turbidity  is  accompanied  by  the  development  of 
color,  which,  however,  disappears  on  the  completion  of  the  process  of 
oxidation  of  the  iron  compounds  and  their  separation  by  sedimentation. 

Color. — Water  may  have  color  or  not,  according  to  circumstances. 
Surfiice-waters  may  derive  it  from  contact  with  grasses,  leaves,  woody 
matters  in  general,  and  peat,  the  degree  of  color  being  dependent  upon 
the  length  of  time  of  contact  and  upon  the  character  of  the  substances. 
Different  kinds  of  leaves,  for  example,  impart  different  shades  and 
kinds  of  color,  but  not  always  to  the  extent  that  their  appearance 
would  indicate.  The  dark-colored  dried  leaves  of  the  oak,  for  instance, 
might  be  expected  to  yield  a   much   darker   infusion   than   the   much 


PHYSWAI.   AND   ClIKMICAL    <'IIMiA(;ri:illSTIcS   Ol'    WATI'.li.    '.W.) 

li^jiicr  colored  Iciivcs  oC  iIm'  in;i|ili',  IhiI  -ikIi  i-  iiol  flic  cane,  art  niuy 
|)c  |)ro\c<l  |-c;i(lilv  l»v  cNiiciiiinnt  ;  .iikI  IIm.m  of  llir^  luiMcniilt  ^MVC  Ji 
color  llinl-  is  ,siir|irisiiin  I  y  linjit  in  coiiiiciri-on.  Loiijr  contact  with 
svvaiiip  \'('}i;clalioii  causes  a  (lcc|»  rctlili-li-hrow  n  color,  wliicji  is  oi'U-ii 
very  s(.al)lc  on  loii^^  keeping-.  Not  nil  snrfacc-watcrh,  liowcvcr,  an; 
exposed  to  color-inip.irl  in^-  snhstances,  and  \vat<'r,~  of  lliis  class  may  Im- 
free  Croni  c(»lor. 

( Ji'onnd-walcrs  ol"  eood  (pinlity  arr'  ordinarily  colorle--  or  ap|tear-  to 
liMA'c,  wlieii  vic\v<'d  tlironeli  considcralile  de|)tlis  a;rainst  a  white  snrl'ac*-, 
a  faint  hhiish  or  oi-eeiiish-hhie  lin^c.  Sometimes  tiicy  contain  iron  and 
()fi>;aiiic  mailer  in  condmial  ion,  and  have  in  e<(nsc(|U('iic('  a  brownish  tint, 
whic^h,  hy  reason  of  \cry  slow  o.xidiilion,  may  |)ersi.st  for  a  lon^  time. 
(yolor  (kM'ivcd  othei'wise  tlian  from  contact  with  vc^ctabh,'  matter  \H 
accompanied  usually  by  more  or  less  turbidity.  Absence  of  (;olor  i.s 
not  a  si<;n  of  pnrity,  for  polhiled  \vat<'rs  may  be  quite  free  i'vum  it ; 
nor  is  its  prescMuu'  an  indication  of  unfitness  for  donicstic  use. 

Reaction. — 'J'he  dissolved  carb(»n  dioxide  in  water  tends  to  ^ive  it  a 
slightly  acid  reaetion,  but  most  potable  Avaters  arc  veiy  faintly  alkaline 
to  delicate  indicators,  owini!;  to  mimite  amounts  of  alkaline  carbonates. 
Ivain-waters,  espeeially  in  the  vicinity  of  cities  and  larj^e  towns,  are 
generally  slightly  acid  on  account  of  impurities  of  the  atmosphere, 
arising  from  combustion.  Peaty  waters  also  are  slightly  acid  on 
account  of  organic  acids  produced  by  the  action  of  the  peeidiar  bacteria 
existing  in  jwat.  River-waters  in  mining  districts  often  contain  con- 
siderable amounts  of  free  mineral  acids. 

Odor. — Pure  water  has  no  odor,  but  good  surface-waters  containing 
coloring  matters  \va\q  more  or  less  odor,  wln'ch  is  especially  marked  on 
heating.  It  is  generally  suggestive  of  vegetable  matter,  and  may  be 
characterized  variously  as  grassy,  peaty,  etc.,  according  to  the  impres- 
sion produced.  Such  odors  may  persist  even  on  long  boiling,  while 
those  due  to  dissolved  gases  will  disappear  quickly  on  heating.  Many 
otherwise  good  surftice- waters  are  particularly  prone  to  the  develoi)- 
ment  of  disagreeable  odors  attributable  to  minute  living  organisms. 

The  subject  has  been  studied  very  extensively  by  Mr.  Gary  X. 
Calkins,^  who  states  that  odors  in  drinking-waters  "  may  be  produced 
by  the  putrefactive  deeom})osition  of  the  body  plasm  through  the  agency 
of  bacteria,  and  by  the  excretion  of  certain  products  of  growth,  or  by 
the  liberation  of  products  by  the  physical  disintegration  of  the  body 
or  breaking  down  of  the  enclosing  cell  walls.  These  three  causes  give 
rises  to  three  classes  of  odors,  as  follows  :  (1)  odors  of  chemical  or 
putrefactive  decomposition,  (2)  odors  of  growth,  and  (3)  odors  of 
physical  disintegration." 

The  group  of  plants  popularly  known  as  '•  blue-green  algje " 
(ScJiizophi/cav)  is  a  very  common  cause  of  the  well-known  "pig-pen" 
and  "  grassv  "  odors  so  frequently  observed  in  shallow,  stagnant,  and 
relatively  warm  waters.  Certain  of  the  DiatomaciW  frequently  cause 
serious  trouble  by  imparting  aromatic  (geranium)  and  fishy  otlors 
1  Eepoit  of  the  State  Board  of  Health  of  ^Massachusetts;  for  1892,  p.  Sob. 
24 


370  WATER. 

aud  disiigreeiible  taste.  Of  these,  the  most  prominent  is  AsterioneUa 
fonnosd,  tuiind  very  (.'oiuiuonly  in  large  ponds  and  reservoirs  of  surface- 
water,  and  ^rowing  with  especial  luxuriance  in  open  reservoirs  of  ground- 
water. According  to  \Vlii[)[)le  and  Jackson,'  3000  astcrionella  per  cc. 
of  water  niav,  under  favorable  conditions,  impart  an  odor  easily  recog- 
nized by  the  consumer.  Several  species  of  Uroglcna,  commoidy,  but 
according  io  G.  T.  Moore,-  perhaps  incorrectly,  classed  with  the  h\Jii- 
sorid,  cause  nuich  trouble  by  the  liberation,  durhig  disintegration,  of  oil 
globules  which  impart  fishy,  oily  odors  and  tastes.  These  oil  globules 
are  yielded  by  many  other  varieties  of  water  organisms. 

A>'liile  sewage  matters  impart  mouldy  or  musty  odors  to  water,  it 
should  not  be  inferred  that  these  odors  are  of  themselves  indicative  of 
sewage  pollution,  for  good  surface-waters  sometimes  acquire  them  on 
standing. 

Sometimes  it  will  be  noticed  that  water  on  long  boiling  not  only  con- 
tinues to  evolve  a  vegetable  odor,  but  gives  it  oti'  in  greater  intensity. 
This  is  true  ])articnlarly  of  waters  rich  in  algaj.  If  they  are  first  filt- 
ered, the  odor  will  not  be  given  off  on  boiling.  But  other  waters  may 
continue  to  evolve  odors  even  after  filtration.  Peaty  waters,  for  in- 
stance, often  persist  in  yielding  odor  on  long  boiling,  and  this  is  not 
affected  in  any  ^vay  by  filtration.  Waters  containing  products  of  physi- 
cal disintegration  and  various  other  substances  also  are  not  influenced 
by  filtration. 

Odors  which  disappear  on  boiling  may  develop  again  after  a  time  if 
their  cause  is  not  removed  ;  if,  however,  the  matters  from  which  they 
are  derived  are  no  longer  present,  the  odor  will  not  return.  Some 
most  troublesome  odors  are  known  to  be  the  results  of  decay.  The 
public  supply  of  Boston  was,  in  1878,  seriously  affected  in  this  way, 
and  gave  off  an  odor  which  was  likened  to  that  of  cucumbers.  This 
was  investigated  by  Professor  Ira  Remsen,  who  found  the  cause  to  be 
decomposition  of  a  fresh-water  sponge. 

Water  sometimes  contains  sulphuretted  hydrogen  from  reduction  of 
sulphates  by  bacterial  action,  and  sometimes  mixtures  of  pro(hicts  of 
organic  decomposition  which  suggest  that  gas.  Very  marked  and 
most  offensive  odors  are  due  often  to  the  presence  of  dead  animals,  such 
as  toads  and  mice  in  wells,  and,  when  they  arise,  the  remedy  is  ob- 
vious. Some  wells  become  stagnant  at  the  bottom,  and  if  organic 
matter  is  present,  it  may  cause  foul  odor,  suggestive  of  dead  animals, 
by  putrefaction  in  the  absence  of  a  sufficient  supply  of  dissolved 
oxygen.  Stagnation  may  be  prevented  by  connecting  the  piunp  nearer 
the  b(jttom,  or  by  filling  up  the  unnecessary  space  with  clean  gravel 
and  sand. 

Odors  in  water  are  not  necessarily  indicative  of  danger  to  health, 
but  distinctly  unpleasant  ones  are  quite  sufficient  as  a  discpialification, 
on  account  of  the  repugnance  which  tlieir  use  for  drinking  and  other 
domestic  purposes  would  cause.     On  the  other  hand,  as  in  the  case  of 

'  Journal  of  the  New  England  Water-Works  Association,  September,  1899. 
'  American  Journal  of  Pliarniacy,  January,  I'JOO. 


SUBSTANd/y   FOUND   NORMALLY   IN    WATHIt.  '371 

color,  al>H(!iic.(!  is  iiol-  iii<lic;ili\c  oC  |tiii-ily,  (or  (IniipToiiH  wai^TH  may  Ihi 
iiiodofoiis. 

Taste.--  I 'lire.  \v;ilcr  li;is  iMt  distiml  l;i-tf,  ;iiiil,  \s  li;il(\(  r  tin'  impntH- 
hIoii  iiiiulc,  il  is  due  to  dissolved  f^ascs.  'I  li:it  this  i.s  .so,  in  riioHt 
(;vid(Mil'  wlicii  our  (•oiii|t;ir(!H  (Ik;  i;iKt(!  oC  a  \V(H-;i(-r:il<;(l  water,  Wcfore 
and  allci'  Ixnliii};  to  (lu'  l)uiliii^-j)()iiil  vvitli  suh.sccjiicnt  cooling.  Saline 
(loiiHtitiK^iits  imparl  no  disliiKil  laslc  iimIcihh  llicy  ar(!  prr-.sciif  in  f|iiite 
\;\Y\n.'.  iimoimts,  :i,s  in  vvalcM's  ol'  a  lii^li  <lc;4rc(;  ol"  pcnniinciil  luirdncHH. 
'I'lu;  only  suhstanct!  \vlii<'ii  impiirls  (msIc  when  it  is  prrs(!nl  in  vw-ry 
.small  (piantilics  is  iron.  dissolved  orjz;anic  mndcrs  cansc  no  tasfc,  nii- 
lesH  present  in  ('(tnsidcr.ihic  nmonnt  ;nid,  as  ;i  rnlc,  .'U'compiiniid  liv  odor. 

Water  eontaininn-  very  little  coloring-  m.'itter  is  often  s;iid  to  ta.'>t(; 
(listinelly,  hut  it  should  lu;  reniiirked  lli;i(  (lie  senses  of  (;ist<'  and  smell 
arc  often  inlluenced  iiiieonseiously  hy  (he  sense  of  sijj:h(,  and  colored 
water  KU[)i)<)sed  (o  h.i\c  both  odor  and  taste  may,  if  drunk  in  the  dark, 
give  no  impression  of  either. 

IJadly  taslino'  water,  whether  diinji:erous  or  not,  is  ohjeetionahlc  on 
the  same  _a,'ronn(ls  as  mentioned  under  odor.  Not  only  is  ahsenee  of 
bad  taste  no  evidence  of  purity,  hut  it  is  well  known  tha(  waters  con- 
taining the  j)roducts  of  oxidation  of  .sewage  are  often  remarkable  for 
unusual  pdatability. 

Substances  Found  Normally  in  Water. 

These  include  : 

1.  Gases  in  solution. 

2.  Organic  matters  in  solution  and  in  suspension. 

3.  Mineral  matters  in  solution  and  in  suspension. 

1.  Gases. — First  in  importance  is  air.  Strictly  speaking,  water  con- 
tains no  air  as  such,  but  only  the  constituents  of  air,  for  the  oxygen 
and  nitrogen,  dissolved  by  water,  are  not  present  in  the  same  propor- 
tion in  wliieh  they  exist  in  the  atmosphere.  In  salt  water,  the  varia- 
tions in  their  proportions  are  less  wide.  We  shall,  however,  consider 
the  two  gases  as  air.  The  dissolved  oxygen  is  the  important  element. 
One  hundred  volumes  of  water  at  15°  C.  will  dissolve  nearly  3  vol- 
umes of  oxygen  ('2.99),  and  at  20°,  2.80  volumes,  and  it  is  not  alto- 
gether removed  by  boiling. 

The  amount  of  oxygen  in  solution  is  fairly  constant  in  waters  of 
uniform  composition  freely  exposed  to  the  atmosphere,  but  when  they 
receive  additions  of  sewage  and  other  oxidizable  matters  they  begin  to 
lose  it.  River-waters  may  thus  show  notable  ditferences  in  the  amount 
of  dissolved  oxygen  present  in  sam]iles  taken  above,  within,  and  below 
towns  situated  on  their  banks.  The  Thames  and  the  Seine,  for  in- 
stance, show  this  in  a  remarkable  degree.  The  progressive  diminution 
is  due  to  the  constant  access  of  organic  matter,  which  undergoes  oxida- 
tion at  the  expense  of  the  dissolved  oxygen.  AMien  a  river-water  is 
deprived  of  its  dissolved  oxygen  in  this  manner,  or  by  reason  of 
chemical  changes  due  to   the  inflow  of  sewage  from  manufacturing 


372  WATER. 

establishments,  containing  compounds — ferrous,  for  instance — having  a 
strong-  affinity  for  oxygen,  fish  life  cannot  be  supported.  Absence  of 
fish  in  polluted  streams  is  due  much  more  to  diminution  of  dissolved 
oxvgen  than  to  tlie  poisonous  effects  of  organic  sewage. 

Aeration  of  water  is  intluenced  very  largely  by  the  dust  which  falls 
into  it,  for  each  particle  carries  ^vith  it  more  or  less  adherent  air,  as 
mav  readily  ,be  seen  when  one  drops  small  particles  into  water  and 
observes  their  descent.  Aeration  of  water  proceeds  to  great  depths, 
as  is  shown  by  chemical  analysis  of  samples  of  water  obtained  by  deep 
sounding,  and  also  by  the  fact  that  great  numbers  of  organisms 
which  require  oxygen  for  their  respiration  are  found  far  beneath  the 
surface ;  but  water  at  40  and  50  feet  below  the  surfiice  may  contain  no 
oxygen.  Water  from  deep  wells  is  very  commonly  free  from  dissolved 
oxygen,  because  of  abstraction  by  compounds  of  iron  or  manganese, 
org*auic  matters,  and  other  substances. 

The  presence  of  considerable  dissolved  oxygen  in  water  leads  to 
beneficial  changes  in  the  organic  matter  present.  Diminished  oxygen 
permits  the  development  of  low  forms  of  vegetable  life,  which  fre- 
quently give  rise  to  unpleasant  tastes  and  odors.  Their  growth  is 
inhibited  by  a  large  degree  of  aeration,  and  their  disagreeable  effects 
are  thereby  prevented. 

Carbon  Dioxide. — The  carbon  dioxide  contained  in  water  is  derived 
largely  from  the  atmosphere,  and  in  great  part  from  the  soil,  where  it 
is  present  in  abundance.  Its  amount  in  any  water  depends  upon  a 
number  of  circumstances  :  upon  the  amount  carried  in  by  rain  and 
dust,  the  character  of  the  soil,  and  the  extent  of  oxidation  of  organic 
matter  occurring  in  the  interstices.  It  is  greatest  in  amount  at  great 
depths,  and  it  may  constitute  almost  the  entire  content  of  dissolved 
gases.  It  has  been  calculated  that  the  ocean  contains  about  ten  times 
as  much  as  the  entire  atmosphere. 

2.  Organic  Matter. — The  organic  matters  in  water  are  of  both  ani- 
mal and  vegetable  origin,  and  consist  of  organisms,  products  of  organic 
life,  and  results  of  disintegration  and  decomposition.  The  animal 
matters  include  dead  and  living  organisms  and  dissolved  and  sus- 
pended products  of  animal  life  and  decay,  such  as  albuminous  sub- 
stances, urea,  and  tissues.  In  the  tropics  and  subtropics,  ova  and 
young  of  various  parasites  are  common.  Ordinarily  our  interest  in 
organic  matter  from  animal  sources  is  confined  to  the  products  of 
human  life  as  represented  by  sewage,  which  may  contain  the  exciting 
causes  of  specific  diseases  (see  Bacteria  in  Water,  page  379).  Vege- 
table organic  matter  exists  as  living  and  dead  organisms  and  tissues  in 
suspension,  soluble  and  suspended  substances  given  off  during  life,  and 
soluble  matters  extracted  by  the  water  after  death. 

The  vegetal)le  organisms  are  represented  by  very  numerous  species 
of  microscopic  plants,  which  act  beneficially  by  absorbing  the  products 
of  organic  decomposition  for  their  growth,  but  which  may,  on  the  other 
hand,  under  favorable  conditions,  become  the  source  of  much  trouble 
by  over-abundant  growth,  disintegration,  and  decay.     They  may  prop- 


SUBSTANCES  FOUND  NORMALLY  TN   WATER.  ?>1'?> 

(;rly  !)('  ro^ardod  ;ih  iionmil  ciiiistitiicnls  of  .siirr;irc-\v:i(«'rs,  for  they  aro 
jilwJiyH  |)r('M<;n(.  in  sik^Ii,  :iihI,  inorcKvcr,  (Jicy  <lcv('lo|»  (jiiirkly  in  Ktorwl 
jrroiiiKl-vvatcr  cxposcid  lo  ll^lil.  ;ui(l  iiir.  When  tlicy  <lic,  most  HpccicH 
u|)j)(!iU'  (,<)  (h^ciiy  rudicr  slowly,  ;iii(l  (lie  prodncl.s  of  tlicir  (lcc,oriii»osi(ioii 
are  ub.sorhcd  l)y  new  •^rowLliH  ;  hut  wImii  |n-csciii  in  {^rc:il,  ;d)nnd;incc, 
the  progress  oC  <\rvwy  may  extvcd  lli;il-  of  }i;ro\vtli,  and  then  their 
pnxhKits  rriiiy  ju'cinnnliit-c  and  eansc  lonhicss. 

There  is  one;  ("oi'Mi  o("  ini(!ros(H)pie  orf:;anisiris,  helonjiin^  to  tli(;  elaHH 
of  run<ri,  which  niei'its  s|)ecial  mention  :  ('reiiolliri.r.  h'ii/iiild.iin.  ThiH 
is  a  (ilamcMitoiis  plant  with  cells  no  larj:;cr  than  the  ordinary  l)aeteria. 
It  ji^rows  eliiefly  in  u;i'onnd- waters  wiiieh  contain  organic  matter  and 
iron,  the  latt(>r  of  which  iiii^-rcdients  it  fixes  in  the;  form  of  f(?rrie  oxide 
in  th(!  <;(^laiin()us  sheath  of  its  filanunits,  which  thcrehy  become  y(!lh)W, 
yellow  brown,  or  brown  in  color.  Jt  (;auses  great  annoyance  by  the 
rapidity  with  whieh  it  grows  in  water-pipes,  the  lumen  of  which  is  not 
infrequently  completely  occluded,  'i'his  may  occur  more  readily  where 
the  surface  prestiuts  roughness  and  imperfections,  to  which  thf!  growths 
may  attiieh  themselves.  When  the  lilaments  an;  broken  off  and  become 
disseminated  through  the  water,  the  latter  is  rendered  unfit  for  laundiy 
use  on  account  of  the  iron-rust.  Sometimes,  it  gives  rise  to  disagree- 
able odors  and  an  iidvy  tiiste.  It  may  be  very  troublesome  within  the 
tubes  of  driven  wells,  or  in  the  reservoirs,  as  well  as  in  the  distributing 
pipes.  Sometimes,  it  may  be  seen  in  large  aggregated  masses  floating 
about  on  the  surface  of  stored  water.  By  its  extensive  growth  in 
pipes,  it  may  seriously  affect  a  whole  public  supply. 

The  presence  of  living  forms,  either  vegetable  or  animal,  indicates 
that  the  water  contains  at  least  whatever  food  materials  are  necessary 
for  their  existence,  but  not  necessarily  that  these  are  in  excess.  Algae, 
for  instance,  require  mineralized  nitrogenous  matter  (nitrates),  and 
other  substances ;  fungi  suggest  the  presence  of  carbohydrates,  pro- 
teids,  and  mineral  substances  common  to  domestic  sewage  ;  infusoria 
suggest  organic  decomposition.  Dissolved  vegetable  matters  ordinarily 
amount  to  but  little  in  weight.  Even  in  some  very  broMU  waters, 
whose  appearance  would  suggest  large  amonuts,  they  may  be  present  to 
the  extent  of  not  more  than  1  or  2  parts  in  100,000. 

The  organic  matters,  both  animal  and  vegetable,  which  are  of  inter- 
est to  the  sanitarian,  consist  chiefly  of  carbon,  hydrogen,  oxygen,  and 
nitrogen,  with,  in  many  cases,  small  amounts  of  phosphorus  and  sul- 
phur. In  the  process  of  decomposition,  which  owes  its  inception, 
progress,  and  completion  to  bacterial  activity,  the  carbon  is  combined 
with  oxygen  to  form  carbon  dioxide,  and  the  hydrogen  unites  in  part 
with  nitrogen  to  form  ammonia,  the  presence  of  whieh  in  water  in- 
dicates that  the  process  of  decomposition  is  under  way.  In  its  turn,  as 
will  be  shown  later,  the  ammonia  is  converted  eventually  to  nitric  acid, 
whieh  unites  with  bases  to  form  nitrates. 

Ammonia. — From  the  standpoint  of  sanitary  significance,  ammonia 
in  water  is  of  prime  importance.  Only  under  very  unusual  conditions 
does  it  exist  in  the  form  of  hvdmte,  but  usuallv  as  chloride  or  car- 


374  WATER. 

bonate.  "We  speak  of  it  eoiuinonly  as  free  ammo))i(i,  for,  on  boiling  the 
water,  these  salts  are  tU'coniposed  and  the  aniinonia  is  expelled  in  the 
steam.  Among  the  direct  sources  of  annnonia  in  water  is  rain,  which 
brings  it  down  out  of  the  atmosphere  in  varying  amounts  according  to 
location.  Rain  always  contains  it,  but  more  is  present  in  that  of 
thickly  ])opulated  districts  than  in  the  open  country.  In  one  instance, 
reported  by  Drown,'  it  was  found  to  the  large  extent  of  0.05G4  in 
100,000.  Its  presence,  however,  in  surface-  and  ground- waters  is 
due  for  the  most  part  to  decomposition  of  nitrogenous  organic  matter. 
It  is  not  abundant  in  ordinary  unpolluted  Avaters,  but  is  present  often 
to  a  very  considerable  extent  in  that  of  deep  driven  wells.  Here  its 
origin  is  not  always  clear ;  in  some  cases  it  is  supposed  to  be  referable 
to  coal  deposits,  in  others  to  reduction  of  accumulated  nitrates. 

Under  ordinary  conditions  in  surface-waters,  ammonia,  after  conver- 
sion to  nitrates,  is  absorbed  very  quickly  by  groM'iug  vegetation,  and 
the  more  active  the  conversion  and  the  growth,  the  greater  the  apjn'o- 
priation.  For  this  reason,  water  from  the  same  source  will  often  show 
less  on  analysis  in  summer  than  in  winter.  But  activity  of  vegetation 
is  not  responsible  alone  for  this  difference  in  amount,  for  in  the  case  of 
large  bodies  of  water,  as  lakes  and  ponds,  the  rate  of  movement  of  the 
water  has  great  influence.  During  the  warmer  months,  when  the 
upper  layers  are  warmer  and  consequently  lighter  than  the  lower,  the 
latter  become  necessarily  stagnant  and  stratified.  The  ammonia  which 
accumulates  in  these  lower  strata  does  not,  therefore,  come  to  the  sur- 
face until  cold  weather  approaches.  Then  the  upper  layers  become 
more  dense  and  tend  toward  the  bottom,  causing  a  displacement  of  the 
lower  layers  toward  the  surface  and  general  uniform  mixing  of  the 
entire  volume  of  water.  Another  element  in  the  stirring  up  of  the 
water  of  ponds  and  lakes  is  the  action  of  wind,  which,  ho>vcvcr, 
does  not  extend  beyond  twenty  feet.  Still  another  influence  to  be  con- 
sidered is  that  of  springs  at  the  bottom  and  sides,  which  tend  to  keep 
the  water  in  motion.  In  the  case  of  flowing  rivers,  the  water  is  of 
comparatively  uniform  composition  at  all  depths. 

Ammonia  is  very  characteristic  of  sewage  pollution,  the  oxidation  of 
which  yields  it  in  abundance  under  conditions  which  do  not  permit  it 
to  be  rapidly  oxidized  to  nitric  acid. 

Ammonia  as  it  occurs  in  drinking-water  is  of  itself  incapable  of 
producing  harmful  effects.  Its  amount,  however,  is  of  greater  or  lesser 
significance  according  to  circumstances  :  that  from  clean  and  properly 
stored  rain-water  is  of  far  less  significance  than  that  from  other  waters. 
In  the  one,  it  may  be  considerable  in  amount  and  mean  but  little ;  in 
others,  it  is  usually  evidence  of  deconqiosition  of  organic  matter.  Its 
amount  in  good  water  is  not  large,  and  on  account  of  oxidation  and 
absorption  by  vegetable  growth  it  does  not  accumulate.  And  even  in 
sewage-polluted    waters,   when    vegetation     is    active,    oxidation    and 

^  Massachusetts  State  Board  of  Health :  Report  on  Water  Sui^ply  and  Sewerage. 
Boston,  1890.     Part  1,  p.  562. 


HJJi;STAN<ll<:S   FOUND    NORMA  LIjV   IN    WATKIL.  'Mh 

iib.sorpi-ioii  ni;iy  so  diiiiiiii^li  its  mimmiiiiI  iIdiI,  Inlscii  alone,  it  iiii^Iit 
1(!U<1    i.o    (iiJ,s(!   coiKiliisioiis   ;is    to    llic   (■\\:\vw\iv   of    llic    \V!il«'r. 

Albuminoid  Ammonia. — The  s(i-e;ill(<l  ;illiiiiiiiiiiii(|  ;miiiii»ni;i  i-  ;i!ii- 
inoiiiii  wlileli  is  produced  In  llif  iiiocc--  of  ;iii;ily:-is  of  \v;it<-r  liy  Hh; 
nciioii  oC  ;dk;iliii<'  |)enii;iiii;;iii;il''  of  [lol.i  -Inm  on  iiili'(»j^enoiih  «»rpiiii(r 
Jiijitler  liillierlo  nndcconipo-cd.  'I  ln'  ii -nil  of  iIk;  ju-lioii  is  a  Hplittiii^ 
lip  oC  ilie  oi'<;;inie  ni:i(  (er  .■ind  I  he  eoii\  ci-ion  ol'  th<;  lii(ro^(!ii  to  atiiMioiiia, 
vvhieh,  MS  is  Ihe  e;ise  with  "  (Vee  "  ;nnnioni;i,  pasHCH  out  of  the  water  in 
th(!  sleiini.  This  matter  may  he  ol'  either  ;inini;d  or  xctretnhle  oriji-in, 
MJid  its  eharaetcr  is  o(  lai"  ^I'ealer  importaiiee  ih.ni  I  he  amonnt  oC  the 
yield.  'I'Ims,  a  water  i;rossl\'  |)ollnl(d  h\'  scw.'ijje  n);i\  yield  li--  ihini 
aiiotlu!!"  (piite  free  I'roin  sneli  conl.iminat  ion,  lint  rich  in  di--ol\(<| 
vegetable   mailer  ol"  no   <ireal    s;inllary    ihi|Hiil,incc. 

Animal  <)r<;'ani(;  matter  is  (leeom|)osed  mneji  nioi'e  rapidly  than  veg- 
elahle  mailer,  some  kinds  ol'  wliieli  are  remaikahly  permanent,  sneli, 
for  instance,  as  the  snbslances  which  uiipart  the  Inowii  color  to  tlio 
waters  ol"  swamps.  Animal  mailer  i>  richci-  in  nitr<iucn  than  vege- 
tables mailer,  and  eonse(|iienlly  a  staled  anionnl  of  idhnminoid  ammonia 
re|)resenls  (lecom|)()silion  ol"  a  larger  amonnt  of  the  l;ittcr  than  of 
tins  Ibrmer.  In  other  words,  a  small  amoiuit  oC  ;ininial  matter  will 
yield  as  mnch  alhnminoid  ammonia  as  a  large  amoinit  of  vcgctal)lc 
matter. 

Jnasnnieli  as  animal  matters  are  of  f"ar  greater  signilieanee  than  vege- 
table matters,  it  ninst  be  clear  that  the  amonnt  of  albinninoid  amnxtnia 
is  of  less  importance  than  its  origin.  And  since,  in  the  analysis  of 
water,  the  ammonias  themselves  give  no  indication  of  their  origin,  their 
significance  can  }ie  measnred  only  with  the  aid  of  estimations  of  other 
substances  ;  and  often,  also,  a  knowledge  of  the  sonree  of  tlie  water  and 
its  surronndings  will  be  recinired. 

Nitrites  and  Nitrates. — The  ammonia  formed  in  the  first  stage  of 
decomjiosition  and  that  washed  ont  of  tlie  air  by  rain  are  oxidized 
eventnally  to  nitrates  nnder  the  influence  of  the  so-called  nitrifying  liae- 
teria,  and  this  stage  marks  the  completion  of  the  process.  The  nitric 
acid  formed,  coming  in  contact  with  earthy  and  alkaline  carbonates, 
attacks  them  and  unites  with  the  bases  to  form  nitrates  and,  in  so  doing, 
liberates  (carbon  dioxide.  The  nitrifying  process  occurs  not  alone  in  the 
body  of  the  water  itself,  but  to  a  much  greater  extent  in  the  interstices 
of  the  soil,  so  that  a  water  rich  in  all  manner  of  org-anic  substance-s 
undergoes,  under  favorable  conditions,  this  purifying  process  in  the 
fullest  degree  when  it  enters  the  soil  at  the  surface  and  percolates  slowly 
downward.  Before  the  stage  of  complete  nitrification  is  reached,  there 
is  an  intermediate  stage,  that  of  nitrous  acid  and  nitrites,  but  it  is 
probable  that  the  time  duriug  which  a  given  amount  of  nitrogen  on  its 
way  to  mineralization  remains  in  the  nitrous  form  is  extremely  short  ; 
in  fact,  the  step  from  ammonia  to  nitric  acid  is  practically  instantaneous. 
Nitrates  are  seldom  absent  in  either  surfiice-  or  ground-waters,  and  may 
be  present,  especially  in  the  lattoM-,  in  ([uite  large  amount  (as  much  a.<  6 
or  7  or  more  parts  in  100,000) ;  while,  on  the  other  hand,  uitritej^  are 


376  WATER- 

not  ordinarily  present  in  unjiolluted  waters,  and  as  little  as  y^^^„-  part 
in  100,000  of  any  water  is  looked  upon  as  ''high." 

It  is  a  fact  that  nitrates  arc  reduced  very  retidily  to  nitrites,  and 
farther  back  to  ammonia,  and  even  to  nitrogen  gas  itself,  by  a  variety 
of  organisms  which  act  in  the  absence  of  oxygen.  These  are  known 
as  the  denitrifying  bacteria,  and  while  these  species  are  doubtless 
very  numerous,  only  a  limited  number  have  been  isolated  and  identified. 
Their  action  is  inhibited  by  oxygen,  as  has  been  jiroved  by  Stutzer  and 
jNEaul,'  who  fdund  that  the  process  of  denitrification  ceases  in  cultures 
through  which  a  stream  of  oxygen  is  passed.  This  was  confirmed  by 
Weissenberg,  who  observed,  further,  that  when  the  bacteria  were  culti- 
vated in  small  volumes  of  nitrate  bouillon  in  flasks  of  such  shape  that 
the  surface  of  the  liquid  was  very  great  in  comparison  to  its  depth, 
and  exposed  to  the  air,  they  did  not  act. 

These  bacteria  are  common  in  sewage  in  A\'hich  the  conditions  for 
their  growth  and  activity — absence  of  dissolved  oxygen,  for  instance — 
are  present.  Grirabert^  has  shown  that  B.  typhosus  and  B.  coll  com- 
munis reduce  nitrates  and  amido  principles  in  culture  media.  The 
production  of  gas  appears  to  be  a  result  of  the  secondary  reaction 
on  the  amido  compounds  by  the  nitrous  acid  formed  through  bacterial 
action. 

Small  amounts  of  nitrites  in  water  may  be  derived  from  the  air  by 
absorjotion  or  by  the  cleansing  action  of  rain,  and  may  be  due  to  con- 
tact of  metallic  surfaces,  brickwork,  and  new  masonry  with  the  nitrates 
in  solution  ;  but  they  are  almost  never  present  in  what  are  called  large 
amounts  (one  part  in  a  hundred  million)  except  as  an  indication  of 
sewage  pollution. 

The  disproportion  between  the  amounts  of  nitrites  and  nitrates  in 
water  may  also,  perhaps,  be  explained  as  follows  :  The  nitrates  are  the 
final  stage  of  complete  oxidation ;  they  do  not  go  on  to  a  higher  form, 
but,  being  permanent  in  character,  accumulate  in  the  water,  unless  with- 
drawn by  vegetable  life  or  reduced.  The  nitrites  cannot  accumulate 
as  such,  but  are  converted  to  the  higher  form.  Thus,  the  lower  form 
is  constantly  passing  into  the  higher,  and  is  stored  as  such. 

Nitrates  vary  considerably  in  amount,  owing  to  various  causes. 
They  are  almost  always  present  in  both  surface-  and  ground-waters, 
unless  there  is  some  process  at  work  causing  a  reduction  to  nitrites. 
In  unpolluted  surface-waters  they  are  usually  low  in  amount,  but 
such  waters  generally  contain  more  nitrogen  in  this  form  than  as 
ammonia.  They  do  not  accumulate  greatly  in  such  waters  during  the 
warmer  months,  for  they  are  absorbed  largely  by  growing  vegetation. 
Hence  they  are  more  abundant  in  winter.  In  the  warmer  months  they 
may  be  absorbed  almost  wholly  by  growing  algse. 

Ground-waters  contain  little  or  much,  according  to  circumstances  ; 
in  virgin  and  thinly  settled  districts  the  amount  is  small ;  in  others,  it 
is  usually  fairly  high.     In  the  former,  it  is  mainly  from  the  ammonia 

1  Centralblatt  fur  Bakteriologie,  Abth.  II.,  Bd.  2,  1896,  p.  473. 
^  Annales  de  I'Institut  Pasteur,  Jan.,  1899. 


SUl!S'rAi\(,'/':s   FOUND   NOIiMM.LY   IN    WATHIi.  'Ml 

of  IIk"  r;iln  ;ui(!  Ili.'ii  fonncd  In  llic  <li(;iv  lA'  llic  <»r^^;iiii<:  tiiafh-rK  ii;it- 
iirally  in  (lie  soil  ;  in  I  lie  liitlcr,  il  i-  <liic  larjj;<iy  an<l  mainly  to  tlu; 
ammonia,  (•('  (lomcslic,  ,s(!\va|z;('. 

(Jronnd-walcrs  i-i<'li  in  nitralcs,  when  cxitoscd  fo  \\^\\l  and  air, 
generally  bcc^onic  nioie  or  Ic-s  licli  in  vc^ctjihU;  growth,  and  poorer  in 
ni(i"ai('S. 

Like  aniniohi;!,  nilratcs  in  water  ai'f  not  of  tlicm.sclvcs  in  any  way 
liai'nilnl  in  llic  anionnls  Coimd.  'riny  sini|(ly  i<|)i-cscnl  wliat  waH  OIICC 
ornaiiic,  nili'o<;('n,  bnl  now  (•om|)lclcly  miiKTali/.cd.  \or  i.«  their  pnjH- 
encu' any  iiidicaiion  ol"  the  nalnrc  of  the  orip;inal  or^anicr  matter,  whether 
animal  or  v<'<;('laltl(',  and  lliis  can  ix;  inferred  oidy  when  ftther  eon.stit- 
iienls  are  considered.  When  present,  in  consiih-rahh;  or  V(;ry  iii^h 
amounts,  tliev  indicate  a  correspon<linL!-  (h'groo  of"  jxixl  jiolhitioii,  j)cr- 
haps  nearby  existinn'  pollution,  and  the  possibility  of  f'ntin-e  danger 
from  its  recin'reuce.  'I'lierefore,  lii^ih  nitrates  should  sometimes  b(! 
looked    u|)on    with   suspicion. 

And,  ("urthcrniorc,  it  should  be  borne  in  mind  that  the  evidence  of" 
extensive  minerali/ation  does  not  preclnfh'  the  existence  of  pre.sent 
processes  and  the  presence  of  active  |)atlioii;enic  niicro-or}_ranisms,  for 
orgar.ic  matter  may  be  oxidized  rapidly  in  the  presence  of  living  ]»athf»- 
geuic  germs.  Sometimes,  very  large  amounts  of  nitrates  are  found  in 
the  waters  of  very  deej)  wells,  so  large  that  they  cannot  be  exi)lained 
by  the  supposition  of  oxidized  sewage.  In  these  cases  the  caii.se  is 
surmised  to  be  fossil   remains  or  natural   nitrate  dejiosits. 

The  presence  of  nitrites  in  water  is  of  far  greater  importance  than 
that  of  nitrates.  It  means  that  fermentative  changes  are  in  progress, 
and  that  oxidation  is  not  being  completed.  AVhen  this  condition 
obtains,  iiitrites  may  be  very  persistent.  Sometimes,  they  mean  a 
reduction  of  the  nitrates,  which  takes  place  mainly  under  the  influence 
of  denitrifying  organisms,  quite  likely  to  be  present  in  large  nund»ers 
in  decomposing  organic  matter.  Sometimes,  neither  nitrates  nor 
nitrites  are  present  in  sewage-polluted  ^vater ;  in  such  cases,  either 
they  have  not  been  formed  or  they  have  been  com]>letely  reduced. 

\Vhen  nitrites  are  ]iresent  at  the  expense  of  the  nitrates  l)y  the  action 
of  metallic  surfaces,  lead  and  iron,  for  example,  the  metals  themselves 
are  present  in  at  least  detectable  traces. 

3.  Mineral  Matters. — Chlorine  as  common  salt  is  a  normal  constit- 
uent of  all  waters.  Kaiii-water  takes  it  up  from  the  air  in  small  traces, 
particularly  near  the  sea  coast.  In  the  specimen  of  rain  referred  to  on 
page  374  as  rich  in  ammonia,  the  chlorine  content  was  0.13  per  100,000, 
Avhich  is  much  in  excess  of  that  found  in  many  inland  waters.  The 
amount  of  chlorine  normally  present  in  the  water  of  a  district  depends 
on  location  and  other  conditions.  It  is  influenced  very  greatly  by 
proximity  to  the  sea,  the  air  above  which  contains  necessarily  more 
than  that  at  a  distance  inland.  It  varies  in  amount  in  the  same  water 
■with  differences  in  the  amount  of  rainfall  and  evaporation,  and  in  the 
directi(ni  of  the  wind. 

Chlorine  increases  du'eetly  with  the  population,  and  its  amount  is 


378  WATER.    . 

influenced  very  greatly  by  a  proper  system  of  sewerage  which  carries 
the  sewage  matter,  rieii  in  common  salt,  beyond  the  limits  of  the  drain- 
age area.  AVhen  its  amount  rises  above  the  normal  of  a  locality,  it  is 
indicative  of  sewage,  though  not  necessarily  of  recent  pollution.  As 
we  have  seen,  the  organic  matters  become  mineralized,  and  no  longer 
exist  in  their  original  form ;  but  no  such  change  occurs  in  the  chlorides, 
which  remain  fixed  and  unchanged,  and  they  may  be  the  only  evidence 
remaining.  Thus  a  water  polluted  by  sewage  may  have  its  organic 
nitrogen  converted  to  nitrates,  and  these  in  turn  may  be  absorbed  by 
vegetable  growth  ;  it  may  be  clear,  colorless,  odorless,  and  palatable, 
free  from  pathogenic  bacteria,  and  in  every  way  suitable  for  drinking, 
but,  nevertheless,  the  chlorine  remains  as  a  witness  that  pollution  has 
occurred  in  the  past. 

According  to  Professor  Drown,  in  a  general  way  4  families,  or  20 
persons,  per  square  mile  will  add  on  an  average  0.01  part  of  chlorine 
per  100,000  to  the  water  of  a  district  in  seasons  of  average  flow,  and 
UK^re  in  time  of  drought. 

Other  Mineral  Matters. — The  total  amount  of  dissolved  mineral  mat- 
tor  in  any  drinking-water  depends  upon  the  character  of  the  soil  with 
which  the  water  has  been  in  contact,  upon  the  length  of  time  of  expos- 
ure, and  upon  the  amomit  of  carbon  dioxide  held  in  solution.  Not  even 
the  hardest  and  most  insoluble  rocks  wholly  escape  the  solvent  power 
of  water  :  no  mineral  is  absolutely  insoluble.  Silicate  of  aluminum, 
which  is  least  acted  upon,  is  soluble  to  the  extent  of  about  1  part  in 
200,000.  Silicious  rocks  in  general  are  attacked  only  very  slightly, 
while  limestones  are  dissolved  with  comparative  ease,  and  yield  con- 
siderable calcium  and  magnesium  carbonates,  especially  if  the  water  is 
rich  in  free  carbon  dioxide.     Gypsum  also  is  acted  upon  very  freely. 

Some  waters  contain  very  large  amounts  of  mineral  matter,  derived 
from  deeply  situated  natural  deposits.  The  Carlsbad  springs,  for  ex- 
ample, are  said  to  bring  annually  to  the  surface  enormous  amounts  of 
sodium  chloride  and  calcium  carbonate,  besides  2,500  kilos  of  calcium 
fluoride,  600,000  of  sodium  carbonate,  and  11,000,000  of  sodium 
sulphate. 

Besides  the  ordinary  salts  of  the  alkalies  and  alkaline  earths,  most 
natural  waters  contain  at  least  very  minute  amounts  of  iron.  Appre- 
ciable amounts  of  iron  make  water  unsuital)le  for  general  domestic  and 
technic  purposes.  It  causes  staining  of  clothes  if  used  in  the  laundry, 
and  headache,  dyspepsia,  and  constipation  if  used  habitually  for  drink- 
ing. It  cannot  be  used  for  dyeing,  and  as  little  as  1  part  in  1,000,000 
makes  it  unsuitable  for  use  in  bloaeheries.  A  cpmrter  of  a  grain  per 
gallon  is  sufficient  to  impart  a  distinct  chalybeate  taste. 

The  permissible  total  amount  of  dissolved  mineral  constituents 
cannot  be  stated,  but  50  parts  in  100,000  are  generally  held  to  be 
excessive. 

Hardness. — Hardness  is  the  capacity  a  water  has  for  decomposing 
soap.  It  depends  on  the  amount  of  salts  of  Mg  and  Ca  in  solution, 
and  hence  upon  the  character  of  the  soil  with  which  the  water  has  been 


nAC'TK/UA   IN   W A '!■/■: n.  ?>70 

in  c.oui'M'A.  W;il('r  (Voni  ro(;I<s  wliirli  yi<'l'l  li'rui  and  rria;riif'«i:i  will 
jn'oh.'iMy  l)('  li.iid,  wliilf  lliiit  (Voin  those  composed  of  nininina,  silirta, 
oU'..,  will  |»rol);il)ly  he  soil.  Soiik;  saiidHtoncs  will  yield  HoCt  and  otliern 
hard  WJiicr,  .'leciordiiit;'  (<i  I  lir  ii.iliiie  o("  llie  ecnient  \vlii<'li  hinds  the 
j^i'iiins  to^'clJier.  The  eleineuls  cniL-iii;,;  h.irdtKrss,  parlieular-ly  llie  eal- 
ciutn  salts,  ha\'e  (Ik;  |)i()perty  of  Mial<in|r  new  eondiinal  ions  with  flie 
tatty  acids  oC  the  soap,  :ind  pinivenlin;:;  <he  foriniilion  of  a  lallier  nntil 
they  iia,V(!  I)e(!n  salislied  :  I  frrain  of"  elinlk,  (or  instanec,  will  iim'  up  M 
of  ordinary  somj)  helorc^  any  elT'eel  can  he  piodiieed  ;  henee  enonnons 
waste  of"  soap  oe(Mii-s  from  the  use  oj"  liai'd  wiiter. 

IJardn(!SS  is  divided  inio  "(emporary"  ;ind  "  |)ermanent."  Tho 
former  is  duo  to  salts  which  are  ix'inovahle  hy  hoilinj^;  the  laffer,  t<^» 
those;  which  are  not  tlionjhy  aU'ectod. 

Water  containini:;  eonsiderahh;  free;  C!0^  can  take  n|)  and  hold  eon- 
sidcrahle  earl)on:t(e  of"  lime  hy  means  of  this  ^as.  Some  claim  that  the 
carhonate  is  chani»od  to  bicarhonate,  hnt  this  eomj)onnd  has  never  been 
isolated.  If  the  f2;as  be  expelled  by  hciitinir^  th(!  solvent  power  no 
louo'cr  remains,  and  the  amonnt  so  held  is  preci|)itated,  and  then  f«n 
cx(M"t  no  more  influence  in  eausiiiL!;  hardness.  "^Flie  chloride  and  sul- 
phate of  calcium  are  not  alfecled  by  boiling.  Magnesium  carbonate  is 
precipitated,  but  redissolves  on  cooling. 

The  difference  betAveen  the  original  hardness  and  the  hardness 
remaining  after  boiling  is  the  "  temporary "  hardness.  Permanent 
hardness  is,  then,  due  to  those  salts  not  affected  by  boiling,  that  is, 
to  calcium  sulphate  and  chloride,  and  magnesium  salts  ;  and  if  above 
5  parts  in  100,000,  is  commonly  regtirded  as  excessive  and  injuri- 
ous. Calcium  sulphate  is  not  alone  objectionable  in  drinking-water, 
but  also  in  water  used  in  boilers,  since  it  is  less  soluble  in  hot 
than  in  cold  water,  and  thus  forms  a  "  scale."  Scale  is  of  two  kinds  : 
that  due  to  the  temporary  hardness,  easily  removed ;  and  that  from 
CaSOj  which  is  hard,  very  adherent,  and  removed  with  difficulty. 
The  latter  is  deposited  the  more  freely,  the  higher  the  temperature  of 
the  water. 

Boiler  scale  sometimes  is  due  also  to  other  causes.  For  instance, 
A.  Reichard '  has  reported  a  case  where  serious  difficulty  was  caused  by 
the  formation  of  a  scale  of  silica  and  lime  from  a  water  which  contained 
only  2.30  parts  of  lime  and  magnesia,  but  as  nmch  as  2.00  of  silic^i. 
Boiler  scale  causes  great  loss  of  fuel,  by  interfering  with  the  transmis- 
siou  of  heat  to  the  water.  Hardness  is  not  only  undesirable  in  water 
used  in  the  laundry  and  bath,  but  also  in  that  used  for  cooking  pur- 
poses, for  it  makes  certain  of  the  vegetables  hard  and  indigestible. 

Bacteria  in  Water. 

The  ordinary  water  bacteria  are  of  tlie  hnrmless  and  beneficent  kinds, 

wdiich,  depending  upon  dead  organic  n\atter  for  sustenance,  bring  about 

its  coivversion  into  simple  chemical  substances.      How  many  species  of 

these  saprophytic  organisms  exist  in  water  cannot  be  s;iid,  l)ut   al>out 

'  Chemiker  Zeitung,  1896,  p.  65. 


380  WATER. 

two  hundred  varieties  have  thus  far  been  described.  Tliey  may  be 
present  in  small  or  in  enormously  larg-e  numbers  without  being  ueces- 
sarilv  of  hvgienic  significance,  although  usually  their  existence  in  large 
numbers  indicates  the  presence  of  an  abundance  of  organic  matter,  and 
yet  they  may  thrive  and  multiply  enormously  in  water  containing  al- 
most no  organic  food  materials.  Indeed,  multiplication  occurs  more 
rapidly  in  pure,  than  in  polluted  water,  but  diminution  in  number  is  also 
more  rapid.  In  impure  water,  they  multiply  slowly,  but  their  growth 
is  jiersistent,  and,  under  ordinary  natural  conditions,  sudden  marked 
diminution  in  number  does  not  occur. 

The  ordiuary  water  bacteria  are  found  in  much  greater  abundance  in 
surface-waters  than  in  those  derived  from  the  soil.  Indeed,  many 
observers,  including  Koch  and  Fraenkel,  have  maintained  that  waters 
from  the  unpolluted  subsoil  are  practically  sterile.  This,  however,  has 
been  shown  by  Sedgwick  and  Prescott  ^  to  be  not  the  case.  Using  im- 
proved methods  of  investigation,  and  paying  special  attention  to  the 
nature  of  their  culture  media,  these  observers  demonstrated  conclusively 
that  wholly  unpolluted  springs,  wells,  and  tube  wells  may  yield  consid- 
erable numbers  of  bacteria  and  sometimes  a  greater  abundance  than  is 
contained  in  some  surface-waters.  In  their  paper  they  state  "  that  the 
plates  are  remarkable  not  only  for  the  slow  growth  of  the  species 
present,  but  also  for  the  absence  of  liquefying  colonies,  and,  in  many 
cases,  for  the  abundance  of  chromogeuic  varieties.  These  facts  are 
especially  important  as  indicating  the  total  absence  of  contamination  by 
ordinary  surface-water,  and,  as  far  as  they  go,  they  strengthen  the  con- 
fidence with  which  well-protected  ground-waters  may  be  regarded  as 
sources  of  public  water  supplies."  Their  conclusions  and  results  have 
been  confirmed  a  number  of  times  by  other  competent  investigators  else- 
where. Ground-waters,  when  brought  to  the  surface  and  exposed 
to  the  air,  soon  become  rich  in  the  ordinary  forms  of  bacteria,  which 
find  in  them  the  conditions  necessary  for  extraordinarily  rapid  multi- 
plication. 

Surface-waters  vary  very  much  m  their  bacterial  content  according 
as  the  conditions  present  at  any  one  time  favor  or  retard  growth  and 
accessions.  Sunshine,  influx  of  food  material  or  of  substances  inimical 
to  bacterial  life,  sedimentation,  and  growth  of  higher  organisms  act  for 
or  against  increase.  Suspended  matters  in  their  descent  carry  down 
with  them  the  bacteria  that  have  gathered  upon  them  or  have  been 
entangled  by  contact.  The  diminution  in  their  number  by  this  means 
is  more  marked  in  still  waters  than  in  rivers  with  rapid  motion.  The 
growth  of  algffi  and  other  water  plants  causes  diminution  by  removal 
of  the  nutrient  materials  upon  which  the  bacteria  depend,  and  probably 
through  some  other  influence  not  yet  discovered.  The  increase  in 
bacteria,  sometimes  noticed  during  the  colder  months,  is  explained  by 
Frankland  ^  by  the  fact  that  in  winter  much  water  runs  in  over  the 
surface  from  manured  fields. 

^  Report  of  the  State  Board  of  Health  of  Massachusetts  for  1894,  p  435, 
2  The  Bacterial  Purification  of  Water,  London,  1897. 


iiA<!'i'i':ni.\  IN  wA'i'Hii.  ;}81 

H(!,si(l('H  ilioH*'  fortiiH  \vlii»K(!  ii;itiii;il  liiihilaf  is  \v;if<;r,  oflicrK  an;  lA'U'.w 
|)r(!S(;nL  \vli(»S('  ii;il.iii;il  Ii;il)i(:i(  i-  \\\i-  liodics  (A'  111:111  iiimI  ;iiiim;il.'-,  and 
wliic.li,  ill  wilier,  ;irc,  I  licicCoic,  in  ;iii  iiiukiI  iii'iil  iririliiiin.  Tlicw; 
loi'ins,  wliicli  iiicliKlc  I  lie  |i;itli(iMciiic  \  ;iii(l  ic-,  |)iiil),il)|y  <]i*  not  in(;r«'aH<! 
in  ninnlu'i'  in  \va((;i",  wlidlicr  llic  hltcr  \n-  |»iiic  or  cxlrnsivcly  pollut^-d. 
'^riicy  live  Coi' a  (icrlain  lime,  rclniiiiiij^  llicir  \iriiiriicc  in  inuliniinihiicfj 
dc^r('(\,  and  liicn  tend  to  hcconic  inodidcd  in  lliis  rc.--|(ccl  and  rapidly  to 
disappcai".  Tli"  ji^crins  o("  cliolcr;!  Ii;i\('  Ixcii  round  in  Seine  waU;r  in 
an  active;  ,sta((!  alter  .seven  days,  iiml  in  ordiiuiry  drinkin^-waterH  a.s 
Vn\\r  a.s  twenty  days  after  addition.  'I  lie  lyplioid  fever  orj^anism  will 
live  for  longer  or  shorter  periods,  aeeordin^  (o  eireninstanees  ;  if  lias  Keen 
fonnd  in  very  jiiire  \v;iter  after  more  than  seven  weeks,  while  in  hadly 
polluted  water  its  life  is  xcry  sliorl.  Siinsliine  :ind  t<'inpcraturc  ap|)car 
to  have  very  decided  iiiliiieiiee  ii|)on  its  vitiilily.  TlKMnfliience  of  Hiiri- 
siiine  is  modified  hy  the  de|)fli  ol"  the  water  in  wliieli  the  or^misni  is 
snspended.  I>uehner  '  has  shown  that  the  rays  of  the  sun  will  kill 
cultLircri  of  the  ty|)hoid  haeilliis  at  a  de|)th  of  nhoiit  five  feet  in  four 
and  a  half  hours,  while  at  double  that  depth  thdr  effects  are  hardly 
|)erce])til)Ie.  While  it  is  true  that  this  orf^^anism  survives  lon^-r  in 
(!old  than  in  warm  weather,  it  cannot  he  said  delinitelv  that  the  rwi- 
sou  lies  in  any  inherent  greater  resistance  to  tin;  infiuenee  of  cold 
than  to  that  of  heat;  and,  indeed,  it  .seems  more  probable  that  the 
ex])lauation  is  to  be  found  in  tlie  fact  that  in  warm  weather  tiie  goxx- 
(htions  are  more  favorable  to  the  growth  of  the  con)mon  species  of 
water  bacteria  anIucIi  are  believed  to  secrete  substances  Mhich  exert  a 
toxic  influence  on  pathogenic  varieties  and  ciiuse  them  to  disapj^ear. 
The  belief  that  such  toxins  are  secreted  i.s  strengthened  by  the  researches 
of  Frankland,^  who  shows  that  waters  which  do  not  favor  bacterial 
multiplication  are  changed  in  this  particular  on  being  ])oiled.  He 
found  that,  while  anthrax  spores  were  nuich  diminished  in  number  or 
actually  destroyed  in  a  sliort  time  in  unsterilized  water,  their  numbers 
were  not  reduced  and  their  virulence  remained  unimpaired  in  sterile 
water  after  upward  of  seven  months.  These  toxic  sul^stances  are  pre- 
sumably not  secreted  by  all  forms  of  water  bacteria,  but  only  ])y 
certain  species  which  may  or  may  not  be  present  in  any  given  water, 
and  it  is  regarded  as  most  likely  that  they  are  not  inimical  to  the  same 
extent  to  all  varieties  of  pathogenic  bacteria,  but  that  substances  harm- 
less to  one  kind  may  act  fatally  on  another.  In  general,  it  may  lie 
stated  that  ]iathogenic  bacteria  which  form  spores  retain  their  vitality 
and  virulence  longest  in  any  kiud  of  water. 

Concerning  the  significance  of  5.  coli  communis,  which  is  exceedingly- 
common  in  drinking-water,  there  is  much  difference  of  opinion. 
Kruse,^  in  1894,  asserted  that  this  organism  is  so  ubiquitous  that  it 
cannot  be  regarded  as  characteristic  of  sewage,  and  in  this  position  he 
has  received  the  support  of  a  number  of  other  investigtitors,  who  have 

^  Centralblatt  frir  Rakterioloeio  uini  rarasitenkunde,  XI.   \\  781 

'■^  .lonnial  of  State  Modieine,  .Tamiarv,  ISvU. 

*  &itschrift  fiir  Hygiene  und  Iiifectiouskraukheiten  XVII.,  p.  1. 


382  WATER. 

succeeded  in  isolating  the  organism  from  all  waters  examined,  although 
in  many  cases  it  was  necessary  to  employ  large  volumes  of  the  samples. 

The  committee  of  the  Laboratory  Section  of  the  American  Public 
Health  Association,  to  wliieh  the  question  of  the  significance  of 
B.  coli  in  water  supplies  was  i-eferred,  reported  ',  ii]  October,  1903,  that, 
in  spite  of  the  fact  that  numerous  investigators  have  found  the  organism 
where  it  could  not  directly  be  traced  to  sewage  or  fecal  pollution,  the 
colon  test  of  water  is  a  safe  index  of  pollution ;  that  their  number 
rather  than  their  mere  presence  should  be  used  as  a  criterion  of  recent 
sewage  pollution  ;  that  evidence  of  the  presence  of  B.  coli  in  a  majority 
of  1  cc.  samples  should  be  required  for  a  conclusion  that  a  water  is 
sewage  polluted ;  and  that  the  examination  of  large  (100-1000  cc.) 
samples  for  B.  coll  should  be  discouraged  (one  of  five  members  dis- 
senting). On  tlie  question  of  the  desirability  of  isolating  streptococci 
as  well  as  B.  coli,  to  confirm  suspicious  evidence  of  pollution  oifered 
by  B.  coliy  there  was  no  agreement,  but  great  diversity  of  opinion. 

According  to  Clark  and  Gage,^  of  the  Lawrence  Experiment  Station, 
whose  conclusions  are  based  on  the  results  of  examination  of  some 
16,000  samples  of  water  from  all  sources  and  of  more  than  2000 
miscellaneous  samples  of  shellfish,  sea-water,  ice,  milk,  dust,  excrement, 
etc.,  the  colon  bacillus,  occurring  more  numerously  than  all  other 
bacteria  in  normal  sewage,  is  the  most  valuable  index  of  sewage. 
When  a  considerable  number  of  samples  from  the  same  source  are 
examined,  100  cc.  samples  frequently  give  more  information  as  to 
quality  than  do  single  cubic  centimeter  samples.  In  filtered  polluted 
water,  bacterial  tests  are  of  greater  value  than  chemical  analysis ;  and 
disturbing  factors  in  filtration,  shown  slightly  or  not  at  all  by  ordinary 
bacterial  counts,  are  often  shown  strongly  by  B.  coli  tests. 

WATER  SUPPLIES. 

Immediate  sources  of  water  supply  comprise  :  1.  Stored  rain.  2. 
Surface-waters,  including  rivers,  lakes,  and  gathering  basins.  3. 
Ground-waters,  including  wells,   filter  galleries,  and  springs. 

1.   STORED  RAIN. 

Where  other  water  is  not  obtainable,  and  where  the  natural  water  is 
unfit  for  drinking  or  for  wasliing  and  other  domestic  purposes,  stored 
rain-water  is  used.  If  this  is  collected  under  proper  precautions  to 
prevent  the  presence  of  extraneous  matters  of  undesirable  character 
from  the  receiving  area,  and  properly  stored,  it  constitutes  a  most 
wholesome  supply.  But  excepting  where  rainfall  occurs  with  regu- 
larity and  frequence,  the  uncertainty  of  supply,  especially  in  periods  of 
drought,  acts  as  a  great  drawback.  An  inch  of  rainfall  is  equivalent  to 
5.61  U.   S.  gallons  per  square  yard,  or  27,152  gallons  per  acre,  but 

'  Public  Health  Papers  and  Reports,  XXIX,  p.  356. 
'  Ibidem,  jx  obG. 


STOIUJ)    ILAIN.  383 

only  :i  SMiiill  proporlioii  of"  lliis  Culls  ii|)(iii  -iiif;u-c>  (roof's,  (•!<!.)  from 
wliicli    !(■   iii:iy    l)('  colicc^lcd. 

'V\\{'    tdl;il     collccl  il|u'    ;irc;i     ()(■    llic    rodf    oC    ;ili\     I  il  I  i  I' I  lllj_'     (|<|ic|mI-     IMit 

upon  flu;  sliiipc  ,'iii(l  style  oC  llic  roof,  Ixif  iijion  ili<-  ;iinoiinl  of  |rroiin«l 
oc,(;ii|)i(!(l  \)y  i\\v.  hiilMinL;'.  'flins,  ;i  lion-c  10  (I'd,  sr|M:ii(!  will  have; 
|)r;u;lic,;illy  1, ()()()  H(jiiai'<;  feel  of  w.ilcrslicd,  or,  allowinji-  for  llic  projco 
(ion  of  (li(!  ciavcs,  sonicwlial  more,  and  this  wlidlicr  lli«!  r<»of  Im-  flat, 
pllcJicd,  <;;iinl)i'cl,  mansard,  or  irregularly  dispowsd.  Upon  Hilcli  an 
a,rea,,  I  ineli  of  lain  will  \'icl<l  nearly  a  llionsand  (1)1)7)  gallons.  TIk; 
mean  annual  rainfall  of  Massaclins(;tts  is  'l."5.17  inclicK,  and  on  tlii.s 
basis,  a,  roof"  of  lliis  sizi;  would  receive  in  a  year  over  'l.'5,000  ^rallons, 
wliieli  would  allow  for  all  the  needs  of"  the  o(t(!Upants,  for  drinkinj^, 
cooking-,  halliini;-,  laundry,  and  oilier  purjwsoH,  neaily  I  20  ^dlouH  jkjF 
(licui.  \\\\l  under  ordinaiy  conditions  of  storage;  in  castxTiiH,  a  very 
lari;o  amount  of  loss  ociMirs  throuf!;h  (A'aporation,  and  thus  th(!  daily 
ullowan(H!  would  fall  sonu!what  helow  this  figure. 

In  (M)lleetini>,'  I'aiii  from  I'oofs,  it  is  scry  necessaiy  to  insuiH;  eleaidi- 
ness  of  the  su|)pl}',  hy  allowing-  the  first  (low  to  run  to  waste,  thcrcl)y 
avoidiuii,'  eonlaniination  hy  dirt,  leaves,  l)ird-(lro])pinti's,  soot,  and  (ttlicr 
maltei's  deposited  u[)on  the  roof"  and  eolleeted  in  the  jxiitt(!rs.  A  num- 
ber of  automatie  devices  are  in  use  for  the  ])urpose  of  diverting;  the 
iirst  washiuj^s  away  from  the  eonductors.  Af"ter  this  has  been  done, 
they  ehani2;e  position,  so  that  the  subsecjuent  fall  is  saved  and  stored. 

rrres^ularity  in  ])r(H'i|)itation  is,  as  has  been  remarked  above,  a  serious 
drawback  to  reliance  upon  rain  as  a  sole  sup])ly.  Partly  owin^  to  a 
general  belief  that  great  battles,  in  which  large  (juantities  of  explo- 
sives are  used,  are  eommonly  followed  by  heavy  rain,  numerous  experi- 
ments have  been  tried  toward  breaking  drought  by  discharging  power- 
ful explosives  in  the  u])]ier  strata  of  the  atmosphere,  but  without 
success.  As  a,  matter  of  fact,  the  idea  of  connection  between  battles 
and  rainfall  is  by  no  means  new,  and  has,  indeed,  come  down  from 
times  antedating  the  use  of  gunpowder  in  warfare.  Furthermore,  in- 
vt'stigation  of  government  records  has  shown  that  the  popular  belief 
has  no  foundation  in  fact,  and  that  great  battles  have  been  as  often 
followed  l)y  j>eriods  of  fair  weather  as  by  days  of  storm. 

Rain-Avater  requires  no  aeration,  for  in  its  descent  it  has  absorbed 
considerable  air  ;  but  melted  snow  and  ice  should  be  shaken  with  air 
or  poured  repeatedly  from  one  vessel  to  another,  in  order  that  they  mav 
lose  the  Hat  taste  so  characteristic  of  unaerated  water.  Moreover,  their 
use  in  the  flat  condition  is  believed  to  conduce  to  gastric  derangement. 
Snow-water  is  usually  more  impure  than  rain,  because  the  suowflakes, 
by  reason  of  their  larger  surface,  are  more  efficient  in  removing  dust 
and  dirt  from  the  air. 

Cisterns  for  storage  of  rain  should  be  so  constructed  and  an*anged 
as  to  admit  of  easy  inspection  and  cleansing.  They  should  be  kept 
covered,  so  as  to  exclude  dirt  and  dust  of  all  kinds,  insects,  mice,  and 
other  animals,  and  to  shut  off  light  as  well,  for  the  presence  of  light 
is  an   important  aid  to  the  development  of  lower  plant  fonus.     The 


384  WA  TER. 

be.-^t  materials  for  their  oonstriu'tioii  :ire  bricks,  stone,  cement,  and 
slate.  Cement  makes  a  good  lininii'  if  one  is  desired  ;  mortar,  how- 
ever, is  objectionable  on  account  of  the  solv(>nt  power  of  water  upon 
lime,  which  will  cause  progressive  increase  in  hardness.  Cisterns 
should  be  provided  with  overflow  jiipcs  dischai'ging  into  the  o])en  air 
rather  than  into  the  house  sewer,  and  their  exits  should  be  ])rotected 
bv  wire  netting  ag-ainst  the  entrance  of  leaves  and  small  animals. 

2.   SURFACE-WATERS. 

For  public  supplies,  especially  of  large  communities,  surface-waters, 
as  rivers,  lakes,  and  collecting  basins,  are  generally  more  available  than 
ground- waters. 

Large  rivers  and  lakes  are,  unfortunately,  very  connnonly  subject  to 
most  extensive  pollution  by  sewage  of  large  communities  and  manu- 
facturing establishments  along  their  borders,  and  by  the  waste  products 
discharged  into  them  from  sailing  vessels  and  steamships.  Many 
rivers  are  subject  to  progressive  increase  of  pollution  by  reason  of 
serving  as  the  most  convenient  receptacle  for  the  sewage  of  a  succession 
of  towns  and  cities  located  at  intervals  from  the  source  to  the  mouth. 
Thus,  one  town  takes  its  water  from  a  point  above  and  discharges  its 
sewage  at  another  place  below ;  a  second,  farther  down,  takes  the 
already  contaminated  water,  and  in  its  turn  discharges  its  sewage  at 
another  convenient  point,  and  so  on  for  the  rest  of  the  course.  On 
account  of  the  dangers  attending  the  use  of  such  ^vaters,  some  process 
of  treatment  is  imperatively  demanded  to  remove  the  objectionable 
elements.  The  different  processes  available  for  this  work  are  considered 
elsewhere. 

The  public  mind  is  being  awakened  gradually  to  the  wrong  practised 
upon  one  community  by  another  by  the  discharge  of  untreated  sewage 
into  what  is  its  only  available  water  supply.  In  the  case  of  cities 
located  upon  the  shores  of  the  Great  Lakes  and  other  large  bodies  of 
fresh  water,  it  is  commonly  the  case  that  the  intake  of  the  water  sup- 
ply is  located  at  no  very  great  distance  from  the  outfall  of  the  main 
sewers.  Smaller  rivers  and  lakes  may  be  subject  to  the  same  influences, 
though  in  lesser  degree  ;  but,  in  general,  it  may  be  said  that  these  are 
controlled  more  easily,  especially  when  they  lie  wholly  within  the 
jurisdiction  of  a  single  law-making  power. 

Basins  for  the  collection  and  storage  of  rainfall  and  surface-waters 
are  constructed  by  throwing  a  dam  across  a  valley  or  other  convenient 
depression.  Experience  has  taught,  that,  even  though  involving  large 
expenditure,  it  is  best  to  strip  off'  the  surface  layers  in  order  to  get  rid 
of  all  organic  matter  and  vegetation,  which,  if  left  in  place,  may  prove 
fruitful  sources  of  trouble.  The  water  which  gathers  in  them  has  op- 
portunity to  rid  itself  of  much  of  its  suspended  matters  by  sedimenta- 
tion, and  is  more  often  used  without  further  treatment  than  otherwise. 

All  surfiee- waters  contain  more  or  less  active  vegetation,  and  on 
that  account  should  always  be  kept  exposed  to  light  and  air,  otherwise 


(iiio  iiyi)-  \v.\  Ti'iiiS.  385 

\\\v.  fniiiiii(!  plniiis  will  die,  mii'I  in  lluir  rjcfotiijKtsilirui  ^iv*-  riM-  to 
iinplcnsiinl.  odor,  ;i|>|)c;ii";iiif<',  ;iihI  Iii-Ic.  Stoi;i}.M'  rc-crvoifH  hlioiiM 
lijivc  siiHic-iciiil,  (lc|>l  li  to  |ii(\iiil  ill*'  \\;il<r  liom  hccoiiiiiij/  liciitcd  lo  an 
liiinlcilSiUii.  (ic^i'ci'  <liiiiii!j  llic  wiiriii  iiiDiilli-  (li  -iiiiiiiicr.  in  ,-liallow 
reservoirs,  lliis  is  (oiinil  In  lie  a  coninMin  <)cciirren<-e. 

All  soiiiVH'S  of  sni'lace-vvater  lor  |»iil)lic  sii|»|tly  sluMiM  he  earcfiilly 
<:;ilMi'(le(l  ;i^aiiisl  sewai^e  eonlarninalioii.  It  is  often  iieees>-arv  to  seeiin; 
protoctioii  IVoni  pollntion  by  taking  f^reat  Inicts  ol'  land  and  l<eej»in^ 
tliein  \'vvv  IVoni  Innnan  liahitaf  ions  and  inrlustrial  plants. 

3.   GROUND-WATERS.     . 

Some  lar^-e  eonininnities  and  many  small  ones  ulierr-  no  Hiiitahlc 
bodies  oi"  snrl'acr-watcr  are  a\ailal)le  (or  pnhlie  sn|)plies,  and  the  major- 
ity of"  thinly  settled  districts  which  do  not  admit  of  |)iil)lic  waterworks, 
depend  u|)on  the  jrround- water  as  tlie  source  of  snp|)ly.  For  piihlic  «iis- 
tribution,  the  wutcr  thus  derived  is  stored  in  suitable  reservoirs,  which 
often  must  be  covered,  in  order  to  exclude  light.  Ground-water  is 
destitute  of  plant  life,  but  is  generally  more  or  less  rich  in  mineral 
constituents — nitrates,  and  lime  salts,  for  example — which  constitute 
apj)roj)riate  plant  food.  If  ex})osed  to  air  and  light,  vegetable  growth  may 
stiirt  up  and  become  very  luxuriant,  and  give  rise  to  unpleasant  tastes  and 
repulsive  odors,  while  exclusion  of  light  and  air  prevents  the  difficulty. 

For  individual  domestic  ;  u])]>ly,  storage  is  not  ordinarily  necessary, 
the  water  being  obtained  oidy  as  immediately  needed  or  ]nimpe<l 
periodically  into  small  distributing  tanks. 

In  general,  unpolluted  ground-water  of  not  excessive  hardness  is 
])referable  to  surtace-water,  on  account  of  the  greater  exposure  of  the 
latter  to  the  many  risks  of  ]iollution.  But  it  should  be  borne  in  mind 
that  all  sources  of  supply,  both  surface-  and  ground-waters,  may,  under 
one  condition  or  another,  be  subject  to  polluting  influences,  and  that  the 
conditions  prevailing  in  one  locality  are  likely  to  be  quite  different  from 
those  in  another. 

Ground-water  is  obtained  from  springs,  or  by  sinking  wells,  or  by 
constructing  filter  galleries. 

Springs  are  merely  local  outcroppings  of  the  water-table,  and  are 
very  subject  to  variations  in  the  volume  of  outflow.  In  time  of  drought, 
they  sometimes  cease  their  flow  com]iletely,  because  of  fall  in  the  level 
of  the  ground-water  ;  and  this  may  happen  even  in  the  case  of  those 
located  at  the  foot  of  high  hills  or  mountains.  The  popular  mind 
endows  springs  with  a  remarkable  and  unvarpng  degree  of  purit^',  but 
they  share  with  other  waters  the  likelihfxxl  of  becoming  ]K>lluted.  The 
possibility  of  contamination  after  and  even  at  the  point  of  issuance  from 
the  ground  is  too  often  overlooked. 

Springs  are  common  to  some  localities  and  rare  in  others  of  similar 

contour,  their  presence  or  absence  being  determined  by  conditions  not 

of  the  surface,  but  of  the  geological  formations  below.     In  Figs.  27 

and  28  are  showu  in  profile  two  depressions   having  the  same  contour, 

25 


386 


WA  TER. 


but  with  very  cliiferent  arrangement  of  the  umlerlyinc;  stmta.  In  Fig. 
27  the  formation  favors  the  outeropping  of  springs ;  in  Fig.  28  the 
opposite  is  the  case. 

Fig.  27. 


Fig.  28. 


Wells  may  be  classed  as  dug,  driven,  and  bored.  Sometimes  they 
are  divided  also  into  deep  and  shallow  ;  but  these  terms  as  a  basis  of 
classification  are  of  doubtful  utility,  since  there  can  be  no  general  agree- 
ment as  to  the  line  of  division  between  them,  and  because  of  the 
absence  of  any  necessarily  distinctive  peculiarities  in  the  water  yielded 
by  ordinary  wells  of  different  depths.  It  is  not  uncommon  to  meet 
with  general  statements  that  the  water  of  shallow  wells  is  dangerous  to 
health,  and  should,  tlierefore,  be  avoided,  and  that  all  shallow  wells 
should  be  condemned  and  filled.  As  will  be  seen,  however,  shallow 
wells  are  not  necessarily  dangerous,  nor  are  deep  ones  always  safe  by 
reason  of  mere  depth. 

By  some  writers,  the  term  deep  is  applied  to  wells  which  obtain  their 
water  from  below  the  first  impervious  stratum,  through  and  l^eyond 
which  they  have  been  extended  ;  while  the  term  shallow  is  applied  to 
tliose  which  draw  from  what  we  designate  as  the  ground-water  ;  tliat  is, 
that  collected  over  the  stratum  above  mentioned,  regardless  of  the  depth 
at  which  it  lies.  With  these  meanings,  it  follows  that  a  shallow  well 
may  extend  farther  downward  than  another  classed  as  deep. 

The  ordinary  dug  well  is  a  hole  dug  in  the  soil  down  as  far  as  is 
necessary  to  reach  water,  and  lined  with  brick  or  stone,  or,  better,  with 
earthenware  tubes  of  large  diameter  made  for  the  purpose  in  short 
lengths  with  bevelled  edges  to  secure  good  joints.  All  brick  and  stone 
linings  should  be  well  bedded  in  cement,  except  near  the  bottom^  and 
should  be  faced  with  the  same  material  throughout  their  upper  part. 
The  impervious  lining  is  necessary  for  the  prevention  of  the  entrance 
of  surface  washings  ;  but  it  is  very  generally  the  case,  in  some  parts  of 


(IILOIINI)    WA  TKIIS.  Wl 

tli(!  v,<n\n\\'y  ;ii  Iciisi,  lli;il.  \\n\  well  is  lined  simply  witli  licM-stoiicH, 
wiUioiil.  (U'liiciil,  iiol,  for  llic  |»iii|)os('  '»("  iiisiiriiij^  fn-cd'tiii  friun  hiirCuri' 
JMipiii'ilics,  bill  l()  prcNciil  (lie  side-  riniii  cuviii^  ill.  Willi  ;i  pntpcr 
liiiiiiji;,  IM)  siirl:icc-\v;il(i'  cnii  ciilci-  iinlil  il  lias  passed  tliroiij_di  a  ijepfli 
of  .soil  sunicieiil   lo  insure  |)i'uper  liltralioii  ami  piiiilicalioii. 

A  {\\\\f  well  should  not  l»e  lell  open,  hiit  should  he  closed  eoiiiplelely 
!i}i;:i,inst  tlu-  eiilraiiee  oC  dirt,  leaves,  and  animals,  sin-h  as  toads,  moles, 
iniee,  and  rals.  The  cover  should  he  Mijiporled  on  a  well-set  curl),  and 
be  siillicienlly  li<;h|,  (o  |)reveiil  the  return  of  ualer  spilled  or  allo\ve<l 
to  run  to  wiistc.  l\  inanholc!  with  ;i  tr;ip<loor  should  be  |)rovided  as  a 
means  ol'  inspection  and  (Oeanini;;. 

lA»r  brinuiiiu'  |||(>  wMier  lo  tJi(!  surface,  |)iinip>-  should  be  us«'d,  and 
not  biKikets  woi'l<e<l  by  windlass  or  well-sweep.  in  country  dJKtricrtH 
it  is  Ji  common  practice  to  em|)loy  buckets  made  \'vn\u  ke^s,  ((ri^dnaily 
usc^d  as  containers  for  whit(!  lead.  It  is  hardly  necessary  to  call  atten- 
tion to  the  injury  which  may  be  caused  by  the  us(!  of  such  vessels. 

The  pumj)  may  stand  directly  in  the  well  or  away  from  it  and  oon- 
ncctotl  therewith  by  means  of  a  jiipe  running  laterally  and  downward. 
The  lattiu-  is  tlie  better  way,  as  any  water  waste<l  at  the  putnj)  is  pre- 
vented by  location,  if  by  nothing  else,  from  running  back  into  the 
well,  and,  moreover,  the  covering  of  tlu;  well,  if  of"  wood,  is  not  continu- 
ally subjected  to  wetting,  which  [iromotes  its  decay.  The  best  fomi  of 
pnmp  is  the  simple  lifting  pnmp,  made  of  iron  or  of  wood,  and  con- 
sisting of  an  eveidy-bored  barrel,  closed  at  the  lower  part  by  a  valve 
opening  upward,  and  a  piston  containing  another.  The  upward  stroke 
of  the  piston,  by  prodncing  a  vacuum,  causes  the  water  to  pass  through 
the  lower  valve,  and  its  downward  stroke  forces  the  water  confined  in 
the  barrel  through  the  upper  valve,  and  then  the  succeeding  strokes  lifl 
and  discharge  it  continuously.  The  old-fashioned  chain  j)unips  cannot 
be  used  without  more  or  less  chance  of  exposure  to  contamination 
from  above. 

The  action  of  the  wind  is  very  commonly  employed  as  a  lalx)r-saver 
for  pumping  water  not  only  from  the  well,  but  upward  into  reservoirs 
and  distributing  tanks.  For  this  purpose  a  variety  of  wind-mills  have 
been  put  upon  the  market. 

There  are  also  a  number  of  makes  of  hot-air  engines  that  are  very 
eflftcient  and  not  unduly  expensive. 

Driven  wells,  otherwise  known  as  "  Norton's  tube  wells,"  "  Ameri- 
can," and  "  Abyssinian  "  wells,  are  made  by  driving  iron  tubes  of  a 
diameter  varying  from  \\  to  4  inches,  according  to  the  needs  of  indi- 
vidual cases,  into  the  ground  until  water  is  reached.  The  first  length 
driven  in  is  provided  with  a  pointed  perforated  foot,  through  which  the 
water  enters  the  tube.  When  this  length  is  driven  sufficiently  far,  an- 
other is  screwed  to  it  and  the  driving  is  continued,  additional  lengths 
being  screwed  on  as  necessary.  When  water  is  reached — and  this  is 
ascertained  by  means  of  a  weighted  string  let  down  inside  the  tube 
from  time  to  time — a  pump  is  applied  and  the  water  lifted.  The  first 
that  comes  contiiins   sand  or  fine  gravel  and  dirt,  and  as  this  is  more 


388 


WATER. 


and  more  removed  from  below,  a  pocket   is  formed  which  constitutes 
an  underground  reservoir. 

Fui.  29. 


CF^ 

\ 
Perv  lous 

} 

' 

- 

,  Z  ^ii/  f  r 


n  it(  r 


Norton  tube  well. 

Bored  wells  differ  but  little  from  tube  wells  ;  in  fact,  they  are  prac- 
tically the  same  except  in  the  method  of  their  making.  They  are 
drilled  or  bored  through  solid  rock  and  other  strata,  and  are  lined  or 
not  with  iron  pipe,  backed  with  cement  according  to  circumstances. 
Their  cost  is  much  greater  than  that  of  the  ordinary  Abyssinian  well, 
since  the  labor  required  is  much  greater.  Sometimes  it  is  necessary, 
after  proceeding  several  hundred  feet  with  no  results,  to  resort  to 
blasting  at  the  bottom,  so  as  to  shatter  the  rock  and  form  waterways 
to  the  well. 

It  is  self-evident  that  wells  of  these  two  kinds  last  mentioned  can- 
not, under  ordinary  circumstances,  become  contaminated  with  surface 
washings.  Both  forms  are  used  very  commonly  not  only  for  individ- 
ual, but  for  public,  supplies.  In  the  latter  case,  they  are  driven  in 
groups,  or  "  gangs,"  the  size  of  which  varies  according  to  the  amount 
of  water  required.  Increase  in  demand  should  be  met  by  extension 
of  the  system  rather  than  by  over-forcing,  for  the  latter  will  cause  an 
undue  lowering  of  the  water  level  and  tend  strongly  to  bring  water 
downward  from  the  upper  strata  at  such  a  rate  as  to  preclude  the  puri- 
fication which  normally  is  brought  about  by  the  saprophytic  bacteria 
of  the  soil. 

In  the  case  of  an  ordinary  well,  the  bottom  should  be  considerably 
below  the  level  of  the  ground-water,  so  that  when  this  falls,  the  well 
will  not  run  dry,  and  also  because  the  farther  the  withdrawal  by 
pumping  carries  the  level  of  the  well  below  that  of  the  water-table,  the 


anoUND-WATIJiS. 


389 


(:isi.(!r  will  he  (lui  (low  iowiinl  llu;  well,  and  flu;  f^r(!{it<;r  tin;  Kiijiply 
iriirii('<lia(.(;ly  availaldc.  I»ii(,  <l('<'|>ciiinj^  a  well  (or  tlu!  piirpoHc  «»('  iii- 
crcilHin^  tlu!  Hiipply  soiiMlirncs  lias  llic  vci y  oppoHiti!  cH'ce^t,,  and  may 
<^V(!n  caiiHo  it  to  niii  pfacti«';illy  di'y.  Suppose,  lor  example,  \\\c  irn- 
p(!rvi<»iis  lay(!r  is  underlaid  hy  a  lliiek  strattuu  o("  coarse  j^ravel,  and  in 
tlu!  pr()(!(!KH  of  d(!epenin}^  tli(!  w<:ll  this  stratuiu  is  entend  :  instead  o("  an 
incr(!iiHC  in  tlic  su|i|)ly,  it  then  may  liap|)en  (liat  the  water  (lowing  into 
the  well  (ind.s  a  niady  exit  downward  hy  the  force  of  (gravity  into  the 
inli^rstiecrt  of  the;  gravel,  an<l  the  uscIuIimss  of  the  well  is  teiiiiinaled. 
(8ee  V\.  ;}0.) 

Included  under  bored  wells  are  thoH<!  known  jis  ArlcHUin.  T1k!M' 
are  bored  through  impi^rvions  strata  until  a  stratum  is  nsiehed  in 
which  the  water  is  nndc^r  hydrostatic  pressure  snlficicaitly  strong  to 
force  it  to  the  sui-iace,  oi-  at   least  to  a    point    nearly  as  high,  the  rise 

Fio.  30. 


Pert/  i  ous,' . 


fV-<t.-t'G  -r . 


. '•■  Si  r  O't  'iJu  -TTv:-  ;• 


Z'^z/^./- 


W<i  f  ^^  ^- 


How  a  well  may  bo  spoiled  by  being  deepened. 


de})ending  upon  the  height  reached  by  tlie  water-bearing  stratum  in 
higher  land  elsewhere.  In  Fig.  31  is  shown  a  formation  favorable  to 
the  obtaining  of  water  by  means  of  this  class  of  wells.  The  water  in 
the  soil  above  the  first  layer  of  clay  may  be  reached  by  sinking  wells 
of  the  ordinary  kinds.  Below  this  is  a  second  suj^ply  confined  between 
two  impervious  strata  inclining  upward.  The  higher  this  formation 
extends  above  the  level  of  the  outlet  ^4  of  a  well  sunk  into  it  at 
that  point,  the  greater  will  be  the  jiressure  at  B  and  the  higher  the 
rise  of  the  water.  Thus,  if  it  extends  upward  to  C,  for  example,  the 
water  will  not  simply  fill  the  tube,  but  will  be  thrown  some  distance 
into  the  air.  In  some  cases,  although  the  head  developed  is  very  con- 
siderable, the  water  does  not  come  to  the  surface,  because  of  the  extent 
of  leakage  into  the  upper  pervious  strata  of  the  soil. 

Sometimes  the  wells  are  connected  with  true  underground  rivers, 
and  sometimes  with  apparently  inexhaustible  reservoirs  which  have 
held  the  water  in  storage  for  ages.     Sometimes  thev  derive  their  water 


390 


WATER 


from  fissures  draining  away  the  water  of  surface  rivers  and  lakes,  as  is 
proved  by  the  occiisional  occurrence  in  the  overflow  of  small  fish  with 
eyes. 

Artesian  wells  have  been  known  in  China  and  Egyjit  from  very 
ancient  times,  and  centuries  ago  they  were  introduced  into  the  prov- 
ince of  Artois  (Artesium),  from  which  their  name  is  derived.  They 
are  exceedingly  numerous  in  the  western  and  southwestern  parts  of  the 
United  States,  Avhere  they  have  produced  enormous  results  in  convert- 
ing arid,  waste  lands  into  fertile  farms.  Some  of  them  are  exceedingly 
deep,  and  pass  through  stratum  after  stratum  of  ditferent  formations 
before  water  is  reached. 

Since  the  temperature  of  the  earth  increases  1  degree  Fahrenheit  for 
about  55  feet  of  depth,  it  follows  that  water  from  these  very  deep  wells 

Fig.  31. 


Ordinary 

Aries 


.Peri'f'rjii,^  Sfrrt 

\ 

t  1'  f>l 

.Srr/-,,  >-r,tirjn 

;„  A/  //'.  ',.  'Vd'/j.  'Ma /,'///„ ',///k 
Geological  formation  favorable  to  the  obtaining  of  water  by  means  of  artesian  wells. 


is  materially  warmer  than  that  from  the  upper  subsoil.  Distinctly  hot 
water  from  deep  sources  is  rarely  fit  for  ordinary  domestic  purposes, 
because  of  the  large  amount  of  mineral  matters  present  in  solution  by 
reason  of  the  greater  solvent  power  of  water  when  hot  than  when  cold. 
Thus  they  acquire  an  abundance  of  salts,  which,  taken  into  the  body, 
influence  its  functions  and  act  as  medicines.  The  presence  of  organic 
matters  is  of  importance  on  account  of  their  reducing  power.  The 
sulphuretted  hydrogen  so  common  to  mineral  springs  is  due  to  the 
action  of  these  matters  on  sulphates. 

Irrespective  of  the  changes  wrought  by  increased  temperature, 
the  water  yielded  by  this  class  of  wells  varies  very  widely  in  charac^ 
ter.  It  may  bear  no  resemblance  whatever  to  the  other  waters  of 
the  same  district,  nor  is  there  any  reason  why  it  should,  for  the  con- 
ditions at  the  surface  and  at  points  hundreds  of  feet  below  are  quite 


(JlLOIINh-WA'I'FJiS.  391 

(liircr'ciit..       M(tr(;()V(!r,  one  ciiiiiiot   I.  now  Iidw  (";ir  llic  \v;il<r  li;i.s  triiV(:ll<:<J 
jVoin  wli(^r(!  il,  ori^iiijilly  <'iil(i<<l  tlic  soil  (o  llic  poinl  wIk/c  it,  rriakoH  itft 

(!,SC,!I|>(;. 

or  Willi M's  (Voin  lour  siirli  wells  sunk  williin  tin-  limits  oCtlic  city  of 
Boston  to  <l('|)t,liH  of  Croiri  870  to  2,r)(),'{  W'vi.^  two  vvcni  (:xt(!riHiv<*ly  irri- 
pn^j^nntc.d  with  coniinoii  suit  jiiid  oilier  iniiicrul  rn.attcr,  onv.  wan  very 
ri(!li  in  ))otli  v<!{^(!ljil)l(!  and  inincra!  siihstiinwiH,  and  tlic  fourtJi  waH  rich 
in  hotli  \\h\hv.  Mild  siilpliiirctlcd  iiydi'o^cn. 

Drainage  Area  of  Wells. — As  to  the  ;inioiiiit  of  soil  wliidi  i-  di:iiii<d 
by  a  well,  tlion;  can  he  no  ^ctKM'al  rule.  It  is  commonly  asserted  tliaf 
tli<!  amount  drained  may  Ik;  descrilnid  as  an  inverted  cone,  having 
the  bottom  of  th(!  well  as  it,s  apox,  and  a  banc  with  a  r.-idins  equal  to 
twic(!  the  depth  of  the  well.  I'nt  mueli  depends  upon  the  nature  and 
conlij^'uralion  of  the  surrouiidin^i;  soil,  and  the  extent  to  which  puni|iiii^ 
is  carried.  If  the  soil  be  sandy  and  opcdi,  the  base  will  l>f  mueh  larjrer 
than  if  it  be  clayey  and  close.  If  extensively  jHimju-d,  the  well  will 
drain  a  p;reat(n'  area  than  if  the  demands  Ix;  moderate  ;  in  fact,  the 
amount  of  water  removed  by  j)umpiiio;  has  a  greater  influence  in  deter- 
mining the  draina<;(!  area  than  mei'c  depth.  Hut  other  thinj^s  bc-ing 
equal,  the  nature  of  the  water-bearing  stratum  determines  the  distance 
to  which  the  measurable  influence  of  pumping  is  felt. 

Pollution  of  Wells. — In  general,  it  may  be  stated  that,  as  between 
wells  of  diil'erent  de]>ths,  the  shallower  an;  more  subject  to  ])o]Iution  than 
the  deeper,  because  of  the  fact  that  the  latter  have  the  advantage  (»f  the 
greater  opportunity  for  perfect  filtration  through  the  soil.  ]5ut  both 
are  subject  to  pollution  by  unoxidized  matters  which  enter  the  soil 
below  the  upper  few  feet  in  which  the  nitrifying  organisms  already 
referred  to  are  found,  as,  for  instance,  from  leaching  cesspools  and  leak- 
ing drains.  It  is  a  practice  only  too  common,  even  on  estates  of  con- 
siderable size,  where  the  excuse  of  limited  area  cannot  obtain,  to  locate 
the  well  and  the  cesspool  very  near  together.  To  avoid  the  necessity 
of  having  to  remove  the  contents  of  the  cesspool  as  occasion  demands 
when  this  receptacle  is  made  water-tight,  and  to  avoid  the  exjx-nse 
attending  this  kind  of  construction,  the  bottom  is  generally  left  o|ien, 
so  that  the  house  sewage  may  drain  away  into  the  surrounding  soil. 
Connection  between  the  cesspool  and  the  well  may  take  considerable 
time  or  may  occur  quickly,  but,  once  established,  contamination  goes 
on  uninterruptedly.  Often  it  happens  that  the  direction  of  the  flow 
of  filth  through  the  soil  is  wholly  away  from  the  well,  and  contamina- 
tion may  never  occur ;  but  this  is  a  point  that  can  never  be  determined 
in  advance. 

It  is  a  common  belief  that,  if  the  well  is  located  in  higher  ground 
than  the  cesspool,  there  can  be  no  danger  of  pollution  of  its  water. 
This,  however,  is  a  most  fallacious  proposition,  for  it  is  not  so  much 
the  location  of  the  outlet  of  the  well  that  determines  the  possibility  of 
pollution,  as  the  relative  position  of  the  cesspool  and  the  point  where 
the  water  enters  the  well.  In  Fig.  32  is  illusti-ated  the  manner  in 
which  the  supply  yielded  to  a  pmup  placed  at  a  point  considerably 


392 


WATER. 


above  the  location  of  the  cesspool  is  ptilluted  directly  by  the  liquid 
tilth  issuing;  tVoui  the  latter.  Again,  the  geological  formation  may  be 
such  that  a  cesspool  on  higher  ground  than  the  nearby  well  will  have  no 
iutiueuce  on  the  purity  of  the  water.  Thus,  a  ledge  of  rock  may  crop 
up  between  them,  as  shown  in  Fig.  33,  and  divert  the  How  of  polluting 
matters  away  from  the  well. 

Fig.  32. 


CessPool- 


How  a  well  located  on  high  ground  may  be  polluted  by  the  contents  of  a  cesspool  lower  down. 

In  locating  wells  and  cesspools,  property  owners  not  infrequently 
lose  sight  of  the  fact  that,  while  they  can  govern  the  disposition  of  the 
surface  of  their  respective  estates,  the  conditions  that  obtain  in  the  soil 
below  are  quite  beyond  their  control.  In  consequence,  they  may 
attempt  to  guard  against  pollution  of  their  own  water  supplies  by  their 
own  excretory  products,  without  regarding  the  possibility  of  contami- 
nation by  those  of  their  neighbors. 

Fig.  33. 


How  a  cesspool  located  on  high  ground  may  fail  to  pollute  a  well  lower  down. 

The  water  of  newly  dug  wells  is  often  of  such  a  character  as  to  lead 
to  the  perhaps  false  conclusion  that  it  is  probably  polluted  by  sewage. 
It  is  generally  turbid,  and  may,  on  analysis,  yield  results  which,  in 
case  the  analyst  has  not  full  information  concerning  it,  may  seem  to 
warrant  a  condemnatory  report.  It  may  yield  figures  indicating  a  high 
content  of  organic  matters,  which   may   disappear  as   the  use  of  the 


(J no  UNI)  -  \VA  'i'i:iis.  '.V.i'.\ 

w.'i,i(r  l)(!(',()rn(!S  ((Hliihlislu^d.  I(  tuny  <'V«'ii  sliow  iiiKlcni.'ililc  cvi'hricc  of 
(li(!  pn^scrKU!  of  liiniiMri  wmsIcs,  fur"  llio,-c  r■|l^^'l{_r(•(l  in  tin-  •lijrj.'iii^';  and 
tlu)  Htoiiiii^  '"iiy  I"'  I'liiic  iiil(i(-(<'(|  III  llic  coiiiplcli*!!)  (»f  tin;  \v<»rk  tliari 
in   tlu!  iMirfdci,  piifily  of  llic  ,sii|i|)ly,  and  niay  Ik-  di>inclin<(|  to  \ru  u\>  to 

lll(i   SUrliuH!   (or   llic   |)lll'|iOSC  oC    relieving;   (he  cull-   oI'lKitlirc.        ( )n   ;i||    ;ir-- 

counls,  (Ji(!r('(orc,  il  is  licllcr  (u  auail  llic  rcsidts  of  a  later  cxatninatiori, 
(iiaii  l.o  <'oii(lciiiii  and  aliaiidoii  loo  lia.-tily  a  i^Mjiply,  wliicli,  within  a 
wliort,  t.irn(!,  may  |)i'ovc  lo  he  ol"  cxccjitional  |iurily. 

Very  (l(M'p  wells  may  Ixcoiik;  l)a<lly  pollnlcd  liv  liltli  wliicli  jraiii.s 
accoHH  tliron^li  open  elianncl-ways,  as  lisHuros  in  I'oek.  A  jr(,(,(]  ex- 
amples oC  this  is  recMirded  in  th(!  Stniildry  IiiKjicclDr  ("or  I  )ecernl)er, 
1<S!>(>:  A  well  hoi'ed  500  Icct.  into  red  sandstone  drained,  thron^h 
fiHSuros,  all  the  sliallow  wells  in  llic  \iciiiily.  'l"lie.-c  licirif^  of  no  ii.sr; 
as  wells,  wore  then  ntili/ed  as  cesspools,  an<l,  diainin^  again  through 
tho  fissures,  caused  the  well  to  l)e(!ome  so  foul  llial  it  had  to  he  ahan- 
(IoiuhI.  Dr.  A.  C/.  Houston  '  shows  how  dee|)ening  a  well  may,  in  a 
similar  manner,  e^iuse  its  ruin.  A  well  of  pure  water,  114  feet  deej), 
was  deepened  hy  farther  horing  to  294  feet,  when  its  yield  was  tfien 
found  to  l)e  impure.  At  a  distance  of  800  feet  was  an  old  fpiarry, 
into  which  drained  the  sewage  of  25  jiersons.  By  fissures  in  the  sand- 
stone, this  reached  the  water  stratum  tapped  by  tlie  extension  of  the 
well  and  thus  s])oiled  the  water. 

On  account  of  the  possibility  of  contamination  of  shallow  wells  by 
the  entrance  of  surface  washings  from  above,  Koch  recommends  that 
pi]ies  be  ])hiced  in  position  so  as  to  reach  the  water  stratum,  and  that 
then  the  wells  be  filled  up,  first  with  stone  and  coarse  gravel,  and 
toward  the  top,  for  at  least  six  feet,  with  fine  sand.  By  this  pro- 
cedure, the  well  is  converted  really  into  an  Abyssinian  well,  and  is 
protected  from  surface  contamination  quite  as  well  as  though  it  had 
originally  been  driven  instead  of  dug. 

Filter  Galleries. — A  filter  gallery  is  a  large  underground  tunnel 
sunk  parallel  to  a  river  or  lake  and  near  to  it ;  it  is  in  reality  nothing 
more  than  a  horizontal  well.  The  idea  which  led  to  their  construction 
was  that  in  this  way  the  river  w^ater,  percolating  outward  from  its  l)efl 
through  the  soil,  would  be  secured  in  a  filtered  state,  and  would  ac- 
cumulate in  the  underground  reservoirs.  Although  this  method  of 
obtaining  water  has  been  attended  by  most  excellent  results,  the  fact 
remains  that  the  water  so  collected  comes  not  from  the  river,  but  from 
the  grouud  on  its  hither  side ;  that  is  to  say,  it  is  the  ground-water 
intercepted  on  its  way  to  the  river. 

The  water  of  a  river  does  not,  except  under  unusual  conditions, 
percolate  outward,  for  the  sUtv  matters  deposited  in  its  flow  clog  the 
interstices  in  the  soil  of  its  bed  and  banks,  and  act  as  a  valve  against 
its  egress.  The  ground-water,  Hewing  to  the  river,  finds  its  way  in 
through  the  silt,  which  gives  way  inward  against  the  side  of  least 
resistance.  Thus  the  silt  yields  to  ingress,  and  is  a  bar  to  egress 
of  water. 

'  Eliiuborougli  Medical  Journal,  Nov.,  1894. 


394  WATER. 

The  fact  that  tlic  flow  of  tiToiind-water  is  toward  rather  tliaii  away 
from  rivers  and  otlier  large  bodies  of  water  is  well  shown  by  the  faet 
that  fresh  water  is  obtainable  from  wells  sunk  in  close  proximity  to 
high- water  mark  on  the  sea-coast.  Such  may  be  not  even  slightly 
l)rackish,  although  sometimes  they  are  distinctly  so  by  backAvard  diffu- 
sii>n  of  the  salts.  In  the  latter  case,  removal  a  short  distance  back- 
ward obviates  the  dilticulty. 

That  the  watei*  derived  from  a  filter  gallery  is  not  due  to  percolation 
from  the  river  along  which  it  lies,  is  farther  proved  by  the  fact  of  dif- 
ference iu  composition,  and  especially  iu  hardness. 

Classification  of  Waters  from  the  Sanitary  Standpoint. 

From  the  standpoint  of  wholesomeness,  waters  may  be  divided  into 
two  classes :  1.  Those  free  from  sewage  contamination.  2.  Those 
polluted  by  sewage. 

Unpolluted  waters  are  not  necessarily  suitable  for  domestic  use,  pre- 
senting as  they  do,  wide  variations  in  character.  They  may  be  clear, 
colorless,  odorless,  and  palatable,  and  contain  but  little  organic  and 
mineral  matter ;  or  they  may  have  high  color,  turbidity,  disagreeable 
odor  and  taste,  and  a  high  content  of  dissolved  and  suspended  sub- 
stances. A  water  which,  by  reason  of  appearance,  odor,  and  taste,  due, 
for  instance,  to  luxuriant  growth  of  algae  or  other  forms  of  life,  is 
repugnant  to  the  senses,  should  not  be  recommended  for  use,  although 
incapable  of  producing  a  specific  disease.  Such  an  one  requires  no 
chemical  analysis  to  determine  its  fitness,  the  evidence  of  the  senses 
being  quite  sufficient. 

Unpolluted  waters  free  from  such  qualities  as  render  them  repug- 
nant to  the  senses,  and  of  low  content  of  organic  and  mineral  matters, 
are  suitable  for  general  purposes  without  regard  to  their  classification 
as  surface-  or  soil-waters.  But,  in  general,  it  is  held  commonly  that 
an  unpolluted  soft  ground-water  of  good  composition  is  preferable  to 
one  of  surface  origin. 

Polluted  waters  may  be  divided  into  two  classes,  according  as  the 
pollution  is  direct  or  indirect.  Direct  pollution  by  sewage  is,  it  is 
hardly  necessary  to  say,  of  prime  importance,  because  of  the  danger  of 
transmission  of  specific  diseases  and  of  lowering  the  physiological  re- 
sistance of  the  system.  But  even  direct  pollution  may  be  productive 
of  no  harmful  results,  provided  sufficient  time  elapses  between  the 
entrance  of  the  sewage  at  a  given  point  and  the  use  of  the  water  at  a 
distance  to  permit  of  the  disposal  of  the  noxious  elements  by  natural 
processes.  Thus,  a  volume  of  sewage  entering  the  upper  part  of  a 
large  system  of  public  supply  may  not  reach  the  distributing  pipes  for 
several  months,  during  which  time  its  dangerous  qualities  will  have 
disappeared.  Notwithstanding  this  fact,  however,  direct  pollution  of 
drinking-water  should  be  prevented  by  all  means  available,  on  account 
of  possible  risk,  and  even  on  aesthetic  grounds  alone. 

Indirect  pollution  is  of  far  less  importance  than  direct.     In  indirect 


ai.Assii'icA'rioN  of  watf/is.  '.Vjr, 

polliillori  ilic  or^iuuc.  riiiillcrH  oC  (lir-  Hc\VJif^<',  irirliidiri^'  iKirfi-ria,  an;  Tilt- 
(•r('<\  lliioii^li  llic  Koil,  ill  wlilfJi  tlicy  an-  licid  Itar-k  nircliaiiically  and 
in(»i-('  or  less  cotriplclcly  oxidi/.cd  IxCiiir  llif  <oiilaiiiiii{^  svah-r  n-ar-licH 
il,n  iill.iiiiiitc.  <l(:,sl,iiialioti.  Ah  I<»  svlml  iii;i\  lie  cidlfd  a  safe  limit  nf'dir- 
tiinco  f'roin  Hourcxw  of  |>()lliil  imi,  no  (ixcd  I'nic  can  Ix-  ;.'iv<'ii  :  cadi  ca-c 
irm.sl.  \h\  iiidj:;cd  ac(M»rdinj^  lo  ils  cii'cMunsfanccs.  Tlic  hoil  :i^  a  wliolc 
has  (Miorriioiis  capax^ily  ("or  pnrilyin^  walcr  of  its  containcrl  or^'^anic 
suhstaiKU'S  and  bacteria,  hot li  hy  rnc.clianical  retention  an«I  hy  r)xidatiori 
[)roc(!SH(\s  sv.i  in  motion  by  the  ha(!tcria  which  iidmliit  it.  lint  all  hoilw 
have  not  this  power  in  an  c((nal  dej!;re(!,  an<l  I  he  comiit  ions  favorable  to 
its  (!xereis(^  nvv  not.  always  present  to  tiie  same  exti^nt.  The  s'tils  most 
fhvorabh;  for  perCee.t  filtration  and  pnrifieatifin  are  sandy  and  gravelly  ; 
in  tiicse,  the  watxM'  is  exj)osed  in  tiiin  layers  on  the  individnal  (grains  to 
the  air  in  the  interstices.  Tiie  lattcjr  should  be  neither  too  coarse;  nor 
too  fine.  If  too  coarse,  the  ])assa^c!  of  water  is  tf)o  rapid  ;  if  too  fine, 
not  snfTicient  air  can  be  present  at  the  same  time,  '^riir-  or^nmisms  are 
fonnd  only  in  the  nj)per  few  feet  of  soil,  and  it  is  here  also  that  the  con- 
tained air  is  riehcst  in  oxygen.  When  the  neecssary  eonditions  for 
filtratioti  are  present  in  a  ^iven  soil,  the  water  whieh  percolates  through 
and  reaclu's  tlie  oToiind-water  is  qnite  free  from  baeteria  of  any  kind, 
even  thonoh  the  snrfaee  is  eontaminated  extensively.  Where  the  soil 
is  very  open  and  permeable  to  water  or  fissured,  pollulinjr  materials 
may  pass  through  so  rapidly  that  they  undergo  but  slight  change  on  the 
way,  while  with  a  not  too  fine  soil,  through  whieh  water  passe.s  with 
slowness,  purification  by  bacterial  action  may  be  completed  within  a 
very  short  distance. 

Again,  there  may  be  greater  safety  at  a  point  quite  near  to,  but  on 
one  side  of  a  center  of  pollution,  than  at  another  at  a  considerable 
distance  away  on  the  other  side,  owing  to  the  direction  of  the  flow  of 
water.     Thus,  in  Fig.  34,  the  point  /S,  located  quite  near  the  point  of 

Fio.  34. 


0  -     —  O-0 


entrance  of  the  polluting  material  P  into  the  soil,  is  far  better  situated 
in  respect  to  possible  contamination  of  water  by  P,  than  the  point  P 
on  the  other  side  but  farther  away,  since  the  movement  of  the  water  in 
the  soil  is,  as  indicated  by  the  arrows,  from  -S"  toward  D,  and  all 
impurities  entering  between  the  two  move  from  the  one  toward  the  other. 
Similarly,  the  point  aS'  may  stand  in  the  relation  of  point  P  to  some 
other  polluting  influence. 

For  the  determination  of  the  question  whether  a  given  well  is 
receiving  pollution  from  any  given  point,  recourse  is  had  to  the  ditfusi- 
bility  of  coal-tar  colors,  such  as  fluorescein.  An  ounce  of  this  sub- 
stance will   impart  a   very  deci^led  color  to  an  enormous  volume  of 


396  WATER. 

water  ;  and  when  it  is  luldrd  to  the  contents  of  a  leaching  cesspool,  it 
will  accompany  the  esca])inu'  pollution  and  reveal  to  the  e}'e  the  presence 
of  the  latter  in  any  neighboring  well-water.      Pollution  may  thus  be 

traced  st^nietiincs  through  hundreds  oi"  feet  of  fairly  close  soil. 

Purification  of  Water. 

Before  proceeding  to  the  consideration  of  methods  employed  to  bring 
about  purihcation  of  water  supplies,  a  few  words  are  necessary  on  the 
subject  of  "  self-puriiication  "  of  surface-waters.  A  river  shows,  for 
instance,  at  a  given  point  in  its  course  a  certain  amount  of  impurity  ; 
at  another  point  farther  down,  this  is  found  to  be  considerably  lessened  ; 
and  farther  yet,  the  diminution  is  still  more  marked.  This  progressive 
lowering  is  attributed  to  the  property  the  water  possesses  of  bringing 
about  its  own  })uriiication.  The  practical  beginning  of  this  theory  was 
the  assertion,  made,  in  1869,  by  the  British  Royal  Commission  on 
Water  Supplies,  that  sewage,  diluted  twenty  times  or  more  by  river- 
water  into  which  it  is  discharged,  will  be  completely  oxidized  before  it 
has  travelled  more  than  a  dozen  miles.  Two  y&irs  later,  the  Rivers 
Pollution  Commission  reported  strongly  against  accepting  this  idea,  and 
concluded  that  oxidation  proceeds  with  such  extreme  slowness,  even 
when  the  polluting  matters  are  diminished  very  largely  by  pure  water, 
that  not  only  will  a  flow  of  a  dozen  miles  not  suffice,  but  that  there  is 
no  river  in  the  United  Kingdom  sufficiently  long  to  accomplish  the 
result  claimed.  It  was  then  believed  that  whatever  changes  occur  are  the 
combined  result  of  oxidation  and  subsidence.  It  is  now  recognized  that 
these  agencies,  assisted  by  more  important  ones,  namely,  dilution,  vege- 
tation, and  bacterial  action,  do  in  many  cases  produce  very  great 
changes,  while  in  others  the  results  are  only  partial  and  of  no  especial 
value.  Drs.  R.  Emmerich  and  F.  Brunner  ^  showed  that  in  spite  of  the 
large  amount  of  sewage  matters  poured  into  the  Isar  in  its  course 
through  Munich,  the  water  after  two  hours'  flow  below  the  city  was 
practically  as  pure  chemically  as  it  was  before  it  reached  it.  Jordan  ^  has 
shown  that,  after  thirty-four  miles'  flow,  the  Illinois  River  is  practically 
free  from  sewage  bacteria.  E.  Duclaux  ^  has  shown  the  same  to  be 
true  of  the  Seine,  and  other  observers  have  proved  it  of  certain  other 
rivers  in  England,  Germany,  and  elsewhere.  On  the  other  hand,  oppo- 
site results  have  been  obtained  by  other  workers  in  the  same  field. 

Oxidation  undoubtedly  plays  a  more  or  less  important  part  in  some, 
but  by  no  means  in  all,  cases.  Dr.  T.  Meymott  Tidy  proved  experi- 
mentally that  water  containing  sewage  could  lose  about  half  its 
oro-anic  matter  in  from  six  to  nine  hours  when  made  to  run  one  mile 
in  glass  troughs  with  abundant  aeration.  Professor  William  P.  Mason,^ 
on  the  other  hand,  agitated  water  in  a  bottle  fastened  to  the  connecting 
rod  of  a  horizontal  engine  with  a  ten-inch  stroke  of  75  to  the  minute, 

'  Die  chemischen  Veriinderungen  des  Isarwassei-s,  Munich,  1878. 

^  Journal  of  Experimental  Medicine,  Dec.,  1900,  p.  271. 

^  Annales  de  I'lnstitut  Pasteur,  1894. 

*  Water  Supply,  New  York,  1897,  p.  175. 


riJiuFidArioN  of  \v.\teii.  \v.)1 

ittid  (oiiikI  (liiii  ;iflcr'  I), 000  codciiHsioiis  tlic'ic  wms  hiif  ;i  triflin^r  <liiiiiiiii- 
iioii  in  I  lie  iinioiiiit  ol"  of^iinic  iiijilicr.  A  hir^rc  jiH-ii^-iirc  '»("  iniiiCwiition, 
HO  iiir  jiw  iiiiiiil)(!rH  of  l»:icl('ri;i  ;ir(!  (•(MM'cnn<l,  i:-  ("iii-crl  Kv  ajritatioti 
wli((ii  iJicrc  arc  s<)li<l  |»!irl  ic-lcs  in  snsjK'nsion  in  (iu'  \v:itir.  TImh  liaH 
been  well  shown  l»y  I'df-y  I' r;inkl;in<l,'  wlio  olix-i'scfl  ;i  <i«Tr(!!iH<5  of 
ildJjr)  |»('i'  ccnL  in  llic  ninnhcr  ol'  bnclciia. 

Dilution  by  acu-css  <»('  i-ain,  niclliiin-  snow,  j.Monn<l-wal*T,  and  ollu-r 
<'.l(^'Ul  inllucnls,  anc(rt,s  cIk  niical  comiKi-ii  Ion  favorably,  Imt  asHJhfH,  for  a 
time  at  least,  increase  in  llie  ninnlxi-  of  pat lio^ciiifr  and  (ttlicr  bacteria. 
I'rofcssor  Kebrelil's  -  (l;iily  baetciii  ilon  ic;i  |  exaMiiliatJonK  of  Hver-wattT 
a(.  I*ra<i,iie  proved  thai,  in  ji;eneral,  IIk;  ininiber  of  bacteria  increases  witli 
risini;'  \vat(!r,  and  is  snbjeet  to  Ncry  wide  variations,  due  to  a  iniinber 
of"  eansos,  anionj:;  vvliidi  he  mentions  clianp-s  in  the  rat<;  of  flow,  with 
con,S(U]uent  alteration  ol"  conditions  inflncncinjr  sedimentation,  and  tlie 
influx  of  teniporary  pollutions,  such  as  washinj^s  from  streets  and  tlnnfr- 
lieaps,  wliicli,  under  some  circumstances,  have  greater  innueiice  than 
the  regular  unclean  inllucnts. 

Sedimentation,  which  formerly  was  believed  to  ])]ay  a  very  great 
])art  in  the  improvement  of  river-waters,  acts  to  oidy  a  sJifrht  extent  in 
those  which,  like  the  Isar,  move  swiftly.  It  is  fiivored  bv  slowing''  of 
the  euri'ent,  especially  at  the  river  mouth  ;  and  when  it  occurs  it  has  a 
very  marked  intiueucc  on  the  nund)er  ol'  bacteria,  especially  if  the  water 
be  muddy.  This  has  been  shown  by  Bruno  Kriiger,^  who,  by  a  scries 
of  ex])eriments,  ])rovcd  that  chemically  indifferent  substances  in  a  state 
of  minute  subdivision  exert  a  "greater  influence,  the  more  slowly,  up  to  a 
certain  limit,  they  settle;  while  other  matters,  which  act  Ixtth  mechanic- 
ally and  chemically,  such  as  lime  and  hard  wood  ashes,  produce  still 
greater  eflPects.  In  still  water,  as  small  lakes  and  ponds,  sedimentation 
g'oes  on  unobstructed. 

Bacterial  action  as  a  pm-ifying  agent  is  favored  by  alkalinity  and 
retarded  by  acidity.  It  may  be  important  or  not,  according  to  circum- 
stances. Destruction  of  pathogenic  species  by  the  sapro])hytic  class  is 
delayed  by  dilution  by  unpolluted  water,  which,  as  above  stated, 
favors  their  increase  for  a  short  time,  after  which  they  rajiidly  decline 
in  number. 

Vegetation  was  not  taken  into  account  by  the  earlier  obsen'ers,  but 
has  now  been  placed  at  the  head  of  the  important  influences  in  tlie 
process.  Pettenkofer*  asserted  that  the  greater  part  of  self-purification 
is  due  to  the  growth  of  alga^  and  other  low  f^rms  of  vegetable  life, 
which  clean  the  \vatcr  of  its  impurities  in  the  same  way  that  the  higher 
forms  take  up  and  dispose  of  the  manurial  mattere  of  cultivated  land. 
This   view  is   endorsed  by  T.  Bokorny,'^  who  proved  that   the.?e   plants 

*  .Tournal  of  State  ^[edicine,  Jannarv,  1S94. 

-  Rioteriologisolio  nml  kritisohe  vStudion  iiber  die  Verunreinigiiiig  uiid  Selbstreini- 
gung  der  Fliisse.     Aroliiv  fiir  Hygiene,  XXX.,  p.  82. 

^  Die  plwsikaliselie  Eimvirkung  von  Siiikstot^en  auf  die  ini  Wasser  liefindliclien 
Mikrooru~inisnien.     Zeitsolnift  fiir  Ilvgieno.  ^'IT.,  11.  8(1. 

''  Zur  Si^lhstreinigung  dor  Fliisse.     Arohiv  fiir  Hygiene,  XII.,  p.  2(i9. 

^  Ueber  die  Ix^theiligung  oliloropliyllfuhrender  Pflanzen  an  der  Selbstxeinigung der 
Fliisse.     Archiv  fiir  Hygiene,  XX.,  p.  181. 


398  WATER. 

take  up  all  manner  of  organic  substances,  including  volatile  fatty  acids, 
amido  acids,  glucose,  and  urra.  He  showed  that  the  water  of  the  Isar 
contains  vast  luiinbers  of  alga>  to  ^vlu)se  acti^m  nnich  of  the  changes 
noted  by  Emmerich  and  Brunner  Mere  undoubtedly  due. 

The  important  effect  of  temperature  on  the  ability  of  streams  to 
purify  themselves  was  brought  out  by  Ruediger  at  the  Annual  Meeting 
of  the  American  Public  Health  Association  in  11)10.  Kuediger  found 
that  colon  bacilli  and  typhoid  bacilli  disap})eared  from  river  water  much 
more  rapidly  iu  summer  than  in  winter.  In  producing  this  result  the 
most  important  factor  was  found  to  be  microscopic  jilants  and  other 
organisms,  which,  in  their  growth,  manufactured  dialyzable  substances 
harmful  to  the  bacillus  coli  and  the  bacillus  typhosus.  These  micro- 
scopic plants  do  not  grow  at  a  temperature  below  0°  C.  Furthermore, 
in  the  winter  time,  the  water  being  covered  with  snow  and  ice,  the 
bactericidal  action  of  the  sun's  rays  becomes  ineffective.  These  facts 
accord  with  the  experience  that  typhoid  epidemics,  due  to  polluted 
water  supjilies,  and  occurring  in  northern  cities,  frequently  take  place 
in  the  winter  time.  Such  a  winter  epidemic,  in  fact,  occurred  at 
Minneapolis  in  1909. 

Methods  of  Purification. — The  methods  employed  for  the  purifica- 
tion of  water  embrace  : 

1.  Chemical  treatment. 

2.  Boiling  and  distillation. 

3.  Filtration. 

1.  Chemical  treatment  is  employed  to  cause  the  formation  of  insolu- 
ble precipitates,  which  settle  out  and  entangle  suspended  matters,  in- 
cluding bacteria,  in  their  descent. 

Alum,  for  instance,  added  to  the  extent  of  a  quarter  of  a  grain 
to  a  grain  per  gallon  of  natural  water  containing  a  moderate  amount 
of  CaCOg,  is  decomposed,  and  forms  an  insoluble  gelatinous  hydrate, 
which  combines  with  the  organic  matters  imparting  color  and  set- 
tles out  as  a  flocculent  precipitate,  which  entangles  the  sus])ended 
matters,  including  the  bacteria.  The  sulphuric  acid,  set  free  by  the 
decomposition  of  the  salt,  unites  with  the  lime  or  other  bases  present, 
and  is  thus  neutralized,  and  the  calcium  sulphate  thus  formed  carries 
down  sus]iendcd  matters  in  the  same  manner.  If  an  excess  of  alum  is 
added,  it  will  necessarily  appear  in  the  purified  water,  and  be  objection- 
able on  account  of  its  effect  on  the  system,  and  in  the  bath  and  in 
washing. 

In  case  of  deficiency  in  CaC03,  liuie-water  sometimes  is  supplied, 
and  identical  results  obtained.  The  addition  of  freshly  precipitated 
alumina  serves  the  purpose  equally  well,  and  avoids  the  presence  of  the 
sulphuric  acid  resulting  from  the  decomposition  of  alum. 

Alum  removes  practically  all  the  bacteria,  as  has  been  proved  by  V. 
and  A.  Babes,^  Professor  E.  Ray  Lankester,  and  others.  The  use  of 
alum   in    the   purification  of  water   is   not  of  recent  origin  :  it  was  de- 

1  Centralblatt  fur  Bakteriologie  und  Parasitenkunde,  1902,  XII.,  p.  45. 


I'Ullll'K'A'riOS'    <>!■■    W'A'I'Kll.  '.V.)'.) 

K(;ril)('(|  ;iH  curly  as  IS.'JO  hy  l''cli,\  d'A  red,'  who  iii<iiti<,ii.s  ils  exleriHive 
ii,s(!  ill  l*'^^yi>t. 

liimc-Wiilcr  or  milk  of  lime,  .idilcd  (o  \\;itcr  coiilaiiiiiiji-  calciimi  <'ar- 
l)()iiai<^  held  in  soliilioii  l)\'  (miIioii  dii»\idc,  (•;iiis(;,s  iirciripitation  tt\  Jli<; 
ioriiKU'  l»y  iiiiilint;'  wllli  (lif  I.iIIit.  Ii  llm-  willidravvH  the  wjlvcnt  frotri 
ii<'tiv(!  service,  causes  |)reci|)il;il  imi  (if  llial  wliicli  was  licid  in  solution, 
and,  becoinin^  ilscIC  coiiverled  loan  iii.-.olnl)lc  snhsluticc,  is  prcr-ipiljiled. 
Ho  a  d(nil)i(!  |)reci|)i(alioii  occurs.  IJiil  walcr  lliiiH  treated  i-  nol  n«'ccH- 
Ha,rily  liiniled  in  ils  eliaiincs  lo  a  removal  of  its  cxcchh  of  c;ilciiiiii  <-jir- 
honaie,  lor,  in  (lie  |)re(^i|»i(aiioii  of  tliis  siibstjinc*!,  conHJdtirahlc  otluT 
mailer  may  he  ca,ri'ied  down  meelianieally,  and  hacfcria  arc  Icsntiicd 
decidedly  in  nnmhci". 

l*(!rmani;analc  of  |tolassimn  is  nsed  more  or  less,  particularly  in  \v<;ll.s 
in  India  dui'in^  the  prevalenc(!  of  cliolera  cpidi'inics.  Enough  is 
addcid  to  secure  a  slight  piid<  tinge,  which  indicates  a  slight  excess. 
This  acts  as  an  oxidizing  ageiil  wilh  good  results.  Vi)V  cxam|»le,  I )r. 
P.  VV.  O'doi-man"  lelates  that  during  an  (tiithreak  at  Midnapore,  the 
number  of  cases,  117,  was  supposed  to  have  been  kept  down  by  its 
use.  These  oeeiu'red  in  all  |»arts  of  the  town,  excepting  in  the  Kiirf)- 
peau  (juarter  and  at  tlu;  jail.  The  li)rmer  used  water  which  was 
filtered  or  boiled  and  tiltered,  and  at  the  jail  especial  care  was  taken  of 
the  water  supj)ly.  Forty-six  public  and  ju'ivate  wells  were  disinl'eeted 
with  the  salt,  and  the  outbreak  thereupon  ceased.  An  ounce  or  ounce 
and  a  half  or  more,  according  to  the  size  of  the  well,  Mas  diss(»]ved  in 
a  bucket,  poured  into  the  well,  and  stirred  about.  If  after  half  an 
hour  the  water  showed  a  red  tinge,  it  was  considered  that  enough  had 
been  added  ;  if  not,  more  was  added  until  a  tinge  was  seen.  Accord- 
ing to  Hankin,^  enough  of  the  salt  to  insure  a  reddish  tint  lasting 
twenty-foiu'  hours  should  be  added  ;  lint  care  should  be  taken  not 
to  add  so  much  that  fish,  frogs,  and  turtles,  put  into  wells  to  keeji  tlie 
water  clean,  are  killed  and  the  water  spoiled  by  their  ])utrefaction. 
Dhingra*  states  that  this  method  can  be  relied  upon  only  under  cer- 
tain conditions,  and  even  then  its  action  is  not  continuous.  The  agent 
nuist  exjiiMid  itself  first  in  oxidizing  organic  matter  and  nitrites  before 
attacking  oi'ganisms,  Avhich,  for  their  destruction,  require  it  in  fairlv 
strong  solution.  He  believes  the  method  to  be  fallacious  in  theory ^ 
defective  in  technic,  and  impossible  of  practical  aj^plieation. 

The  hypochlorite  treatment  of  public  water  supplies  has  received  new 
impetus  during  the  last  few  years.  The  value  of  the  mi-thod  was  recog- 
nized, to  be  sure,  as  early  as  1888  by  the  late  Thomas  M.  Drown,  but  up 
to  1908  the  use  of  hypochlorites  had  not  received  serious  consideration. 

Clark  and  Gagc,^  in  a  paper  entitled  "  Disinfection  as  an  Adjunct  to 
Water  Purification,"  state  that  "  the  action  of  hypochlorites  and  per- 
manganates in  water  are  quite  similar ;  both  are  oxidizing  agents,  and 

1  Note  relative  :i  la  elarification  de  I'ean  du  Nil,  et  en  gi^n^ral  des  eaux  contenant 
des  snbstanees  terreuses  en  suspension.     Annales  d'Hygiene  publique,  IV.,  p.  375. 
'^  Indian  Medieal  Gazette,  Jidv,  1890. 

3  Ibid.,  .July,  ISIUI  ■  <  British  Medieal  Journal,  Aug.  17,  1901. 

*  Journal  of  tlie  New  England  Water  ^Vorks  Atjsoeiation,  1909,  p.  302. 


400  WATER 

it  is  to  this  oxidation  that  their  disinfectino:  action  is  dno.  Unlike 
copper  .sidts,  neither  of  them  retains  its  identity  lor  any  length  of  time 
in  the  Ayater,  and  the  slight  increase  in  the  ]>ernianent  hardness  cansed 
by  the  amounts  of  bleach  ordinarily  used  in  water  puritication,  or  the 
small  traces  of  manganese  which  may  remain  in  solution  after  perman- 
ganate treatment,  probably  haye  no  physiological  action  upon  the  con- 
sumer." ^ 

"  AA'hen  bleach  (a  double  salt  of  calcium  hypochlorite  and  calcium 
chloride)  is  used  in  combination  with  sulphate  of  alumina  in  mechanical 
filtration,  a  satisfactory  bacterial  remoyal  may  be  obtained  at  nmch  less 
expense  for  chemicals  than  when  sulphate  of  alumina  is  used  alone. 
In  such  a  process  the  disinfection  occurs  in  the  coagulation  basin  before 
the  water  reaches  the  filter,  and  subsequent  filtration  introduces  a  factor 
of  safety  which  greatly  adds  to  the  elfectiye  purification  of  the  water, 
aod  greatly  reduces  the  chances  of  the  occasional  failure  of  the  process. 
Experiments  showed  that  an  effluent  of  better  quality  l)acterially  was 
obtained  by  the  use  of  about  0.9  grain  sulphate  of  alumina  and  about 
0.7  grain  of  soda  per  gallon  in  combination  with  bleaching  powder 
equiyalent  to  0.11  part  per  100,000  available  chlorine  than  when 
nearly  double  the  amounts  of  sulphate  of  alumina  and  soda  were  used 
without  the  disinfectant." 

These  writers  state,  furthermore,  that  no  form  of  disinfection  should 
be  practised  without  competent  bacteriological  supervision,  for  "  such 
disinfection  would  tend  to  introduce  a  feeling  of  false  security,  which, 
in  case  of  the  failure  of  the  process,  at  any  time,  might  result  in  serious 
consequences  to  the  health  of  the  consumers.  For  this  reason  alone, 
if  for  no  other,  disinfection  should  be  followed  by  filtration,  which 
would  tend  to  reduce  the  chances  of  failure." 

Johnson  -  states  the  following  to  be  the  advantages  and  disadvantages 
of  the  use  of  hypochlorites  in  connection  with  water  purification  : 

Advantages  of  the  Process. 

1.  Substantially  complete  destruction  of  objectionable  bacteria,  par- 
ticularly those  of  intestinal  origin. 

2.  Reliability  and  ease  of  application  of  the  chemical,  together  with 
the  small  variation  in  the  required  dose. 

3.  Total  al^sence  of  poisonous  features,  either  in  the  chemical  product, 
as  applied  to  the  water,  or  in  any  of  its  resulting  decom])osition  products. 

4.  Merely  nominal  cost  of  the  chemical  and  its  application. 

5.  Speed  of  reaction,  making  unnecessary  any  substantial  arrange- 
ments as  to  basins  other  than  storage  facilities. 

6.  Sulistantial  saving  in  the  cost  of  coagulation  of  waters  that  are  of 
sufficiently  unsatisfactory  appearance  to  require  clarification  or  filtration. 

7.  Permitting  rates  of  filtration  materially  in  excess  of  those  pos- 
sible where  high  bacterial  efficiency  is  required  of  the  filtration  process 
in  the  absence  of  sterilization. 

^  .Journal  of  the  New  England  Waterworks  Association,  1909,  p.  318. 
2  Engineering  Record,  Sept.  17,  1910. 


rillUFKIATION    Oh'    WATKIi.  ^()\ 

H.  |{,<!(lii(M'(l  (•lo^uiiiti;  (»("  llic  (illrr  Ixd-,  will)  ;i.  (•()ji.'-«'(|iicril  Icii^tlicn- 
iiiji,' ()("  llic  runs  I)('(av<<ii  (•Icniiinij-,  <Ihc  Io  iIic  (Icstriiction  of  variouH 
loniis  of  ;tl^iu. 

Liiiill'i/i(iii:<  (if  llic  rrnceMH, 

1.  1  nnhiliiy  lit  I'ciiiovc  or  (Ic-i.roy  all  oC  tlic  ,'-|nii<'-('()riiiiii|/  l)a<"l<-ria, 
bill,  wliic.l:  kinds  (i("  Itactcria  ai'f  nol  considrrcfl  to  he  pat  |jog(Mii<;  to 
man,  ;ii  N'asl.  (hose  conniion  to  watfr. 

2.  Inahilily  to  rctnovc  liaclcria  wliicli  arc  cinldddcd  in  jiarli<-|c-  of 
.Slis|)(!n(lc(l  mailer. 

.'5.    Inubilil}'  lo  n^niovc  Inrhidily. 

4.  In.'ibiliiy  lo  I'cmovc  a|>[)rccial)l<'  amonnt'-  of"  <'olor  or  dissc*) vcfl 
vof!;otal)I(!  slain. 

T).    Inability  to  remove!  orifjinie  matter  a|)|)n!eial>l y. 

(5.    Inahilily  to  remove  swiunpy  tastes  or  odors. 

7.  Jnahility  to  remove  creosote  tastes  or  odors  eominjr  from  the 
cleaning  of  stills  used  in  the  destriK'tiv<!  distillation  of  wood. 

<S.  Inability  to  soften  water;  as  a  matter  of  fact,  the  addition  of 
liypoclilorite  of  lime  usually  results  in  a  slight  increase  in  the  hardness 
of  the  water,  althon<;'h  this  is  not  ordinarily  measurable,  notwithstand- 
int>;  the  fact  that  the  commercial  ])r()diiet  usually  contains  a  little  free 
({uicklimc,  which  reduces  slin'htly  the  carbonic  acid  in  the  water. 

9.  Difficulties  encountered  in  a])plyin<^  this  process,  except  with  tlic 
greatest  care,  to  waters  which  contain  substantial  quantities  of  reducing 
agents  or  com])ounds  capable  of  oxidation,  such  as  nitrites  and  unoxi- 
dized  iron. 

Johnson  and  other  experts  also  believe  that  ''the  use  of  hypochlor- 
ites cannot  be  considered  in  the  light  of  a  substitute  for  filtration.  .  .  . 
As  an  adjunct  to  filtration  jirocesses  it  has  a  distinct  field  of  applica- 
bility, for  at  a  moderate  cost  it  is  feasible  to  obtain  water  practically 
above  suspicion  ;  and,  furthermore,  there  is  l)rought  about  a  substantial 
economy  in  the  first  cost  of  a  filtration  ])lant.  It  is  made  possible  by 
the  use  of  higher  rates  of  filtration  than  are  ordinarily  used,  and  the 
required  filter  area  may  also  be  reduced.  It  also  effects  a  substantial 
economy  in  the  cost  of  operation. 

Ijromine  also  has  its  advocates  as  a  chemical  purifier,  both  on  a 
small  and  on  a  large  scale.  Schumburg'  reconnnends  a  process  which 
is  said  to  kill  in  five  minutes  nearly  all  of  the  ordiuarj'  bacteria  and 
all  pathogenic  organisms  found  in  water.  He  uses  a  solution  of 
20  parts  each  of  bromine  and  potassic  bromide  in  lOO  of  water,  1  cc. 
of  whicli  suffices  to  sterilize  5  liters  of  Spree  water.  After  five  minutes' 
contact,  the  bromine  is  neutralized  with  ammonia,  and  the  result  is  a 
clear,  tasteless,  sterile  water.  Very  hard  waters  and  grossly  polluted 
river  and  marsh  waters  require  larger  amounts,  because  of  the  presence 
of  lime  salts  in  the  former  and  of  ammonia  in  the  latter,  whi^-h  ct^m- 
bine  with  the  bromine  before  it  has  opportunity  to  act  as  a  germicide. 
AVith  such  waters  it  is  necessary  to  add  enough  of  the  solution  to 
produce  a  yellow  tinge  which  will  persist  at  least  half  a  minute.  In 
1  Deutsche  medicinische  Wocheusohrift,  March  4,  1S97. 
26 


402  TT^J  TER. 

anv  case,  Avbatevor  the  amount  of  the  hroniine  sohition  used,  an  etiual 
volume  of  9  jiei-  cent,  ammonia  water  should  be  added.  (In  a  later 
eomnumie:iti(»n,  sod'uuh  sulphite  is  reeommended.)  This  ]>roees8  is 
reeommended  partieularly  for  use  in  the  army,  and  in  the  tropies,  for 
ships'  supplies,  and  for  individual  use  in  times  of  epidemics.  A  kilo- 
gram of  bromine  is  said  to  suffice  to  sterilize  16,000  liters  of  ordinary 
water.  In  practice,  however,  the  process  has  not  met  with  a  large 
measure  of  success.  Schiider^  has  tried  the  scheme,  and  finds  it  unre- 
liable. It  was  tested  in  the  Soudan  Expedition  in  1898,  but  the 
difficulties  attending  its  use  were  enough  to  lead  to  its  abandonment. 

Treatment  with  metallic  iron  in  the  form  of  borings  and  punchings 
is  employed  in  a  number  of  ]>laces  in  Europe  with  most  successfid 
results.  The  best  known  of  the  processes  in  which  this  agent  is 
emjiloyed  is  that  of  Anderson,  in  wdiich  the  water  is  delivered  into 
long  iron  cylinders,  on  the  inner  surface  of  which  are  curved  partial 
dia])hragms  which,  as  the  a]>paratus  slowly  revolves,  carry  upward  the 
jiieces  of  iron,  which  fill  about  a  tenth  of  the  volume  of  the  cylinder, 
and  cause  them  to  shower  constantly  downward  through  the  water  in 
its  passage.  The  carbon  dioxide  in  the  water  attacks  the  iron  and 
forms  ferrous  carbonate,  which,  when  the  water  is  discharged  into  the 
oi)en  air,  becomes  oxidized  and  converted  to  ferric  hydrate.  This  floc- 
culent  matter  entangles  much  of  the  organic  matters,  including  the 
bacteria,  and  then  the  whole  is  passed  through  sand  filters,  the  effluent 
from  which  is  very  pure  and  practically  sterile.  The  process  is  unneces- 
sarily expensive,  involving  as  it  does,  in  addition  to  the  first  cost  of 
the  ])lant,  considerable  outlay  for  ]io\ver  and  otlier  items,  while  the  same 
results  in  the  end  may  be  obtained  by  the  more  simple  process  of  sand 
filtration  alone.  Moreover,  it  appears  that  with  peaty  waters,  the 
organic  constituents  of  which  form  soluble  compounds  ^^'ith  the  iron,  the 
results  are  unsatisfactor}-. 

The  use  of  ozone  has  Ijcen  recommended  as  a  very  efficient  method 
of  sterilizing  drinking-water,  and  experiments  on  a  large  scale  have 
yielded  favorable  results.  Experimenting  on  very  small  quantities 
with  a  Siemens-Halske  apparatus,  Weyl^  found  that  2.3  milligrams  of 
ozone  were  sufficient  to  destroy  99  per  cent,  of  the  bacteria  contained 
in  200  cc.  of  water  from  the  Tegel  Lake.  AVith  3  and  4  milligrams, 
he  obtained  complete  sterilization  of  0.5  liter  of  water  containing  6,000 
bacteria  to  the  cc.  For  purification  on  a  large  scale,  the  impure  water 
is  caused  to  percolate  through  a  tower  filled  with  pebbles,  through 
which  the  ozonized  air  passes  upward.  The  Siemens-Halske  apparatus 
used  will  produce  20  grams  of  ozone  in  an  hour.  The  bacteria  are 
reduced  at  least  99  per  cent,  and  the  percentage  of  organic  matter  is 
greatly  diminished,  but  the  process  is  at  present  very  imperfect,  for 
more  than  70  per  cent,  of  the  ozone  produced  is  lost.  The  ozonized 
water,  although  free  from  odor,  has  an  unpleasant  taste,  and  with  many 
persons  its  use  causes  derangement  of  the  stomach.  This  fault  neces- 
sitates further  electi'olytic  treatment  with  aluminum  electrodes,  Nvhereby 

1  Zeitschrifl  fiir  Hygiene  und  Infectionskrunkheiten,  XXXVII.  (1901),  p.  307. 
3  Centralblatt  fiir  Bakteriologie,  XXVI. 


l-UniFICATIOS   OF    WA'IKli.  403 

jllmiiimiin  liy(lr';il(!  is  luinicd  ;iii<l  iIh;  vvutcr  is  (;l;iri(i<  d  ;iii'l  fioil  Irom 
o/oiic. 

Soditiiii  l»isiil|ili;ili'  li;is  Imcm  i«c(iiiiiiiiii<Ii'I  Ii\  I'miI  i  ;im'I  l.'i'lc'il'  in 
iJic  |(i'()|»(»rli(»ii  of  15  <:r;iiii^  In  iIk'  |Hnl.  'I'lii'V  hl;it<'  tli:il  //.  Ii/jJiomhh 
is  lulled  w'illiiii  (i\c  iiiiiiiilcs,  ImiI  icr. ,iiiiih  iid  ;i  ronlnrl  of  fiClccii  iiiiri- 
iilcs,  ill  (ir<l('r  in  insure  sleiilil\.  W.-iiner^  li;i~  f'<inn<l  lli;it  llii-  i- 
sunieieiiir  lo  einise  ;t  sli'ikiiiL;  i<'<ln<'l  ion  in  llie  nunilH-r  ol"  :i<ided  ^eiin-, 
I)m(  not.  coniplelc  sicrili/.iilion.  In  rno.-l  cascH,  />.  Ii/jj/ioxiis  is  «lc.stroyc«| 
in  lliiiiv,  niid  />'.  c/m/crtr  in  ten,  niinnles.  ('(»nh';iry  to  llie  slatein<'iit 
tlial  ilie  a,t;-eiil  ini|»ai-(s  an  a<i;reeal)le  aeitl  (asle,  W'arnrT  linds  that  to 
some  persons  llie  tasie  is  unpleasant,  and  to  all  woidd  prohaldy  iM-como 
Irksome.  Moreover,  a  person  (••insninina'  •"'  pints  oC  \\at<'r  in  a  dav 
wonid  swallow  7i")  jrrains  oC  tlie  salt,  wlileli  woidd  lend  to  inere;i-e 
rather   than    to   (pieneh    tliirsi. 

(Iienneal  |)nriliealioii  ol"  waiei-  sometimes  oecnrs  witliont  the  inter- 
vention of  pi-oeesses  especial  h'  pro\'ided,  o("  which  l;ic|  I 'ror(j,ss(»r  LcH- 
mann''  reeortls  a conspienons  instance.  The  Sehnylkill  Jliver  in  tin* 
npper  part  of  its  conrse  receives  nmeh  refuse  mine-water,  and  hceonics 
impregnated  with  iron  salts  and  free  mineral  acids.  "  In  its  eoin-se  of 
about  one  liundred  miles  it  passes  over  an  extensive  limestone  district, 
and  receives  several  large  streams  highly  charged  with  cahinm  car- 
bonate. The  resnlt  is  a  nentrali/.ation  of  the  acid  and  a  precipitation 
of  the  iron  arid  mnch  of  the  calcinm.  The  river  hecomes  ])in-er,  and 
at  its  junction  with  the  Delaware  River,  at  J*liiladeli)liia,  it  contains 
neither  free  sulphuric  nor  hydrochloric  acid,  only  traces  of  iron,  and 
but  a  small  amount  of  calcium  sulphate.  In  this  manner  there  is  pro- 
dtuied  a  soft  water,  superior  to  that  of  the  river  near  its  source,  or  to 
the  hard  waters  of  the  middle  Schuylkill  region." 

Ultra-violet  Rays. — One  of  the  most  recent  methods  of  sterilizjition 
of  potable  water,  but  one  still  iu  its  experimental  stiige,  is  by  means  of 
the  ultra-violet  rays  of  light.  In  190(3  the  bactericidal  action  of  these 
rays  was  demonstrated  by  Nogier  and  Therenot,  and  Xogier  conceived 
the  idea  that  the  rays  might  be  utilized  for  the  sterilization  of  water. 
Two  kinds  of  apparatus  have  been  devised,  one  of  which  is  immersed 
in  the  water  to  be  sterilized  and  the  other  acts  from  the  outside.  The 
water  must  be  fairly  clear.     Turbidity  greatly  interferes  with  its  action. 

The  following  experiment  by  Thresh  and  Bealc  *  will  illustrate  the 
marked  sterilizing  power  of  these  rays  : 

"Water  from  main  run  into  a  dirty  cistern  and  well  stirred.  Samples 
of  treated  water  taken  at  half-hour  intervals.  Rate  of  flow,  30  gallons 
})er  hour  throughout.  Under  the  head  of  'gelatin'  is  recorded  the 
number  of  bacteria  per  ec.  capable  of  growing  on  jelly  in  four  davs 
at  20°  C,  and  under  'agar'  the  number  of  bacteria  per  cc.  growing 
iu  two  days  at  37°  C.  upon  an  agar  medium : 

1  Transactions  of  the  Epidenuolo£;ical  Society,  London,  XX.,  1900-1901. 

-  rublic  Health.  Jnly,  1901,  p.  700. 

•^  Examination  of  Water  for  Sanito.rr  and  Technical  Purposes,  Phila.,  ISOo,  p.  1-1 

*  The  Lancet,  Dec.  24,  1910. 


404  TT".  1 TER. 


Gelatin. 

Agar. 

Bacillus  coli. 

Untreated  water 

Treated  water,  1 

Treated  water,  2 

Treated  water,  3 

3200 
0 

2 

4 

o  ocoo 
cc 

1—1 

Present  in  100  cc. 
Absetit  in  500  cc. 
Absent  in  500  cc. 
Absent  in  500  cc 

The  water  wastluis  ])ractieally  sterilized  and  freed  from  tlie  Bacillus  coli" 
With  a  fairly  clear  water,  therefore,  the  ultra-violet  rays  converted 
a  dangerously  polluted  water  into  a  safely  potable  water.  In  view  of 
the  fact,  however,  that  turbid  w^aters  are  not  much  affected  by  this 
agent,  such  waters  will  have  to  receive  a  preliminary  treatment  through 
filtratiDU  before  this  method  of  disinfection  can  be  a])plied. 

2.  Boiling  and  Distillation. — Boiling  as  a  means  of  purification  has 
been  practised  from  very  early  times,  and,  in  fact,  was  advised  by  Hip- 
pocrates (400—377  B.  c. )  for  the  avoidance  of  enlargement  of  the  spleen. 
This  process  is  quite  efficient  so  far  as  destruction  of  the  micro-organ- 
isms is  concerned,  but  it  does  not  diminish  the  amount  of  organic 
matter.  It  does,  how^ever,  reduce  the  amount  of  dissolved  mineral 
matter,  in  that  calcium  carbonate  held  in  solution  by  carbon  dioxide 
is  precipitated,  and  calcium  sulphate,  being  less  soluljle  in  hot  than  in 
cold  water,  tends  to  separate  out.  Boiling  is  available  only  to  a 
limited  extent ;  that  is,  it  is  a  process  which  can  be  carried  out  in  the 
household,  but  not  on  a  large  scale  before  public  distribution  of  water. 
Boiled  water  is  not  palatable  until  aeration  has  restored  the  proper 
taste,  but  this  is  easily  accomplished  by  passing  it  from  one  vessel  to 
another,  or  by  agitation  in  contact  with  air. 

Di.stillation  constitutes  a  most  efficient  process  for  obtaining  pure 
water.  This  process  produces  necessarily  a  sterile  water,  which,  how- 
ever, needs  thorough  aeration.  In  the  apparatus  used  in  the  United 
States  Navy,  the  steam  goes  to  the  condensers  in  company  with  air,  so  that 
condensation  and  aeration  occur  coincidently.  While  no  bacteria  from 
the  original  water  can  pass  over  into  the  distillate,  other  volatile  matters 
can  and  do,  and  instances  are  common  to  ]irove  that  the  distillate  of  a 
foul  harbor  water  may  produce  nausea  and  diarrhoea  in  all  who  drink  it. 

3.  Filtration  is  a  process  of  purification  which  is  most  efficient  and 
available  for  large  water  supplies.  It  is  employed  on  an  extensive  scale 
by  numerous  large  cities  in  Eiu-ope  and  in  this  country.  Before  describ- 
ing the  process,  however,  it  is  in  order  to  consider  filtration  in  the 
household. 

DOMESTIC   FILTERS. 

The  domestic  filters  in  common  use  are,  as  a  rule,  useless  except  for 
the  removal  of  suspended  matters,  such  as  iron-rust,  dirt,  and  other 
coarse  ])articles,  and  worse  than  useless  in  respect  of  bacteria,  the  re- 
moval of  which  is  claimed  but  not  accomplished,  in  that  they  engender 
a  false  sense  of  safety,  while  they  favor  the  growth  and  multiplication 
of  organisms.  Most  of  them  are  small  affairs  for  attachment  to  a 
water  faucet,  filled  with  a  filtering  mediuna  of  coarse  sand,  animal  char- 


1)  OMKSTff '  Fl  />  7  'F.JIS. 


405 


I'Kl.  S."). 


cojil,  .s}K>njjj(!,  ^roimd  }^1;ihh,  wool,  (Ihj.iriil  oiIki'  -iiltstaiu'cs  \vlii(;li  htraiti 
out  tli(!  viHil)l(!  ,Mii,s|icii(lc(l  iiiaf,lcf.->  iiol,  a  wliii  hctlcr  fliaii  tlic  KiriipK; 
fiaiiiKtl  ha^  in  coMiiiioii  use  in  New  lOnulanfl  and  clsfwlicn' a  (jiiartcr  oC 
a(!('iilnry  ati:;o.  'rix'y  pcrniil,  IIk;  passage  ol"  a  j^ood  ,s(rc;irn,  and  fliis  fiu-t 
iiscK"  is  proof  o("  llicif  incllicicncy  as  hatttcria  (ihci-,  for  any  niat«rial 
Hndicac^njly  coarsi;  to  |icniiil  rapid  |)aHsa^(;  of  \va(<r  i.s  not  Kiifliri<'ntlv 
lin(!  to  hold  hack  such  cxiucfhii^ly  niinnfc  sii>-|niidcd  inaftcrs  as  hartcria. 
Most  of  the  materials  used  hccdinc  v<iy  foul  in  a  >liorl  time,  and  in 
(M)ns<'(|n('nc(!  the  water  is  richer  in  hacteria  on  issuing  than  it  wa« 
before  eiiti'aiiee.  'l'heoreli<'all\-,  animal  ehareoal, 
on  aceonnt^  of  its  oxidi/.iiiu  a<'liiiii,  -hmild  he  ;iii 
ideal  llllcrino;  medimn,  and  at  lir>l  it  will  re- 
mo\'e  a:  Iari2;e  |)i*opor(ion  (»f  t  he  hacteria  and  more 
or  less  of  any  eolorinji;  matters,  lint  \-ery  shortly 
it  he(M)mes  fonl  ;  tlu;  calcinm  phosjihate  which 
it  (contains  is  of  great  assistance  In  t  he  growth  of 
hae.teiaa, ;  (^leaning  is  impossihle,  an<l  the  ellhient, 
if  stored,  soon  becomes  very  fonl  and  nnj)leasant. 

The  only  domestic  filters  worthy  of  the  name 
are  tliosc  wliich  remove  mechanically  all  the 
bacteria  of  the  water  and,  at  the  same  time,  add 
notliing  of  their  own  substance  to  the  water. 
Such  are  the  Chamberland-Pasteur,  the  Berke- 
feld,  and  others  based  on  the  same  principle. 
]  n  these,  the  iiltering  medium  is  unglazed,  well- 
baked,  hollow,  porcelain  cylinders  closed  at  one 
end  like  a  test-tube,  enclosed  witln'n  a  metallic 
or  glass  jacket,  with  sutlicient  intervening  space 
for  the  water,  which  enters  directly  from  the  tap 
under  its  usual  pressure  or  "head."  The  open  lower  end  of  the 
cylinder  discharges  the  w^ater,  which  passes  directly  through  the  walls 
of  the  cylinders,  or  "  bougies,"  in  the  same  way  in  which  it  wrtuld  go 
through  blotting-paper.  The  material  is  such  a  very  fine  strainer  that 
it  excludes  all  suspended  matters  whatsoever.      (See  Fig.  35.) 

The  bougies  of  the  Chamberland-Pasteur  filter  are  made  of  well- 
baked  kaolin  of  the  proper  degree  of  porosity  and  hardness  ;  formerly 
those  of  the  Berkefeld  filter  were  made  of  a  soft  friable  infusorial  earth 
peculiar  to  Germany,  called  Kieselguhr,  but  as  they  were  very  brittle 
and  very  liable  to  fracture  Avhile  being  cleaned,  they  are  now  made  of 
a  special  blend  of  clays  used  in  the  manufacture  of  the  finest  porcelain. 
Bougies  of  other  makes  are  of  porcelain  of  varying  grades. 

All  these  filtering  tubes  are  purely  mechanical  in  their  action,  and 
remove  none  of  the  matters,  poisonous  or  otherwise,  in  solution. 
While  they  remove  and  retain  on  their  external  surface  all  the  bacteria, 
they  cannot  prevent  the  growth  of  the  organisms  from  without  inward 
through  their  walls,  and,  indeed,  this  occurs  so  quickly  that,  in  order 
to  secure  absolutely  sterile  water  continuously,  it  is  necessary  to  clean 
and  sterilize  the  bougies  daily,  and  thus  it  is  advisable  to  have  two 
sets,  one  of  which  can  be  cleaned  while  the  other  is  in  use. 


Chamberland-Pasteur  filter. 


406  WA  TEE. 

It  Ims  boon  ]-n*ovecl  rojioatodly  that  nornaal  water  and  water  artifi- 
cially and  oxten.sivoly  infected  will  yield  on  the  first  day  cif  the  use  of  a 
clean  bougie  a  perfectly  sterile  filtrate,  and  that  on  the  second  or  third 
day  Ji  very  small  number  of  bacteria  will  most  likely  be  present ;  but 
these  are  invariably  ordinary  water  bacteria,  and  if  the  })athog'enic 
varieties  occur  in  the  filtrate,  they  come  considerably  later.  Rejieated 
experiments  with  water  infected  with  B.  coll  communis,  B.  typhosus, 
and  B.  cholerce  have  failed  to  prove  the  passage  of  any  of  these  organ- 
isms, while  the  ordinary  water  bacteria  go  through  very  readily.  To 
secure  a  regular  sup})ly  of  M'holesome  if  not  completely  sterile  water, 
it  is,  therefore,  sufficient  to  clean  the  tubes  by  scrubbing  and  boiling 
or  by  baking  about  twice  a  week.  It  appears,  however,  that  the 
Chamberlaud-Pasteur  and  Berkefeld  l>ougies  are  not  equal  in  efficiency, 
for  Horrocks  '  has  succeeded  in  gi\)wing  B.  typhosus  through  the  walls 
of  the  latter.  He  attributes  this  result  to  the  larger  size  of  the  lacunar 
spaces  and  to  the  consequently  diminished  immobilizing  and  devitalizing 
influences.  Since  the  shortest  time  required  for  the  bacilli  to  traverse 
the  bougie  is  four  days,  sterilization  by  means  of  boiling  water  should 
be  carried  out  every  three  days,  in  order  to  insure  complete  safety 

In  general,  the  requirements  of  a  satisfactory  domestic  filter  may  be 
stated  as  follows  :  It  should  yield  a  sufficient  supply  of  clear,  colorless 
water,  free  from  taste  derived  from  the  filter  itself;  should  arrest 
all  bacteria  and  their  spores  ;  and  should  be  simple  in  construction,  and 
offi'red  at  a  low  price.  Thus  far,  those  made  on  the  principle  of  the 
Chamberland-Pasteur  filter  have  met  these  requirements  best.  Their 
introduction  into  use  in  the  French  army  in  1889  was  followed  within 
two  years  by  a  reduction  of  more  than  50  per  cent,  in  the  number  of 
cases  of  typhoid  fever  occurring  therein. 

Filtration  of  Public  Supplies. 

Filtration  on  a  large  scale  is  accomplished  by  the  aid  of  fine  sand  in 
filter  beds  of  proper  construction,  which  act  both  mechanically  and 
biologically.  The  first  beds  of  which  we  have  accurate  knowledge 
were  those  constructed  by  Simpson  in  London,  in  the  year  1829, 
which  were  intended  primarily  for  the  removal  of  dirt  and  other  sus- 
pended matters  causing  turbidity.  The  process  was  regarded  at  that 
time  as  a  purely  mechanical  one,  and  though  in  course  of  time  this 
kind  of  filtering  medium  came  into  very  extensive  use,  it  was  gen- 
erally believed  that  as  carried  on  there  was  no  marked  chemical 
change  in  the  water,  and  that  what  did  occur  was  attributable  to  oxi- 
dation of  organic  matter  by  air  in  the  interstices  of  the  sand.  This 
was,  indeed,  the  view  held  generally  up  to  the  time  when  the  extensive 
researches  begun  by  the  State  Board  of  Health  of  Massachusetts  in  the 
summer  of  1887  proved  the  great  influence  of  biological  agencies,  al- 
though it  had  been  shown  by  Meade  Bolton,  Herseus,  Plaggc,  Pros- 
kauer,  and  others,  that  filtration  removed  all  but  a  trifling  percentage 
1  British  Medical  Journal,  June  15,  1901,  p.  1471. 


FIl/niATION   O/''   I'UIlhK!  Sl'I'f'fJf'IS. 


407 


of  (ni(;n)-or<i|;!iiiisriis,  mid  llinl.  \v;it(i"  l>;i'-tcfi;i,  cxcrl*-*!  .'-omc  inlliiciK'*-  on 
Lli(i  uirioiml-  <»("  (Iw!  iisii;il  consl  idiciils  ol'  \v;ilcr. 

Al(li<»iii;li  smihI  nil  I'liiioii  (if  piihlic  supplies  i,~  o("  (•()iiip;ir;itiv(!ly  r<'f;i!iit 
ori^'iii,  ils  use  (or  iii(li\'i<lii;il  lion-c  -iipplic-  .•iiilcdatcs  Siriipsoii  In'  at 
Icust  ;i  cciidiry  mikI  ;i  linU,  for  I'oiiliii-,'  williiit'  in  I  fJMOj  rcI;il«'H  that 
the  VcnctiuiiM  w<!r(^  ii('.(Mist.oiiu<l  lo  ril(<i-  Ihcir  (Irinkin^-wat^ir  tliroii^h 
layers  of  sand  williin  (lieir  ei.-lciiis,  in  order  to  lid  it  of  disagrwuible 
odor  and  tast(!. 

'I'lic  first  beds  constiMu^tcd  hy  Sitnpson  \v<!r(!  broad  basins  tw(;lv('  i'c.ct 
in  (i(!pth,  witb  impervious  bo( loins  and  sides,  containing  layers  of  HUtuoif 
gravHil,  and  san<l,  wliicOi  oecnpiid  li.ilf  their  depth.  I>(!neatli  tlu;  stontas 
were  laid  ordinary  drain  J)ipes,  throiij^^h  \vhi(;li  the*  liltererl  water  waH 
discharn-ed.  As  th(!  top  layers  of  sand  became  c\(>^^<:<\,  they  were 
seraped  and  renewed.  The  beds  of  I  he  present  day  are  c<)nstru<;t(!d  on 
V(!ry  similar  lin(!S.  They  are  virliially  immense  tanks  of  varying  size, 
sha|)e,  and  eonstruetion.  The  walls  an;  som(!tirnes  vertical,  but  more 
often  slo|)in<;-,  sometimes  bnill,  of  stone  or  concrete,  and  sometimes  con- 
sisting t)f  ordinary  embankment.  Upon  the  j)aved  bottom  of  a  bed  is 
laid  a  system  of  ])erforated  or  disjointed  drain  pipes  leading  to  a  cen- 
tral culvert  or  well,  from  which  the  filtered  product  is  drawn.  Alxn-e 
the  drains  are  successive  layers  of  coarse  gravel,   fine  gravel,  coarse 

Fig.  36. 


FINE     SAN  D 


OARSE    SAND 


GRAVEL 


COARSE    GRAVEL 
DRAIN   PIPES 


Partial  vertical  section  of  one  form  of  filter  bed. 


sand,  and,  at  the  top,  one  of  tine  sand  from  three  to  five  feet  in  dejith. 
(See  Fig.  36.) 

The  tine  sand  is  sharp-grained  in  character,  such  as  is  obtainable 
at  the  seashore,  and  it  should  not  contain  clay  or  other  material  of 
similar  minuteness  of  particle  ;  if  present,  such  should  be  removed 
completely  by  thorough  washing.  As  to  the  size  of  the  sand  parti- 
cles, it  may  be  stated  generally  that  the  finer  the  grain,  the  better  the 
eflHuent ;  but,  it  should  be  added,  the  more  rapidly  it  lx>comes  clogged 
and  the  more  frequently  it  needs  to  be  scraped  off,  and  finally,  the  more 
ditiieult  it  is  to  wash  for  future  use.  With  the  finest  sands,  the 
bacteria  are  removed  absolutely,  but  filtration  proceeds  so  slowly  that 

*  De  luilitis  in  custris  sanitate  tuenda,  auctore  Luca  Aiitouio  Portio,  Vienna,  16S5. 


408  WATER. 

their  use  is  not  practicable.  The  most  effective  si/e  of  orain  is  a 
matter  on  which  opinions  differ  ;  but  whatever  the  size  adopted,  it  is 
imjiortant  that  care  be  taken  to  insure  uniformity.  It  is  stated 
variously  to  be  from  a  fifth  to  one  millimeter  in  diameter,  that  is, 
the  diameter  of  a  sphere  in  volume  equal  to  tiiat  of  the  grain 
without  regard  to  the  shape  of  the  latter.  The  higher  figure  is  the 
one  adopted  by  the  authorities  at  Haniburg. 

Before  the  water  is  applied  to  the  bed,  it  may  be  advisable — and 
if  it  is  from  a  turbid  river,  it  will  be  necessary — to  allow  it  to  stand 
several  days  in  a  settling  basin  or  reservoir,  in  order  that  the  sus- 
pended matters  may  subside,  and  thus  the  too  rapid  clogging  of  the 
interstices  of  the  sand  with  mud  be  prevented  or  retarded.  Observ- 
ance of  this  precaution  will  result  in  lessened  necessity  of  frequent 
cleaning.  Not  only  are  the  suspended  matters  lessened  in  amount, 
but  organic  matters  in  solution  may  be  destroyed  more  or  less  com- 
pletely by  bacterial  action,  and  the  bacteria,  too,  may  be  diminished  in 
number  by  being  carried  down  with  the  settling  matters  with  which 
they  are  in  contact,  and  by  the  death  of  the  less  hardy  varieties.  In 
the  case  of  waters  from  ponds  and  lakes,  the  preliminary  sedimenta- 
tion proceeds  in  situ  and  the  settling  tank  is  not  needed. 

The  water  is  delivered  continuously  at  the  surface  of  the  bed  by 
devices  automatically  regulated,  and  percolates  downward  through 
the  various  layers  of"  sand  and  gravel  to  the  outlet  pipes.  Except 
with  very  fine  sands,  the  first  water  of  the  effluent  is  not  much,  if 
any,  purer  than  the  original,  but  in  a  short  time  a  sediment  layer  is 
formed  on  the  surface  and  a  slimy  algoid  growth  occurs.  This  super- 
ficial layer  acts  both  mechanically  and  by  its  contained  bacteria  to 
cause  the  removal  and  oxidation  of  organic  matter  and  destruction 
of  bacteria.  The  resulting  effluent  is  quite  pure  and  practically  sterile. 
The  Lawrence  filter,  for  instance,  removes  more  than  97.50  per  cent, 
of  the  organisms  present  in  the  water  as  delivered,  and  the  reduction 
is  still  more  marked  at  the  house  service  pipes,  where  99.17  per  cent. 
is  recorded,  the  increase  in  purification  being  supposedly  due  to  the 
fact  that  their  necessary  food  material  has  been  removed,  and  hence  they 
cannot  long  survive.  At  Hamburg,  Altona,  Stuttgart,  London,  and 
other  places,  the  reduction  in  bacteria  is  about  the  same  as  at  Lawrence, 

All  organic  matters  are  not  acted  upon  to  the  same  extent  during 
filtration ;  some  are  decomposed  very  rapidly  and  mineralized,  while 
others  are  attacked  so  slowly  that  complete  removal  during  the  short 
period  elapsing  between  entrance  and  exit  is  often  quite  impossible. 
This  latter  class  includes  the  brown  coloring  matters  so  commonly 
present  in  surface-waters.  These  are  very  stable  compounds  :  they 
persist  during  long  storage  and  are  nitrified  but  slowly.  In  the  proc- 
ess of  chemical  treatment  with  alum,  however,  they  are  coagulated 
and  removed  very  quickly. 

The  slime  layer,  mud  layer,  or  "  schmutzdecke,"  is  believed  by 
some  to  constitute  the  sole  actual  filtering  medium,  the  sand  beneath 
acting  only  as  a  means  of  support.  But  experiments  conducted  at 
Lawrence  and  elsewhere  show  that  this  is  not  true,  and  that  if  the 


FILTRATION   OF  /'ll/UJf  Sfir/'LUX  409 

ffr(.'at(!st  (;!ir('  lo  l)c  <'X('rcisc(|  nol  Id  di-liirl*  I  lie  imnK  <li;it(ly  iindcrlyiii^ 
hiukI,  ;iliii()s(,  (li(!  whole  <»r  l,li(!  sliiiic  l;iy<r  iiwiy  be  -tri[)|>fr|  oil'  wiliioiil 
<!:msiii}jj  any  cliaii^c  in  (lu;  bacteria  coiiiil.  'I'lie  ^re;iler  p.arl  of  tlu; 
WOl'k  is  (lone  in  (lie  n|)|ter  lay<'rM  of  llie  bed,  ;ii)d  yel  b;ie|eri;d  eHieiency 
is  nol,  neeessaiily  ('slabliHJK^d  as  soon  as  a  c.oalinji;  li;i-  bei  n  loniufi. 
A  pcrfw-Uy  new  (ilior  dooH  not  show  its  best  nwiiltH  nntil  it  Iiuh  lM!<-n 
in  use  ("or  some,  li(il(!  lime,  during  which  ihe  sand  |iarliclc.s  for  a 
considerable  de|)lh  become  coaled  willi  the   jelly-like  deposit. 

The  aclive  ai^cnls  in  brinjrin^  aboni  the  death  of  the  bacteria  con- 
tained in  the  elllnent  and  in  aecom|»lishinL''  the;  d«:>lruclion  and  mincr- 
ali/alion  of  the  ori;;inie  matters  are  of  the  sanio  chiHH  of  nitrifying 
or<j:;anisms  as  are  constantly  at  work  in  th<'  -oil.  The  dejilli  <>{'  the 
l)actcria  is  not  directly  dne  to  the  process  of  nitrification,  for  it,  lian 
been  proved  thai  a,  \'ery  marked  increa.-e  in  the  pinccHH  i.s  not  no(x;.S- 
sarily  accom|)ani('d  by  any  dimimition  in  (he  inmd)er  of  orfrjmisms 
whi(Oi  manatee,  to  pass  lhron<;h  to  the  drains.  It  i-  |)OKsibl('  that  the 
snpposcd  relation  of  cause  and  vWcvA,  is  merely  a  coincidence  of  con- 
ditions, that  is,  that  the  conditions  favorable  to  nitrification  arc 
unfavorable  to  the  vitality  of  the  ordinary  bacteria.  Jt  is  also  jkw- 
sible  that  thron<;'h  nitrification  the  latter  arc  deprived  of  at  least  ])art 
of  the  food  materials  necessary  to  their  continued  existence'  and  mul- 
tiplication. 

Nitrillcation  sometimes  ceasca  suddenly  after  it  has  been  proceeding 
for  a  long'  time  at  a  proper  rate,  and  then,  after  an  interval,  begins 
again  without  apjiarcnt  reason.  One  explanation  oflcred  is  that  the 
process  begins  only  when  a  certain  amount  of  nitrogenous  matter 
has  accumulated  within  the  interstices,  that  it  then  proceeds  until  the 
store  is  consumed,  and  that  pending  a  further  accumulation  the 
process  lapses.  In  winter  it  does  not  begin  again  until  the  tem- 
]HM-ature  of  the  effluent  reaches  at  least  39°  F.,  but  after  it  is  once 
started  it  is  unaffected  by  a  fall  to  35°.  The  most  favorable  tem- 
peratures for  the  process  are  those  of  the  hot  summer  months. 

As  to  the  rate  of  filtration,  it  is  im])ortant  that,  whatever  the  rate,  it 
shall  be  uniform  all  over  the  filter.  It  has  been  proved  by  the  Massa- 
chusetts State  Board  of  Health  that  2,000,000  g-allons  jx-r  day  can  be 
filtered  through  each  acre  of  filter  bed  with  the  removal  of  sul)stantial1y 
all  the  bacteria  originally  present.  The  Imperial  Board  of  Health  of 
Germauv  fixes  2,500,000  gallons  per  acre  as  the  maximum  amount  per- 
missible. Koch's  three  rules  of  filtration  are  that  the  rate  of  down- 
ward movement  should  not  exceed  100  millimeters  an  hour,  that  the 
filtrate  of  each  section  should  be  examined  daily  while  the  bed  is  at 
work,  and  that  filtered  water  containing  more  than  100  bacteria  to 
the  cc.  should  not  be  allowed  to  enter  the  pure  water  reservoir,  but 
should  be  rejected  or  refiltered.  The  bacteriological  test  is  much 
superior  to  chemical  analysis  for  watching  the  efficiency  of  a  filter, 
and  a  simple  count  is  quite  sulficient  without  attempting  to  identify 
the  species. 

When  the  filter  begins  to  discharge  slowly  on  account  of  the  extent 
of  the  algoid  growth  at  the  surface,  it  is  not  safe  to  increase  the  press- 


410  WATER. 

ure  imdiily  bv  flooding  the  bed  with  an  increased  deptli  of  water,  for, 
as  was  shown  by  an  experience  at  Berlin,  such  a  procedure  may  force 
the  bacteria,  ■\vhicii  havi'  accunuilated  hirgvly  in  the  meshes  of  the 
growth,  down  through  the  tiker  at  such  a  rate  tliat  they  are  not  de- 
stroyed by  the  usual  agencies.  In  this  case  the  water  level  was  raised 
two  feet,- with  the  result  thtit  tlic  poition  of  the  city  which  was  supplied 
with  the  water  of  that  ])artieuhir  bed  was  visited  by  an  epidennc  of 
tvphoid  fever.  The  sjime  sort  of  accident  occurred  at  Altona  some 
vcars  ago,  when,  a  year  after  successfully  going  through  the  cholera 
epidemic  which  devastated  the  neighboring  city  of  Hamburg  so  extcn- 
siveU',  a  defect  in  the  filter  beds  was  followed  by  an  outbreak  of 
cholera,  which  disease  had  then  died  out  in   Hamburg. 

When  the  sediment  layer  becomes  so  thick  and  dense  that  with  the 
maximum  pressure  allowable  the  required  amount  of  water  liiils  to 
pass,  it  becomes  necessary  to  scrape  otf  the  inch  or  so  that  has  formed, 
and  then  to  proceed  as  though  the  bed  were  new. 

It  will  require,  as  a  rule,  several  days  for  the  formation  of  a  new 
sediment  layer,  and  until  it  is  well  developed  the  effluent  should  either 
be  rejected  or  pumped  back.  The  frequency  with  which  a  bed  will 
require  to  be  scraped  depends  npon  individual  circumstances,  such  as 
the  size  of  the  grains,  the  character  of  the  water  as  applied,  the  rate  of 
movement,  the  season  of  the  year.  The  removal  of  the  top  is  not 
difhcult.  It  is  quite  compact  and  distinct  from  the  sand  beneath  it, 
and  is  readily  pared  off  with  shovels  or  other  tools.  Successive  clean- 
ings may  take  place  without  replacement  of  the  sand,  until  the  depth 
of  the  tiltering  material  is  reduced  to  about  15  inches,  but  not  below 
12.  The  scraped-otf  sand  may  be  washed  thoroughly  in  a  machine  for 
the  pur])ose  until  a  sample  in  a  beaker  yields  no  turbidity  to  clean 
water,  and  it  may  then  be  stored  until  needed  for  future  application. 

Experiments  have  been  tried  repeatedly  in  Massachusetts,  Berlin, 
and  elsewhere  in  sterilizing  sand  by  boiling  it  in  water  or  otherwise 
subjecting  it  to  high  temperatures,  and  then  determining  its  cfiiciency. 
The  results  have  proved  invariably  that  more  bacteria  are  found  in  the 
filtrate  than  in  the  original  water,  and  this  is  ex])lained  by  the  suppo- 
sition that  the  bacteria  that  enter  find  in  the  cooked  organic  matter  a 
food  supply  most  favorable  to  enormous  multiplication,  and  that  the 
bacteria  in  the  washed  sand  are  necessary  for  the  destruction  of  organic 
matter  and  of  some  of  the  varieties  of  water  bacteria. 

During  and  immediately  after  the  scraping  process,  the  bed  is  neces- 
sarily out  of  use,  and,  therefore,  it  is  necessary,  in  order  to  insure  con- 
tinuous filtration,  to  have  a  number  of  separate  beds,  and  to  scrape  them 
in  turn.  In  this  way,  while  one  is  out  of  use,  the  others  can  carry  on 
the  work. 

In  cold  weather,  owing  to  increased  viscosity  of  the  water,  the  rate 
of  filtration  is  less  than  in  the  warmer  months.  In  very  cold  climates, 
the  formation  of  thick  ice  makes  proper  cleansing  of  the  surface  im- 
possible ;  and  imperfect  scraping  causes  imperfect  filtration.  The  re- 
moval of  the  ice  augments  considerably  the  cost  of  maintenance,  and 
this  item  alone  is  one  of  sufiHcient  importance  to  warrant  the  expense 


FII/riL\Tlf)N  OF   I'lJlUJC  SdJ'I'fj/J'JS.  411 

(tf  (5(»v((rin^  tli(!  I)i(ls.  I'.iil  aside  Ironi  cost,  tlu;  clVicu-wy  of  (Ik;  jiro<!CH» 
is  S(»  rmutli  ^vc-.iicr  ;iiiil  llic  (l;iii'j<r  'if  ciiidctnirs  of  WiiU'l'-horiUf  fiiwraHC 
is  s<t  iiiiicJi  (liniiiii-licd  lli.il  ilic  |)I;imI  in  :i 'old  cliinatc  hIioijKI  iilwayn  Ik; 
(H)V('r('d.  Willi  ;iii  uncos  cicd  Ullir  -nlijccl  l<»  (rce/inj;  («'iii|)cra(ur«  h, 
irii|)('i'("c('l.  (ill  r;i(  idh  is  nlnm-^l  -ni'c  In  urcnr  |iiri(idic;(ll  y,  and  this  ih  iiidi- 
(^alcd  hy  ;iii  incrc'isc  in  llic  d;iil\-  li.iclcria  cmnrl.  dlnis,  WallicliH  '  luiH 
nolcd  iJiat  .'d'lcr  CicczinL!'  Iiad  nccniTcd  in  llic  filler-  of  Alloiia  in  Kel»- 
rnaiy,  I  HSIi,  January,  J.SST,  l'"elM-nary,  Is.ss,  ;iiid  .January,  Islil,  i\u' 
number  oC  e-ernis  in  llie  iillcred  water  rose  eonsideiahly,  and  in  eaeli 
inslaiiee,  in  iJie  I'ollowinL;;  inontli,  tlierc!  was  an  nniisnal  increase  in  lli«f 
aniounl.  of  l\|»lH)id  (cnci". 

b'l'ee/int;'  of  llu;  sin'faee  eansos  inij)or(eet.  fill  I'al  ion  \>y  l)iin;_dng  it 
a,l)i>iit.  tliat  tlu;  bed  is  owirwoi'ketl  in  those  plaees  which  are  still  |»er\ioiin. 
The  application  of  water  to  the,  Iro/en  sni'faee  thaws  the  ice  slowly  and 
iine(|iially,  and  when;  the  liltei'  is  active,  it  is  doin^  the  work  of  its 
fro/en  iieinhhorin^-  areas. 

»Scra|)in!j,'  of  a  l)ed  l)clow  the  ico  cake  is  pcirfbrniod  with  a  machine 
wliich  runs  helwceii  the  sand  and  the  ice,  cuts  the  layer  and  receives  it 
in  a,  ha*;'  as  liist  as  it  is  removed.  It  is  (h'ay'LTcd  from  sidi-  to  side  with- 
out breaking'  the  ice  above  it. 

Covering  a  filter  is  a<l\anta<;(>oiis  in  anntlier  direction,  for  by  the 
exchision  of  liglit,  growths  of  alg;e  are  inhibited,  and  tliere  is,  there- 
fore, k'ss  need  of  frequent  cleaning. 

On  the  other  hand,  open  filters  get  the  l^enefit  of  the  sterilizing  in- 
fluence of  direct  sunlight,  but  this  is  more  than  offset  by  tiie  promotion 
of  luxuriant  growth  of  algae  and  other  microscopic  ])lants  in  the  warmer 
months.  It  is  sometimes  hardlv  possible  to  keeji  filters  in  good  work- 
ing order  in  summer  owing  t^)  these  growths,  which  clog  the  inter.-tices 
very  (piiekly  and  cause  diminished  efficiency  just  at  a  time  when  the 
demand  for  water  is  greatest.  The  coincidence  of  greater  demand  and 
more  frequent  cleaning  does  not  permit  of  sufficient  intervals  of  rest 
after  the  conijiletion  of  the  scrajiing  process. 

In  what  is  known  as  ''intermittent  filtration,"  the  filter  l)c<l  is  used 
for  the  roce]ition  of  water  during  ]iart  of  one  day,  say  sixteen  hours,  or 
even  during  several  days,  and  then  is  allowed  to  drain  off  and  rest  for 
a  while.  As  the  water  drains  away,  the  interstices  of  the  sand  become 
filled  with  air,  that  is,  the  bed  becomes  aerated,  and  thus  the  nitrify- 
ing bacteria  which  bring  about  the  destruction  of  org-anic  matter  and 
its  subsequent  mineralization  to  nitrates  are  assisted  to  maintain  their 
vitality.  The  intermittent  process  is  sujierior  to  the  continuous  iu 
that  nitrification  proceeds  more  strongly,  the  organic  matter  is.  there- 
fore, more  completely  removed,  and  the  ordinary  bacteria  do  not  sur- 
vive so  long  in  aerated  sand  ;  but,  on  the  other  hand,  it  is  inferior  iu 
that,  being  so  much  out  of  active  use,  the  main  plant  needs  to  be  so 
nuich  the  larger  for  the  accom]^lishment  of  a  given  amount  of  work. 
As  a  matter  of  fact,  however,  all  sand  filters  are.at  one  time  or  another 
intermittent,  since  each  time  a  bed  is  scraptnl  the  water  is  drained  away, 
and  the  space  formerly  occupied  by  it  is  then  filled  with  air.  Sometimes 
*  Deutsclie  mediciuisclie  Wocliensolirift,  1S91,  p.  25. 


412  WATER. 

it  is  proposed  to  ])nt  the  water  tlirouo-li  a  process  of  double  filtraticni, 
that  is,  to  pass  the  tiltrate  on  to  another  bed  for  still  further  jiurilication. 
But  if  the  first  filtration  has  been  carried  out  properly,  the  filtrate  M'ill 
have  been  deprived  of  all  the  materials  necessaiy  for  the  formation  of 
the  real  filtering  surface  on  the  second  bed.  Thus  the  passati'C  of  the 
water  through  a  second  filter  would  be  much  in  the  nature  of  a  mere 
form,  for  it  would  pass  practically  unchanged. 

Sand  filtration,  when  properly  managed,  has  ])i'oved  itself  so  efficient 
that  the  number  of  cities  and  towns  making  use  of  it  is  growing  almost 
daily.  Although  jirotection  of  a  supply  at  its  source  may  be  prefer- 
able to  pollution  followed  by  sand  filtration,  it  is  not  always  so  trust- 
worthy, since  pollution  may  creep  in  by  accident  at  any  time  in  the 
best  guarded  supplies.  The  ideal  course  is  protection  at  the  source, 
followed  by  filtration  before  distribution.  This  is  the  method  now 
adoi>ted  by  the  authorities  of  a  number  of  cities  in  Europe. 

"Mechanical  Filtration." — In  some  places,  particularly  in  the 
United  States,  the  water  supply  is  treated  in  what  are  known  as 
mechanical  filters,  of  which  there  are  a  number  of  varieties,  all  based 
on  a  common  principle.  Such  a  machine  consists  chiefly  of  an  iron 
or  wooden  cylinder  filled  with  rather  coarse  sand  or  crushed  quartz, 
through  which  the  water  passes  by  gravity  or  is  driven  under  pressure 
at  a  much  faster  rate — from  50  to  150  times  faster  than  it  moves  in  a 
bed.  To  take  the  place  of  the  sediment  layer  which  forms  in  the  latter, 
an  artificial  film  is  produced  by  the  use  of  alum  as  a  coagulant.  This 
is  formed  quickly  and  serves  the  same  purpose,  though  not  with  the 
same  thoroughness.  The  filter  is  called  mechanical  only  because  power 
and  mechanical  devices  are  employed  in  regulating  the  rate,  pressure, 
the  application  of  the  alum  solution,  and  the  raking  and  shaking  of  the 
sand  in  the  process  of  cleaning,  which  process  it  is  necessary  to  carry 
out  at  short  intervals.  Instead  of  removing  the  top  layer,  the  whole 
body  of  sand  is  thoroughly  agitated  and  washed.  Filtered  water  is 
pumped  through  from  below  for  five  or  ten  minutes,  and  the  sand  layer 
is  agitated  by  revolving  rakes  or  by  compressed  air  introduced  from 
below.  The  process  is  not  suited  to  all  water  supplies,  but  for  the 
highly  colored  and  turbid  waters  so  common  in  the  South  and  West  it 
is  particularly  well  adapted,  and  is  cheaper,  more  efficient,  and  more 
easily  managed  than  filtration  through  beds  of  sand.  With  careful  man- 
agement, upward  of  99  per  cent,  of  bacteria  are  removed. 

Within  the  last  two  years  the  combination  of  mechanical  filtration 
and  chemical  disinfection  with  hypochlorites  has  been  found  to  be  more 
efficient  than  either  process  alone,  and  has  been  recommended  by  com- 
petent authorities. 

Destruction  of  Algae. 

For  the  destruction  of  overgrowths  of  alga),  Moore  and  Kellerman^ 
recommend  the  use  of  copper  sulphate  in  extreme  dilution  (about  1  part 
of  the  crystals  to  4  or  5  millions  of  water).      In  the  practical  appli- 
cation of  this  agent  to  ponds  or  reservoirs,  the  crystals  are  placed  in 
^  U.  S.  Department  of  Agriculture,  Bureau  of  Plant  Industry,  Bulletin  64. 


IlKMOVAL    OF   IIMIDNKSS.  413 

^iiiiiiy  s!i(;l<s,  vvliif^li  .'ire  llicii  diviwii  lliroii|rli  tli«-  \v;if<T  hy  rnr-arm  f)f 
f()\v-l)<>;its,  wliicli  (r;iv(;r,s(;  tin;  .'ircu  in  conmitrif  lines  Ironi  2.">  to  10  i'cft 
apuri.  'V\\v.  process  lias  hccn  tiiid  in  \;nions  plru-r-H  witli  roHults 
varyinj;'  IVoin  (;ornpl('L(!  snc.ccss  (<>  nttcr  I'lilinc  .  In  some  iriHtiincf;.-,  the 
(l(!Hi,rn(!(<ion  of  one;  Hjxicies  of  jiI^jo  lias  Itccn  followfil  liv  ovcr^rowtlm 
<)('  ('(inally  ohjcctionahlc  and  more  liardy  forms.  Tlie  a.'^sertion  tliat 
tli(!  copper  is  (piiekly  precipilaied  is  dis|)nle'l  Wy  many  who  h.'ive  ^iveri 
the  process  a,  (rial,  and  Ihc  claim  (liat  patho<i;enic  l)a(;teria  are  destroyed 
with  the  iiV^w,  ap|)ears  (o  have  litlle,  if  anything,  to  sii[)port  it. 

Removal  of  Hardness. 

On  ax'conni  o("  ilie  enormons  wasle  o("  soaj>  as  well  a-  Im.~-  (if  (ime 
which  the  nse  of  hard  walers  in  washinjx  entails,  and  oC  the  injnry  to 
which  hoileis  and  liol-uater  pipes  arc  sul)jo(!t  from  their  action,  it  often 
becomes  neeessaiy  (o  :i|»|»ly  some  remedy  wherehy  the  de^-ree  (»f  hard- 
ness may  be  lessened.  This  may  be  accomplished  by  tin;  aid  of  heat 
or  by  the  addition  of  chemicals.  J'xiiling,  as  wo  have  scon,  drives  off 
the  contained  cai'boii  dioxide  and  canses  precipitation  of  the  earbf)nat<:« 
which  ha\e  been  held  in  solntion  by  this  afz;en(,  bnt  it  lia.s  no  effeet 
on  the  salts  which  canse  the  permanent  hardness.  I-'or  nse  on  a  large 
scale  I'or  publico  snpplies,  this  means  is  liardly  applicable,  on  account 
of  the  cost  of  ])lani  and  of  fuel  ;  but  for  domestic  purposes  the  co.st 
is  com])aratively  slight,  in  that  the  fuel  uecessaiy  in  cooking  may  be 
utilized  coincidently  for  the  purpose  of  lieating  water.  For  the  chemical 
treatment  of  hard  waters,  the  first  process  devised  was  that  of  Clark, 
patented  in  1841.  This  process  is  based  upon  the  affinity  of  caustic  lime 
for  carbon  dioxide,  Avith  which  it  forms  the  practically  insoluble  carbonate. 

On  the  addition  of  lime  water  to  water  containing  chalk  and  mag- 
nesium carbonate  held  in  solution  by  carb(Mi  dioxide,  the  reaction  occurs, 
and  a  double  precijiitation  of  the  carbonates  present  and  of  that  formed 
is  brought  about.  Tlic  process  is  veiy  ecouomiciil  so  far  as  cost  of 
material  is  concerned,  in  that  a  few  cents'  Avorth  of  lime  will  remove  an 
amount  of  hardness  which  will  decompose  many  dollars'  worth  of  soaj). 
Lime  water,  however,  does  not  affect  the  chlorides  and  sulphates,  and 
hence,  like  boiling,  reduces  only  the  temporary  hardness.  Yor  the 
employment  of  this  process  on  a  large  scale,  various  forms  of  apparatus 
have  been  invented,  consisting  of  chambers,  or  tanks,  in  which  the 
lime  is  mixed  with  water  and  from  which  the  mixture  passes  into  other 
large  receptacles,  wherein  it  meets  the  water  to  be  treated.  Thence, 
according  to  the  nature  of  the  apparatus,  the  water  passes  on  to  settling 
tanks  or  to  mechanical  filters,  Avhere  separation  of  the  precipitate  is 
completed.  The  largest  plant  of  this  kind  in  the  world  is  located  at 
Southampton,  England,  where  2,(X^0,000  g-allons  of  water  are  treated 
daily  at  what  may  well  be  reg-arded  as  an  almost  insignificant  cost. 
The  building  in  which  it  is  installed  covers  less  than  a  seventh  of  an 
acre,  and  is  sufliciently  large  to  accommodate  additional  apparatus 
whereby  its  working  capacity  may  be  increased  by  half.  Whatever  the 
forms  of  apjiaratus  employed,  the  process  must  be  carefully  suj>ervised, 


414  WATER. 

:ui(l  tlie  amount  of  liino  added  must  ho  constantly  roo-ulatod  ;  for  if  too 
little  is  employeil,  the  lull  extent  of  ]ios-^ihle  soi'teninii-  is  not  reached, 
while  with  too  much,  the  \\:il('r  is  i\\:u\v  alkaline  and  tlu'  cai'honate  of 
magnesium  is  retained. 

Caustic  soda  may  be  used  for  softenino-  waters  ecmtainino'  carbon 
dioxide  and  the  salts  eausino-  permanent  hardness,  Adtled  in  ])roj)er 
amount  to  combine  with  all  of  the  free  carbon  dioxide,  it  forms  car- 
bonate of  sodium,  which,  in  its  turn,  attacks  and  decomposes  the  other 
salts  and  causes  their  precipitation.  Sodium  carbonate  itself  may  be 
added  in  the  absence  of  free  carbon  dioxide  to  bi'ing-  about  the  same 
result.  In  some  processes  for  softening  water,  both  lime  and  caustic 
soda  or  sodium  carbonate  are  employed,  the  object  being  the  reduction 
of  both  temporary  and  permanent  hardness. 

Removal  of  Iron. 

Some  ground-waters  contain  iron  in  such  amounts  as  to  be  objection- 
able, both  on  account  of  its  infltieuce  on  the  system  and  because  of  its 
production  of  stains  on  linen  and  other  textiles  in  the  laundry.  There 
are  two  principal  methods  of  removing  it,  both  of  which  depend  upon 
the  conversion  of  the  ferrous  compounds  into  the  ferric  form,  with  con- 
sequent separation  as  a  precipitate.  These  are  filtration  and  aeration. 
Filtration  may  be  conducted  through  sand  or  coke  or  animal  charcoal, 
and  with  either  material  the  iron  in  solution  is  exposed  to  the  action  of 
air  in  the  interstices  and  becomes  oxidized  to  the  sesquioxide,  which  is 
left  on  the  filtering  material.  If  the  air  supply  is  insufficient,  and  if 
there  is  mtich  organic  matter  present  in  the  ^vater,  the  sesquioxide  may 
be  reduced  to  the  ferrous  form  and  again  pass  into  solution.  When 
ground-water  containing  less  than  3  parts  of  iron  per  1,000,000  is  ex- 
posed in  large  volumes  to  air,  the  iron  will  settle  out  almost  completely 
within  a  day  or  a  day  and  a  half. 

Another  method  of  removal  by  chemical  treatment  involves  the  use 
of  ferric  chloride  and  caustic  lime  in  the  proportion  of  1  and  5  to  10 
grams  respectively  to  each  100  liters  of  water.  By  this,  the  "  Kronke  " 
method,  all  the  iron  can  be  removed,  but  it  necessitates  the  use  of  a 
mixing  tank,  constant  attention,  and  eventual  filtration  for  the 
removal  of  the  precipitated  iron. 

Action  of  Water  on  Lead,  and  Other  Metals. 

Action  on  Lead. — The  question  as  to  the  best  material  for  house- 
mains  and  distributing  pipes  is  always  an  interesting  one,  and  never 
more  so  than  when  a  considerable  number  of  persons  in  a  community 
begin  to  show  symptoms  of  lead-poisoning,  and  evidence  is  presented 
which  incriminates  the  water  supply.  Aside  from  the  matter  of  cost, 
the  advantage  of  using  lead  pipes  lies  in  the  comparative  ease  with 
which  lead  is  worked,  since  it  may  be  bent  to  any  necessary  extent, 
and  thus  may  be  fitted  to  all  manner  of  irregularities  of  construction 
withont  the  need  of  the  frequent  cutting,  thread-making,  and  coupling, 
which  the  use  of  inflexible  material  involves. 


AiJTION   OF    WA'I'Eli    ON   LEAD   AM)    O'lllKIL   METALS. 


■\\ 


All  (»r'(lliiju'y  WMJcrs  liiivc  ;i  ^icwlcr  or  Icsj^cr  (ciKlciicy  to  atlju-k  K-ad, 
iUic-onllii^'  lo  IIh'  ii.'idirc  and  aiiionnl  of  lln-  siib.'-laiK'c.'^  Ii<'l«l  in  .--oliitioM, 
'V\\v  i.-.i)\\\uun\\\  a(<'c|»(('il  sl.ilciiKiit ,  llinl  pure  soil  \val<T  is  jtroin-  (ri  at- 
(a-cl<  lead,  and  lliai  hard  walcis  lend  lo  |(ri»(c('l  if  hy  (onniiig  incniHta- 
tions  over  (lie  cxitoscd  sni'("acc,  i,-  true  only  in  p.nl,  lor  Homc!  very  pure 
soil,  walcrs  (iNcrl.  (udy  very  .slij^lil  ai-tion,  while  .■-onic  very  hard  onr-h  a«l 
wilh  nnnsnal  inlcnsity. 

Waters  coiii.'iiiiiiiM  \(  i\-  .-^miill  ;nnonnt,-^  of  or^anie  ;ind  mineral 
niaticrs  aei  or  nol,  aeeordin'j  .i-  llie\  eonhiin  niiieh  or  lillle  di^-dKed 
<)Xy^'<"i  •"■  <'arl)(Hi  dioxide,  oi'  holh. 

A  (ijienueally  |iimc  walei-  wonid  |irol»al)ly  exei't  no  aelion  \\lialev<T 
on  chcinieallv  [mic  le.id,  Iml  <'oniinoiil\-  neither  (he  one  .'•uh.'^fancc  nor 
(he  odier  is  seen  in  sneh  a  slale  of  |inril\-.  ()rdinary  (iis(illed  walrr, 
ho\v<'\('r,  which  is  a  neiinr  a|i|iro;ieh  lo  ahsohite  |inri(y  (han  any  othf-r 
natural  \\a(er  can  lie,  will,  luider  eeitain  e(»nditions,  act  very  corrosively, 
the  conditions  heini;'  (he  presence  of  (he  ahovc-nicndoncd  piscs.  It  is 
hold  generally  (hat  either  o.\v<i-en  or  carbon  dioxide  alone  in  Avatcr  haw 
but  little  inlhience,  Imt  tlint  the  ( w  <i  (onet  hei' aei  wi(li  \arving  inten- 
sity U[)  to  a  certain  point,  directh'  proporl  ioiiali'  to  the  amount  of  car- 
bon dioxide.  This  lieliel',  l)as(<l  on  e\|ieriniental  obsj-rvations  <»f' 
Miiller,'  was  strent;thened  by  l)rs,  Antony  and  J>enelli,'-  who  found 
that  the  liiii'hest  results  in  lead  corrosion  were  obtained  by  the,  use  of 
ai-raled  water  charged  with  carbon  dioxide.  Invcstigiiting  the  plunii>o- 
soKent  proi)erty  of  a  ])ai-ticnlar  water,  A  Liebrieh  ''  came  to  tlie  same 
conclusion  :  that  the  simultaneous  ])rcscnce  of  air  and  carbon  dioxi<le 
favors  action,  while  either  alone  has  no  power.  Kecently,  however,  a 
very  extensive  inquiry  into  the  subject  of  metallic  contamination  of 
Avater  sup])li(>s  has  been  conducted  by  Mr.  H.  A\'.  C'lark,^  chemist  of 
the  State  ]>oard  of  Health  of  Massachusetts,  whose  results  indicate  that 
oxygen  is  the  more  actively  corrosive,  and  that  either  gas  can  act  alone, 
lie  employed  distilled  water,  freed  in  the  first  phice  as  comjjletely  as 
possible  from  these  and  all  other  gases,  and  then  impregnated  with 
known  amounts  of  either  or  both.  Clean  bright  lead  pipe  in  equal 
amounts  was  placed  in  half-gallon  bottles  filled  with  water  containing 
the  gases  in  the  jiroportions  stated  below,  then  sealed  and  set  aside  at  a 
tenqKn-ature  of  (58°  F.  for  one  week,  at  the  end  of  which  time  the 
amount  of  lead  taken  np  was  determined.  The  results  are  shown  in 
the  following  table  : 


No. 

Gases  present. 

Amount  of  lead  taken  up 
(parts  per  100,000). 

1 

2,4100 

2 
3 
4 

Carbon  dioxide  4  inu-ts  per  100,000 

Ciu-bon  dioxide  20  jiarts  per  100,000 

Oxygen  y\,  of  saturation,  CO.j  4  parts  per  100,000  . 

0.4993 
0.8935 
O.0S61 

'  Journal  fiir  praktische  Chemie,  Series  2,  36,  p.  317. 
-  Gazetta  ohimiea  italiana,  Jan.  21,  lS9(i,  p.  275. 
■^  Zeitsoiu-if't  fiir  angewandte  Chenne,  1S98,  p.  703. 
*  Annual  Eeport  lor  1S9S,  p.  541. 


416  WATEB. 

A  specimen  of  load  in  a  bottle  containing  water  from  which  the 
oxviicn  had  been  boiled  ont  as  completely  as  possible,  and  the  carbon 
dioxide  removed  by  barinm  hydrate,  was  kept  at  8*2°  F.  for  a  week  un- 
changed. At  the  end  of  the  second  week,  slight  action  was  discernible 
in  spots  on  the  surface,  and  analysis  showed  0.0774  part  per  100,000 
of  water.  A  specimen  of  ordinary  distilled  water  in  a  bottle  with  a 
small  air  s[)ace  in  the  upper  part  attacked  a  similar  piece  of  lead  pipe 
to  such  an  extent  that  it  yielded  10.58  parts  per  100,000.  In  this  case, 
the  temperature  at  which  the  water  was  kept  was  81°  F. 

Inasmuch  as  all  drinking-water  contains  more  or  less  air  in  solution, 
oxygen  is  always  present  in  some  amount,  and  since,  furthermore,  car- 
bon dioxide  is  also  generally  present,  it  follows  that,  uidess  substances 
with  a  decidedly  deterrent  influence  are  present,  more  or  less  corrosion 
is  to  be  expected.  Numerous  instances  of  chronic  lead-poisoning 
due  to  water  rich  in  carbon  dioxide  are  on  record.  At  Sonmierfeld,^ 
for  instance,  where,  in  1888,  numerous  cases  occurred,  it  was  found 
that  the  very  pure  water,  rich  in  this  gas,  dissolved  lead  to  the  extent 
of  about  6  milligrams  per  liter.  At  Lowell,  Massachusetts,  numerous 
cases  were  observed  during  the  years  1898  and  1899,  and  it  was  dis- 
covered that  one  source  of  supply  was  rich  in  dissolved  oxygen,  and 
that  the  other,  which  caused  by  far  the  greater  number  of  cases,  was 
rich  in  carbon  dioxide. 

Professor  A.  W.  Hoffmann  believes  that  a  moderate  amount  of  cai'- 
bon  dioxide  lessens  corrosion  by  forming  a  protective  coating  of  car- 
bonate, but  that  an  excess  of  the  gas  dissolves  it  as  bicarbonate.  The 
gas  is  said  also  to  have  no  action  on  lead  coated  with  suboxide. 

Water  containing  free  acid  of  any  kind  attacks  lead.  Sulphuric 
acid,  which  is  supposed  erroneously  to  form  an  absolutely  insoluble 
compound,  the  sulphate  of  lead,  is  particularly  active.  In  the  ordinary 
chemical  sense,  sulphate  of  lead  is  insoluble  in  water ;  but  in  the  hy- 
gienic sense,  it  is  sufficiently  soluble  to  be  capable  of  producing  serious 
symptoms.  This  acid  is  not  an  uncommon  constituent  of  water  in 
minute  amounts,  especially  in  the  vicinity  of  cities  and  large  towns, 
where  it  exists  in  the  atmosphere  as  an  impurity  due  to  the  combustion 
of  coal.  The  peat  acids  also  have  considerable  action  on  lead,  but 
they  are  not  always  present  in  waters  from  peaty  deposits.  Some  very 
brown  waters  appear  to  exert  but  slight  action,  while  others  are 
intensely  corrosive.  The  peat  acids  are  due  supposedly  to  the  growth 
of  certain  micro-organisms  found  in  peaty  soils,  for  a  neutral  sterilized 
decoction  of  peat  to  which  a  small  amount  of  fresh  peat  is  added  will 
in  a  short  time  develop  an  acid  reaction  and  ability  to  dissolve  lead. 
Liebrich  ^  reports  a  peaty  water  poor  in  carbon  dioxide  and  carbonates 
which  took  up  300  parts  of  lead  per  100,000  over  night,  and  more 
when  calcium  carbonate  was  added. 

The  ammonium  compounds  and  the  nitrates  have  been  supposed 
commonly  to  have  a  marked  corrosive  acition  on  lead.     That  this  sup- 

'  Dcutsclie  Yiorteljalirssc-lirift  fiir  (iffentliclie  Gesundheitspflege,  Suppl.  XXIV. 
'  Zeitschrift  fiir  augewandte  Clieniie,  1898,  p.  703. 


ACTION   OF    WATFIi    ON    I. KM)    AND    OTIIEIi    MIITM.S.         117 

jxisitioii  is  ('(HTccI,  liMS  l)ccii  |>r<)vc<l  ;iiii|)ly  hy  Mr.  ('lurk's  rc-c-ircjich ; 
bill,  iii(((iis(!  ;\v\\()\\  is  mniiiCcslcd  <»iily  when  llic  \s';i(cr  rdiiljiiniii^  (ln-ni  \n 
ox|»(),S(!(l  (<)  :iir. 

'^riic  cons!  il  iiciils  fif  wilier-  \vlii<-li  IcihI  (o  liriii^^  :il)rHil  corrohjon  oi' 
Ie;i(l  :ire,  llieii,  ciirlMHi  dioxide,  oxy^jcii,  ;iiiiiiioiii:i,  iiilrat<'H,  :iimI  fVe(r 
acids.  The  sdhslanees  which,  <»ii  the  other  hand,  excrl  a  prolcetivc 
aiilion  inehide  ehhtrides,  earhoiiales,  and  silicates,  an<l,  j)rol)al»lv,  .'-iil- 
|)hales.  yXeeordinn  to  ( 'rookes,  (  )dliiit:,  ;ind  TidN',  O.o  jrrain  of'siliea  |<( 
i\\v  ini|»eriai  eajjon  is  sudieient  to  ;ill'or<l  cfdniiiete  protection  in  all  hut 
exce|)(ional  <'ases,  escn  when  tree  aeids  , ire  present ;  hut  certain  waters 
containiiit;'  consideral)l(!  anioinils  of  silica  arc;  known  to  ix;  cf)rrosiv<.' 
to  a  decided  cxient.  The  |)i"otectioii  due  to  silicu  niav  he  ohlained  hv 
allowing;'  the  water  to  (low  Ihroiieh  iirokeii  (liiil,  lliiil  and  chalk,  or 
IinK!stoiie,  hut  such  li'cat  iiieiit  soiiK'tinics  has  the  niidesirahle  ellV'<'t  of 
in(M'casin<>^  corrosive  power. 

Sodinin  an<l  calcinin  carhonales  are  very  eflicient.  "^J'lie  hicarhonate 
oi'  sodium  is  <2,<'nei"ally  present  in  those  very  soft  waters  which  liave 
the  .slightest  action  ;  calcinin  carixniate  is  ellicieiit  whether  (tr  not  car- 
hon  dioxide  is  present  in  the  water  at  the  same  time.  l''onr  ^n-ains  j)er 
j2,'allon  are  generally  considciX'd  to  he  (piitc  sulhcient  lo  ailord  jinttection 
under  most  circumstances.  As  an  illustration  ot"  the  influence  of"  thi.s 
agent,  may  he  (iited  the  fact  that  the  very  pure  water  with  which  Glas- 
gow is  su])plied  lias,  heibrc  its  entrance  to  the  aqneduct,  a  marked 
pi um bo-sol V cut  ])roperty,  hut  loses  it  entirely  in  its  j)assage  to  the  city, 
owing  to  contact  with  this  suhstance.  In  1(S87,  the  Avater  of  De.ssau 
was  treated  successfully  Avith  calcium  carhonatc.  Sodium  carlxmate  is 
even  more  efficient  than  the  calcium  salt,  but  is  not  always  e<jual  to  the 
bicarbonate.  At  Emden,  in  1897,  treatment  with  the  latter  was  suc- 
cessful after  the  carbonate  had  failed. 

Inasmuch  as  the  influences  for  and  against  corrosion  are  numerous 
and  conflicting,  the  surest  method  of  determining  whether  a  given 
water  \vill  attack  lead  is  to  ascertain  the  truth  by  actual  experiment. 

Ivegardlcss  of  the  character  of  a  A\ater  itself,  it  may  he  said  that  its 
action  is  greater  if  the  lead  is  in  contact  with  other  metals,  so  that  a 
galvanic  couple  is  formed.  Such  may  occur,  for  instance,  when  a  tin- 
lined  lead  pipe  is  bent  so  that  the  lining  is  fractnred.  Then  the  two 
metals  being  in  contact  with  each  other  in  a  more  or  less  saline  liquid, 
the  lead,  being  the  more  easily  oxidized,  is  dissolved.  Again,  the  tin 
lining  may  develop  weak  spots  which  may  l)ecome  corroded,  and  as 
soon  as  the  lead  casing  is  reached,  galvanic  action  becomes  established. 
Lead  pipe  containing  a  small  percentage  of  tin  will  yield  more  lead  to 
water  than  will  ordinary  lead  pijie,  especially  if  free  carbon  dioxide  is 
present. 

A  new  lead  surface  will  yield  more  than  an  old  one,  as  is  shown  by 
Professor  iSIasou,  who  fonud  that  the  same  water,  stored  for  three  and 
a  half  months  in  contact  with  new  and  old  lead,  yielded  58.10 and  3.65 
jxirts  per  1,000,000,  respectively. 


418  WATER. 

Hot  water  is  more  corrosive  than  eold  ;  and  in  the  case  of  either,  the 
solvent  power  is  increaseil  hy  pressnre. 

The  resnlt  of  the  continnoiis  iiiuc-tion  ot"  minute  amounts  of  lead 
mav  be  /*//  or  the  production  of  more  or  less  marivcd  manifestations 
of  chronic  lead-poison ing-.  From  tlie  fact  that  lead-jiipe  is  in  very 
general,  use  for  house-mains  and  distributing-  pipes,  and  that  chronic 
lead-pt)isoning  is,  comparatively  spcjiking,  a  not  very  common  trouble, 
it  seems  reasonable  to  conclude  that  with  the  great  majority  of  persons 
the  metal  is  eliminated  with  sufficient  rapidity  to  ])revent  accumulation 
and  cumulative  action.  In  jMassachusetts,  notwithstanding  the  enor- 
mous use  of  lead  for  service-pijH's,  in  but  few  connnunities  has  there 
been  any  considerable  amount  of  lead-poisoning  reported,  and  in  all  of 
these  the  water-supply  comes  from  driven  Avells. 

Occasionally,  fatal  lead-poisoning  is  caused.  In  one  such  case, 
reported  by  V.  Schneider,'  the  water  was  very  soft  (hardness  1.40)  and 
contained  0.95  milligram  of  lead  per  liter.  After  three  months'  use 
of  the  w^ater,  a  girl  of  seventeen  died  with  all  the  characteristic  symp- 
toms of  lead-poisoning.  Analysis  of  the  organs  yielded  lead  to  the 
extent  of  7.5  milligrams  from  the  esophagus,  stomach,  and  duodenum, 
and  24.7  milligrams  from  the  kidneys,  liver,  and  spleen. 

Action  on  Iron. — Corrosion  of  iron  is  favored  by  the  presence  of 
nitrates,  nitrites,  ammonium  compounds,  mineral  and  organic  acids, 
chloride  of  magnesium,  oxygen,  and  carbon  dioxide.  The  latter  is 
especially  active,  as  has  been  shown  by  Professor  Lctt'mann  and  by  R. 
Petit.  The  latter/  investigating  the  cause  of  the  destructive  action  of 
water  rich  in  this  gas  and  poor  in  lime,  placed  a  certain  amount  of  iron 
filings  in  each  of  three  vessels,  one  of  which  contained  ordinary  water, 
the  second  contained  water  through  which  a  stream  of  carl)on  dioxide 
was  conducted  for  several  minutes,  and  the  third  was  filled  with  water 
to  which  sufficient  caustic  lime  had  been  added  to  bind  the  dissolved 
carbon  dioxide  and  to  give  an  alkaline  reaction  to  phenolphthalein.  After 
a  time,  the  iron  in  each  specimen  was  determined,  with  the  following 
results,  which  prove  the  great  influence  of  the  gas  : 

1.  3.15  milligrams  per  liter. 

2.  200.60  railigrams  per  liter. 

3.  Only  traces. 

Both  cast-iron  and  Avrought-iron  pipes  may  be  acted  upon  rapidly 
unless  their  inner  surfaces  are  covered  by  some  protective  coating,  such 
as  asphaltum,  and  even  then  at  the  joints  where  the  protecting  surface 
is  not  continuous  or  becomes  detached.  Some  surface-waters  form  a 
protective  layer  of  vegetable  matter  on  the  surface  of  the  pipe,  and  this 
is  far  more  efficient  than  artificial  applications,  and  possesses  the  addi- 
tional merit  of  imparting  no  unpleasant  taste. 

Action  on  Zinc. — On  account  of  the  action  of  water  on  ])lain  iron 
pipes,  pipes  of  galvanized  iron,  that  is,  iron  coated  within  and  without 
with  metallic  zinc,  have  been   recommended.     This  lining,  however,  is 

^  Gesundheits-lngcnieur,  Miircli  31,  1897, 
^  Comptes  rendus,  1896,  p.  1278. 


AdTioN  Oh'  \vA'ri':n  on  i.kad  asi>  otiii:il  Mi:r.\i.s.      WW 

corrvtdcd  very  easily,  cspcciiilK-  iC  llic  w.-itcr  cuiilairiH  oxyj/cti,  carhoii 
(li(».\i(le,  a.iiiiindiia,  or  nil  rates,  ami  lln'  walcr  i^  made  inill<\'  Itv  (lie 
oxide  aii<l  earboiiale  in  snspension. 

VVlielJier  or  not  I  lie  /im-  ((iniiioii  nd-  occnrriiijr  in  water  eaii  he  jtro- 
dlieXivi!  ofiiarni,  is  a  point  on  which  anthorili<'s  difler.  IJiit  at  legist  it 
llUIHt-  h(!  admit  t-ed  that  they  may  (•.•m.-c  chronic  and  ol»st  iliut<!  coilhf  ijKl- 
tioii,  even  wiien  present  only  in  small  amounts,  and  that,  /iiie  is  not  a 
eiininlative  |)oisoii.  I  )i'.  John  ( '.  'Thresh'  mentions  a  ease  o("  oh.-tina^<• 
('.()Mstipation  in  a  child,  Awv  to  the  n-c  of  drnikiii}.'--\vater  wliieh  paswd 
tliron^'h  a  hall'  mile  ol"  i;al\ani/,ed  pipe.  Iv'elieC  (olhiwed  diseontinii- 
HIKie  of  the  sn|)|)ly. 

(Jindettii"  has  re|iortcd  an  extensive  onthreak  of"  |)ois(»niii^;  attrihiit<'d 
to  water  stoi'ed  in  oalvani/ed  iron  tanks.  Of  of]  consumers,  \'-\  wen; 
attacked  w  itii  <;astro-intestinal  t  ronl)l(;H,  the  sympt^jms  presented  hcinj; 
colic,  diai'rh(ea  w  ith  eonse(pient  anaMiiia  and  emaciation,  and  a  sjiin'ions 
kind  of  dysentery.  Analysis  of  tlie  watei*  revealed  lar^c  amounts  of 
zinc. 

Analysis  of  water  drawn  from  pd\ani/,e<l  pipes  often  has  reveahd 
very  lar^c  amounts  of  /inc.  Messrs.  J.  A.  and  10.  W.  Vfxilekcr' 
reeoi-d  an  interestiuo-  ease  in  wln'ch  the  hot-water  |)ipes  of  a  house 
suj)plied  hy  water  ])iped  a.  half  mile  through  galvanized  iron,  were 
blocked  completely  by  a  de])osit  of  /inc.  The  water  was  very  pure 
and  soft,  and  contained  but  (j  grains  of  total  solids  per  gallon.  I'he 
deposit  contained  64.32  per  cent,  of  basic  carbonate  and  21.96  per 
cent,  of  oxide  of  /inc. 

Zinc  is  sometimes  a  normal  constituent  of  water.  Myelins  '  fonml 
about  CT)  grain  per  gallon  in  the  water  supply  of  Tntendorf,  and 
V\\v\  T.  Morner  ^  has  reported  the  presence  of  0.015  part  of  zinc  car- 
bonate per  1.000,000  in  the  water  of  a  well  near  Upsala.  This  well, 
which  was  about  fifteen  feet  deep,  had  been  in  use  for  more  than  a  year. 
The  water  was  sul)mitted  for  analysis  solely  on  account  of  its  jieculiar 
taste,  and  beyond  the  fact  that  it  yielded  zinc,  the  source  of  which 
could  not  be  determined,  the  results  of  the  analysis  were  very  favor- 
able. No  unpleasant  etfects  had  been  noted  among  those  who  used 
the  water.  Two  springs  in  Missouri,  according  to  Hillebrand,*  yield 
much  larger  amounts.  In  both,  the  /inc  exists  in  the  form  of  sul- 
phate. The  yield  amounts  to  120.5  and  132.4  parts  per  1,00,000, 
resjHH'tivoly. 

Action  on  Tin. — It  is  supposed  commonly  that  tin  is  unaffected 
by  water,  but  such  is  far  from  being  the  case.  Tin  is  attacked  by 
water  to  a  considerable  extent,  although  not  so  readily  as  the  other 
nietiils  mentioned  ;  but  the  compounds  formed  are,  so  far  as  we  know, 
incapable  of  causing  the  slightest  injury  to  the  system,  and  this  metal 

'  WiUor  and  Water  Su]ipHos,  London,  1896. 

-  Rrilisli  Modioal  Journal,  Sept.  7,  1901. 

=*  Tlie  Analvst,  Julv,  1890. 

*  Ibidem,  iV.,  p.  ol. 

■■'  I'psala  Liikaretorenincfs  Forliandlinsrar,  189S,  Vol.  Ill, 

•^  United  States  Geologieal  Survey,  Bulletin  No.  13. 


420  WATER. 

is  recommended  highly  as  a  lining  for  iron  pipes.     Its  cost  alone  pre- 
vents it  from  supplanting;  lead  for  house-mains  and  distributing;  ])ipes. 

Water  and  Disease. 

The  use  of  impure  water  for  drinking  and  other  domestic  purposes 
may  be  a  direct  cause  of  disease,  and  such  water  is  supposed  also  to 
act  upon  the  system  in  such  a  Avay  as  to  lower  the  resistance  of  tiie 
body  to  the  action  of  infectious  matters ;  but  it  should  be  borne  in 
mind  that  the  nature  of  the  })olluting  material  is  of  far  greater  impor- 
tance than  its  mere  amount.  To  maintain  that  water  containing  any 
considerable  amount  of  organic  matter,  regardless  of  its  (character  and 
source,  will  tend  inevitably  to  produce  a  general  imjiairnient  of  health, 
is  as  great  an  error  as  to  underrate  the  danger  possible  to  arise  from  a 
small  amount  of  specific  contamination.  It  is  quite  as  improbable,  for 
instance,  that  the  amount  of  dissolved  vegetable  matter  necessary  to 
yield  albuminoid  ammonia  in  what  may  be  designated  "considerable" 
amount  can  do  any  great  injury,  even  when  constantly  ingested,  as  that 
an  infusion  of  tea,  which,  by  the  same  process  of  analysis,  would  yield 
results  which  would  be  startling  in  comparison,  could  of  itself  conduce 
to  the  development  of  an  infectious  disease. 

Alarmists  may  reject  as  unsuitable  for  household  purposes  a  water 
containing  an  amount  of  vegetable  matter  sufficient  to  give  a  yellow- 
brown  color,  and  accept  as  sufficiently  pure  another  containing  less 
organic  matter  and  less  mineral  matter,  but  with  it  the  micro-organisms 
of  infectious  disease.  They  go  to  the  extreme  of  saying  that  organic 
matter  in  solution  must  "  lo^ver  the  tone,"  and  should,  therefore,  be 
avoided,  and  if  asked  why  this  is  so,  fall  back  on  "  general  principles  " 
and  "common  sense,"  upon  which  so  much  illogical,  unexplainable 
theory  is  based.  As  a  matter  of  fact,  we  kno^v  that  water  which  is  in 
a  sense  impure,  but  not  specifically  polluted,  may  be  used  year  in  and 
year  out  without  injury.  We  know,  farther,  that  water  containing 
much  less  organic  matter,  but  infected  with  bacteria  of  certain  kinds,  is 
likely  to  cause  disease  in  at  least  a  proportion  of  those  who  use  it  once, 
occasionally,  or  habitually.  We  know  also  that  a  water  once  specific- 
ally polluted  may,  under  similar  conditions,  Ije  polluted  again,  and  in 
the  interval  may  be  of  good  quality. 

We  know  that  water  containing'  large  amounts  of  dissolved  vegc- 
table  matter  in  process  of  decomposition  or  of  a  definitely  poisonous 
character  may  produce  disturbances  of  a  very  serious  nature ;  tliat  an 
abundance  of  minute  water  plants,  as  algie,  and  animal  organisms,  as 
infusoria,  may  produce  ill  effects ;  that  decomposing  animal  matters 
sometimes  yield  toxic  substances  of  great  potency,  and  that  excessive 
mineral  matter  in  suspension  or  solution  is  not  without  its  deleterious 
effects. 

Therefore,  it  may  be  laid  down  as  a  general  rule,  regardless  of  the 
fact  that  all  impurities  do  not  necessarily  breed  disease  or  undermine 
the  health,  that  all    water   containing   or   likely  to   contain   domestic 


WATI'.n    AND    I) IS/: ASK  ■        421 

H('w;i|i;'c,  .'ihiiiidiitii  ^rovvllis  of  miniili'  \cjsi'ii\\>\i'  .'iri<l  ;iniiii;il  or^ranihiiiK, 
(l('(;(»rii|)osiiii;'  iii:iilcr  «»("  ;iiiiiii;il  orii^iii,  dissoKc*!  vcji-cl.'ihlc  tii;il(«'i'  of  an 
ilili(!i"('iil  ly  loxic  nnliirc  or  niMld'joiii^-  (|cciiiii|)().-i(if)ii,  or  cxcAtHHive 
jiiiioiiiils  (•("  iiiiiK'i'iil  iri;illcr,  slioiiM  iiol  \h-  ;i(((  |)t((|  ;i,s  (it  I'ur  iiutiian 
(i()iisiiin|»(  ion.  h]s|)C(riiilIy  slioiiM  \\<-  \u-.n-  in  mind  lli;il  polluted  waler 
vviiicli  is  (jiiilc  {'vcc  (Voiii  discMsc  or^iinisuis  ;ind  tox  ic  iiiatt<;rH  t<Mlay 
in;iy  conliiiM  (licni  in  iihniidiincc  Io-mkhtow. 

Disorders  Connected  with  Mineral  Matter. —  It  is  n<.ii<<(l  very 

<M>niMi<)nly  liiai  when  one  ciiim^cs  suddenly  f'loni  the  ii.-c  of  a  Hr»ft 
water  to  anotlier  (li;i(,  is  <|iiit(!  iiiii'd,  tiiei'e  I'dIIou-  ;i  |(  iii|i.,rary  distnrh- 
aiK'CM)!'  tJie  ("mietioMs  of  llic  di<;cstivc  a|)|);ii;iliis.  'I  lie  iMf)st  marked 
olTcHit  is  iisiialiy  eoiislipatioii  vvitli  oeensional  di;iiTlio;i.  Loss  of"  ;i|»|k-- 
tit(;  a,n<l  Klif>'li(,  iiansea  are  not.  nneonnnon.  Tlie  eU'ects  are  dne  to  the 
infliienee  ol'  the  salts  (lansinj;'  |)ernianeM(  hardness,  (hanj^e  iVftrii  hard 
to  sol't,  water  is  (jiiito  as  likely  to  cause  iinaeeeiistoined  lo(»seness  of"  the 
bowels  from  the  withdrawal  ol"  this  inflneiiee  on  the  intestinal  .scere- 
tions.  Just  how  imieh  of  any  one  of  thes(!  salts  may  l»e  s;Hd  to  he  dis- 
tiiietly  injurious  to  health  is  a  matter  of  doubt,  but  commonly  from  10 
to  15  ])arts  in  1()(),()00  of  water  are  regarded  as  undesirable.  Jt  lias 
been  asserted  that  tlu>  use  of  hard  water  is  one  of"  tlu,"  chief"  causes  of 
stone  in  the  bladder,  but  such  a  connection  is  extremely  improbable. 
How  the  use  of  ciirbouate  and  sulphate  of  calcium  can  brin^  about  a 
deposit  of  uric  acid,  or  of  oxalate  of  calcium,  or  of  |)liosphates  in  the 
bladder,  can  hardly  be  explained.  The  fact  also  that  stone  is  very 
common  in  some  districts  where  water  is  soft,  and  rare  in  some  others 
where  it  is  hard,  suggests  that  the  cause  is  to  be  looked  for  ratlier  in 
the  individual  himself — his  food,  bis  metabolism,  his  liabits  of  life, 
and,  perhai)s,  hereditary  predis]iosition. 

Suspended  mineral  matter,  as  clay  and  marl,  will  often  cause  diar- 
rluea  in  persons  not  habituated  to  its  ingestion,  and  not  infrequently  in 
those  who  are. 

The  disease  most  commonly  connected  with  mineral  matters  in  water 
is  goitre.  That  this  disease  may  be  produced  by  drinking-water,  can 
hardly  be  doubted,  for  it  is  a  well-known  fact  that  in  Switzerland  and 
France,  for  instance,  there  are  wells  which  yield  waters  which  are  used 
successfully  for  the  intentional  production  of  the  disease,  with  the  view 
to  escape  compulsory  niilitary  service.  The  enlargement  is  not  neces- 
sarily a  permanent  disfigurement ;  disuse  of  the  Mater  may  be  followed 
by  disappearance  of  the  swelling,  but  oftentimes  the  disease  thus  inten- 
tionally acquired  persists. 

The  exciting  cause  has  been  attributed  to  the  presence  or  absence  of 
certain  mineral  substances,  but  the  wide  variety  of  the  sujiposeil  agents 
is,  of  itself,  strong  evidence  of  the  pom*  foundation  upon  which  the 
mineral  matter  theory  rests.  It  is  noticed,  for  instance,  that  in  some 
districts  where  the  disease  is  especially  prevalent,  the  soil  is  largely 
magnesian  limestone,  and  that,  as  might  be  supposed,  the  ground-water 
is  rich  in  lime  and  magnesium  salts.  Therefore,  it  is  reasoned,  mag- 
nesian limestone  must  be  the  cause  :  but  there  are  manv  such  districts 


422  WATER. 

where  goitre  is  unknown.  j\Ioro  than  that,  tlie  disease  is  endemic  in 
some  quarters  wliere  the  water  is  suit  and  ahnost  free  from  lime  and 
magnesium  salts.  Again,  it  lias  been  attributed  to  the  presence  of  cer- 
tain salts  of  iron,  but  this  theory  also  cannot  bear  the  test,  for  these 
may  be  present  where  no  goitre  is  seen,  and  may  be  absent  where  the 
disease  prevails.  Absence  of  iodine  is  another  explanation  based  on 
nothing  worthy  of  credence. 

The  most  probable  cause  is  now  believed  by  some  to  be  an  organism 
Avhich  flourishes  in  the  water.  The  tirst  to  promulgate  this  theory 
were  Italian  observers,  who,  in  1890,  reported  facts  of  interest  bearing 
on  the  question,  since  wiiich  time,  other  observers,  particularly  in  India, 
have  contributed  farther  evidence  of  its  probable  truth. 

The  most  striking  facts  have  been  presented  by  Surgeon-Lieutenant 
E.  E.  Walters,^  whose  observations  were  pursued  in  a  district  in  India 
2,000  feet  above  sea-level,  with  extremely  porous  soil  and  a  water  sup- 
ply containing  but  slight  amounts  of  organic  and  mineral  matter,  and 
but  minute  traces  of  iron.  The  inhabitants,  who  live  under  the  same 
climatic  conditions,  but  with  diifereut  occupations,  may  be  divided 
into  two  classes  :  the  native  Bhutias  and  the  Sepoy  troops  from  the 
northwest  provinces.  The  former  are  carriers  and  coolies ;  they  are 
omnivorous,  but,  by  reason  of  poverty,  mostly  vegetarians.  Their 
chief  diseases  are  goitre,  syphilis,  and  malaria.  The  temporary  inhab- 
itants, the  Sepoys,  are  all  vegetarians,  and  are  a  healthy  lot,  practically 
free  from  syphilis,  and  living  under  excellent  hygienic  conditions.  They 
had  been  in  the  district  twenty  months.  Examination  of  169  Bhutias 
showed  that  more  than  75  per  cent,  had  goitre ;  nearly  70  per  cent,  of 
those  over  twelve  years  of  age  were  afflicted.  Of  380  Sepoys  examined, 
54  per  cent,  had  goitre.  The  Bhutias  say  that  their  goitres  increase 
during  the  rainy  season,  and  this  is  borne  out  by  the  out-patient  register 
and  regimental  admission  book  for  1895.  All  the  British  officers,  too, 
had  suffered  from  enlarged  thyroids  during  the  preceding  rainy  season. 
Their  drinking-water  was  passed  through  a  Pasteur  filter;  all  other 
water  used  was  taken  as  tea  or  soda.  Taking  up  the  several  conditions 
which  have  been  alleged  as  the  cause  of  the  process,  he  shows  them 
to  be  not  at  fault  in  this  particular  district.  Iron  was  present  in  the 
water  in  only  minute  quantities,  and  the  highest  degree  of  permanent 
hardness  was  but  3.5.  As  to  lime  as  a  cause,  it  appears  that  many  of 
the  Bhutias  without  goitres  are  great  eaters  of  lime,  while  of  the  Sepoys, 
who  never  touch  it,  more  than  50  per  cent,  developed  goitres  within 
twenty  months  after  arrival.  The  theory  that  the  disease  is  due  to 
carrying  heavy  loads  up  and  down  hills,  might  satisfy  in  the  case  of 
the  Bhutias,  but  not  in  that  of  the  Sepoys,  who,  though  not  carriers, 
yet  have  goitre.  Farther,  as  to  age,  it  appears  that  55  per  cent,  of 
the  children  under  twelve  had  no  goitres  after  living  there  all  their 
lives,  or  about  the  same  percentage  as  developed  them  among  the  Sepoys 
after  a  visit  of  only  twenty  months.  He  believes  the  disease  to  be  due 
to  an  organism  of  the  amoeba  type,  with  a  selective  power  against  the 
^  British  Medical  Journal,  September  11,  1897. 


WATEli   AND    I  US  HASH.  423 

tliyi'oid  or  its  Hocrcl-ioii.  I'\)i'  ;i  linic  llir  -y-l<'iri  ()|i|)OS(!H  it,  utirl  Homc- 
iiliutH  ,sii(',<H!Hsflllly  ;  l)ill  wIkii  llir  <;iii-<'  ()\  (iixiw  cr-  flic  [)li;i{;«K'Vt'u; 
r(!H()iir(!{!S  of  (Ik;  syst<!iii,  lln'  llixioid  (•iilii-;j(-  in  the  cll'dit  t<i  coiiilmt 
tlic  poison.  IIihIci-  (liyioid  Iccdiii;^  (Iwo  U-\i\;[\\\  (aldoid-  dailvj  tlic 
records  show  ;t  \ve<'l<lv  diiniinit  ion  of  ;i  (|n;ir(er  lo  \\:\\\'  ;in  inch  in  tlic 
circund'erence  of  (he  S<'|io\s'  necks,  Wul  when  i  he  ire;ilnien(  (icawfH, 
tliu  ^'liind  ;i,!i,';un  incrciiscs  in  size.  '\\\:\\  \>  (<»  >;\\ ,  ;iildi(ion;d  rcKistitifr 
power  is  conCerred  by  (liyi'oid  tiil)l(»ids,  wliicli  kcc])  the  poi-on  in  <-licck 
juid  niiow  (lic^liind  (o  recrovcr  i(s  normal  si/e  ;  hnf  on  u  ididraw  in^ 
tlio  accessory  a'4(ii(,  (here;  is  dinunished  i'esis(ane(;  and  (lien  aj^ain  an 
increase  in  si/c. 

Disorders  Connected  with  Organic  Pollution. — Ordinary  ve^e- 
tabh;  niaitcr  in  suspension  and  al)nndan(  erow  i lis  o("  al^a;  and  oilier 
water  plants  sometimes  (unise  diarriio'al  (i'onl)lcs,  hut  tlicy  d')  not  eau.«e 
Hpeeilie  disease.  Pc^aty  matters  in  solution  ha\'e  now  and  then  aj)peare(l 
to  be  connected  wi(h  in(es(inal  deraiitrcnieiit,  hut  we  have  no  al)Sf)lute 
knowledge  that  they  actually  lia\'e  heen  or  can  he  a  caux;  of  such 
trouble. 

We  know  three;  epidemic  diseases  w  liieli  \\q  may  say  witli  certainty 
can  he  earried  by  water.  These  are  :  cholera,  typhoid  fever,  and 
dysentery,  hut  it  is  said  commonly  that  water  is  a  great  factor  in  the 
spread  of  di})litheria,  yellow  fever,  and  malaria.  In  the  case  of  dij)h- 
theria,  the  weiidit  of  evidenee  is  certainly  against  its  being  a  water-horne 
disease.  There  is  some  evidenee  of  its  spread  through  the  use  of  a 
common  water  supply,  hut  in  these  cases  there  is  usually  a  common 
drinking  vessel,  and  probably  a  preexisting  case  of  the  disease  among 
the  drinkers.  The  diphtheria  organism  cannot  long  survive  in  water 
which  is  jiot  very  extensively  polluted. 

As  to  yellow  fever,  there  is  no  evidence  whatever  of  value,  but  in 
the  older  literature  of  hygiene  many  outbreaks  attributed  to  polluted 
water  are  recorded.  In  the  light  of  our  present  knowledge,  these 
instanees  have,  naturally,  no  staTuling,  but  in  justiee  to  those  Avho 
recorded  them  it  must  be  said  that,  before  the  discovery  that  the  disease 
was  mosquito-borne,  the  evidence  presented  seemed  to  be  uncontro- 
vertible. For  example,  outbreaks  occurring  at  sea  aboard  ships  that 
recently  had  been  in  infected  ports,  where  the  water-casks  had  been 
reii lied,  could  not  be  attributed  to  telluric  influences,  and  the  rejtlenished 
water-supply  offered  the  only  explanation. 

As  with  yellow  fever,  so  with  malaria,  abundant  evidence  of  con- 
nection with  water  as  a  cause  has  been  recorded,  although  the  fact  has 
long  been  known  that  water  from  malarial  districts  may  be  used  by 
communities  at  a  distance  witliout  harm,  as  is  the  case  with  the  city  of 
Rome. 

One  of  the  best  cases  which  have  been  accepted  as  proof  of  trans- 
mission by  water  is  that  reported  by  Laveran,  who  failed,  however,  to 
furnish  certain  facts  which  (nir  present  knowledge  Mould  require.  A 
detachment  of  soldiers  drank  at  a  certain  well,  and  then  enjoyed  a 
hearty  meal ;  another  detachment  ate  flrst,  and  later  drank  from  the 
same  well.     Of  the  former,  all  beairae  sick  with  malaria  ;  of  the  latter, 


424  WATER. 

not  one  was  affected.  The  ditferenoe  in  the  results  was  thouo;lit  to  be 
due  to  the  fact  that  those  who  escaped  took  no  water  until  the  o;astric 
juice  was  secreted  in  the  process  of  dioestiou.  C^uite  a  number  of 
cases  are  recorded  in  which  men  on  shipboard  have  used  the  water  of 
certain  casks  which  others  had  declined,  the  former  becoming  sick  with 
malaria,  and  the  latter  escaping. 

There  is  evidence  that  certain  animal  diseases  may  be  spread  by 
water  containing  the  specific  organism.  Hog  cholera  and  anthrax 
have  certainly  been  spread  by  water  into  which  the  bodies  of  those  that 
had  died  of  these  diseases  had  been  thrown,  and  glanders  may  be 
spread  from  horse  to  horse  by  the  use  of  a  common  drinking  trough. 

The  diseases  of  greatest  interest  in  connection  with  drinking-water 
are  two  which  we  know  can  be  spread  by  infected  water — cholera 
and  typhoid  fever.  The  first-mentioned  happens,  with  us,  to  be  one  of 
minor  interest,  inasmuch  as  it  is  a  most  uncommon  visitor ;  the  other, 
however,  is  always  with  us,  and  we  have,  therefore,  constant  oppor- 
tunity for  observation  of  the  influence  of  polluted  water  in  its  causa- 
tion. 

The  strongest  proof  of  the  value  and  efficiency  of  the  purification  of 
water  by  filtration  through  sand  is  the  drop  which  occurs  in  the  mor- 
tality from  typhoid  fever  when  a  community  abandons  the  use  of  un- 
treated polluted  water,  and  adopts  this  method  of  improving  the  quality 
without  changing  the  source  of  supply.  The  city  of  Lawrence,  Mass- 
achusetts, for  example,  prior  to  and  including  part  of  the  year  1893, 
used  the  unfiltered  water  of  the  Merrimac  E,iver,  into  which  is  poured 
the  sewage  of  a  succession  of  large  cities  and  towns  having  an  aggre- 
gate population  of  several  hundred  thousands.  In  the  year  mentioned, 
the  process  of  filtration  was  adopted,  and  good  results  were  almost 
immediately  evident.  Following  are  the  death-rates  from  typhoid  fever 
per  10,000  of  population  for  the  four  years  immediately  preceding  and 
for  the  same  period  following  the  change  : 


Preceding  change.  Year  of  change.  Following  change 


1894  .    .    .4.7 

1895  .    .    .3.1 

1896  ...  1.9 

1897  ...  1.6 


It  is  but  fair  to  add  that  about  half  the  deaths  from  the  disease  in 
1894  and  1895  were  of  persons  who  persisted  in  drinking  unfiltered 
water  directly  from  the  canals. 

The  city  of  Hamburg  adopted  filtration  in  May,  1893,  after  a  most 
devastating  epidemic  of  cholera  in  the  preceding  year.  Typhoid  fever 
had  always  claimed  a  very  large  number  of  victims  annually,  and  dur- 
ing the  four  years  1890-1893,  the  death-rate  from  the  disease  was  2.6 
per  10,000  ;  but  in  the  next  two  (1894-1895),  it  fell  to  0.75. 


1889  . 

.  12.7 

1890  . 

.  13.4 

1891  . 

.  11.9 

1892  . 

.  10.5 

WAT/':/:  AN/>  /)IS/':asI':.  426 

'V\\o.  cxpcricMcf"  of"  I 'liil;i(l<'l|)lii;i.  williiii  (vf.ciif,  year-!  fiiriiiHliCH  a  nio.st 
iiisi.riic,(,iv(;  (rxiiiiiplc  ol  tlu;  (laiiLr<'i'  ol  iisiiit^  polliilcd  w;it;<;r.  ])iiririg 
tli(!  first  six  rnoiillis  of"  fJi(!  yiVAV  1H!)I),  in  ;i  |)<i|)iilal,I<»Ji  of  ov^t  ;i  million, 
7038  ciiscH  of  (yplioid  fovcr,  wit.li  800  (Icatli.s,  wen;  rcroivlcd.  [)iiiiii^ 
the  first  five;  \V(!('ks  of  1002,  510  cases  of^ciirrcd,  willi  )!»  <l<atli.s. 
JJotwceii  .laiiiiary  1  and  April  II,  II>01,  in  a  jiopMlalion  of  .ahoiit 
1,300,000,  tli(!r(!  o(;cMi'r(!d  nearly  2500  (;as(;s  ;  and  of"  tliesr-,  no  fi-wer 
than  38!)  won!  n^ported  in  a  single  w<;(!k,  tins  niirnhctr  beinj^  tlie  lar^a^st 
ever  roporfod  in  any  W(!ek  in  tlio  iiisfory  of  IIk;  eify.  In  that  [»art  of 
the  city  to  wlii(!li  the  new  sn[)j)ly  of  filtered  vvalor  w.'is  f"nrnished,  tluTe 
was  an  almost  immediate  fall  in  tlu;  typhoid  rale,  the  immediate  nrnj^h- 
borhood  not  so  snppiied  eonfimiin<r  to  mainl^iin  a  mneli  higher  rate. 

Typhoid  Infection  of  Water  Supplies. — Tyithoid  infection  of  a 
water  supply  may  be  dii-ec^t  or  indirect.  1  )ir(  ct  inf"ection  occurs  throufrli 
the  eutranc(>  of  ordinary  sewa<;<'  containing  the  essential  organism,  or 
of  feces  or  mine  discharu;ed  alon^  tht;  hanks  of"  a  river  or  lake,  for 
example,  by  persons  sulTei-iiiL!;  with  or  convalescent  from  the  disea.«e. 
Indirect  infection  occui's  from  discharfi;cs  deposited  in  or  upon  the  soil, 
and  thence  washed  by  rain  into  bodies  of  water  or  down  w  a  id  intowell.s. 
Ordinary  sewa<>;e  ])ollution  is  not  sufiieient  to  brinjr  about  an  outbreak 
of  the  disease,  nor  will  sjiecific  ])ollution  necessarily  always  be  f"olh>we<l 
by  the  occurrence  of  cases.  The  sjK'cific  or<i:;anism  has  only  a  limited 
tenure  of  life,  and,  in  the  absence  of  conditions  favorable  to  its  exist- 
ence, it  may  perish  before  it  reaches  tlu^  consumer.  IVforeover,  the 
number  present  may  be  very  small  and  the  effects  produced  so  slight 
as  to  occasion  little  notice.  It  is  to  be  borne  in  mind  that  not  every 
mouthful  of  a  polluted  su])ply  contains  the  orn;anism,  and  that  not 
every  person  to  whose  system  it  gains  access  must  necessarily  come 
down  with  the  disease. 

Until  quite  recently,  it  has  been  supposed  tiiat  tlie  infecting  organ- 
isms had  their  origin  only  in  the  freces  of  preexisting  cases;  but  it  is 
now  known  that  this  is  far  from  being  the  case,  and  that  they  exist  in 
the  fixx'al  discharges  during  only  tlie  early  stages  of  the  disease,  or  up 
to  the  twentieth  day  or,  perhaps,  even  somewhat  later.  Petru.schky ' 
has  shown  that  the  urine  may  contain  millions  of  living  bacilli  in  each 
cubic  centimeter,  and  that  they  may  be  found  for  many  weeks,  and  even 
after  convalescence  is  well  established.  They  may  appear  as  early  a.s 
the  fifteenth  day,  when,  perhaps,  they  are  no  longer  demonstrable  in  the 
faeces.  Dr.  Mark  W.  Richardson  ^  found  them  in  very  large  numbers 
and  in  practically  pure  culture  in  the  urine  of  nine  out  of  thirty-eight 
patients.  They  appeared  late  in  the  ciHU'se  of  the  disease,  and  continued 
to  be  eliminated  in  several  of  the  cases  after  discharge  from  the  hos- 
pital. These  observations  of  Petruschky  and  Richardson  have  been 
confirmed  by  other  bacteriologists.  It  appears,  then,  that  an  apparently 
well  ]ierson  is  capable  of  infecting  a  water  supply  to  a  greater  extent 
and  with  less  optical  evidence,  or  none  at  all,  by  a  discharge  of  urine 

'  Centralblatt  fiir  Bakteriologie  und  Parasitenkunde,  1S9S,  XXIII.,  Xo.  14. 
*  .Tounial  of  Experimental  Medicine,  Maj',  189S. 


426  WATER 

into  a  water  course  tlimi  an  evidently  siek  one  by  a  deposit  of  his  faeces 
into  it  or  upon  its  hanks. 

Whatever  the  mode  of  infection  of  apnblie  water  supply,  the  results, 
if  any,  are  seen  in  an  increase  in  the  number  of  cases  ordinarily  occur- 
ring in  the  eonununity  su|)])lied,  and,  except  in  those  instances  vhere 
the  disease  is  spread  by  infected  shell Hsh  or  other  foods,  any  considerable 
augmentation  of  cases  points  unmistakably  to  the  consumption  of  pol- 
lutwl  water,  even  though  the  system  of  filtration  is  followed.  In  the 
latter  instance,  investigation  almost  certainly  will  show  some  defect  in 
the  filters,  or  that  their  capacity  has  been  overtaxed.  Even  after  sub- 
sidence of  the  outbreak,  the  disease  may  continue  to  be  more  prevalent 
than  usual  for  some  little  time,  especially  in  the  absence  of  a  proper 
system  of  sewerage. 

Influence  of  Introduction  of  Public  Water  Supplies  on  Typhoid 
Rates. — Contrary  to  what  might  be  expected,  the  highest  death-rates 
from  typhoid  fever  in  thickly  settled  countries  are,  generally  speaking, 
uot  in  the  crowded  cities,  but  in  the  towns  which  have  no  public  water 
supplies.  In  Massachusetts,  for  example,  the  5  towns  highest  in  this 
respect  had,  during  the  eighteen  years  prior  to  1890,  an  average  typhoid 
death-rate  of  12.82  per  10,000  of  population,  while  the  average  of  the 
five  highest  rates  for  cities  with  public  supplies  was  but  7.65,  and  of 
all  the  cities  of.  the  Commonwealth  only  4.62.  In  the  town  with  the 
highest  mortality,  Ware,  the  average  for  fifteen  years  prior  to  1866 
was  16.0  in  10,000;  in  that  year  a  public  supply  was  introduced, 
and  at  the  expiration  of  four  years  the  mortality  had  diminished  60 
per  cent. 

In  1870,  only  20  cities  and  towns  in  Massachusetts  had  modern 
public  supplies;  at  the  end  of  1896,  all  of  the  32  cities  and  127  of 
the  322  towns,  comprising  89.8  per  cent,  of  the  entire  population,  were 
thus  pro  voided,  and  but  3  towns  with  populations  exceeding  3500  had 
none;  at  the  end  of  1904,  but  8  per  cent,  of  the  entire  population  of 
2,805,000  were  without  public  supplies,  and  this  was  made  up  very 
largely  of  the  very  small  towns  with  scattered  inhabitants,  where  the 
introduction  of  public  works  would  be  beyond  the  financial  possibilities. 
As  a  result  of  this  very  general  introduction  of  a  common  supply  in 
place  of  that  derived  from  individual  wells,  largely  of  the  open  variety 
and  situated  in  close  proximity  to  sources  of  pollution,  a  decided 
decline  in  typhoid  fever  has  been  noticed.  This  result  is  by  no  means 
peculiar  to  IVIassachu setts,  but  is  found  to  be  the  consequence  wherever 
the  selection  of  the  source  is  made  with  judicious  care  and  measures 
are  taken  to  protect  it  from  avoidable  pollution.  It  is  uot  to  be  sup- 
posed, however,  that  the  mere  introduction  of  a  common  supply 
without  the  observance  of  this  necessary  precaution  will  best  serve 
the  interests  of  the  public  health.  In  the  following  table,  compiled  by 
Mr.  Hiram  F.  Mills,'  is  shown  the  change  in  the  typhoid  death-rates 
per  10,000  in  each  of  the  cities  of  Massachusetts  which  introduced 
water  within  the  years  1869  to  1877  : 

1  22(1  Annual  Report  of  the  State  Board  of  Health  of  Massachuaetts,  1890,  p.  534. 


WA'J'/':n   AND    hISKASE. 


A21 


ClliaH 


llol.yokc!      .     , 
Ij!ivvr(iiice    . 

|j(>VV('ll      .     . 

l*';ill  Ivivcr 
Spriiii^licld 

'^riiiiiiioii    .  , 

N(>rlli!iiiii)l,on 
IjyiMi  .    .    .    . 
New  I'ciK'nnl 
Ncwtoii   .    . 
Mal(lci)   .    .    . 
l<^itc'lilnirjj;  . 
Woliiini  .    .    . 
Soriici'villc 
Clii'lsca  .    .    . 
WiilUiiun    .    . 


Yonrly  niiiiilmr 
of'(l<!iil.liH  fnirii 
lyplidlit  fovi.T 
per  1(1,0(10,  IH/li) 
to  IK(i8. 


YOHrly   rniiii>>(:r  fXjatliN  In 

r>nt<!  of  Intro-     of  itcuili*  rroiii  iu:f>iu<\  \>i-rUA 

(Jiictionof          ty|iliol(l  fcv(;r  |M;r  Imtnlri'd 

wiiU-r  NUpply.      \h:t  IO,(HKi   IH7m  of  lli'/«<-  in 

to  \m).  ftrnl. 


1873 

1H75 
IH72 
1.S74 

isyr, 
is7(; 

1.S7I 
I.S71 

1  si;'.) 
IS70 
1.S70 
1H7'2 
1 H7.", 
lKfi7 
1807 
1873 


8.93 
8.33 
7.(53 
0.32 
.'i.2!> 
r..r)2 
4.04 

:i.87 

."..KO 

'.',M 
3.  If) 

2.9r, 

2.95 
2.89 
2.42 


133 
1(K) 
124 
81 
65 
82 
37 
43 
49 
56 
44 
30 
3»} 
«9 
48 
30 


It  will  be  noiiccd  ||i;i(  oC  (licsc  sixlccii  cities  llicrc  were  three  whieli 
showed  no  iniproveineiit,  and  two  of  these  wore  worse  (iff  than  before. 
The  reason  for  tliis  is  clear.  All  three  arc  niannfacturing  cities, 
sitnated  on  rivers  ])olhiled  by  sowau;e.  At  Holyoke,  while  the  public 
supply  is  but  .slightly  liable  to  eontaniination,  the  operatives  in  the  fac- 
tories used  water  from  two  other  sources,  subject  to  gross  pollution  ; 
namely,  from  the  canals,  the  entrance  of  one  of  which  is  sitnated  close 
to  the  outlet  of  one  of  the  main  sewers  of  the  city,  and  from  wells 
indirectly  supplied  by  the  canals.  Comparison  of  the  death-rates  from 
typhoid  fever  among  those  of  different  occupations,  brought  out  the 
fact  that  the  operatives  in  the  mills  which  used  canal  water  suffered 
from  the  disease  three  times  as  much  ]iro  rata  as  all  other  jiersons. 
Lowell  and  Lawrence,  at  the  time  mentioned,  were  using  the  pollutwl 
water  of  the  Merrimac  River.  Lowell  took  its  supply  fourteen  miles 
below  the  point  of  entrance  of  the  sewage  of  Nashua,  N.  H.,  and  con- 
sumed it  without  treatment.  Ijawrenee  drew  upon  the  same  supply, 
after  its  enrichment  by  the  sewage  of  Lowell,  at  a  point  but  nine  miles 
below  the  outfall  of  the  latter's  sewage.  In  ISUl,  Lowell  sutiered 
unusually  from  typhoid  fever  by  reason  of  the  additional  contamina- 
tion by  feces  of  typhoid  patients  discharged  into  Stony  Brook,  a  small 
tributary  of  the  jNlerrimac,  only  three  miles  above  the  intake  of  the 
water-works. 

The  conditions  of  all  three  ])laces  have  since  been  changed.  At 
Holyoke,  warnings  were  posted  for  the  benefit  of  the  operatives ; 
Lowell  abandoned  the  river  in  favor  of  ground-water  in  LS9o,  and  in 
the  same  year  Lawrence  instituted  filtration.  In  all  of  the  three  cities 
the  expected  happened  ;  namely,  a  marked  diminution  in  the  death-rate. 

Examination  of  the  above  table  reveals  the  fact  that  in  the  majority 
of  the  sixteen  cities  the  reduction  in  the  typhoid  death-rate  was  most 
pronounced.  In  some  of  them,  the  diminution  has  proceedini  to  a 
much  greater  extent  than  is  shown  here.     In  180G,  three  cities  with  aa 


428 


WATER. 


aggregate  population  of  70,000  showed  less  than  1  death  per  10,000 
from  this  disease,  and  in  one  of  them,  Wi»burn,  there  was  none  at  all. 

That  the  favorable  effects  produced  hv  iiltration  of  water  sup])lies 
have  not  been  confined  to  tlie  decreased  incidence  of  tv])li<)id  fever  is 
shown  by  the  following  fact:  In  1893  it  was  noticed,  independently, 
by  Hiram  F.  Mills,  C.  E.,  of  the  State  Board  of  Health  of  Massa- 
chusetts, and- Dr.  J.  J.  Reincke,  of  Hamburg,  Germany,  that  not  only 
was  there  a  marked  decrease  in  the  incidence  of  tyi>hoid  fever  subse- 
quent to  the  installation  of  filtration  ])lants,  but  that  the  general  death- 
rate  also  suffered  an  equal  or  larger  decrease.  As  a  factor  in  this  de- 
crease in  the  general  death-rate  the  mortality  of  children  under  one 
year  of  age  undoubtedly  plays  a  considerable  ])art,  as  will  be  seen  by 
the  following  table,  taken  from  one  of  Dr.  Reincke's  annual  reports 
and  referred  to  by  Sedgwick  and  MacNutt.^ 

The  following  table  shows  the  deaths  of  infants  under  one  year  of 
age  in  Hamburg  from  gastro-intestinal  diseases  : 


Preceding 

change. 

Year  of  change. 

Following  change. 

1884. 

.  .  1143 

1889  .  . 

.  1557 

1893. 

.  857 

1894  . 

.  708 

1885  . 

.  .  1159 

1890  .  . 

.  1198 

1895  . 

.  918 

1886  . 

.  .  1601 

1891  .  . 

.  1500 

1896  . 

.  767 

1887  . 

.  .  1758 

1892  .  . 

.  2541 

1888  . 

.  .  1063 

In  1904  this  decrease  in  the  general  mortality,  due  to  the  purifica- 
tion of  public  water  supplies,  was  defined  numerically  by  Hazen  in  the 
following  statement,  which  has  come  to  be  known  as  Hazen's  Theorem  : 

"  When  one  death  from  typhoid  fever  has  been  avoided  by  the  use 
of  better  water,  a  certain  number  of  deaths,  probably  two  or  three, 
from  other  causes  have  been  avoided." 

Sedgwick  and  MacNutt,  as  a  result  of  further  investigation  of  this 
subject,  came  to  the  conclusion  that  Hazen's  estimate  of  the  decrease 
in  the  general  mortality  has  been,  if  anything,  too  conservative.  In 
fact,  the  improvements  noted  at  Lawrence,  Mass.,  and  Lowell,  Mass., 
seemed  to  indicate  that  in  the  former  city  4.4  deaths  and  in  the  latter 
city  6  deaths  were  avoided  from  causes  other  than  typhoid  fever,  where 
1  death  from  typhoid  fever  had  been  avoided  by  the  substitution  of  a 
pure  for  a  polluted  water  supply. 

The  following  tables,  taken  from  the  article  by  Sedgwick  and 
MacNutt,  show  graphically  the  effect  of  this  substitution,  both  upon 
the  typhoid  fever  death-rate  and  upon  the  total  death-rate,  minus  the 
typhoid  component,  for  the  cities  of  Lawrence  and  Lowell,  Mass.  It 
will  be  noted  that  the  unused  portions  of  the  scale  below  each  curve 
have  been  cut  off,  so  that  no  base  lines  are  shown  : 

^  On  the  Mills-Reincke  Phenomenon  and  Hazen's  Theorem  concernins;  the  decrease 
in  mortality  from  diseases  othei'  than  tyjihoid  fever,  following  the  purification  of  public 
water  supplies.     Journal  of  Infectious  iJi.seases,  Aug.,  1910. 


WA'I'h'n    DISK  ASK. 

Vut.  .",7. 
DEATH  RATES-LAWRENCE,  MASS. 


420 


cc     •*      in     «D 


^     ^yt     '.t      -r 


Fio.  :-;s. 

DEATH   RATES-LOWELL,   MASS. 


1 

\m 

1 

TYPHOID  FEVER 

\ 

/ 

100 

\ 

/ 



X 

-AU-« 

I 

^ 

J~^ 

<— 

< 

k:=|— 3 

1-^ 

~\ 

T^"^ 

f 

*»-4— 

60 

1 

— 



— 

i"  -H 

J 

1 

1 









V 

i,^,^,      ,    .....       .1.           i        ^t          ' 

1  " 

-     - 

1- 1 

—i. 

r'^^=^-<b    0) — e — =>—-*=' — <~ — ^> 

2G0O 

1 

/ 

^ 

■ 

1      1      1      1 

) 

k  1 

/ 

N 

TOTAL  DEATH  RATE 

MINUS 

TYPHOID  COMPONENT 

2-100 

1 

/ 

V.^ 

>. 

/ 

( 

,       1 



/ 

^ 

"-( 

y-— < 

\ 

2200^ 

/ 

\ 

^. 

7 

t 

) 

^ 

r — '^ 

K, 

/ 

L 

2000 

1^ 

y 

\ 

^, 

/ 

N 

li 

r 

t 

9 1 

^^^^ 

'Si 

<, 

>' 

laK) 

1 

1 

^^^ 

co"*»o<:Di—      ooa5Q"-ioico-*iocoi.—     ooo»0'HC«cO'»»<      >a 


Examples  of  Typhoid  Fever  Epidemics  and  of  Limited  Out- 
breaks Traced  to  Infected  Water. — For  the  purpose  of  illustrating 
to  what  an  extent  speoiHcally  polluted  water  can,  under  favorable  con- 
ditions, bring  about  a  sudden  outbreak  or  explosion,  the  following 
cases  have  been  selected  from  the  many  which  are  to  be  found  in  the 
literature  of  hygiene. 

Epidemic  at  Lausen,  Switzerland. — This  best  known  and  most  often 
qnoted  of  epidemics  of  typhoid  fever  was  practically  the  first  one  of 
any  considerable  extent  to  be  traced  undisputably  to  the  use  of  sj>e- 
cifically  polluted  Mater,  although  many  outbreaks,  large  and  small, 
had  been  ascribed  to  the  use  of  water  "  containing  considerable  organic 
matter,"  and  only  supposedly  infected. 

Up  to  1872,  this  village  of  780  inhabitants  had  not  been  visited  by 
typhoid  fever,  even  in  sporadic  cases,  for  sixty  years.  On  August  7th, 
with  no  previous  warning,  ten  persons  Mere  seized,  and  during  the 
next   ten   davs   nearlv  sixtv  more.      The   number  of  cases   increased 


430  WATER. 

from  day  to  day  until  130  persons,  or  one-sixth  of  the  entire  popula- 
tion, had  been  seized.  So  largo  a  percentage  of  involvement  pointed 
to  some  common  cause,  and  the  iinnnniitv  enjoyed  by  the  inmates 
of  a  group  of  houses  not  connected  with  the  public  water  supply 
directed  attention  to  the  latter,  wliicli  was  derived  from  a  spring  at 
the  foot  of  a  ridge  about  300  feet  high,  between  the  village  and  the 
Fiihrler  valley.  In  this  valley,  at  a  ])oint  between  one  and  two  miles 
distant  from  Lausen,  was  an  isolated  farm  where  dwelt  a  man  who, 
on  June  10th,  s]u)rtly  after  his  return  from  a  visit,  was  taken  sick 
with  typhoid  fever.  Before  the  end  of  July,  three  cases  more  devel- 
oped in  the  same  house.  The  discharges  of  all  four  were  thrown 
into  a  brook  in  which  the  family  washing  was  done,  and  which  served 
to  irrigate  the  meadows  hclow.  AVhenever  it  was  dammed  up  for 
this  purpose,  the  volume  of  the  water  su})ply  l)eyond  the  ridge  was 
noticeably  increased.  Between  July  15th  and  the  end  of  the  month, 
the  meadows  had  been  submerged  by  this  process,  and  in  three  weeks 
from  the  beginning  of  the  operation,  the  explosion  occurred  in 
Lausen. 

The  sequence  of  events  was,  then,  the  appearance  of  the  initial  case 
on  June  10th,  and  of  three  more  in  the  same  house  before  the  end  of 
July,  the  daily  pollution  of  the  ^v'ater  of  the  brook,  the  damming  of 
the  brook  in  the  middle  of  July,  and  the  appearance  of  the  first  cases 
in  Lausen  on  August  7th.  Everything  pointed  to  direct  connection 
between  the  impounded  water  and  the  spring  a  mile  or  more  distant 
on  the  other  side  of  the  ridge,  and  its  existence  was  established  by 
dumping  about  a  ton  of  salt  into  the  brook  and  noting  its  speedy 
appearance  in  the  Lausen  spring.  As  a  very  large  amount  of  flour, 
deposited  at  the  same  place,  gave  no  evidence  of  its  appearance,  even 
in  traces,  it  was  proved  that  the  water  passed  through  a  coarse  filter- 
ing medium  rather  than  through  an  open  underground  passage. 

The  Plymouth,  Pa.,  Epidemic. — The  town  of  Plymouth,  Pennsylvania, 
had,  at  the  time  of  the  epidemic  in  1885,  a  population  of  about  8,000 
people.  The  general  water  supply  w^as  derived  from  a  mountain 
brook,  which  was  dammed  at  intervals  so  as  to  form  a  series  of  im- 
pounding reservoirs,  but  a  large  part  of  the  population  was  supplied 
by  individual  wells.  A  citizen  who  spent  the  Christmas  holidays  at 
Philadelphia  returned  in  January  to  his  home,  ill  with  typhoid  fever, 
and  had  a  very  protracted  sickness.  During  the  entire  period,  his 
excreta,  which  were  in  no  way  disinfected,  were  thrown  upon  the  snow 
and  ice  on  a  slope  not  forty  feet  away  from  the  brook,  at  a  point  mid- 
way between  two  of  the  dams.  At  this  time  the  brook  Avas  frozen 
over,  and  it  remained  so  until  the  approach  of  spring.  During  the  la.st 
third  of  the  month  of  March,  there  was  a  sudden  period  of  warmth, 
and  the  snow  and  ice  began  to  melt.  Shortly  afterward,  the  warm 
spring  rains  began,  and  the  ice  and  snow  and  frozen  excreta  upon  the 
slope  were  melted,  and  the  entire  accumulation  was  washed  into  the 
brook,  and  thence  into  the  water  mains.  AV-ithin  three  weeks  there- 
after, cases  of  tyjihoid  fever  by  tlie  score  made  their  appearance 
throughout  the  town.  On  some  days,  more  than  a  hundred  new 
cases   were   reported,  and    on   one,   tiie    number    reached    nearly   two 


WATKIl    AND    D/Sh'ASh:  431 

liiiM(h'('(l.      'IMk!   lol.il    iiiiMihcr   <>('    -ciziircH   lius   viirioiihly   Ik-cii   t-lal('<l, 

iJlc  lovvcsl,  csl.iiii;!!*'  IxiiiL'  I  ,000  , •III. I  ihc  lii^rlicHf  |  ,;">()().  'I"|ic  iiiltilhfr 
of  (Iciillis  \v;is  tiol,  lc,-s  lli.'iii  III,  ;iMil  ii.i-  liccri  |tl;icx'(|  ,'is  lii;^li  as  1 'jO. 
I  (.  WiiH  <II,S(^<)\'<'f('(l  tlinl  llii'  <|ii(l'  mil'  w.i-  liiiiilcd  |>riic.ti('!illy  fo  IIiohc 
wh(>H((  lioiiscH  wci'c  sii|i|>li((l  liy  llic  lown  ni.-iins,  aii<l  fo  lliosc  who, 
wllil(!  supplied  n\  lioiiic  hv  well-,  ilr.ink  of  llic  piihlic  siipplv  wliilr- 
al)S(!nt  (Votii  lnMiic  (liirinji;  woikiiiL;  Jiniir-.  'Ihi-  dislribiition  \\a-  par- 
tic.lllarlv  <'i>ipliasizf(l  in  nnc  sin'cf,  wln'ir  IIh'  Iioiiscm  f»ii  otic  -idf  all 
had  OIK!  or  more  cases,  while  iho-e  mi  I  he  nihcr  Ii;id  Done  at  alL 
'riic.  lormci'  were  supplied  l)\  (lie  lowii  iii;iiii.-,  ;iiid  fhc  lafter  depr-iifh-d 
upon  wells. 

Outbreak  at  Uvernet. — A  sotiie\\li;il  siniilar  onlhi'eak,  on  a  iiiueli 
snialhiT  scale,  is  repoffeil  hy  I  )r.  l)iipai<l'  as  oceurrinj;  at  a  small  vil- 
Iai!;e  in  I. he  /Vlps,  the  details  of  which  arc;  as  follows  :  In  Octoher,  1  XOS, 
a,  detaehnieni.  o("  157  infantry  soldiers  were  (piartered  in  fonr  houses  in 
ihe  \'illa_ii;((,  cai^h  house  shelleriiii;'  a|)pi'o,\iiii;ite|\-  ;i  ruiii-ih  of  tlii' men. 
In  ono,  where  ')7  wer<'  ([uarlered,  there  appeared  within  u  few  wocks  '22 
cases  of  typhoid  fever,  (5  of  whicih  terminated  fatally.  At  tlu;  time  of 
seizure,  there  wei'e  no  other  eases  in  tlu;  villafi;e,  nor  did  any  appear  in 
any  other  house  than  this  one.  Investigation  revealed  the  iiiet  that,  a 
few  days  before  the  arrival  of  the  troops,  a  child  of  ten  years  had  been 
taken  ill  with  the  disease  in  another  house  situated  on  higher  gn)und, 
about  400  feet  away  from  the  house  in  (question.  Where  the  child  lay 
ill,  there  was  no  ]>rivy,  and  his  exc^'eta  were  thrown  u])on  the  ground 
in  a  neighboring  field.  His  soiled  clothes  were  washed  in  the  sj)ring 
nearby.  At  the  time  of  the  soldiers'  arrival,  a  mniiber  of  heavy  rains 
occurred,  by  wdiich  the  surface  impurities  of  the  soil  in  the  neighbor- 
hood of  the  house  where  the  child  lived  would,  by  reason  of  the  incli- 
nation of  the  ground,  be  washed  toward  the  house  occupied  i)y  the 
soldiers.  This  was  supplied  by  water  from  a  small  stream  through 
a  rude  main  constructed  of  worm-eaten  hollow  logs  laid  in  a  shallow 
depression  in  the  surface  of  the  soil.  There  could  be  no  question  of 
the  probability  of  contamination  of  this  supply  by  the  ftccal  discharges 
thrown  upon  the  ground  iu  the  vicinity,  and  in  the  absence  of  any  other 
cases  and  with  the  high  percentage  of  seizures  in  the  one  house,  no 
other  explanation  appears  to  be  possible. 

Epidemic  at  Ashland,  Wisconsin,  in  1893-94. — This  outbreak  is  one 
of  })eculiar  interest,  iu  that,  iu  addition  to  serving  as  an  excellent  illus- 
tration of  the  danger  of  using  the  same  body  of  water  as  a  place  for 
the  disposal  of  sewage  and  as  a  source  of  drinking-w^ater,  it  Avas  made 
the  basis  of  an  action  at  laAV,  Avhich  established  the  liability  of  AAater 
companies  and  nuuiicipalities  in  case  of  sickness  and  death  caused  bv 
the  distribution  and  use  of  infected  water. 

The  city's  supply  is  derived  from  an  arm  of  Lake  Snj>erior,  Che- 
quamegon  Bay,  upon  which  the  city  is  situated.  This  bay,  which  is 
about  t\\el\e  miles  long,  and  of  an  average  width  of  live,  varies  from 
eight  to  thirty-six  feet  in  dejith.  Xorth  of  the  city,  and  extending 
outward  in  a  northwestwardly  tlire^'tion,  is  a  lireakwater  consrructetl 
1  Lyon  medical,  Jan.  1,  1890,  p.  5. 


432 


WATER. 


for  the  protection  of  the  hnrhor  ao:ainst  nortlierly  p^les  ;  ami  between  it 
and  the  city  the  mouth  of  the  water  intake  is  located  about  a  mile 
from  the  shore.  (See  Fig.  39.)  The  sewage  of  the  city  is  discharged 
farther  to  the  west  and  south.  The  currents  in  the  bay  follow  the 
course  indicated  by  the  arrows  in  the  tigure,  and  carry  the  sewage 
toward  the  breakwater  and  over  the  mouth  of  the  intake.  Tliis  con- 
dition of  aliairs  was  brought  to  the  attention  of  the  company  by  the 
health  boards  of  the  city  and  state  repeatedly,  but  without  results. 
That  the  water  \vas  polluted,  was  evident  on  mere  ocular  inspection,  for 
it  was  often  cloudy  or  markedly  turbulent.  During  the  Avinter  of 
1893—94,  typlu)id  fever  made  its  apjiearance  in  the  city,  and  from  the 
initial  crises  a  disastrous  c])idemic  developed,  w^hich  led  to  the  establish- 
ment of  a  model  filtering-plant. 

The  action  at  law  referred  to  above,  w^as  brouglit  by  the  Avidow  of 
one  of  the  victims.  In  evidence,  it  was  shown  that  he  lived  continu- 
ously in  Ashland,  and  drank  no  water  other  than  that  supplied  by  the 


Fig.  39. 


Conditions  obtaining  at  Ashland,  Wis.,  prior  to  the  epidemic  of  1893-94. 

water  company  ;  that  previous  to  his  seizure  the  disease  had  prevailed 
in  the  city,  and  that  the  discharges  from  the  antecedent  cases  had 
passed  into  the  waters  of  the  bay  by  way  of  the  city  sewers.  The 
court  found  for  the  ])laintiff  in  the  sum  of  |5,000. 

Epidemic  at  Luneburg  in  1895. — The  ancient  town  of  Liineburg,  with 
a  population  of  22,000,  has  a  system  of  sewers  which  empty  at  two 


WA'I'KIl    AN/}    DISK  ASK.  4.*}3 

poiiiis  iiiio  llic  hiiimII  Iv-ivcr-  I  liiiciiaii.  Tlic  piiMir-  \v:il<r  supply  if^  in 
tlid  liiuids  ()("  :i  iiiMiil)(;f  <»("  s('p;ir:il<'  cmiix. rations,  wliicli  liad  llu-ir  orijriii 
ill  iiKMli.'iiVal  t;iiil<ls  ;  and  a.s  iJic  I. wo  pi'in(-i|>:il  ones  .'■iipply  tlic  haiiic 
jKii'ts  of  Ui(!  lown,  il  happens  (lial  (heir  mains  run  llirou^li  the  Hariic 
Htrcots,  and  thai-  nol  alone  adjoininij;  lioii.-es,  Iml  even  din'crciit  Ht^jfiw* 
of  {\\{\  HaiMc  hniMine;  arc  snp[»lied  hy  either  one  aeeordin^  to  fMrnirn- 
stiiiK'dS.  'i'he  IJalhs  ( 'Oinpany  fnrnislies  a  ^n-ouiid-\vater  wiiieji  is  |»er- 
((•(•iJy  ^ood,  except  lor  ils  rather  liiLdi  eonteiit  of  iron,  which  soinetiiiicH 
has  (!iUiS(!d  more  or  less  tronhlc.  The  oilier  lai'L'^c  corporation,  known 
as  the  Abis  ( !omi)aiiy,  obtains  its  water  IVom  the  nincnun,  iisnally  at  a 
point  above  tlic  town  ;  bnt  between  -Inly  loth  and  "JOtli,  it  drew  it  from 
a  place  in  the  middle  of  the  town,  opposit*-  the  |)umpinc'-si;ition,  wlien* 
th(^  water  was  exIreiiieU'  inipnre.  l*re\ions  to  ihe-e  dat<'S,  ty|)boi<l 
fever,  which  was  always  pi-eseni  in  some  amoinit  in  the  town,  had 
bcjjjiin  to  appear  to  an  unnsnal  extent  ;  and  in  the  llr.-t  half  of  AngUHt, 
there  was  a  sudden  and  n^markablc  increase  in  the  number  (»f  (5is<'h. 
On  tlie  tei-miuation  of  the  outbreak,  liOo  eases  liad  been  reporte<l,  1  <jJ>, 
or  <S2.  I  I  per  cent.,  of  \\lii(;h  were  anions;  familic-  sup])lied  witli  the 
water  of  the  river. 

It  was  proved  that,  for  a  pci-iod  o("  some  days,  which  inehidcd  the 
dates  above  mentioned,  the  diarrh(cic  discharges  of  a  young  girl,  sick 
with  typlioid  fever,  were  tin-own,  without  being  disinfected,  into  the 
river  at  a  point  about  300  feet  above  the  intake  and  on  the  same  side. 
In  addition  to  this  one  source  of  tiic  causative  agent  which  produced 
such  a  sudden  rise  in  the  curve,  it  was  know'n  tliat  the  river  had  been  p(»l- 
lutcd  by  the  discharges  of  another  patient  in  May,  and  that  the  epidemic 
iiad  its  real  beginning  in  June.  It  is  conceival)le  that  in  a  town  where 
the  house  supplies  are  so  complicated  that  different  stories  have  differ- 
ent kinds  of  water,  a  fair  percentage  of  the  victims  of  an  e]»idemic  may 
accjuire  the  disease  through  neighborhood  visiting,  tliough  tiieir  own 
domestic  supply  is  of  the  proper  quality.  In  this  whole  outlireak,  only 
I  7.5()  per  cent,  of  the  cases  were  among  people  whose  premises  were 
supjilied  by  the  other  companies. 

Epidemic  at  Zehdenick  in  1897. — This  was  a  local  outl)reak  traced 
to  the  contamination  of  a  well  by  the  discharges  of  a  child  sick  with 
typhoid  fever.  The  water  was  used  by  the  inmates  of  the  houses  in 
the  immediate  vicinity,  and  the  disease  was  limited  to  them  alone. 
Of  303  persons  making  up  the  29  households  of  the  neighborhoixl,  94, 
or  nearly  a  third,  were  seized  within  a  short  period,  while  not  another  case 
was  known  in  the  town.  The  inmates  of  nine  houses  within  the  infected 
area,  who  obtained  their  water  from  another  source,  were  untouched. 

Limited  Outbreak  Among  Soldiers. — An  infantry  regiment,  returning 
from  the  autumn  mananivres,  ]iassed  through  a  small  village  where 
typhoid  fever  existeri,  and  halted  for  water.  Two  days  afterward,  3 
men  W'ere  seized  with  great  suddenness,  and  within  two  weeks,  36  men 
were  down  with  the  disease.  They  had  been  exposed  to  no  other 
source  of  infection,  and  other  troops  who  passed  through  the  same  vil- 
lage without  stopping  for  Avater  were  unatlected.  Knowing  the  day 
28 


434  WATER. 

wlieu  the  infoctioii  occnrred,  and  since  in  every  case  the  onset  was 
marked  by  very  acute  symptoms,  l)r.  Erail  Jauchen  '  was  able  to 
determine  the  exact  period  of  incubation  :  3  were  seized  on  the  second 
day,  7  on  the  third,  6  on  the  fourth,  4  on  the  fifth,  4  on  the  sixth, 
5  on  the  seventh,  and  7  between  the  ninth  and  the  fourteenth.  The 
short  ])eriods  are  explainable  by  the  fact  that  the  men  were  in  a 
state  of  exhaustion  at  the  time  of  drinkin^r^  and  all  took  co2)ious 
draughts. 

Epidemic  at  Butler,  Pa.,  in  1903. — Butler,  Pennsylvania,  is  a  thriving 
city  of  about  16,000  inhabitants,  supplied  with  water  from  three  sources, 
two  of  which  are  situated  at  different  points  on  Connocjuenessing-  Creek, 
and  the  third  is  an  impounding  reservoir  on  Thorn  Run,  ^vhich  is 
the  chief  tributary  of  the  creek.  On  August  28,  li>03,  the  dam  at 
Boydstown,  some  seven  or  eight  miles  above  Butler,  was  carried  away, 
and  the  main  source  of  supply  being  thus  lost,  the  water  company  was 
obliged  to  use  water  from  the  Thorn  Run  reservoir  and  to  pumj)  directly 
from  the  creek  at  the  pumping-station.  Before  distribution,  the  water 
was  treated  in  a  rapid  mechanical  filter,  from  which  it  was  sent  to  the 
city  reservoir.  On  October  21,  the  filter  plant  was  shut  down  for 
repairs,  and  during  the  next  ten  days  the  city  was  supplied  with  un- 
filtered  water,  taken  directly  from  the  creek  at  the  pumping-station. 
On  November  2,  an  epidemic  of  typhoid  fever  began,  and  so  rapidly 
did  it  spread  that,  by  December  1 7,  no  less  than  8  per  (ient.  of  the  popu- 
lation (1270  cases)  had  been  attacked,  and  56  persons  had  died.  That 
the  epidemic  was  due  to  the  water-supply  was  emphasized  by  the  fact 
that  a  portion  of  the  city,  known  as  Springdale,  with  a  population  of 
about  2500,  not  provided  with  city  water,  but  supplied  by  deep  wells, 
was  almost  wholly  exempt,  there  being  but  2  cases  within  the  district. 
The  source  of  the  infection  was  not  far  to  seek.  Throughout  the  sum- 
mer and  autumn,  fairly  numerous  cases  of  typhoid  fever  had  occurred 
at  various  points  on  the  watershed,  and  there  was  amj)le  opportunity 
for  the  dejecta  to  be  carried  into  the  numerous  small  tributaries  and 
thence  into  the  creek.  In  one  house,  for  example,  provided  with  a 
privy  overhanging  a  small  stream  which  empties  into  the  creek  within 
a  short  distance  from  the  pumping-station,  there  occurred,  subsequent 
to  October  1,  no  fewer  than  5  cases  of  the  disease.  In  another  house 
near  Thorn  Run  dam  there  was  a  case  about  the  middle  of  August,  and 
this  was  followed  by  3  others. 

Epidemic  at  Ithaca,  N.  Y.,in  1903. — At  the  time  of  this  outbreak,  Ithaca, 
New  York,  the  seat  of  Cornell  University,  was  a  city  of  about  13,000 
people,  with  an  additional  student  population  of  nearly  3000.  Its 
location  and  surroundings  are,  in  general,  unusually  favorable  to  health  ; 
in  1900,  the  death-rate  from  all  causes  was  but  16.3  per  thousand.  The 
public  water-supply  was  furnished  by  three  creeks,  which  flow  into 
Lake  Cayuga,  but  many  of  the  population  depended  upon  private  wells, 
of  which  there  are  about  1500  within  the  corporate  limits.  The  water 
company  which  supplied  the  city  proper  derived  its  water  from  Six-mile 
Creek  and  Buttermilk  Creek  ;  the  University  was  supplied  by  Fall 
Creek,  under  its  own  management.  The  watersheds  of  these  three 
1  Wiener  klinische  Wocbenschrift,  July  7,  1898. 


WATI'Hi   AND   n/Sh'ASl':.  '4.'}5 

creeks  an;  nol,  liu'trc  ;iihI  (Ixy  iirc  more  or  Ic-s  fjiiickly  popiilutcd, 
Ahuridiirit  ((pporLimilics  cxisl  for  <]ii('(;l,  iiili-ction  of  :ill  tlin-r;  crcJfkH, 
privicH  ;iri<l  odtlioiiscs  hciiijr  ,si(,ijat(!(l  in  iriiiiiy  inKtanf;(!K  within  a  few  feet 
of  tiiC'  banks.  <  )ii  Six-mile  (IvcA'.k  alone,  afteordin^r  to  I )r.  Oerirj^e 
A.  8oj)er,  the  pr<)|):il)lc  sonrees  of  infection  at  llu;  (irn*;  of  the  epidemic 
numbered  a  hundred  or  inorc  The  ('onditionH  exihting  within  the 
\Viit(!r,slied  of  IJiitlcnnilk  ( -Viuik  are  said  to  liave  been  <'qually  bad, 
whil(5  lln>s(!  alonjj;  i'':ill  ('reek  were  (iveri  worse,  altimuj;!!,  as  will  be 
seen,  this  source  of  supply  appears  not  to  have  be<'n  specifically  pol- 
luted. In  addition  to  the  usual  sources  ol"  contanduation  of  the  wnie.T 
of  8ix-itdlc  Creek,  (here  were  employed  during  November  and  j)art  of 
J)e(U'ml)cr,  11)02,  about  (JO  laborers  in  tlu;  (!oiistruetion  of  a  dam,  but 
candul  iiKpiiry  failed  to  show  (he  existenc(!  of  any  sickness  among  them 
during  the  period  of  their  employnKsnl. 

The  j)ul)lic  supply  had  long  been  vit^wed  with  susjucicm,  and  many 
of  the  popukition  wlio  used  it  were  accustomed  to  boil  the  water  before 
drinking  it.  l)iarrh(eal  disturl)anceK  and  a  nnld  form  of  tyj)hoid  fever, 
known  as  "  Ithaca  lever,"  had  for  many  years  })een  very  eonunon. 
During  January  and  February,  11)02,  it  is  said  tliat  tliere  were  nearly 
100  cases  of  ty])hoid  fever  in  the  city.  During  the  spring  of  that 
year,  repeated  bacteriological  and  chemical  analyses  of  the  water  of 
Six-ndle  Creek,  taken  from  the  servi(;e  ])ipes,  yielded  results  which 
indicated  dangerous  pollution,  and  the  ])eople  were  warned  through 
the  newspajiers  against  its  use  without  previous  boiling.  On  January 
1,  11)03,  several  cases  of  undoubted  typhoid  fever  were  reported,  and 
thereafter  the  number  reported  daily  increased  to  such  an  extent  that, 
on  February  2,  there  were  no  fewer  than  237  cases  under  treatment. 
15y  the  middle  of  March  nearly  800  eases  had  been  reported,  l)ut  the 
actual  number  of  persons  alFected  was  undoubtedly  much  larger.  It 
is  asserted  that  more  than  1000  cases  existed  at  that  time,  and  that 
during  the  first  six  months  of  the  year  there  were  more  than  1300. 

Investigation  showed  that  those  infected  were  users  of  the  water 
supplied  by  the  water  eomjiany,  and  that  practically  no  cases  occurred 
among  those  who  drank  well-water  from  Fall  Creek.  Although  the 
University  was  supplied  by  the  latter,  a  large  proportion  of  the  student 
body  lived  in  boarding-houses  supplied  by  the  comj)any,  and  among 
these  the  cjiideraic  found  many  victims.  Accounts  as  to  the  number 
of  students  seized  ai'e  very  variable,  for  a  large  proportion  left  t<jwn 
during  the  height  of  the  outbreak  and  were  sick  elsewhere ;  but  they 
agree  that  several  hundred  were  seized  and  more  than  40  died. 
According  to  Coville',  about  200  students  had  tyj)ical  typhoid  after 
leaving  t(,)wn. 

Although  it  was  evident  tliat  the  cause  of  the  disease  was  the  water 
of  Six-mile  Creek  and  perhaps  that  of  Buttermilk  Creek,  it  was  im- 
possible to  trace  the  original  infection  ;  but  the  head-Maters  of  the 
former  drain  a  district  within  which  considerable  typhoid  fever  had 
been  known  to  exist  within  previous  yeai's,  and,  as  has  been  stated, 
there  was  abundant  opportunity  for  any  infective  material  to  have 
^  American  Medicine,  January  19,  1904. 


436  WATER. 

reached  the  water  directly.  Furthermore,  the  rate  of  flow  is  so  ^reat 
and  the  total  volume  of  water  so  small  that  infective  matter  discharged 
into  the  head-waters  could  have  reached  the  pumping-station  within 
four  hours  ;  and,  there  being  no  storage,  it  could  have  beeu  delivered 
iu  a  fresh  condition  to  the  consumers. 

Asiatic  Cholera. — This  disease,  which  is  endemic  in  India,  wlience 
it  makes  periodical  excursions  to  other  parts  of  the  world,  sometimes 
most  widespread  and  with  the  most  disastrous  results,  is,  perhaps, 
more  exclusively  than  tyjihoid  fever,  a  water-borne  disease.  Since 
the  discovery  by  Koch  of  the  exciting  cause,  and  the  detection  of 
the  same  in  drinking-water  during  epidemics  of  the  disease,  the 
older  theories  of  its  method  of  spread  have  been  abandoned  save 
by  the  few  remaining  adherents  of  the  "  localist "  theory,  whom 
not  even  the  facts  revealed  during  and  after  the  great  epidemic  of 
1892  can  move  from  their  dogged  attachment  to  the  creed  of  their 
revered  teacher. 

During  the  course  of  the  widespread  devastating  epidemic  of  1892, 
which  in  its  journey  from  the  valley  of  the  Ganges  through  Persia 
claimed  20,000  victims  in  Teheran  alone,  and  in  its  course  through 
Russia  destroyed  215,157  more,  and  which  extended  through  Ger- 
many, Austria,  France,  Belgium,  Holland,  and  even  to  the  harbors  of 
the  Western  Hemisphere,  no  more  instructive  example  of  the  connection 
between  the  disease  and  polluted  water  and  of  the  immunity  conferred 
by  the  use  of  a  pure  supply  could  have  been  yielded  or  desired  than 
the  experience  of  Hamburg,  Altona,  and  Wandsbeck.  These  cities  ad- 
join one  another  so  closely  that  there  is  no  visible  line  of  demarkation, 
and  in  a  geographical  sense  they  may  be  regarded  as  one  place.  In 
one  important  respect,  however,  the  three  places  diifer  very  materially  ; 
namely,  their  public  water  supplies.  A¥andsbeck  was  supplied  with 
filtered  water  from  a  lake  but  little  subject  to  pollution ;  Altona  drew 
upon  the  Elbe  at  a  point  below  the  entrance  of  the  sewage  of  Hamburg, 
but  filtered  the  water  through  sand ;  Hamburg  used  unfiltered  Avater 
from  the  Elbe  above  the  city.  During  the  summer  of  1892,  or  between 
August  17th  and  October  23d,  Hamburg,  with  a  population  of 
640,000,  had  nearly  17,000  cases  of  cholera,  of  which  slightly  more 
than  half  terminated  fatally  ;  Altona,  with  a  population  about  a  quarter 
as  large,  had  but  500  cases,  or  only  onc-thirty-fourth  as  many  (400  of 
these  are  supposed  to  have  come  from  Hamburg),  and  Wandsbeck  had 
practically  none.  Very  noticeable  was  the  fact  that  where  Hamburg 
and  Altona  come  together,  the  Hamburg  side  was  plentifully  sprinkled 
with  cases,  while  the  other  was  comparatively  free  (see  Fig.  40),  and 
this  was  still  more  particularly  remarked  along  a  certain  street  that  for 
a  distance  formed  the  boundary  line,  in  which  the  houses  on  the  Ham- 
burg side  had  plenty  of  cases  and  those  opposite  had  none.  Almost  as 
though  intended  for  the  purpose  of  marking  yet  more  sharply  the  dis- 
trijjution  of  the  two  kinds  of  water,  it  happened  that  a  group  of  tene- 
ment houses  on  the  Hamburg  side  of  the  boundary  was  supplied  with 
water  from  the  Altona  mains,  and  in  these  houses,  densely  peojaled  hy 


WATKIL   AND    D/Sh'ASK 


4:n 


tlui    laJxH'Inn;  cImhm,  not   n   sitij^lc    case    occiiiTcfl,  wliilc   In    iici}.'lil)oriiij.^ 
li(»iiS('S  (lie  (lis(';is(!  vvmh    i';i<ziii<i;. 

TlillM  we  li;i,V(:  ;i  imisl,  cloiiiiciit  i  ii  -  l;iii(c  dC  ||ic  \;ilii<'  of  -;iii'l  f'lltni- 
tioii,  !Ui(l  ol"  (lie  (l;iii^'(r  (if  ii.hiil';  |i'iIIiiI<'<I  .-ii|)|ili<-.  I  l;iiiil»iir^'ri  im- 
lilUirc.d  vViit(M"  cniric  (Voin  ,il)i)\c  llic  city,  \vliil(!  -Alloiiii  liad  to  rlc|)ciirl 
upon  Wider  \vlii<'li,  l)('(or(!  hcinir  lillcicd,  Ii;h1  rcccivi-d  tlic  cnfin;  M-waj^o 
of  nioi'dlliiiM  I  ln'('('-(jiiarlcrs  o("  a  million  |»co|)|c.  TJic  initial  specific 
polluiion  ol"  llic  ri\  <'i'-\\al(i'  was  I  raced  hack  to  l»'n--ian  enii^rant«, 
li(!rde(l  in  hari'ax^ks  on  one  di'  the  wliaives  jiendin;^  llieir  end)arlvation 
for  lli(!  United  Stales.  At-  tin'  (iin(!  of  the  outl)reak,  there  were,  on  an 
n,V(!ra<^e,  ahotilr  a  thousand  of  Ihesc!  people  on  jiand  all  the  linie.  Many 
of  them  canu!  fi'om  <lislriets  in  I'.nssia  which  had  hci^n  and  were  then 
Hulfcrinf^  He.v<n'ely  from  cholera,  and  all  \\ci-c  well  ~np|ilie(j  with  dirty 
elothini!;  and  blankets,  some  ol"  which  they  washed  wliih;  they  werr; 
luiinji,'  tietained.      It   is   believed   that   among   tlio   thousands   that   had 

Fio.  40. 


Portion  of  tho  boniularv  lino  liotween  Ilamburs  and  Altona.    The  dots  indicate  cases  of  cholera. 


arrived,  there  must  have  been  some  mild  cases  of  the  disease,  or  at 
least  some  convalescents  with  cholera  germs  still  iu  their  evacuations 
two  or  three  weeks  after  recovery.  All  of  the  sewage  matters  of  every 
description  from  these  people  were  dischai'ged  directly  into  the  river  at 
the  wharf. 

With  the  exception  of  a  few  straggling  cases,  there  was  no  cholera  iu 
either  of  the  two  cities  from  October  23d  to  December  6th,  when  a 
small  outbreak  occurred  iu  Hamburcj.  This  reached  its  culminatiufr 
point,  5  cases  in  one  day,  on  the  26th,  and  then  the  disease  began  to 
reappear  iu  Altona,  but  under  very  ditfereut  conditions  from  those 
which  characterized  the  epidemic  iu  August.  Of  the  oOO  cases  which 
then  occurred,  about  400  were  connected  iu  one  way  or  another  with 
Hamburg,  but  in  the  later  (nitbreak,  most  of  the  patients  were  of  the 
well-to-do  class  of  workmen  whose  occupation  did  not  call  them  to 
Hamburg — women,  young  children,  inmates   of   hospitals,  and   others 


438  WATER. 

having  no  reason  to  go  there.  Consultation  of  the  records  of  bac- 
teriological examination  of  the  Altona  filtered  ^vater  showed  an  increase 
in  the  first  week  of  Deeeiii])er,  and  again  in  the  last  days  of  that 
month,  and  at  intervals  in  January,  ^\•hieh  indicated  that  some  disturb- 
ance must  have  occurred  in  the  working  of  the  filters.  Investigation 
showed  where  the  fault  lay,  and  also  its  nature  :  the  surface  of  the  sand 
had  been  frozen  luider  the  mud  layer,  and  had  thawed  over  only  a  part 
of  its  area,  so  that  the  whole  work  of  the  filter  was  thrown  upon  a 
part.  The  imperfect  Avorking  in  early  December  was  not  followed  by 
cholera,  for  at  that  time  the  river  was  practically  free  from  the  germs. 
Then  came  the  few  new  cases  in  Hamburg,  27  in  number,  and  rein- 
fection of  the  Elbe,  followed  by  faulty  working  of  the  Altona  filters, 
and  consequent  distribution  of  a  small  amount  of  infective  material 
through  the  water  mains.  The  organisms  were  found  in  the  water  just 
below  the  mouth  of  the  main  sewer  of  Hamburg,  and  also  in  one  of 
the  settling  basins  of  the  filter  plant,  where  the  water  stood  prior  to 
delivery  to  the  beds. 

The  Propagation  of  Cholera  in  India. — As  has  been  stated,  the  home 
of  cholera  is  India,  and  so  long  as  the  natives  are  faithful  to  their 
religion  and  to  the  observance  of  old-established  customs,  just  so  long 
will  that  country  supply  the  rest  of  the  world  with  occasional  infection. 
Considering  the  extreme  conservatism  of  all  classes  of  East  Indians  and 
the  national  reverence  of  the  Hindoos  for  holy  places,  it  may  be  safe 
to  predict  that  before  any  marked  change  for  the  better  is  accomplished, 
the  rest  of  the  civilized  world  will  have  advanced  so  far  in  sanitary 
affairs  that  cholera  will  be  feared  no  more  than  varicella.  As  illustrative 
of  w^hat  sanitary  reform  in  India  would  have  to  encounter,  the  follow- 
ing extracts  from  the  report  of  Dr.  Simmons,  quoted  by  Professor 
Mason,  will  be  found  of  interest.  It  may  be  stated  by  way  of  ex- 
planation that  Orissa,  below  mentioned,  is  a  province  covering  more 
than  24,000  square  miles,  every  part  of  which  is  holy  ground.  Every 
town  contains  consecrated  land  and  is  filled  with  temples,  and  every 
little  hamlet  has  its  shrine. 

"  The  drinking-water  supply  is  derived  from  wells,  so-called  '  tanks ' 
or  artificial  ponds,  and  the  w^ater-courses  of  the  country.  The  wells 
generally  resemble  those  in  other  parts  of  Asia.  The  tanks  are  exca- 
vations made  for  the  purpose  of  collecting  the  surface-water  during  the 
rainy  season  and  storing  it  up  for  the  dry.  Necessarily  they  are  mere 
stagnant  pools.  The  water  is  used  not  only  to  quench  thirst,  but  is 
said  to  be  drunk  as  a  sacred  duty.  At  the  same  time,  the  reservoir 
serves  as  a  large  washing-tub  for  clothes,  no  matter  how  dirty  or  in 
what  soiled  condition,  and  for  personal  bathing.  Many  of  the  water- 
courses are  sacred  ;  notably  the  Ganges,  a  river  1,600  miles  long,  in 
whose  waters  it  is  the  religious  duty  for  millions,  not  only  of  those  living 
near  its  banks,  but  of  pilgrims,  to  bathe  and  to  cast  their  dead. 

"  The  Hindoo  cannot  be  made  to  use  a  latrine.  In  the  cities  he  digs 
a  hole  in  his  habitation ;  in  the  country  he  seeks  the  fields,  the  hill- 
sides, the  banks  of  streams  and  rivers,  when  obliged  to  obey  the  calls 


WATKIl   ANh    hlSHASK.  i'iO 

of  ii.'itiirc.  TFcuuin  it,  is  ili;i,l  I  he  \i(iiii(y  <>('  towns  ;iii<l  llic  hanks  of 
ilu!  I;i,itl<.s  and  waicr-conrscs  arc  reel,  iir^  willi  lillli  of"  iIk-  worst,  flc- 
S('ri|)l  ion,  wlilf^li  is  oC  ncccssily  washed  inio  llic  |iiil)lic  water  Hn[)|)ly 
willi  ev(!ry  rainCall.  /\dil  to  lliis  llie  mi-eiy  of  |iil^'iinis,  tliejr  povfTty 
and  dis(.'a-S(!,  and  their  leiiiMe  (•rowdin^r  into  ihe  nnrin-rons  fowiiH 
wliich  contain  some  leni|Je  or  shiine,  die  ohjeel,  of  llieir  devotion, 
and  W(^  can  sec  liow  India  has  heeome  and  remains  the  hot-l»ed  of  tln! 
diohwa,    e|)i<lenMc. 

"In  the,  llnilcd  Slates  olHeial  repoi't,  tlie  horrors  ineideni  npoti  flic 
|)il<j:;rimai;'c.s  -aw.  detailcf!  with  appalling;'  !ninntcncss.  W.  W.  Ilnntcr, 
in  liis  Orissa,  stales  thai  '1  I  hin'h  Ccsfivals  tal<(!  |)lacc  annnally  at  Ju^- 
o'crnaiil.  At.  one  of  Iheni,  ahonl.  Master,  |(>,()()0  p(;rson.s  indni^^c  in 
hemp  and  hashe<'sh  io  a  sho.  kin^^  dcLiree.  |''((r  wcck.s  Ixifon;  tluj  aw 
I'cstiv^a!  in  Jinie  and  -Inly,  |)ilt;rims  eome  Iroopin^r  in  l»y  thoiisanrlH 
every  day.  Thev  are  led  by  the  temple  cooks  to  the  nntnlx-r  of 
!)(),()()().  ()\'er  100, ()()()  men  and  women,  many  of  I  hem  nnacciistonicd 
to  work  or  c\posnr(>,  \\\\:i:^  and  strain  al  the  r-.w  nntil  they  droj)  ex- 
hanstcd  and  hh»ek  Ihe  road  with  their  hodie-.  I  )nrinf:;  every  month 
of  the  vear  a  stream  of  devotees  Hows  ah)n<:;  the;  L:;i"eat  ( )rissa  n»ad  from 
Cah-nlta,  and  every  vi!IaL;;(;  for  three  Imndred  miles  has  its  pilgrim 
oncainpmenls. 

"The  ])eople  travel  in  small  bunds,  which  at  tlie  time  of  the  ^reat 
feasts  actually  touch  each  other.  Five-sixths  of  the  whole  are  females, 
and  1)5  ])er  cent,  travel  on  foot,  many  of  them  marchinti'  hiindn-ds  and 
even  thousands  of  miles,  a  contingent  having  been  drmnmed  up  from 
everv  town  or  village  in  India  by  one  or  other  of  the  three  thousand 
(Muissaries  of  the  temple,  who  scour  the  country  in  all  directions  in 
search  of  dupes.  When  those  pilgrims  who  have  not  died  on  the  road 
arrive  at  their  journty's  end,  emaciated,  with  feet  bound  u]i  in  nigs  and 
plastered  with  mud  and  dirt,  they  rush  into  the  sacred  tanks  or  the  sea, 
and  emerge  to  dress  in  clean  garments.  Disease  and  death  make  havoc 
with  them  during  their  stay ;  corpses  are  buried  in  holes  scooj^ed  in  the 
sand,  and  the  hillocks  are  covered  with  bones  and  skulls  washed  from 
their  shallow  graves  by  the  tro]>ical  rains. 

"  The  temple  kitchen  has  the  monopoly  of  cooking  for  the  multitude, 
and  provides  food  which,  if  fresh,  is  not  unwholesome.  Unhappily,  it 
is  invsented  before  Juggernaut,  so  becoming  too  sacred  for  the  minutest 
portion  to  be  thrown  away.  Under  the  influence  of  the  heat  it  soon 
undergoes  putrefactive  fermentation,  and  in  forty-eight  hours  much  of 
it  is  a  loathsome  mass  unfit  for  human  food.  Yet  it  forms  the  chief 
sustenance  of  the  pilgrims,  and  is  the  sole  nourishment  of  thousands 
of  beggars.  Some  one  eats  it  to  the  very  last  grain.  Injurious  to  the 
robust,  it  is  deadly  to  the  weak  and  wayworn,  at  least  halt'  of  whom 
reach  the  place  suffering  under  some  form  of  bowel  complaint.  Badly 
as  they  are  fed,  the  poor  wretches  are  worse  lodged. 

"  Those  who  have  the  temporary  shelter  of  four  walls  are  housed  in 
hovels  built  upon  mud  platforms  about  four  feet  high,  in  the  center  of 
each  of  which  is  the  hole  which  receives  the  ordure  of  the  household, 


440  WATER. 

and  arouiKl  whieli  tlio  inmates  cat  ami  sleep.  Tlie  ]>latforms  are  covered 
with  small  cells  without  any  windows  or  other  a})ertures  for  ventilation, 
and  in  these  caves  the  pilgrims  are  packed,  in  a  country  where,  during 
seven  months  out  of  twelve,  the  thermometer  marks  from  85°  to 
100°  F.  Hunter  says  that  the  scenes  of  agony  and  suflbcation  enacted 
in  these  hideous  dens  baffle  description.  In  some  of  the  best  of  them, 
thirteen  feet  long  by  ten  feet  broad  and  six  and  one-half  high,  as  many 
as  eighty  persons  pass  the  night.  It  is  not,  then,  surprising  to  learn 
that  the  stench  is  overpowering  and  the  heat  like  that  of  an  oven.  Of 
300,000  wlio  visit  Juggernaut  in  one  season,  90,000  are  oi'Um  packed 
together  for  a  week  in  5,000  of  these  lodgings.  In  certain  seasons, 
however,  the  devotees  can  and  do  sleep  in  the  open  air,  camping  out 
in  regiments  and  battalions,  covered  only  by  the  same  meagre  cotton 
garments  that  clothe  them  by  day. 

"The  heavy  dcAvs  are  unhealthy  enough  ;  but  the  great  festival  falls 
at  the  beginning  of  the  rains,  when  the  w^ater  tumbles  in  solid  sheets. 
Then  lanes  and  alleys  are  converted  into  torrents  or  stinking  canals, 
and  the  pilgrims  are  driven  into  the  vile  tenements.  Cholera  invariably 
breaks  out.  Living  and  dead  are  huddled  together.  In  the  numei-ous 
so-called  corpse-fields  around  the  town  as  many  as  forty  or  fifty  bodies 
are  seen  at  a  time,  and  vultures  sit  and  dogs  lounge  lazily  about  gorged 
with  human  flesh.  In  fact,  there  is  no  end  to  the  recurrence  of  inci- 
dents of  misery  and  humiliation,  the  horrors  of  which,  says  the  Bishop 
of  Calcutta,  are  unutterable,  but  which  are  eclii)sed  by  those  of  the 
return  journey.  Plundered  by  priests,  fleeced  by  landlords,  the  sur- 
viving victims  reel  homeward,  staggering  under  their  burdens  of  putrid 
food  wrapped  up  in  dirty  clothes,  or  packed  in  heavy  baskets  or  earth- 
enware jars.  Every  stream  is  flooded,  and  the  travellers  have  often  to 
sit  for  days  in  the  rain  on  the  bank  of  a  river  before  a  boat  will  venture 
to  cross. 

"At  all  these  points  the  corpses  lie  thickly  strewai  around  (an  Eng- 
lish traveller  counted  forty  close  to  one  ferry),  which  accounts  for  the 
prevalence  of  cholera  on  the  banks  of  brooks,  streams,  and  rivers. 
Some  poor  creatures  drop  and  die  by  the  way ;  others  crowd  into  the 
villages  and  halting-places  on  the  road,  where  those  who  gain  admit- 
tance cram  the  lodging-])laces  to  over-flowing,  and  thousands  pass  the 
night  in  the  streets,  and  find  no  cover  from  the  drenching  storms. 
Groups  are  huddled  under  the  trees  ;  long  lines  are  stretched  among 
the  carts  and  bullocks  on  the  roadside,  their  hair  saturated  with  the 
mud  on  w^hich  they  lie ;  hundreds  sit  on  the  wet  grass,  not  daring  to 
lie  down,  and  rocking  themselves  to  a  monotonous  chant  through  the 
long  hours  of  the  dreary  night. 

"  It  is  impossible  to  compute  the  slaughter  of  this  one  pilgrimage. 
Bishop  Wilson  estimates  it  at  not  less  than  50,000.  And  this  descrip- 
tion might  be  used  for  all  the  great  Indian  pilgrimages,  of  which  there 
are  probably  a  dozen  annually,  to  say  nothing  of  the  Inmdreds  of 
smaller  shrines  scattered  through  the  peninsula,  each  of  which  at- 
tracts  its  minor  hordes   of  credulous  votaries.     So  that   cholera   has 


PAIIASI'I'KS  ANh    DIUSKINd-WATEH.  411 

al)lin(liiii(,  ()|»|)(»i(  iiiiilics  (or  ,s|)r<';i(liii^'-  over  tlu;  \vIh»I<'  oC  I  f  Ii)(|<.-t;iii 
iwvxy  yviiv  \)y  iri;uiy  lin^jc  ;iniii<'s  o(*  lillliy  |til^rirMH  ;  and  llw  coiint.ry 
\tHv\\'  well  <l(^H(!rv<'H  IIk-  r(|»iil;ilinii  il  iiiii vcrwally  |)<)HH(;hh(.'H  ui'  hciii^  the 
!)ii-(li|»!:i(!(!  ;iii(I  S('(ll<'<l  home  of  IIm-  iiiiihdy." 

Parasites  and  Drinking-water. 

Tlicrc  is  MhtiiKlMiil  evidence  o("  llie  ;ij^eiicy  oC  d iiid< iiii^-w ;i(er  in  flif 
,s|)r(^a(l  of  eerlaiii  ol'  the  ;iniiii!d  |Kir;isi(es,  Ixil  uilli  re.-^peel  <o  certain 
oIJku-h  tlic  d:iii,<;('r  is  niiicli  o\ei--r;iled  (l;i|)e-\voi-msj,  or,  indeed,  imag- 
inary (l-ricliinie). 

Ivotind  worms,  Ascaris  lumbricoides,  iinilonl)t(<lly  arc  spread  in  part 
I )y  water.  'V\\v  CemMle  de|»osits  enoi'nn>us  nnnd»ers  ol"  ejr^s  inllie  small 
intestine,  and  these  are  expcHed  in  the  f:eces.  \\'h<'tlicr  IIk;  freshly 
diseharii;ed  e<!,<i,s  !ire  (\'i.pal)lc  ot"  repr(Klnein<i;  the  worm,  is  a  matter  of* 
(loiil)t ;  l)ut  it,  seems  probable  that  the  intervention  of  atiotlior  host  i.s 
nc'('.(>ss;uy.  Whcirever  this  parasite  is  known  to  |»re\;nl  extensively,  the 
people  nso  pollnted  water  for  drinkino^. 

Pin  worms,  or  scat  worms,  Oxyuris  vermicularis,  are  spread  |)rol»al)]y 
by  water.  They  locate  in  the  ciccum  and  npper  colon,  where  the  female 
de})osits  ejijgs  in  large  numbers,  which,  reaching  a  water-supply  after 
being  discharged  through  th(^  bowel,  may  be  taken  into  tlie  stomach, 
where  the  enveloj)e  of  the  embryo  is  disintegrated  by  the  gastric  juice. 
The  larv;e  develop  in  the  small  intestine  and  come  to  maturity  in  about 
four  w'eeks. 

Guinea  worms,  Dracunculus  medinensis,  are  said  to  invade  the  body 
through  the  skin  during  bathing  or  through  the  stomac^h  in  drinking- 
water ;  the  evidence  of  the  latter  method  is  detinite.  In  the  stomach, 
the  embryos  are  developed  rapidly,  aud  soon  the  impregnated  female 
proceeds  from  the  alimentary  canal  to  the  subcutaneous  tissues  in  various 
parts  of  the  body,  where  she  finally  breaks  through  the  skin  and  esca]x>s. 
The  living  embryos  which  are  then  liberated,  finding  their  \vay  into 
fresh  water,  enter  the  bodies  of  the  comn^ou  fresh-water  flea,  Cijclops 
quadrieoniis,  which  acts  as  the  intermediate  host  and  conveys  the 
organism  to  the  human  stomach.  In  a  case  reported  by  Dr.  John 
Patterson,^  the  pati(mthad  an  abscess  on  the  upper  part  of  the  left  tibia, 
from  wdiieh,  when  it  was  excised,  a  pi^rtiou  (4  inches)  of  a  worm  was 
removed.  I-iater,  he  had  an  abscess  aud  sinus  of  the  left  calf,  followed 
by  a  swelling  back  of  the  inner  malleolus,  aud  in  this  a  portion  of  a 
worm,  25  inches  iu  length  and  devoid  of  a  head,  was  found.  Dr. 
Edward  Francis  -  had  under  observation  for  six  weeks  at  the  U.  S. 
Immigrant  Hospital  (N.  Y.),  a  native  of  the  Gold  Coast,  who  arrived 
iu  June,  1901,  with  a  history  of  having  been  troubled  with  these  para- 
sites during  the  preceding  three  months.  During  his  stay  at  the  hos- 
pital five  woru:is  appeared  :  one  on  the  front  of  the  right  ankle,  one  on 
the  dorsum  of  the  right  foot,  one  on  the  front  of  the  left  ankle,  one 

^  Medical  Eecord,  October  7, 1899. 

'^  American  ^ledicine.  October  26,  1901. 


442  WA  TER. 

below  the  left  external  malleolus,  and  one  on  the  dorsum  of  the  left 
foot,  near  the  toes.  Que  Nvorni  presented  26  inches  in  one  piece ;  the 
others  measured  10  to  18  iuches,  but  were  removed  in  pieces. 

AVhip  worms,  Trichocephalus  dispar,  which  are  said  to  be  extremely 
common  in  Paris  and  some  other  places  outside  the  tropics,  are  spread 
wholly  by  water,  without  which  the  embryo  cannot  develop  within  the 
egg.  Taken  into  the  stomach,  the  envelope  is  dissolved  and  the  liber- 
ated larva  attaches  itself  to  the  wall  of  the  intestine,  A\here  it  proceeds 
very  slowly  to  develop.  It  does  not  reach  full  maturity  until  about  a 
year  has  elapsed. 

Filaria  sanguinis  hominis,  the  parasite  which  produces  chyluria,  ha-ma- 
tochyluria,  and  elephantiasis,  is  believed  to  find  its  way  into  the  system 
through  water  contaminated  by  mosquitoes  which  have  sucked  the  blood 
of  persons  suifering  from  the  parasite.  The  adult  female  ]>roduces  an 
enormous  nuuiber  of  minute  embryos,  which  pass  into  the  blood ;  and 
when  these  are  taken  into  the  stomach  of  the  mosquito,  they  wander 
to  other  parts  of  the  insect,  where  they  become  farther  developed,  and 
later  may  be  transferred  to  water,  through  which  they  are  believed  to 
pass  into  the  human  stomach,  where  the  cycle  is  completed.  This  para- 
site is  not  confined  wholly  to  the  tropics,  and  occasionally  is  seen  in  our 
Southern  States.      (See  Chapter  XII.) 

Bilharzia  hasmatobia,  the  cause  of  a  peculiar  heematuria  common  in 
parts  of  Africa,  is  believed  by  many  to  be  transmitted  by  drinking- 
water  contaminated  by  the  urine  of  persons  suffering  with  the  disease. 
The  embryos  probably  enter  the  system  of  some  other  organisms,  which 
play  the  part  of  intermediate  hosts  and  advance  their  development  one 
stage. 

Ankylostomum  duodenale  (XJncinaria  duodenalis),  the  cause  of  the 
anaemia  formerly  supposed  to  be  peculiar  to  miners  and  others  engaged 
in  underground  operations,  was  until  recently  believed  to  be  disseminated 
chiefly  by  polluted  water ;  but,  as  has  been  said  in  the  consideration 
of  the  relation  of  soil  to  disease,  this  idea  is  no  longer  tenable,  the 
chief,  if  not  the  only,  source  of  infection  being  soil  polluted  by  the 
intestinal  discharges  of  those  already  infected  with  the  parasite. 

Strongyloides  intestinalis,  the  parasite  of  an  endemic  diarrhoea  of 
Cochin  China,  first  described  by  French  investigators  who  discovered 
its  rhabditiform  embryos  in  the  stools  of  soldiers  returning  from  China 
in  1876,  was  found  by  Perroncito  to  occur  in  association  with  Ankylos- 
tomum duodenale  in  the  discharges  of  laborers  afflicted  with  "  St.  Gothard 
tunnel  anaemia",  has  been  reported  in  various  countries  of  Europe,  in 
Egypt,  Brazil,  the  Indies,  and  Pliilippine  Islands,  and  within  recent 
years  in  various  parts  of  the  United  States.  According  to  Dr.  M.  L. 
Price  ^,  the  occurrence  of  eggs  in  the  stools  is  very  rarely  observed, 
unless  there  coexists  an  uncinarial  infection,  and  the  parasite  is 
probably  introduced  by  way  of  the  mouth  as  the  filariform  embryo, 
though  infection  of  animals  has  been  produced  by  means  of  the  eggs. 
He  believes  that  the  vehicle  by  which  the  parasite  gains  access  to  the 
^  Journal  of  the  American  Medical  Association,  September  12  and  19,  1903. 


WE.  1  l.'^> 

systom  is  fr(;(|Uoiiily  \\u'  drinkiiit^  wafer,  hiit  lli;it,  fnsli  v"<.'Pt'il»l(H  from 
IjukI  in:uiiir<'(l  willi  liiiirKiii  <X(r<(;i  play  a  pari.  1 1,  \<  (lie  Ixlirf  of 
Sl.iloH  thai,  1,1  ic  !:;<•(  »^ra[)liica  I  di,  I  til.iil  ion  of  IIk'  paruKifc  in  llii.-,  roiiiil  ry 
will  l)(!  (biiii(l  to  corrcspoii'l  lo  lli:it.  of  iiiiciiiaria. 

ICE. 

It  IH  ii  common  idea,  lliat  \v.v.  is  necessarily  pure,  beeanse,  in  frer'/.infr, 
"  waix^r  pnrides  ilsell."  Ice  may,  lio\ve\cr,  he  <|nile  as  im|)Mn- as  (Ik; 
orifjjinaJ  waier  or  \'er\'  purr,  accoiiliiiL;  In  rMicnni-lances.  'I'lie  first  for- 
mation is  (piite,  likely  to  contain  ini|)niitics,  sneli  as  llx;  (Inst  an<l  f»tlnrr 
mailers  lloalinj:;  on  the  surfaec.  Under  (trdinary  (ronditions,  tlie  im- 
|)nrities  will  he  liinile(|  t(»  this  layer,  (or,  in  the  <i;ro\vtli  of  Hie  iec  from 
ai)oV(!  downward,  all  hut  truces  of  dissolved  snhslaiiecs  and  praf^ticallv 
all  of  the  suspended  matters  are  excluded. 

Ice  may  hccomc  impun;  in  several  ways.  If  snow  fall>  upon  it  and 
h(>(!omes  wet  cither  hy  rain  or  hy  water  from  helow,  and  then  freezes 
and  he<^om(>s  part  of  the  ice,  it  will  contain  all  the  im|)nrities  whieh  have 
hccn  washed  out  of  the  air.  Tf,  whih;  tin;  ice  is  ihin,  holes  are  cut  so 
as  to  permit  flooding  from  helow,  it  will  contain  all  the  impurities  of 
the  water.  Cut  from  shallow  ponds,  it  will  he  pure  or  imj)ure  acc<»rd- 
ing  to  the  (luality  of  the  watci-  and  the  depth  to  whieh  it  freezes.  Water 
from  such  ponds,  if  ])ollute(l  hy  surface  washings  or  sewage  matters,  is 
likely  to  yield  ice  which,  wlieu  melted,  will  give  off  olfeusive  odor.s. 

It  is  a  common  belief  that  bacteria  are  killed  in  ice,  but  many 
varieties  will  retain  tli(>ir  vitality  in  it  for  a  very  long  time.  As  early 
as  1871,  Burdou  Sanderson  showed  that  even  the  purest  ice  is  likely 
to  contain  them  in  some  degree.  Chantemesse  and  Widal  ])rove<l  in 
1882,  Prndden  in  1887,  and  Riche,  Fninkel,  and  others  at  different 
tim(\s,  that  pathogenic  bacteria  may  maintain  their  vitality  to  a  sur- 
prising degree  in  ice,  and  that  the  bacillus  of  typhoid  fever  is  ]iarticu- 
larly  resistant.  Prndden  ^  showed  that  ice,  made  from  water  whieh 
contained  them  to  an  innumerable  extent,  yielded  at  the  expiration  of 
103  days  no  less  than  7,348  per  cc. 

Bacteria  are  resistant  not  only  to  the  ordinary  low  temperature  of 
ice,  for  Pietet  and  others  have  proved  that  even  the  extraordinary  cold 
of  liquefied  air,  — 315°  F.,  is  not  sufticient  to  destrov  them.  On  the 
other  hand,  Sedgwick  and  Winslow,2  W.  H.  Park,''  and  H.  W.  Hill,* 
who  have  made  independent  investigations  of  the  possible  danger  of 
ice  as  a  cause  of  outbreaks  of  typhoid  fever,  agree  that  it  is  but 
slight.  Sedgwick  and  AVinslow  found  that  the  bacilli  perish  rapidly  ; 
50  per  cent,  at  the  end  of  the  first  Aveek,  90  per  cent,  in  two  weeks, 
and  practically  all  (2  or  3  in  1000  remained)  after  twelve  weeks.  It 
is  pointed  out  by  the  several  observers  named  that  the  majority  of 
bacteria  in  water  are  eliminated  in  the  process  of  freezing  ;  that  the 
majority  of  those  included  die  within  a  few  weeks  ;  that  the  bacteria 

1  Medical  Rooord,  ]iraivh  2(1,  1887. 

^  Abstract  ill  Kcvuo  Sciontifiqne,  April  28,  1900. 

*  Journal  of  (he  Bot^ton  Society  of  Medical  Soienoei;,  IV.,  p.  213. 

*  Boston  Medical  and  Surgical  Journal,  Isovember  21,  1901. 


444  WATER. 

in  ice  are  commonly  harmless  in  character ;  and  that  cities  which  use 
ice  from  polluted  streams  (c.  (j.,  New  York,  Lowell,  Lawrence)  suffer 
a]ijKirently  none  at  all  therefrom.  The  State  Board  of  Health  of 
Massachusetts  says  (Annual  Keport  for  1900),  concerning  the  bacterial 
content  of  the  domestic  supply,  "  In  not  one  instance  of  the  still 
freezing  of  ordinarily  polluted  water  ....  have  we  been  able  to  find  B.  coli 
in  the  ice  formed." 

Recent  experience  at  Ogdensburg,  N.  Y.,  seems  to  indicate  that  ice 
taken  from  a  polluted  river  having  a  fairly  rapid  flow  may,  however,  be 
a  source  of  danger.  In  October,  1902,  after  almost  total  freedom  from 
ty])lioid  fever  for  nearly  two  years,  an  outbreak  occurred  among  the 
inmates  of  the  St.  Lawrence  State  Hospital,  the  water-supply  of  which 
was  beyond  reproach.  The  attack  was  purely  local,  other  users  of  the 
w^ater  not  being  affected.  The  possibility  of  infection  from  other 
sources  having  been  eliminated,  attention  was  directed  to  the  ice,  and 
it  appeared  that,  about  six  days  before  the  development  of  the  first 
cases,  a  new  su])ply  taken  from  the  St.  Lawrence  River  and  stored 
for  more  than  seven  months  had  been  brought  into  use.  Sjiecimens  of 
the  ice  yield  a  black  sediment,  which,  on  examination  by  Hutchings 
and  Wheeler,^  was  found  to  contain  bacilli,  cultures  of  which  responded 
to  the  tests  for  B.  typhosus,  including  clumping  when  treated  with 
serum  from  a  typhoid  patient. 

Artificial  ice  is  frozen  in  blocks  of  the  size  and  shape  of  the  tanks 
in  which  the  water  is  held.  As  the  entire  mass  of  water  in  each  tank 
is  frozen,  it  naturally  must  contain  in  its  inner  portion,  which  is  the 
last  to  freeze,  all  of  the  matters  originally  contained.  Unless  the  water 
used  is  pure  and  colorless,  the  ice  will  not  be  of  good  quality,  and,  par- 
ticularly in  the  center,  will  not  be  of  good  appearance.  When  colored  or 
impure  water  is  used,  it  is  a  common  practice  to  remove  the  impurities 
and  coloring  matters  by  tappmg  the  center  before  the  freezing  process 
is  completed,  and  drawing  off  the  liquid  in  which  they  have  become 
concentrated.  On  account  of  the  possible  retention  of  part  or  all  of 
the  contained  impurities  and  bacteria  of  the  water  from  which  it  is 
made,  artificial  ice  should  be  manufactured  only  from  distilled  water 
or  from  natural  water  of  the  highest  degree  of  purity. 

CHEMICAL  EXAMINATION  OF  WATER. 

Collection  of  Samples. — In  taking  samples  of  water  for  chemical 
analvsis,  great  care  is  necessary  in  order  to  secure  specimens  which 
shall  be  fairly  representative  of  the  supply  under  investigation.  They 
should  be  taken  only  in  clean  glass  bottles  or  demijohns  of  from  half 
a  gallon  to  a  gallon  capacity,  and  never  in  stone  jugs,  tin  cans,  or 
wooden  kegs.  The  best  form  of  bottle  has  a  glass  stopper,  but  a 
perfectly  clean  cork  is  unobjectionable.  In  spite  of  directions  most 
carefully  given,  one  often  sees  specimens  sent  in  stone  jugs  stopped 
with  wooden  plugs  wrapped  with  old  cotton  rags  or  pieces  of  news- 
'  American  Journal  of  the  Medical  ScienceSj  October,  1903,  p.  680. 


DKTI'HIM  I  NATION   OF  FltKh:   ANI>    A  LI'.IIM  I NOI  I)    AMMONIA.     \  \'i 

paper  to  Hctciint  ;i,  li^lilcr  fil.,  ;iii<l  sotncliiiicH  Hincarcd  with  HliocmakcrK' 
wax,  pil-cli,  or  <vcii  hillow.  Analysis  of"  siidi  .s|icciiii(ii-,  i-  lil<c|y  to 
^iv(!  rciStilts  (»r  no  \;iliii'  wlialcs'cr,  lor  il  hlionM  lie  riiM<'iiil)<'i<<l  ihat.  we 
ar(!  <l('alin<:;  willi  cxcrcdin^ly  small  anionnts  ol  atnnionia  an<l  other 
|)ro(ln(!(.s,  and  that,  anylliin^  shoiM  <»r  al)soliit<!  (th'anlincss  of  rcrcpfach-H 
inlrodniM's  crrc)!-. 

The  holilc,  sii|>|toscdlv  (^Ic.'in  at  t  lie  sl:i  rl ,  should  he  rin-cd  thoroughly 
with  lh((  walci-  to  he  saniphd,  t  lien  lillcd  to  the  neck,  and  scfiurely 
stoppered.  11"  the  sample  (ionics  from  a  pump,  the  harrcl  ol'  the  latter 
.should  be  ein|)(ied  eoniplctely  of  I  he  water  which  has  been  standing  in 
it  for  any  lena;lh  of  lime;  if  from  a  pi|)c,  the  water  .should  he  allowed 
to  run  to  waste,  until  the  ulioh;  of  the  orijjjinul  contents  has  esca|M-d  ; 
if  from  a  pond  or  other  body  of  water,  the  bottle  should  be  plunged 
snlllieiently  far  beneath  the  surface  to  avoid  the  entrance  of  (loafing 
matters,  and  at  a  sunieient  distanc(!  from  th(!  banks  to  avr»id  rnatt<'r.s 
that  \\\\\r  the  shore. 

After  tlie  .sain])le  is  secured,  as  littJe  time  as  j)ossible  .should  elapse 
before  bejj^inning  the  analy.sis,  bccau.se  of  the  rapidity  with  which 
clumg-cs  occur  in  tlu;  orijjanic  matters,  ammonia,  nitrites,  and   nitratt'8. 


Determination  of  Free  Ammonia  and  Albuminoid  Ammonia. 

Solutions  Required:  1.  Standard  Solution'  of  Amm(»mim 
CiiLoiiiDi;. — ^I)iss(»lve  3.138  grams  of  pure  dry  ammonium  c-liloride 
in  1  liter  of  distilled  water  free  from  ammonia.  One  ec.  of  this  solu- 
tion represents  1  mgr.  of  ammonia. 

2.  Standard  Dilute  Solution  of  Am.aionium  Chloride. — 
Dilute  10  cc.  of  the  strong  solution  u|i  to  1  liter  with  water  free  from 
ammonia.     One  cc.  of  this  solution  re})resents  0.01  mgr.  of  ammonia. 

3.  Solution  of  Sodium  Carbonate. — Dissolve  200  grams  of  pure 
sodium  carbonate  in  1  liter  of  w^ater  free  from  ammonia. 

4.  Alkaline  Potassium  Permanganate. — Dissolve  8  grams  of 
potassium  permanganate  and  200  grams  of  cau.stic  ]>otash  in  2  liters 
of  distilled  water,  and  boil  down  to  1  liter,  to  get  rid  of  any  free  am- 
monia present.  Fifty  cc.  of  this  solution  are  required  for  each  anal- 
ysis. The  author  finds  it  convenient  to  omit  the  boiling-down  ]iroc- 
ess  when  the  solution  is  prepared,  and  to  take  100  cc.  and  boil  down  to 
50  at  the  time  of  analysis.  This  insures  freedom  from  ammonia  when 
used,  and  avoids  the  bumping  which  is  so  likely  to  occur  when  the  cold 
solution  is  added  during  the  process  of  distillation. 

5.  Nessler's  Reagent. — Dissolve  35  grams  of  potassium  iodide  in 
150  cc.  of  distilled  water.  Dissolve  about  16  grams  of  corrosive  sub- 
limate in  300  cc.  of  distilled  water.  Add  the  latter  to  the  former, 
both  solutions  beinff  cold.  Then  add  200  2:rams  of  caustic  soda,  dis- 
solved  in  0.5  liter  of  distilled  water,  and  mix  thoroughly.  Xext  add, 
with  constant  stirring,  a  saturated  solution  of  corrosive  sublimate  until 
the  precipitate  wdiich  forms  is  permanent ;  then  dilute  the  whole  to  1 


446 


WATER. 


liter.  Let  stand  until  clear,  when  the  supernattmt  liquid  should  have 
a  pale-straw  color. 

6.  Ammonia-free  Water. — This  may  be  obtained  by  distilling 
Avater  made  slightly  acid  with  sulphuric  acid.  The  first  25-50  cc.  of 
distillate  shoukl  be  rejected,  and  the  next  50  cc.  should  be  tested  with 
Nessler's  reagent.  If  no  color  appears,  the  distillate  is  ammonia-free, 
and  the  operation  may  then  be  continued  until  the  contents  of  the  re- 
tort are  reduced  to  very  small  volume.  If  the  test  shows  traces  of 
ammonia,  successive  portions  should  be  tested  until  a  negative  result 
is  secured.  It  is  well  to  prepare  a  goodly  supply,  and  to  keep  it  on 
hand  in  glass-st<)pj)ered  bi)ttles. 

Apparatus  Required. — Distilling  Apparatus. — Some  analysts  pre- 
fer glass  retorts  ;  others,  distilling  Ilasks  with  side  tubes.  Whichever 
is  used,  the  connection  with  tlie  Liebig  condenser  should  be  tiglit. 
The  author  prefers  a  distilling  flask,  with  a  side  tube  of  such  a  size 
that  it  enters  the  condenser  tube  easily,  but  without  making  a  loose 
joint.  A  bit  of  clean  rubber  tubing  on  the  side  tube  may  serve  to 
make  the  joint  more  perfect  at  the  point  of  entrance.     The  mouth 

Fig.  41. 


Distilling  apparatus  used  in  determining  the  ammonias  in  water. 

of  the  flask  should  be  closed  with  a  rubber  stopper  with  a  single  per- 
foration, carrying  a  funnel  tube  which  reaches  to  the  bottom  of  the 
flask. 

The  flask  or  retort  may  be  heated  either  by  a  rose  burner  or  by  the 
free  flame  of  a  Bunsen  lamp.  In  laboratories  where  water  analysis 
is  conducted  on  a  large  scale,  it  is  found  convenient  to  have  the  dis- 
tilling flasks,  arranged  in  the  form  of  batteries,  connected  with  block 
tin  condensing  tubes  which  pass  through  a  common  cooling-tank  fed 
by  a  single  tap. 

In  Fig.  41  is  shown  the  form  of  apparatus  which  the  author  finds 
convenient  for  ordinary  work. 


Dh'T/'JUJUNA'J'ION   <>!<'   I<'l;.l':i':   and    MJlllMISniH    AM.\fO.\/A.     117 

Nes.slerizing  Tubes. —  I'oi-  ni.ikiiiH;  \\i<'.  (IclcrmiiKiiiipn  i,{'  atiitnonla  l»y 
ili(!  coloriiiicl  ric  iiiclliod,  (iiIk-  oI' ('(ilorlcss  ^^las.^,  ahoiil  lli^  x  jj  in<;li(;H, 
vvidi  a  mark  al   tlic  oO  (•<•.  |)oiiil,  arc  rcijnircW. 

Determination. -TIk'  i\:\A<  and  coiHlin-cr  arc  rinsi'd  with  airiiiio- 
iila-l'rcc!  \val'<'r,  ().;'>  lilcr  of  llic  walcr  nnd  •")  re.  (,('  sodium  carlxmaU; 
solill-ioii  arc  iiilrodiiccd  inl(.  ihc  ll;i^-k,  and  lic;it  i-  a|i|ilicd.  'I'lic  (li.s- 
tillai(!  is  cdlhM'Icd  cillici-  in  llic  .\c,--lcr  tnlics  or  in  .,iO  a-.  liaHk.s,  Irorn 
wliicJi  it  Is  (ranslcrrcd  lo  iIh'  liihcs;  and  wIhii  I  lircc  |)(M'ti()nH  of  50 
(i(\  each  have;  been  collcclcd,  ;dl  of  the  free  ainnioni;i  in  ihc  samph! 
will  iia\'(^  |)asscd  o\cr. 

On  h('i;iniiini;'  (he  di.-;!  IMal  ion,  lODcc.  of  I  he  nnroiicciitraU'd  alka- 
line permanganate!  sohilion  arc  healed  in  a  sin.dl  lla.-l<  and  hoilcd 
down  to  50  (!(!.,  and  on  (he  coniiiht  ion  of  the  distillation  lor  free 
ammonia,  the  hot  reagent  is  a<lded  through  th(!  tnnnci  tnhe,  and 
boiling  is  eontiimed.  If  tin;  I'eagcnt  has  been  eoiieentratcd  in  a«l- 
van(;e,  50  ee.  arc  added.  The  nitrogenous  organic  matter  is  now 
attax'ke(l  b\'  the  permanganate!  solution  and  moi'c  anunonia  i.s  evolved. 
While  this  in  no  way  dilTers  from  the  free  amni'mia,  it  i.s  given  tin; 
distinguishing  name  "albuminoid  anunonia,"  lo  indicate  its  origin, 
I'lie  pi'o(H'ss  is  now  (continued  as  long  as  ammonia  pas.ses  over,  but 
usually  no  reaction  is  observed  al'tei'  four  portions  of  50  cc.  have 
been  collected.  In  the  laboratory  of  the  >State  Board  of  Healtli  of 
Massachusetts,  it  is  the  custoin  to  fill  five  tubes,  and  then  to  cea.sc 
distilling.  'I'o  each  of  the  tubes  containing  the  animonia,s,  2  cc. 
of  NessU>r's  reagent  are  added.  lu  the  presence  of  ammonia,  a  yel- 
lowish-brown color  is  produced,  the  depth  of  which  depends  upon  the 
amount  of  ammonia  prevSeut.  Some  exceptionally  rich  waters  yield 
such  an  amount  of  ammonia  that  a  precipitate  is  formed  on  addi- 
tion of  tlu^  r(>agent.  Then  it  is  necessary  to  rejieat  the  process,  and 
to  take  an  aliquot  part  of  the  distillate  and  dilute  it  with  anmionia- 
free  \vater  to  50  cc.  before  nesslerizing.  Should  a  ]irecipitate  agjiin 
occur,  a  smaller  part  should  be  taken,  and  so  on  until  the  proper 
reaction  is  obtained.  The  amount  in  the  whole  distillate  may  then  be 
determined  mathematically.  Having  nesslcrized  the  several  tubes, 
the  next  step  is  to  determine  the  amounts  present  by  comparison  of 
colors  \vith  a  scale  made  as  follows  :  Into  a  series  of  tubes,  held  in 
a  rack,  ditferent  amounts  of  the  M^eaker  solution  of  ammonium  chlo- 
ride are  introduced,  then  ammonia-free  water  is  added  to  each  up  to 
the  50  cc.  mark,  each  tube  inverted  to  insure  thorough  mixing,  and, 
finally,  2  cc.  of  Nessler's  reagent  added  to  each.  A  convenient  scale 
is  secured  by  using  0.25,  0^50,  0.75,  1.00,  1.50,  2.00,  2.50,  3.00, 
3.50,  4.00,  and  5.00  cc,  representing  0.0025,  0.0050,  0.0075,  0.010, 
0.015,  0.020,  0.025,  0.030,  0.035,  0.040,  and  0.050  mgr.  of  ammo- 
nia. The  first  of  these  will  have  a  very  faint  yellowish-brown  tint, 
and  the  last  a  very  decided  reddish-brown  color,  while  the  intervening 
tubes  show  a  progressive  deepening.  With  these  tubes,  the  distillates 
are  compared,  and  the  matching  of  colors  gives  the  desired  results. 
If  a  given  tube  falls  betw-een  any  two  of  the  scale,  a  new  comparison 


448  WATEB. 

tube  may  be  prepared  ;  but  the  practised  eye  can  determine  very  accu- 
rately ^\'ithout  this  extra  aid.  Having  read  the  cok^r  of  each  tube, 
the  amounts  of  th(\>^e  representing  the  free  anunonia  are  added  together, 
and  the  total  multiplied  by  2,  to  get  the  amount  per  liter  of  water ; 
the  same  process  is  carried  out  for  the  determination  of  the  albu- 
minoid annnonia.  The  results  represent  parts  per  million,  since  1 
liter  equals  1,000,000  milligrams. 

ExAJiPLE. — The  three  free-ammonia  tubes  show  0.023,  0.006, 
0.000  :totiil  0.029  mgr. ;  multiplied  by  2  =  0.058  per  liter.  By 
moving  the  decimal  point  one  place  to  the  left,  we  have  0.0058  part 
per  100,000,  in  which  terms  the  results  ordinarily  are  ex])ressed. 

Precautions. — Since  the  depth  of  color  caused  by  Nessler's  reagent 
is  atitected  more  or  less  by  temperature,  and  since  in  all  processes  of 
comparison  the  conditions  must  be  the  same  so  far  as  is  possible,  the 
reagent  should  not  be  added  until  the  distillates  and  the  contents  of 
the  comparison  tubes  have  the  same  temperature.  Equality  in  this 
respect  is  secured  without  any  manipulation  or  trouble  by  leaving  the 
tubes  over  night,  so  that  all  will  acquire  the  temperature  of  the  room. 
It  is  hardly  necessary  to  point  out  that  the  air  of  the  room  in  which 
the  distillation  is  conducted  should  be  quite  free  from  laboratory 
fumes,  such  as  ammonia  and  sulphuretted  hydrogen,  which,  being 
absorbed  by  the  distillate,  would,  in  the  one  case,  give  erroneous 
results,  and,  in  the  other,  react  upon  the  mercury  salt  iu  the  Nessler's 
reagent. 

The  heat  applied  to  the  distilling  flask  should  be  so  regulated  that 
the  time  required  for  each  portion  of  50  cc.  will  be  about  fifteen 
minutes,  since  with  more  rapid  distillation  there  is  likely  to  be  some 
loss  of  ammonia  by  imperfect  condensation. 

The  reading  of  the  tubes  should  not  be  undertaken  until  at  least 
five  minutes  have  elapsed  after  the  addition  of  the  reagent.  The 
extreme  depth  of  color  obtainable  is  reached  somewhat  Avithin  that 
time. 

The  practice  of  some  analysts  of  distilling  the  free  ammouia  out  in 
one  lot  of  150  or  200  cc,  collecting  the  albuminoid  ammonia  in 
another  single  portion  of  200  or  250  cc,  nesslerizing  a  portion  of  each, 
and  calculating  the  total  amount  of  each  by  multiplication  by  the 
proper  factor,  gives  correct  results  ;  but  it  has  been  shown  that  by  pro- 
ceeding in  this  way,  one  may  lose  useful  information  obtainable  from  a 
knowledge  of  the  rate  at  which  the  ammonia  is  evolved,  since  organic 
matter,  well  advanced  iu  decomposition,  yields  it  more  copiously  in  the 
first  distillate,  whereas  fresh  material  yields  it  more  slowly  and  uni- 
formly. 

Some  analysts  make  duplicate  distillations  of  one  water  at  the  same 
time,  determining  the  free  ammonia  in  one  sjDCcimen,  and,  by  add- 
ing the  permanganate  at  the  start  in  the  other,  determining  the 
total  free  and  albuminoid  ammonia  together.  By  subtracting  the 
lesser  from  the  greater,  the  amount  of  albuminoid  ammonia  is 
obtained. 


DI'JTI'JIiM  I  NATION   OF   F/ih'/':  AND   A  I.IHJ  M I  NOl  l>    AMMONIA.    \V.) 


Permanent  Ammonia  Standards.  In  onh't-  to  uvoid  tlu-  nocx*m\{y 
of  |)r('|»:u'iii;4'  si;iii(l;ir(ls  cncli  liin.'  llus'  .'iiv  rc(|iiin'<l,  for  tlioM!  made  ;ih 
:iJ)(»V(' soon  iindcri^o  cJiiiiif^a!,  Mr.  I ).  I  >.  .l.i'I; -'-n  '  li;is  propoHcd  rii:d<iii;.' 
ii  ))(!niiiui(!iil,  set  vvirli  |)otiissiiiiii  phil  inic  (ililoridc  ;iiid  c.ohulf.oii.s  (;l)l(H-id(;, 
witJi  wliicJi,  Willi  -A.  liMlc  |)r:i(;ti<r,  ih..  X.iHHlor  Holiition  nijiy  Ix;  prcpjin^l 
to  (it  c.xiuitly.  Since  liis  nicllio.l  of  \m'\y^r'\u\r  flu-  1;iM«t  dilllirH  iiiat<- 
riully  (Voni  that  ahovc  dcscrihcd,  it  is  iv|n-odnc(;d  licrc:  "  Di.-solvc  <;i.75 
frnmis  oC  poiassinni  iodide  in  j!o()  n-.  ol'  rcdi.stillcd  water,  an<l  add  a 
cold  solution  oC  nicrcniic  diloiidc  w  liicli  lias  l)C(!n  saturated  hy  ixtilin^ 
with  excess  oC  tlu;  salt,.  I'onr  in  I  he  niorcury  Holiitloii  caiitioiisly,  and 
add  :in  aiiionnt,  just  siillieient  to  nnike  the  color  a  |>ernianent  hrijrlit 
red.  With  a  little  practice,  the  e.\a<'t  depth  of  color  can  Ik;  easily 
duplicated.  It  will  take  a  little  over  lOO  cc.  ol"  the  mercuric  (•hloride 
solution  to  reaeh  this  end  point.  Dissolve  the  red  precipitate  l»y  add- 
iuo-  e,\a,ctly  O.TT)  <rra,in  of  powdered  potassium  Iodide  'I  hen  add  l-d) 
^rauis  of  potassinni  hydrate  dissolved  in  -JoO  cc.  of  water.  Make  up 
to  1  liter.  Mi.\  thoroughly  aud  allow  the  pnicipitate  fortued  to  settle. 
It  18  best  to  uiake  up  a  large  amount  of  Nes.sler  solution,  and  if  hy  its 
use  the  anunouia  standards  do  not  fit  the  artificial  ones  |)repared  from 
the  platinum  and  cobalt  solutions,  a  little  more  mercuric  chloride  to 
int^rease  sensitiveness,  or  potassium  iodide  to  decrwi.se  it,  will  brinj:;  the 
Ncssler  solution  to  the  point  where,  if  just  2  cc.  are  used,  the  re<ridar 
ammonia  standards  will  exactly  fit  the  artificial  ones.  .  .  .  Of 
course,  each  new  lot  of  Nessler  solution  should  be  compared,  to 
see  that  it  has  the  proper  degree  of  sensitiveness  to  fit  the 
.standards." 

To  ])repare  the  permanent  standards,  two  separate  solutions,  one  of 
potassium  platinic  chloride  and  one  of  cobaltous  chloride,  are  necessar\\ 
The  first  is  made  by  dissolving  2  grams  of  the  salt  in  a  small  amount 
of  water,  adding  lOt^  cc.  (^f  strong  hydrochloric  acid,  and  diluting  to  1 
liter.  The  second,  by  dissolving  12  grams  of  the  salt  in  water, 
adding  100  cc.  of  strong  hydrochloric  acid,  and  diluting  to  1 
liter.  ^ 

"  Varying  amounts  of  these  two  solutions  are  required,  because  the 
color  of  the  Nessler  standards  becomes  more  and  more  reddish  as  the 
amount  of  ammonia  increases.  The  standards  are  made  up  in  50  cc. 
Nessler  tubes  1.7  cm.  {W")  in  diameter  and  21  cm.  (8^")  from  the 
bottom  to  the  50  cc.  mark."  Sixteen  standards  are  prepared  with  tlis- 
tilled  water  up  to  the  50  cc.  mark,  as  follows  : 


Ft.  solution, 
cc. 

1.0 
1.8 
3.2 
4.5 
5.9 
7.7 
9.4 
10.4 


Co.  solution. 
cc. 

0.0 
0.0 
0.0 
0.1 
0.2 
0.5 
0.9 
1.3 


Ammonia, 
mgr. 

0.000 
0.001 
0.003 
0.005 
0.007 
0.010 
0.013 
0.015 


Pt.  soUition. 
cc. 

12.7 
15.0 
17.3 
19.0 
19.7 
19.9 
20.0 
20.0 


Co.  solution, 
cc. 

2  2 

3!.3 

4.5 

5.7 

7.1 

8.7 
10.4 
15.0 


Ammonia, 
msrr. 

0.020 
0.025 
0.030 
0.o:i5 
0.040 
0.045 
0.0-50 
0.060 


29 


1  Technology  Quarterly,  XIII.,  No.  4,  December,  1900. 


450  WATER. 

AVbile  these  agree  perfectly  with  tlie  regular  Nessler  ammonia  stand- 
ards on  lengthwise  examination,  they  do  not  at  all  agree  on  side  view, 
the  artificial  standards  a])pearing  decidedly  pink,  instead  of  brownish 
yellow. 

Determination  of  Other  Nitrogen  Compounds. — Preliminary- 
Treatment. — Should  the  s])eeimen  of  water  have  an  appreciable  color, 
due  to  dissolved  vegetable  matters,  it  is  necessary,  before  atteni])ting 
the  determination  of  the  above-mentioned  substances  or  of  the  chlorides, 
to  decolorize  a  suifieient  volume  by  means  of  milk  of  alinnina.  This 
is  prepared  by  mixing  gradually  very  dilute  solutions  of  sodium  hydrate 
or  ammonia  and  alum  or  aluminum  sulphate ;  the  resulting  pieciiiitate 
is  allowed  to  settle,  and  is  then  washed  several  times  by  deeantation. 
The  water  used  in  washing  should  be  free  from  chlorides,  nitrates,  and 
nitrites.  If  strong  solutions  are  used,  the  gelatinous  precipitate  soon 
undergoes  change  both  in  appearance  and  character.  It  becomes  chalky 
"and  loses  its  property  of  removing  color.  In  order  to  remove  all 
coloring  matter,  0.5  liter  of  the  water  may  be  shaken  in  a  flask  with  a 
few  cc.  of  the  thick  "  milk,"  and  then  filtered  through  paper.  By  this 
means,  the  most  highly  colored  swamp  Avaters  are  made  colorl-ess  in  a 
very  few  minutes. 

Determination  of  Nitrogen  as  Nitrites. — Solutions  Required. — 1. 
SuLPHANiLic  Acid  Solution  (paramidobenzene-snlphonic  acid). — Dis- 
solve 0.50  gram  in  150  cc.  of  acetic  acid  (sp.  gr.  1.040). 

2.  Napiithylamine  Solution  (a-amidonaphthaleue). — Dissolve 
0.10  gram,  in  20  cc.  of  boiling  water,  filter,  and  add  180  cc.  of  acetic 
acid  (sp.  gr.  1.040). 

3.  Standard  Sodium  Nitrite  Solution. — Dissolve  0.275  gram 
of  pure  nitrite  of  silver  in  pure  distilled  water  and  add  a  dilute  solu- 
tion of  pure  sodium  chloride  until  precipitation  ceases.  Dilute  to  250 
cc.  and  preserve  in  the  dark  in  an  amber  bottle. 

4.  Standard  Dilute  Sodium  Nitrite  Solution. — Dilute  10  cc. 
of  the  preceding  to  1  liter  with  pure  distilled  water  and  preserve  in  the 
same  Avay.     One  cc.  equals  0.001  mgr.  of  nitrogen  as  nitrite. 

Process. — To  50  cc.  of  water  in  a  Nessler  tube,  or  to  100  cc.  in  a 
tube  of  larger  diameter,  add  2  cc.  of  each  of  the  two  first-mentioned 
solutions.  If  nitrites  are  present,  a  pink  to  a  garnet  color  is  developed 
within  a  half  hour,  the  intensity  of  color  depending  upon  the  amount 
of  nitrite  present.  If  no  change  is  observable  at  the  end  of  a  half 
hour,  nitrites  may  be  recorded  as  absent ;  if,  on  the  contrary,  a  color- 
ation is  produced,  the  test  may  be  repeated,  and  at  the  same  time  one 
or  more  comjiarison  cylinders  pix'pared.  In  similar  tubes,  dilute  to 
the  mark  with  distilled  water  free  from  nitrites  0.25,  0.50,  and  1  cc.  of 
the  dilute  sodium  nitrite  solution,  and  add  to  each  the  proper  amounts 
of  the  test-solutions.  At  the  end  of  half  an  hour,  compare  the  color 
acquired  by  the  water  sample  with  the  standards,  and  nmltiply  by  the 
proper  factor,  to  determine  the  amount  ])er  liter. 

Since  the  air  of  laboratories  in  which  gas  is  burning  is  very  likely 
to  contain  traces  of  nitrites,  which  are  absorbed  readily  by  water,  it  is 


nF/nCllMINA'I'ION   ()!•'  FIIEI':  AND   A  LIU!  M I  SOI  I)    AMMdSIA.    \')\ 

wcill  ('•>  I<<'('|>  I'Ik-  IiiIx'S  corked  or  otiicru  !.-(■  |)rr,tcct(<l.  A  tiilx-  Icl'l, 
oncii  soriK;  liidirs  is  iiliiiosi  sure  to  (l(\(l;i)|)  iiiorf  or  If-s  <'olor. 

'I'lic  color  rc;iclioii  is  due  firsl  lo  llic  ;ictioii  oC  lln'  nilriU:  pnjwait  on 
tli<!  siii|)li;iiiilic  ;i,ci(l,  whereby  :i,  new  eoiii|toiiii(l  ((liii/olteiizcnc-siilplionic 
jinliydridc!)  is  produced,  wlilcli  is  llicii  acted  ii|ioii  Wy  llic  ii;iplilliyl;tfiiiii(! 
iind  coiivci'ted  into  ;ino(lier  (!iy-o-'^r-;iini<lon:i|)lit  li;d(iie-p;ir:i/,ol»eiizenc- 
siilplioiiic  iicid)  wliicli  iiiipiirts  llie  color. 

Permanent  Nitrite  Standards. —  Mr.  .hick-nn  Ii,i-  prr.p.i.-cd  eiiiployin)_r 
|K!rni;in(Mit  st-iuidiirds  (or  llic  nil  rite  dcteriniiiiitioii  ;dsr).  Tlicy  ;irc  nindc 
(roni  two  solutions,  one  ni;ide  liy  dissolving  24  ^nuns  of  cohiiltoiis 
clilori(l(^  in  distilled  w.iirr,  ;iddin<;'  100  vr.  oC  strttn;:;  liy<lrocliloric  ;ici<l, 
jind  diliilin<:;  lo  I  liter;  und  liic!  oilier  l)y  dissolving  1  2  <;niins  of  dry 
{!ii])ric  chloride,  ;iddin<;-  100  co.  of  strong  hydi-oehloric  jutid,  :in<l  dilut- 
ing likewise^  (o  1  liter.  The;  standurds  arc  made  u|)  in  100  cc.  tuhcs, 
,']  cm.  {\l")  in  diameter  and  1:5.2  cm.  (5}")  to  the  100  cc  mark. 
The  followiuf^  tai)h'  j^ives  the  |)roportions  of  ciujh  solution  lo  he  niado 
np  to  the  100  cc.  mark  : 


Co.  .solnliiin. 
cc. 

Cii 

.  solution. 

cc. 

Parts 

of  N  ns  nitrite 
|icr  million. 

1.1 

+ 

1.1 

■-- 

O.OOl 

3.5 

+ 

:^.o 

z=z 

O.OOS 

6.0 

H- 

5.0 

= 

0.005 

12.5 

4- 

8.0 

= 

0.010 

20.0 

H- 

8.0 

= 

0.015 

The  method  of  (k'termiiiiiio'  nitrites,  as  <^iven  hy  Mr.  Jackson,  is  as 
follows  :  Fill  a  100  cc.  Nesslcr  tube  with  the  water  to  be  tested,  add 
1  cc.  of  hydrochloric  acid  (1  :  4),  then  2  cc.  of  sulphanilic  acid  (8 
grams  per  litei'),  and  finally  2  cc.  of  naplithalamine  hyflrochl orate  (8 
grams  per  liter  with  10  cc.  of  strong  hydrochloric  acid)  ;  allow  to 
stand  twenty  minutes  until  the  full  development  of  the  color  appears. 
If  100  cc.  of  water  develop  a  color  corresponding  to  the  second  of 
the  above  standards,  for  example,  it  contains  0.003  part  per  1,000,000 
of  nitrogen  as  nitrite. 

Determination  of  Nitrogen  as  Nitrates. — Solutions  Required. — 1. 
PiiENOLDisuLPiioxiG  AoiD. — Heat  together  for  six  hours  in  a  water- 
bath  555  grams  of  strong  sidphuric  acid  and  45  grams  of  pure  phenol. 
Should  the  resulting  compound  solidify  on  cooling,  it  may  be  liquefied 
again  in  the  bath  and  then  poured  into  a  number  of  small  bottles  pro- 
vided with  ground  stoppers.  Then,  as  needed,  one  of  them  may  be 
placed  in  the  bath  and  the  contents  liquefied. 

2.  Standaed  Solution  of  Potassiu:^!  Xitrate. — Dissolve  0.722 
gram  of  pure  potassium  nitrate  in  1  liter  of  pure  distilled  water. 
One  ec.  equals  0.1  mgr.  of  nitrogen  as  nitrates. 

Process. — Evaporate  10  cc.  or  more  of  the  water  with  1  drop  of 
sodium  carbonate  solution  to  dryness  in  a  small  porcelain  dish.  To 
the  residue,  add  1  cc.  of  phenoldisulphonic  acid,  Avhieh  should  be 
brought  into  contact  Mith  every  ]iartiele  1iy  means  of  a  glass  nxl. 
Dilute  with  water,  make   strongly  alkaliue   with   ammonia   or  caustic 


452  WA  TER. 

potash,  and,  finally,  make  nj)  to  50  or  100  cc.  with  Avater.  Evaporate 
measured  volumes  of  the  standard  nitrate  solution,  treat  the  residues 
with  a  like  amount  of  the  reagent,  and  jiroceed  in  the  same  way  to 
make  a  comparison  scale.  The  addition  of  the  alkali  converts  the 
picric  acid,  formed  by  the  action  of  the  nitrate  on  the  phenoldisul- 
phonjc  acid,  into  the  corresponding  picrate,  which  imparts  a  l)rit>'ht- 
yellow  color^  the  intensity  of  which  depends  upon  the  amount  of 
nitrate  present.  The  comparison  of  tints  may  be  made  directly  in  the 
porcelain  dishes  or  in  tubes  of  the  same  sort  as  used  in  the  nitrite 
deterniination. 

The  accuracy  of  the  test  is  diminished  ))y  the  presence  of  chlorides 
in  notable  amounts,  say  more  than  2  parts  in  100,000,  but  not  by 
nitrites.  On  this  account.  Mason  recommends  the  addition  of  cor- 
responding amounts  of  sodium  cliloridc  in  the  jjreparation  of  the  color 
scale. 

The  standards  made  as  above  do  not  change  on  keeping,  and  hence 
may  be  made  up  in  sets  and  preserved. 

Determination  of  Chlorine. — Solutions  Required. — 1.  Standard 
SoLUTiox  OF  Silver  Xitrate. — Dissolve  4.797  grams  of  pure 
silver  nitrate  in  1  liter  of  distilled  water.  One  cc.  of  this  solution  is 
the  equivalent  of  1  mgr.  of  chlorine. 

2.  Solution  of  Potassium  Chromate. — Dissolve  5  grams  of 
potassium  chromate  in  100  cc.  of  distilled  water,  add  nitrate  of  silver 
solution,  for  the  removal  of  any  traces  of  chlorides  present,  until  a  red 
precipitate  of  chromate  of  silver  is  formed.  Let  stand,  and  separate 
the  precipitate  by  decantation  or  filtration.  This  solution  is  to  be  used 
as  an  indicator. 

Process. — Place  in  each  of  two  beakers  of  similar  size  100  cc.  of 
water  and  5—10  drops  of  the  indicator.  The  beakers  standing  side  by 
side  upon  a  w^hite  surface  of  porcelain  or  filter-jmper,  the  silver  nitrate 
solution  is  added  to  one  of  them  from  a  burette  little  by  little  until,  in 
spite  of  stirring  with  a  glass  rod,  a  faint  reddish  tinge  begins  to  be 
perceptible.  This  is  seen  more  easily  by  comparison  with  the  water 
in  the  other  beaker.  The  burette  reading  is  now  taken,  and  then  a 
drop  or  two  more  of  the  reagent  Avill,  by  intensifying  the  red  color, 
show  that  the  end  point  has  been  reached.  The  process  depends  upon 
the  fact  that  silver  has  a  greater  affinity  for  chlorides  than  for  chrom- 
ates,  and  that,  so  long  as  any  of  the  former  is  present,  no  permanent 
union  will  occur  with  the  latter.  When,  however,  all  the  chlorine 
has  combined  with  the  silver,  the  red  chromate  begins  to  form,  and 
makes  its  presence  known  by  the  change  of  color.  On  completion  of 
the  process,  the  amount  of  the  standard  reagent  used  indicates  the 
amount  of  chlorine  present,  each  cc.  used  representing  1  milligram. 

Inasmuch  as  a  certain  amount  of  the  reagent  is  required  to  give  the 
beginning  tint  in  100  cc.  of  distilled  water,  a  correction  should  be  made 
before  setting  down  the  result.  This  amount  differs  somewhat  with 
different  observers,  since  all  eyes  are  not  equally  quicsk  to  discern  the 
appearance  of  the  reddish  tint,  and  hence  the  best  method  of  fixing 


i)i<yn<:iiM  I  NATION  of  iniia-:  and  ai.iii:)iinoii>  ammonia.   1.",:', 

th(i  iiiiioiiiil  U)  l)(!  Hiil)l  riidcd  is  (ur  c'lcli  one  In  (IflcnniiK'  il,  liimsc-ir  hy 
(!X|K'riiiiciil.iii<i;  wllli  100  re.  (iC  (li>lillc(l  \v:il<T  coiihiiniii^'-  lln;  n'<jiiihif(! 
iUiioiinf'  <>r  llic  iii(li<-:iti)i'. 

Should  tlic  ;iiii()iiii(  dl"  cliliirinc  in  ;i  ^ivcii  ?-;iiii|»lc  he  sn  miiiiII  that 
[\\{\  end  r(!!i(!li<>ii  ii|)|)(!;ii's  on  the  jiddilioii  of  hiil.  a  fi'W  drops  of"  tfu; 
.silviM"  sohidon,  il.  is  best  in  coiiccnl  r.ilc  UoO  or  oOO  cc.  of  (h*;  water  to 
100  ('.{'..,  and  r-cpcal.  the  titration. 

Determination  of  Residue. —  I'lvaiioratc  loo  cc.  of  water  to  dry- 
ness in  a,  perfect  ly  eiean,  (h-y,  aeem-ately  w'eij^hed  platinnni  di.-h.  When 
c!onij)IeleIy  evaporated,  transfer  the  dish  from  the  water'-hath  to  an  air- 
hatli  kept,  at  l()r)°('.,  and  leaAc  it  for  an  hour,  at,  the  expiration  of 
which  time,  |)la(te  It,  in  a  desiccator  to  cool.  |{ew'ei;^h  and  not<!  the 
^ain  in  weight,  which  ri'prcsents  the  ainonnt  of  total  .solid.s  in  the  vol- 
ume of  water  taken.  The  nnmi)er  of  niilli<:;rams  j^ained  rcjiresents  the 
ninnberof  j)arts  pei'  100,000.  The  wei^hinL;;  should  he  done  a- (piickly 
as  possible,  in  oi-der  to  avoid  error  due  to  the  al)sorptioii  of"  atmo.splieric 
moisture  by  hydroscopic  matters  in  the  residue. 

In  order  to  determine  the  amount  of*  volatile  substances,  the  di-h  i.s 
newt  heati'd  to  dull  redness  on  a  platinum  trian<;le  over  a  iiunsen 
lamp.  The  oi-o-anic  matter,  in  the  prcxx'ss  of"  burning  off",  ^ives  rise  to 
more  or  less  blackeuini;:,  and  may  also  evolve  odors  which  often  convey 
some  idea  of  its  nature.  The  blackening  may  disappear  quickly  or 
may  persist  for  some  time,  especially  in  the  case  of  woody  matters,  such 
as  are  ])res(Mit  in  brown  swaiu])  waters.  Animal  matters  cause  an  odor 
like  that  of  burnt  horn  ;  vegetabh^  substances,  one  sUjLrgestive  of  burning 
peat.  The  loss  in  weight  represents  not  only  the  organic  matter,  but 
also  th(>  nitrates,  nitrites,  ammonium  salts,  combined  carbonic  acid,  and, 
if  the  tem]HM'ature  has  been  raised  too  far,  part  of  the  chlorides.  The 
residue  after  ignition  represents  the  "fixed  solids." 

Determination  of  Hardness. — For  the  determination  of  hardness, 
a  number  of  processes  are  in  use ;  but  for  practical  utility,  that  known 
as  the  "soa])  method"  is  to  be  preferred. 

Solutions  RecLuired. —  1.  Standard  Solution  of  Calcium  Chlo- 
RTDi:. — ^^V^gh  out  l  gram  of  pure  calcium  carbonate,  dissolve  it  in  as 
little  as  possible  dilute  hydrochloric  acid,  and  evaporate  to  diyness. 
Add  to  the  residue  a  little  distilled  water,  and  again  evaporate  to 
dryness.  Dissolve  in  distilled  water  and  make  up  to  1  liter.  One  cc. 
represents  1  milligram  of  calcium  carbonate. 

2.  Standard  Solution  of  Soap. — Scnipe  about  10  grams  from 
an  old  dry  piece  of  pure  Castile  soap  free  from  sodium  hydrate  and 
carbonate,  and  dissolve  it  in  1  liter  of  diluted  alcohol.  Let  stand  over 
night  and  filter.  This  should  next  be  standardized  in  the  following 
manner  :  To  100  cc.  of  distilled  water  contained  in  a  glass-stoppered 
bottle  of  about  250  cc.  capacity,  run  in,  from  a  burette,  successive 
small  portions  of  the  soap  solution  until,  on  vigorous  shaking,  a  lather 
is  formed  which  persists  at  least  two  minutes,  and  note  the  amount 
used. 

Repeat  the  operation  with  99  cc.  -j-  1  cc.  of  the  standard  solution  of 


454  WATEE. 

calcium  chloride,  and  then  with  2,  3,  4,  5,  6,  7,  8,  9,  and  10  cc.  of  the 
same  solution  made  up  to  100  cc.  with  distilled  water,  and  note  the 
amount  used  in  each  test.  It  will  not  suffice  to  determiue  the  amount 
necessary  to  produce  a  lather  with  distilled  water  and  with  10  cc.  of 
the  calcium  chloride  solution,  made  up  to  the  same  volume,  ami  divide 
the  diiference  by  10,  since  as  we  go  up  in  the  scale  a  gradual  lessening 
of  the  amount  of  increase  for  each  degree  is  noted.  In  this  way  we 
obtain  a  scale  of  values  for  the  particular  lot  of  soap  solution  made  at 
one  time.  It  will  save  some  trouble  if  one  makes  up  a  number  of 
liters,  but  it  is  necessary  to  make  occasional  tests  to  see  that  the  strength 
does  not  deteriorate,  or,  if  it  does,  to  correct  the  scale. 

Process. — To  100  cc.  in  the  bottle  above  mentioned,  add  the  soap 
solution  in  the  same  manner  as  employed  in  making  the  scale,  and, 
when  the  end  point  is  reached,  note  the  amount  used,  and,  by  reference 
to  the  scale,  ascertain  the  number  of  degrees  of  hardness.  Should  the 
water  be  harder  than  10  degrees,  it  is  best  to  take  a  smaller  amount 
and  make  it  up  to  100  cc.  with  distilled  water  and  then  proceed  anew, 
remembering  at  the  end  to  calculate  accordingly. 

The  result  obtained  expresses  the  "total  hardness."  If  it  be  desired 
to  ascertain  the  temporary,  or  removable,  hardness,  100  cc.  of  the  water 
may  be  boiled  five  minutes  and  then  allowed  to  cool.  The  original 
volume  is  restored  by  the  addition  of  the  necessary  amount  of  distilled 
water,  and  then  the  operation  is  repeated.  The  second  result  indicates 
the  permanent  hardness,  and  the  difference,  if  any,  is  the  temporary 
hardness. 

Determination  of  "  Oxygen  Required." — All  organic  substances 
are  susceptible  of  oxidation  ;  but  as  they  are  widely  variable  in  character, 
they  require  very  different  amounts  of  oxidizing  agents  for  the  attain- 
ment of  the  same  result.  The  several  methods  proposed  for  determin- 
ing the  oxygen-consuming  capacity  of  drinking-waters  have,  therefore, 
only  a  limited  value  ;  but,  in  general,  it  may  be  said  that  a  high  require- 
ment indicates  an  amount  of  organic  matter  inconsistent  with  purity 
when  it  cannot  be  accounted  for  by  the  presence  of  ferrous  salts. 
Since  the  amount  of  organic  matter  is  indicated  pretty  fairly  by  the 
ammonia  and  albuminoid-ammonia  determinations,  the  estimation  of 
the  "  oxygen  required  "  serves  only  as  confirmatory  evidence. 

Solutions  Eequired. — 1.  Standard  Solution  of  Potassium  Per- 
manganate.— Dissolve  0.395  gram  in  1  liter  of  distilled  water.  One 
cc.  is  equivalent  to  0.1  mgr.  of  available  oxygen. 

2.  Standard  Solution  of  Oxalic  Acid. — Dissolve  0.7875  gram 
in  1  liter  of  distilled  water.  One  cc.  corresponds  to  an  equal  measure 
of  the  permanganate  solution. 

3.  Dilute  Sulphuric  Acid,  1:3. 

Process. — The  determination  is  based  on  the  fact  that  potassinm 
permanganate  gives  up  its  oxygen  readily  to  organic  matter,  especially 
in  the  presence  of  acid  and  with  the  application  of  heat.  The  reaction 
is  expressed  in  the  following  equation  : 

4KMnO,  +  6H,S04  --  2K,S0,  +  4MnS04  +  6H,0  +  50,. 


DMri'lfiMf NATION    OF   FH/'H':   AND    A  Li: I ! M I NOI I)    AMMONIA.    155 

TluiM  4  inolcciilcs  (»('  |»crm;iii^uiiiil<'  will  \  I'M  ■>  <>("  ow}z;i-ii,  «.r,  dilliir- 
enlJy  <!X|»i-cssc(l,  0.".2  piirls  Ity  \vci<.'lil  <il'  IIh-  <iiif  will  yield  MiO  |);irt« 
by  WCii^lll  of  (Jic  oilier;  lieiiee,  ."., !)"»')  mI'  |.eiiii;ili;^;iii;ile  e(jii;ils  1,000 
()('  oxygen. 

Ill  iJiis  ()|»ei';iti<»ii,  elciiilinesM  of  vessels  is  ((ftlie  ^r^ltCHt  iiii|)orl;iiif<!. 
A  |)(>r<!(!liiiii  ciisseiole  oi  evil |)or;it iii^'  (lisli  (»r  siinieieiif  size  '\>  made  (it 
for  use  by  boiiiii;;-  it.  in  distilled  water  aeidiilaled  willi  siil|iliiirie  aeid, 
and  addiiij;-  |)erinaiii;aiial(;  solution  iiiilil  no  fnrllier  deeoloratioii  Ih 
()l)S(H"ve(l. 

VVm'v.  200  rv.  of  ilie  sample  in  tlie  di.di,  add  10  ee.  <.f  lli<-  dilute 
siil|)liuri(!  iicid,  and  heat  (o  hoilinj;-.  Add  from  a  biirelfe  siillieienl  of 
\\\v.  |)erman<;analc  solution  to  cause  a  very  distinct  redness,  and  boil 
aj^aiii,  addiiit;'  \\n'.  |)eriiiantj:;aiiate  as  tlie  e<)|or  lend-,  to  lade,  so  as  Ut 
rclaiii  as  nearly  as  possible  tlie  orieinal  color.  When  (intlier  boiling 
for  livctotcn  minntes  fails  to  diminish  the  iiilen.--ity  of  the  color,oxida- 
tion  is  complete.  Add  now  10  ce.  of  the  oxalic  acid  solution,  which 
will  di,scliar}«;o  tlu;  vaAov  if  the  peiMiani;anate  ha.s  not  been  added  Uh) 
freely.  Should  the  coloi-  not  be  discharfred  by  10  cc,  add  10  more. 
Tlavini*;  now  a,  colorless  solution,  add  more  pennan<r;inate  until  a  slight 
pink  color  a,i;aiii  appears.  Note  the  total  amount  of  [H-rmaiifrauate 
used,  subtract  from  it  that  used  up  by  the  oxalic  acid,  multiply  the 
number  of  cc.  remaining  by  5,  in  order  to  arrive  at  the  amount  which 
would  be  wonsumed  by  1  liter,  and  divide  by  10  to  express  the  result  in 
milli^Tains  of  o\vt2;en.  Inasmuch  as  any  nitrites  present  are  oxidized 
to  nitrates,  a  correction  should  be  made  for  them.  This  can  be  done 
very  readily,  since  16  parts  of  oxygen  are  required  for  14  j)ai'ts  of 
nitrooHMi  as  nitrites. 

Since  the  permanganate  solution  is  not  wholly  stable,  it  should  be 
titrated  against  the  oxalic  acid  solution  every  time  it  is  used.  This 
may  be  done  most  conveniently  by  adding,  after  the  operation  is  com- 
pleted and  the  reading  of  the  burette  is  noted,  10  cc.  more  of  the  oxalic 
solution  and  titrating  to  the  same  point  as  before. 

'i'he  oxalic  solution  keeps  better,  if  a  few  cc.  of  strong  sulphuric 
acid  are  adtlcd  when   it  is  being  dilated  to   1    liter. 

Determination  of  Color. — The  color  of  water  may  be  observed  by 
vi(>wing  a  sulhcient  depth  of  the  specimen  in  a  glass  cylinder  against  a 
white  surface.  Color  may  be  expressed  quantitatively  by  comparison 
with  the  standards  for  the  ammonia  determinations. 

Determination  of  Odor. — Place  about  200  cc.  of  water  in  a  500 
cc.  beaker,  cover  with  a  watch-glass,  and  heat  to  about  40°  C.  Give 
the  beaker  a  rotary  motion,  so  that  the  water  is  set  in  motion,  remove 
the  watch-glass,  and  with  the  nose  well  inside  the  beaker  note  the 
character  of  the  odor.  Some  analysts  prefer  to  heat  the  water  in  a 
glass-stoppered  bottle,  the  use  of  which  permits  a  nuich  more  thorough 
agitation  of  the  water  before  applying  the  nose.  The  odor  should  be 
designated  according  to  the  substance  which  its  presence  suggests. 

Determination  of  Reaction. — A  most  delicate  reagent  for  alkalinity 
in  water  is  a  1  per  cent,  solution  of  toluylene-red.     Fifty  ce.  of  water 


456  WATER. 

distinctly  alkaline  will  become  intensely  yellow  on  the  addition  of  2 
or  3  drops.  A  less  deji'rec  of  alkalinity  will  cause  an  orange  or  pale- 
red  color.  It  is  so  delicate  a  test  that  1  part  of  alkaline  carbonate  in 
1,000,000  is  revaded  by  it. 

The  presence  of  acids  is  shown  by  another  sensitive  indicator,  lac- 
moid.  This  is  not  affected  by  carbonic  acid,  nor  by  ferrous  and  other 
metallic  salts  which  are  acid  to  litmus,  but  is  aifected  by  ferric  salts. 
It  may  be  used  as  a  1  per  cent,  solution  in  diluted  alcohol.  Phenol- 
phthalein  solution,  0.5  per  cent.,  is  colorless  in  neutral  and  acid  solu- 
tions, and  pink  in  alkaline.     It  is  aifected  by  carbonic  acid. 

In  the  determination  of  reaction,  a  drop  or  two  of  the  indicator  may 
be  added  to  a  volume  of  the  Avater  in  a  long  glass  tube.  A  very  faint 
change,  due  to  acids  or  alkalies,  is  perceptible  on  looking  down  through 
the  column  against  a  white  background.  If  the  reaction  is  acid,  the 
sample  should  be  boiled,  then  cooled,  and  tested  again  to  ascertain  if 
the  acidity  is  due  wholly  or  in  part  to  carbonic  acid.  Acidity  and  alka- 
linity are  determined  quantitatively  by  titration  Avith  centinormal  solu- 
tions of  sodiuin  hydrate  and  hydrochloric  acid,  using  lacmoid  or 
phenolphthalein  and  methyl-orange  as  indicators. 

Determination  of  Turbidity. — For  the  determination  of  the  degree 
of  turbidity,  several  methods  are  in  use,  among  which  the  following  may 
be  mentioned  :  Mason  ^  recommends  standards  made  by  adding  weighed 
amounts  of  kaolin  to  distilled  water,  each  representing  parts  per 
1,000,000  of  kaolin.  Whipple  and  Jackson^  employ  finely  powdered 
diatomaceous  earth,  instead  of  kaolin,  because  of  the  greater  uniformity 
in  the  size  of  the  particles.  Hazen  ^  measures  it  by  determining  the 
depth  at  which  a  0.1  mm.  platinum  ware  can  no  longer  be  seen. 

Detection  and  Determination  of  Lead. — Many  processes  have 
been  proposed  for  both  qualitative  and  quantitative  determination  of 
this  most  undesirable  contamination.  The  simplest  test,  but  by  no 
means  the  best,  consists  in  adding  a  drop  or  two  of  ammonium  sul- 
phide to  a  volume  of  water  in  a  tall  glass  cylinder,  and  noting  the 
character  of  the  discoloration  produced.  If  darkening  occurs,  due  to 
the  formation  of  a  metallic  sulphide,  the  addition  of  dilute  hydrochloric 
acid  will  distinguish  between  lead  and  iron,  the  sulphide  of  the  latter 
being  soluble.  To  those  who  have  had  practical  experience  in  de- 
tecting minute  amounts  of  metals  in  water,  this  method  is  far  from 
satisfactory.  More  or  less  color  is  imparted  by  the  ammonium  sul- 
])hide,  and  more  or  less  turbidity  is  produced  commonly  on  the  ad- 
dition of  the  acid.  Moreover,  when  unconcentrated  water  is  used  for 
the  test,  no  reaction  may  occur,  although  the  poisonous  metal  is  present 
in  minute  traces. 

Another  simple  test,  depending  upon  the  formation  of  lead  chromate, 
has  been  offered  by  S.  Harvey,*  who  claims  that  water  containing  0.30 

'  Journal  of  the  American  Chemical  Society,  XXI.,  p.  516. 
2  Technology  Quarterly,  XTII.,  No.  3,  September,  1900. 
»  Journal  of  the  Fi-anklin  Institute,  1899,  p.  177. 
*  The  Analyst,  April,  1890. 


DI'ITHIIM  I  NATION    OF  FIIKE  AND    ALIUIMINOIl)    AMMONIA,    l-'j? 

iiiilli;i,r;iiii  (»('  lc;ul  in  I  liter  will  show  :i  liiihidil y  IVorn  (•liroinnte  \vli<-n 
'250  {•.{',.  ■A.vr.  ti'c.'ilcd  vvilli  0.10  ^I'miii  oI' |»f)f;i.~siiiiii  hiclirf)iii:il<' ;  and  that 
in  tw(!lv(;  hours  the  |  tree!  pilule  will  -d  t  !<•  ;ind  licconHr  si  ill  tuorc  dislinr-f . 

Since;  small  ainoiinis  <i("  lead  siil|)lii<lc  remain  in  sohilion,  and  ciiii 
\h\  Koparalc^d  only  willi  <4r('al  diilicnlly  wli'n  I  lie  volume  of  wat(!r  \h 
lai'<i;(',  it  is  best  to  (Mtncenlrale  the;  speeimi  n  lo  a  very  small  l>idl<  hefon; 
a,tt(Mn|)tiniif  to  |)re(ri|>ilalc  (he  lead.  IVom  I  his  point  onward  the 
nudhods  ('m|)loye(l  \ary  xi'vy  eousideralily. 

Li(!l)i'i('Ji  '  precipitates  llie  lead  as  sulphide  in  acid  solution,  coiivortrt 
it  to  sulphate  l)y  tn^atuK^nt  with  nitric  and  sulphuric  acids,  an<l  dissolvcH 
this  by  wai'miuo;  with  a  lew  (!c.  oC  caustic  potash  (I  :  lOj.  The  solnti<(ri  '\h 
iiIt(M'(>d  and  made  up  to  20  c(^,  and  2  vr..  of"  anuuonium  sulphi<l(!  arc 
a-<Ided,  whereby  a  brown  eohir  is  proihieed,  wliieh  may  be  compjirod 
with  the  shades  produced  by  similar  treatment  ol'  e(pial  volumes  of 
distilled  water  (^ontaiuiuL!;  known  amounts  of  a  solution  of  lead  snljthatc 
in  (caustic  potash. 

Antony  and  IJenelli  •^  recommend  the  addition  ol' mereurous  chloride; 
before  precipitation  as  sidphides,  l)elieving  that  thereby  no  trace  of  lead 
can  escape  (VMuplete  separation.  The  cond)iiu'(l  sulphides  are  filtered 
and  dried,  then  heated  to  such  an  extent  that  the  mercury  salt  is  driven 
olT,  leavlnjj;  the  lead  as  a  residue. 

Mr.  li.  W.  Clark,*  after  trying  all  known  methods,  iinds  most  satis- 
faction in  the  following  process  devised  in  his  laboratory  :  3,500  cc. 
are  evaporated  to  25  or  .')0  cc,  10  or  15  cc.  of  ammonium  chh)ride 
solution  added  to  assist  separation  of  the  sulphides,  and  a  considendjle 
excess  of  strong  ammonia.  Hydrogen  sulphide  is  then  added  and  the 
dish  allowed  to  stand  some  hours,  after  which  more  ammonia  and 
hydrogen  snl[)hide  are  added.  After  boiling  to  ex]iel  the  excess  of  hydro- 
gen sulphide,  the  preci])itate  is  filtered  off.  It  contains  any  lead,  iron, 
copper,  or  zinc  as  sulphides,  and  other  suspended  organic  and  mineral 
substances.  It  is  w^ashed  once  with  hot  water,  and  the  paper  is  then 
boiled  in  dikite  nitric  acid  (1  :  5).  It  is  then  filtered,  and  washing  is 
continued  as  long  as  any  acid  is  removed.  The  filtrate  and  the  wash- 
ings are  concentrated  to  about  10  or  15  cc,  cooled,  and  then  mixed 
with  5  cc.  of  concentrated  sulphuric  acid  (specific  gravity  1.84)  and 
heated  until  copious  fumes  of  sulphuric  acid  are  evolved.  In  the 
absence  of  more  iron  tlian  0.025  in  100,000,  acetic  acid  and  ammonia 
are  added  directly.  The  mixture  is  next  boiled  and  filtered,  all  the 
iron,  dehydrated  silica,  and  insoluble  organic  matter  beuig  left  on  the 
paper.  The  filtrate  is  then  used  for  the  colorimetric  determination  of 
lead  by  means  of  comparison  of  the  shade  produced  by  the  addition 
of  hydrogen  sul]-»hide  solution  with  a  set  of  standards  containing  known 
amounts  of  lead. 

With  more  than  0.025  iron  in  100,000,  the  process  is  somewhat 
different :  the  lead  sulphate   is  washed  into  a  beaker  with  alcohol  and 

»  Cheiiiiker-Zeitung,  189S,  XXII.,  p.  2-25. 

'^  .Tounial  do  pharniacie  et  de  chemie,  1898,  No.  7,  p.  72. 

*  Loco  citato,  p.  582. 


458  WATER. 

water,  and  allowed  to  stand  over  niulit,  and  then  filtered  off  and  washed 
with  oO  per  eent.  aleohol  until  free  from  iron.  The  lead  sulphate  is 
then  dissolved  by  boiling  the  filter  with  ammonium  acetate  in  a  porce- 
lain dish.  Experience  has  demonstrated  that  this  process  is  extremely 
accurate  and  reliable. 

The  author  finds  the  following  process  simple,  rapid,  and  accurate. 
E\-aporate  3,000-4,000  cc.  of  water  to  about  15-'20  cc.  in  a  porcelain 
dish  ;  add,  little  by  little,  and  with  gentle  heat,  sufficient  dilute  hydro- 
chloric acid  to  dissolve  any  incrustation  of  salts  on  the  sides  and  bottom, 
and  to  give  a  slight  acid  reaction  ;  then  add  5—10  cc.  of  hydrogen  sul- 
j>hide  water  of  good  strength.  Any  lead  })resent  is  preci])itated  in  a  very 
fine  state,  but  not  so  fine  but  that  the  entire  amount  can  be  collected 
on  II  Swedish  filter.  AVash  twice,  and  then  treat  on  the  filter  with  boil- 
ing dilute  nitric  acid  until  the  black  deposit  is  wholly  dissolved.  Wash 
with  hot  water  as  long  as  the  washings  are  acid,  and  add  them  to  the 
nitric  acid  filtrate.  Evaporate  to  dryness  in  the  original  dish,  add  dis- 
tilled water,  and  again  dry.  Dissolve  the  residue  in  hot  distilled  water 
and  make  up  to  50  cc.  Take  5—10  cc.  and  dilute  to  about  80  cc.  with 
distilled  Avater  in  a  glass  comparison  tube  of  100  cc.  capacity,  add 
hydrogen  sulphide  water  in  sufficient  amount,  make  up  to  100  cc.  with 
distilled  water,  and  mix  thoroughly  by  inverting  the  tube  a  number  of 
times.  Compare  the  depth  of  color  with  those  of  a  series  of  tubes 
containing  known  amounts  of  lead  as  lead  nitrate,  treated  with  hydro- 
gen sulphide  in  the  same  way. 

The  standard  solution  is  made  by  dissolving  0.160  gram  of  pure  lead 
nitrate  in  1  liter  of  distilled  water:  1  cc.  represents  0.1  milligram  of 
lead.  A  convenient  scale  is  made  with  1,  2,  3,  4,  5,  6,  7,  8,  9,  and 
10  cc.  of  the  solution  in  100  cc.  If  the  hydrogen  sulphide  water  is 
added  after  diluting  to  about  80  cc,  the  result  is  a  series  of  sufficiently 
clear  standards  showing  sharp  and  regular  stages  of  color.  If  the 
reagent  is  added  before  the  lead  salt  has  been  sufficiently  diluted,  the 
standards  are  very  turbid,  and  are  lacking  in  the  very  essential  grada- 
tion of  color. 

Should  the  depth  of  color  obtained  in  the  preliminary  test  be  greater 
than  that  given  by  No.  10,  a  smaller  amount  should  be  taken  and  the 
experiment  repeated.  Should  the  color  be  very  faint,  the  whole  of  the 
remainder  may  be  treated  and  compared.  From  the  result  obtained  by 
matching  the  colors,  the  amount  of  lead  in  parts  per  100,000  is  easily 
calculated. 

Example. — Ten  cc.  treated  as  above  gave  a  color  reaction  midway 
between  standards  6  and  7  ;  hence,  one-fifth  of  the  whole  contains  0.65 
milligram  of  lead,  and  the  entire  amount  contains  3.25  milligrams. 
The  amount  of  water  concentrated  was  3  liters.  Hence  1  liter  of  water 
contains  1.08  milligrams,  and  100  cc,  or  100,000  milligrams  of  water, 
contain  0.108  milligram  of  lead. 

Detection  of  Zinc. — One  is  reasonably  safe  in  assuming  that  water 
which  has  ]>een  in  contact  with  galvanized  iron  will  show  the  jirescnce 
of  zinc.     This  may    be   determined  quantitatively  by   evaporating  a 


INFEIIKNCI'IS  AS   '!'()    (HI MiAC'ri'.li    (fF    WATF.Il.  459 

qiiiiiilKy  oC  \v;ilcr  lo  ;i  .sniiill  liiills,  licjiliii^';  IIk-  I.iII<t  willi  :i  siillicicnl 
,'Urioiiiil,  <»("  (liliilc  li^drocliloric  iicid  in  order  In  l;i|<c  ii|i  ;itiy  oxidr'  or 
Oiirhoiiiii-c,  ;ui(l  l-licn  iirficccdinu  lo  llic  |ir(cij)ii;ii  Ion  of  llic  .-iil|)liidf 
iii'iw  inii,Iviii<;  nlkaliiK!  willi  :iiiiiiioiii;i.  Kor  (|ii;ilil;ilivi'  |iiir|M)-c-,  a 
voliliru!  of  Wilier  is  made  slitjlilly  alkaline  willi  ainiiioiiia,  l)oile(|,  ;uid 
lilt(M*(i(l.  'V\\v  addition  of  a  lew  drops  of  tcsl-soiiilioii  of  |)ola--iinii 
f'crrocyiuiidc!  to  (lie  lillialc  will,  in  tin;  |)reH(;iK!(!  (»(' Irarcs  of  zinc,  c;iu.-.(t  a 
wliiUf  ))rc(',i|)itiit(',  or  at  least  an  opalcHcoiicc,  wliirli,  liowcvcr,  may  not 
\u\  distinct,  wltliin  a  half  lioin*. 

Detection  of  Tin.  —  Alllioni;li,  so  fai-  as  known,  tin  in  water  has  mo 
sanitary  si^nifieance,  it  sometimes  is  desirahle  to  aseeilain  its  presence 
in  water  and  in  other  substances.  I*'or  rapid  testing  lor  this  inetnl, 
tiic  nuithod  recommended  by  (J.  Dein'fres'  may  be  employed.  This 
depends  npon  the  fact  that  stainious  componnds  canse  a  n^ldi.sli-violet 
color  with  nitrate  of  brncine.  The  bnuaiie  solution  is  made  by  dis- 
solving O.T)  irrain  of  bru<'ine  in  ')  (•(•.  of  nitric  acid,  dilulin^  to  lio'l 
cc.  with  distilled  water,  boiling  for  fifteen  minutes,  and,  after  eool- 
in<2^,  makin<^  up  the  volume  to  '250  v.v,.  aii;ain.  The  water  is  evapo- 
rated to  dryness  with  a  little  hydi-ochloric  aci<l.  The  residue  is  dis- 
solved in  a  very  little  water,  and  to  it  is  added  1  cc.  of  the  brncine 
solution.  If  so  little  as  tlm  twentieth  part  of  a  milliirram  of  tin  is 
present,  the  color  chano;c  will  be  distinctly  shown  even  in  tlu;  presence 
of  iron  and  co])per. 

Detection  and  Determination  of  Iron. — This  very  common  and 
frequently  troublcsonie  constituent  of  water  is  detected  very  easily  by 
concentratino;  a  sufficient  volume  of  the  sample  to  a  small  bulk,  eon- 
verting  the  iron  present  from  the  ferrous  to  the  ferric  form  by  boiling 
with  a  little  nitric  acid,  and  adding  a  few  drops  of  a  solution  of  |iotas- 
sium  sulphocyjinate,  which  causes  a  deep-red  coloration.  By  means  of  a 
scale  made  with  known  amounts  of  ferric  iron  treated  with  the  .same 
volume  of  test-solution,  the  amount  of  iron  may  be  determined  quite 
accurately.  A  standard  solutiou  of  iron  may  lie  made  by  dissolving 
0.10  gram  of  pure  metallic  iron  in  aqua  regia  and  diluting  to  1  liter 
with  distilled  Nvater  :  1  cc.  represents  0.10  milligram  of  iron.  The 
comparison  scale  is  made  by  diluting  progressively  increasing  volumes 
with  distilled  water  up  to  nearly  100  cc,  adding  a  fe^v  cc.  of  a  5  J5er 
cent,  solution  of  potassium  sulphocyanate,  and  then  making  up  to 
100  cc. 

For  other  determinations  of  a  strictly  technic  character,  the  reader 
is  referred  to  the  many  excellent  treatises  bearing  on  the  subject. 

Inferences  as  to  Character  of  Water  from  the  Results  of 
Sanitary  Chemical  Analysis. 

It  is  impossible  to  fix  any  absolute  standards  by  which  to  pass  upon 
the   potability  of  water    without  reference  to  its  origin,  for  surface- 
waters  cannot  be  judged  by  the  same  standards  as  ground-waters,  and, 
*  Eevue  Internatiouale  des  Falsitioations,  VIII.,  p.  9S. 


460  WATEE. 

moreover,  those  which  ajiply  to  waters  of  either  class  from  one  locality 
may  be  wholly  inapjilicahle  to  those  from  another.  A  surface-water, 
for  instance,  may  without  prejudice  yield  an  amount  of  albuminoid 
ammonia  which  would  be  most  suspicious  in  the  case  of  a  ground- 
water ;  while  the  latter  may  contain,  under  some  circumstances,  an 
amount  of  free  ammonia  inconsistent  with  purity  in  the  case  of  the 
Ibrmer.  Again,  an  amount  of  chlorine  which  in  a  water  from  near 
the  sea  would  be  normal,  would  indicate  in  another  from  far  inland  the 
presence  of  sewage  matters. 

Ammonia  may  be  expected  in  some  amount  in  any  water  ;  it  is 
characteristic  of  decom])osition  of  organic  nitrogenous  matter  of  inno- 
cent character  as  well  as  of  sewage,  and  it  may  be  present  in  consider- 
able amounts  in  both  normal  and  polluted  waters.  Furthermore,  it 
may  be  present  in  higher  amounts  in  water  from  an  uncontaminated 
deep-bored  well  or  in  stored  rain,  than  in  polluted  water  that  has 
undergone  chemical  change.  Albuminoid  ammonia  may  be  yielded  in 
equal  amounts  by  a  water  contaminated  by  sewage,  and  by  one  quite 
free  from  it,  but  rich  in  dissolved  vegetable  matter  derived  from  leaves. 
Richness  in  mineral  matter  may  be  present  equally  in  normal  and  pol- 
luted waters.  A  pure  water  may  be  rich  in  nitrates,  while  a  sewage- 
water  may  have  lost  them  by  reduction.  Either  may  be  colored  or 
not,  clear  or  turbid,  and  odorous  or  odorless. 

There  is  one  constituent,  however,  the  presence  of  which  in  more 
than  measurable  quantity  is  a  tolerably  sure  indication  of  pollution, 
that  is  to  say,  the  nitrites  ;  but  their  absence  is  not  a  guarantee  of 
purity,  for  in  grossly  polluted  waters  they  may  be  wholly  wanting.  In 
general,  however,  it  may  be  set  down  as  a  safe  rule,  that  nitrites  and 
high  free  ammonia  together  mean  recent  pollution  ;  occurring  continu- 
ously, they  indicate  constant  pollution  ;  and,  with  chlorine  fairly  above 
the  local  normal,  ordinary  sewage  contamination.  High  ammonia 
with  nitrites,  but  with  no  marked  increase  in  chlorine,  may  indicate 
contamination  by  matters  from  manured  farming  land. 

The  results  obtained  in  the  chemical  analysis  of  a  specimen  of  water 
are  often  quite  sufficient  for  the  formation  of  an  opinion  of  its  suit- 
ability or  unfitness  for  general  domestic  purposes,  but  more  often  a 
knowledge  of  the  source  and  the  surroundings  thereof  is  necessary 
for  their  intelligent  interpretation.  They  may  be  such  as  to  indicate 
that,  whatever  its  source,  the  water  which  yielded  them  is  very  good 
or  distinctly  bad  ;  but,  on  the  other  hand,  they  may  be  such  that  full 
knowledge  <jf  all  the  facts  is  imperatively  necessary  for  the  formation 
of  a  correct  judgment.  A  water  yielding  the  following  results,  for 
instance,  may  unhesitatingly  be  pronounced  to  be  of  undoubted  purity 
so  far  as  chemistry  can  determine,  quite  irrespective  of  source  (the 
figures  express  parts  per  100,000) : 

Free  ammonia 0.0002 

AlVjuniinoid  ammonia 0.0018 

Nitrogen  as  nitrates 0.0240 

Nitrogen  as  nitrites .  0.0000 


iNi''i<:ni':N<'i<:s  as  to  (juahactiiii  of  watkii.  MW 

(!lil()i-iri(; 0.07 

Vnliililc  residue \  .2^ 

l<'ixc(l  ((tsidlic l.'iO 

'\\)[;,\\  R'sidiic '-i.H-'> 

llMI-dllcSM I.'H) 

A|ipciii;iiicc,  <'li:ir  :iiiil  lirifjhl. 

( Idlor,  iiliHciil. 

( )di)r,  mIwciiI. 

( 'li.llincs  oliscrvc<l  III!  i;^niilii)ri  (if  residue,  im  liliiekeiiillf,'. 

Ill  (liiscnsc  llic  limine-;  imlicilc  ;iliii(i-l  lolnl  ;il»-riicc  <i("  <»r;_Miiic  iii;it- 
(ci's,  M.iid  l)iir  sli^lil-  ;iiiiiiiiii(s  <d'  iiiiiiiT;il  f<)ii>t  it  iirnls.  'I'licrc  is  no 
sii^}i;(!s(.i()ii  ol"  coiilniiiiiKil  iiHi  of  ;iiiy  kiii<i,  .-11111  tlu;  cMily  coiifliisinii 
lliat.  (!iiii  !)('  drawn  is  dial  I  In-  water  is  pure  and  sol"!,  and  snifaMt;  for 
all  donicslie  |)iir|)(iscs. 

Oil  tlic  other  hand,  the  (nllow  iiiu-  results  may,  in  the  same  way,  he 
sufficient  for  uiKiiialified  eondeni nation. 

l^'rec  ;nniii(iui;i 0.4750 

Alliuininuid  luiimdnia O.0")85 

Nitn).sj;c'n  ;is  iiitnitos 4.(i()0 

Nitni.m'ii  ;is  nitritfs 0.0.">4 

Ciiloriue 4.27 

Volatile  residue 11.10 

l<^ixed   residue 23.30 

'I\.tal  residue 34.40 

Hardness 14.00 

Appea ranee,  clear  and  lirinlit. 

Color,  al)sent. 

Odor,  I'oul  alter  lioalinc;. 

Changes  ohserved  on  ii^Miilion  of  residue,  sliylit  Vjlackening. 

These  results,  which  are  actual  ones  obtained  from  a  sj^eeimen  sent 
to  the  author  with  no  statement  of  origin,  warranted  a  report  of 
gross  pollution,  regardless  of  source,  for  the  presence  of  sewage  mat- 
ters was  undeniable,  and  under  no  circumstances  of  geographical  loca- 
tion could  any  other  report  be  made.  Inquiry  concerning  the  origin 
of  the  water  brought  the  informatiim  that  the  M'ell  from  -which  it 
came  was  located  at  no  great  distance  from  a  leaching  eessjxtol,  and 
was  used  only  when  the  usual  source  of  supply,  a  spring,  ran  dry. 
Repeated  attacks  of  illness  of  no  great  seriousness  had  been  noticed 
whenever,  during  the  preceding  three  years,  this  Avater  had  been  used. 

These  two  waters  may  serve  as  good  examples  of  uiuhmbted  purity 
and  extensive  pollution.  Both  are  ground- waters,  and,  Avhat  is  not 
without  interest,  they  came  from  one  and  the  same  small  inland  town. 

Such  results  as  the  above  require  no  long  consideration — they  S]ieak 
for  themselves.  But  it  very  commonly  happens  that  even  a  single 
ingredient  may  cause  susjiicion  of  sewage  p(^llution  to  arise  when 
information  as  to  the  location  of  the  supply  is  withheld.  Thus,  the 
amount  o'i  chlorine  may  be  very  considerably  higher  than  the  lowest 
normal  commonly  observed  inland,  and  yet  well  under  the  amount 
which  excites  no  adverse  comment  in  a  water  from  the  coast.  Thus, 
3.85  ]iarts  in  a  well-water  from  an  island  in  Btiston  Harbor,  and  1.35 
in  another  from  the  bonlers  of  Long  Island  Sound,  may  be  regarded 


462  WATER. 

as  fairly  low  ;  while  if  found  in  s]nnni2:.s  in  the  Green  IMonntain  range, 
they  would  be  most  aljuornially  high  and  of  much  signitieance. 

Again,  such  an  amount  might  come  in  connection  with  fair  yields 
of  the  ammonias,  and  then  under  one  class  of  conditions  the  organic 
matters  Avould  apjx'ur  to  be  of  vegetable  origin  and  in  another  to  be  a 
part  of  sewage. 

It  IS  also  impossible  to  draw  shar]i  dividing  lines  between  small, 
considerable,  and  high  amounts  of  the  ammonias ;  but,  in  general 
terms,  it  may  be  stated  that  up  to  0.005  or  0.006  part  per  100,000 
may  be  regarded  as  low,  from  thereabouts  to  0.015  or  0.020  as  con- 
siderable, and  beyond  as  high.  Measurable  amounts  of  nitrites  are 
most  significant,  while  nitrates  may  run  up  to  several  Mdiole  parts 
per  100,000.  Thus,  it  may  readily  be  understood  that,  in  the  major- 
ity of  cases,  the  results  should  be  considered  in  conjunction  with  all 
material  facts  connected  with  source,  surroundings,  and  opportunity 
for  receiving  pollution. 

Bacteriological  Examination  of  Water. 

The  bacteriological  analysis  of  water  may  be  divided  into  quanti- 
tative and  qualitative  determinations.  The  former  is  commonly  ex- 
tended over  long  periods,  and  has  for  its  object  the  determination  of 
the  normal  bacterial  content  of  a  given  w^ater  supply  and  the  observ- 
ance of  any  unusual  variation  therefrom ;  while  the  latter  is  pursued 
for  the  purpose  of  determining  the  nature  of  the  organisms,  and,  more 
particularly,  whether  they  are  such  as  are  to  be  found  in  the  excreta 
of  the  body.  The  finding  of  such  does  not  mean  necessarily  that  the 
use  of  the  water  will  inevitably  produce  disease,  but  it  indicates  the 
possibility  and  probability  that  water  containing  non-pathogenic  organ- 
isms from  this  source  may,  if  not  to-day,  to-morroM',  or  later,  become 
infected  \vith  others  from  the  same  source,  capable  of  acting  as  the 
exciting  cause  of  grave  disaster. 

As  is  the  case  with  chemical  analysis,  it  is  impossible  to  fix  any 
standard  of  safety  based  on  the  mere  amount  expressed  by  the 
quantitative  results,  since  it  is  the  nature  and  not  the  amount  of 
the  contaminating  matters  which  determines  the  question  of  pota- 
bility. But  sudden  deviations  from  the  seasonal  normal  suggest 
unusual  access  of  contamination,  and  serve  as  warnings  of  possible 
danger. 

The  isolation  and  systematic  study  of  the  various  species  of  bacteria 
in  a  given  water  to  determine  whether  or  not  they  may  be  patho- 
genic, involve  much  labor  and  an  intimate  knowledge  of  bacterio- 
logical technic  which  can  be  acquired  only  by  thorough  training  in 
a  bacteriological  laboratory.  Familiarity  with  the  methods  of  pre- 
paring culture  media  -and  making  cultures,  of  isolating  species  and 
studying  their  characteristics,  is,  therefore,  a  necessary  qualification 
for  the  pursuit  of  bacteriological  examination  of  water,  and  anything 
more  than  a  brief  outline  of  special  methods  employed  in  this  par- 


iiA(;'ri':iu()iJ)(ii(:.\L  I'-.xamisatios  of  wateh.  4<j.'i 

ticiiliU"  (IcM    <»r   icsc.'ircli  would  lie  Imn'iikI  \\\>-  cojic   ()(■  ;i  \v<ir'l<  of  iIiLh 
cliiiivu'lc.r. 

Collection  of  Samples. —  In  l;il<iii^  k:uii|iI'  ,  li  i-,  of  courHc,  ru;<«.'H- 
Hiiiy  i<>  <)l).s(!rv<!  the  most-  Y'\\f\{\  prccriintioiis  w^.uwA  I  lie  iiil  lodijftion  of 
(\xi.l';iii('-(HiH  <)l'<;'!UiisiMS.  y\ll  v<ws(!1h  hIkmiM,  llicrcroic,  lie  ;il)soliil<'ly 
(',l(!:ui  and  sl.crih'.  ('ollcction  ina\'  Ik-  made  cillicr  in  small  Ixdl)  fiilx--, 
di'awn  out  inl(»  a  |>oinl  and  sr;dcd  liv  (ilosnrt-  in  a  lamp  llamc,  or  in 
lioillcs  ofaUonl,  police,  c'l  |)acit  \'  willi  ;.!ronnd  stoi)])!'!-,-.  Tlu'  liniijs  arc 
made.  casiU'  !>>■  an\'l)odv  who  lias  lia<l  <»rdinary  cxiM-ricnci-  in  <|nali- 
lalivc  analysis.  \\\  llic  application  o("  (lie  licat  of  a  lanij)  imimdiauly 
bcCorc  scalint;-,  or  l»\'  \  apoiiziii^'  a  drop  o("  contained  water  Wy  llic  same 
means  and  sealing'  jiisl-  as  llic  la-^l  of  I  he  .sicam  is  oscapinj^,  tliey  will 
contain  lint-  lidlc  air,  and  when  used  ai'c  lilhd  easily  through  the  in- 
lliUMUH'.  of  the  partial  \aciinni. 

Ill  takiiii:;  the  sample,  the  pulnl  Is  inlrodnecd  IhIow  the  .-iirface  of 
th(^  water  and  then  lirokeii  olV  willi  >lcrile  forceps.  The  hull)  is  filled 
partly  almost  imniediaIeK',  and  (hen  ihc  hroken  point  is  sealed  as  hc- 
i'oro  by  the  application  of  heat  from  a  L;as  (lame  or  alcohol  lamp.  If" 
hottlcs  ar(>  nsed,  they  should  (irst  he  washed  on  the  outside  in  the 
water  (()  he  sampled,  and  then  plnnL:;ed  heiieath  the  siirfac*-.  The 
Kt()])pc'rs  aiv  then  withdrawn,  and,  when  lilliii<:;  is  completed,  ihey  are 
replaced. 

If  any  considerahle  time  must  elapse  before  cultures  can  be  made, 
the  samples  should  be  |)acked  in  ice,  iu  order  to  retard  multiplication 
of  the  coutr.ined  bacteria;  and  since  very  low  tem])eratures  have  no 
harmful  influence  on  the  vitality  of  the  organisms,  the  addition  of  a 
small  amount  of  salt  to  the  ice  may  be  of  advantage,  although  freezing 
should  not  be  permitted,  on  account  of  the  danger  of  bursting  the  eon- 
taiucrs. 

Planting  the  Samples. — If  i)ossible,  the  ]>]anting  shf)uld  be  accom- 
plished on  the  spot,  on  account  of  the  multiplication  which  is  inevitiible 
with  delay.  If  this  is  not  j)ossible,  no  greater  delay  should  be  per- 
mitted than  is  absolutely  necessary. 

For  (qualitative  determinations,  two  sets  of  plates  should  be  made  : 
one  on  reaular  amir  and  one  on  litmus  lactose  arrar.  On  the  second 
and  third  days  the  regular  agar  plates  should  be  looked  over,  and  any 
which  show  bad  spreaders  or  a  number  of  colonies  so  large  that  danger 
of  obscuring  the  count  would  result  if  they  were  inen bated  longer 
should  be  transferred  to  the  refrigerator.  On  the  fourth  day  all  the 
regular  agar  plates  should  be  removed  and  counted.  The  tcmpcratin*e 
at  which  they  should  be  kept  is  20°  C.  The  litmus  lactose  agar  ])lates 
should  be  incubated  at  40°  C.  for  18  to  24  hours  only,  after  which 
they  should  be  removed  for  counting.^ 

\Mien  w'orking  on  a  water  of  unknown  character  hitherto  uncxam- 
inetl,  ditfereut  amounts  of  the  sample — 1,  2,  3,  and  more  drops — should 
be  used,  since  one  cim  have  no  deiinite  idea  of  its  bacterial  richness. 

1  IVrsonal  oonimmiioation  from  Mr.  II.  W.  (^lark,  chemist  in  charge  of  the  Lawrence 
Experiment  Station  of  the  Mas§acliusetts  State  Board  of  Heahh. 


464  WA  TER. 

In  quantitntivo  work,  the  nniouiits  taken  should  be  measured  with 
the  irreatest  aceuraey,  es]X'eially  N\hen  preliminary  determinations  have 
sho\vn  sueh  a  number  of  organisms  as  to  make  great  dilution  with 
sterile  A\ater  necessar}-,  for  any  departure  from  absolute  accuracy 
introduces  an  error  which  will  be  multiplied  according  to  the  degree  of 
dilution. 

When  bull)  tul)es  are  used,  their  contents  are  expelled  with  the  aid 
of  gentle  heat,  Avhich  causes  the  small  amount  of  contained  air  to 
expand  and  force  the  liquid  through  the  stenij  which  is  broken  at  the 
point  by  pressure  from  sterile  forceps.  The  expelled  water  is  received 
in  a  sterile  tube,  from  A\hieh  it  may  be  withdrawn  in  a  sterile  graduated 
pi])ette. 

Quantitative  Determination. — The  value  of  quantitative  determi- 
nations lies  in  the  eouq)arisons  which  one  is  enabled  to  make  from  a 
series  of  periodical  examinations  of  the  same  water,  for  the  information 
to  be  derived  from  a  single  examination  has  very  limited  utility.  By 
means  of  periodical  counts,  one  is  enabled  to  form  an  idea  of  the  con- 
ditions normally  present  under  different  circumstances,  and  to  note  at 
once  any  disturbing  influence.  Quantitative  determinations  are  of 
special  value  in  noting  changes  in  the  efficiency  of  sand  filtration  of 
public  supplies. 

Knowing  from  preliminary  tests  or  from  past  experience  how  much 
water  should  be  taken  for  each  plate,  and  the  degree  of  dilution  neces- 
sary, two  sets  are  made,  one  on  regular  agar  and  one  on  litmus  lactose 
agar,  and  the  growths  allowed  to  develop,  llegular  agar  cultures  are 
kept  at  20°  C  ;  the  litmus  lactose  agar  plates  are  kept  at  40°  C.  The 
lower  of  these  two  ranges  of  temperature  is  much  more  favorable  to  the 
multiplication  of  ordinary  water  bacteria  than  the  higher,  and  conse- 
quently it  will  be  found  that  the  colonies  developing  on  the  regular 
agar  will  be  decidedly  more  numerous  than  those  on  the  litmus  lactose 
agar.  In  expressing  results,  therefore,  mention  should  be  made  of  the 
culture-medium  employed ;  and  in  making  comparisons  of  one  day's 
results  with  those  of  another,  the  importance  of  limiting  them  to 
figures  obtained  under  like  conditions  of  culture-medium  and  tempera- 
ture is  too  obvious  to  need  further  mention. 

In  counting  colonies  the  following  method  is  pursued  at  the  Law- 
rence Experiment  Station  : 

The  plate  is  placed  on  a  glass  plate  ruled  in  centimeter  squares,  a 
modification  of  the  Wolffhiigel  counting  frame,  and  the  number  of 
colonies  is  counted  with  the  aid  of  a  four-inch  reading-glass.  The 
total  number  of  colonies  on  the  regular  agar  plates,  and  both  the  total 
number  and  the  number  of  red  colonies  on  the  litmus  lactose  agar 
plates  are  counted,  the  results  being  entered  upon  the  record  slip,  to- 
gether with  the  date  and  the  initial  of  the  bacteriologist  who  makes 
the  count.  On  plates  containing  less  than  300  colonies  all  the  colonies 
are  counted.  On  ])lates  containing  more  than  300  colonies  a  fractional 
part  of  tlie  plate  is  counted  and  the  result  multi])lied  by  the  proper 
factor.  On  plates  containing  l)etwc('n  300  and  800  colonies  one-half 
of  the  plate  is  counted.      On   plates  containing  more  than  800  colonies 


I'.Ad'ri'Huoi.ocidM,  I'.xAMisA'rios  or  w.\ri:ii.  105 

a  line  acroHH,  /.  r.,  ;i  stri|»  (nic  cciitiirHlfr  wific  tlir<.ii'_-li  thr-  ttiiiMIc  <>{' 
the  plate,  is  coiinlcd,  wliilf  <iii    |»l;iic.-  wliidi  i'uwi-.uw   colrMiic,-   in  ^n-at 

(!X(!(!HH  Jl  llllliilxl'  <i(  siii.'ill  ,ii(.i-  iri;iy  l)C  cdiiiiIciI,  :i,s,  for  cxiitilplc,  fivc 
K(!l(!(;l(!(l  s(jiiai'(' <"ciil  iiiiclds.  'i'lic  ;i|)|tro|»ri;ilc  I'ikIui-  I'm-  these  two  latter 
coiinls  lor  pl;ilcs  of  (lini'reiil  <li;iiiic(ers  i,-^  shown  in  ;i  l;il>le  atta(:ljc<l  to 
the  eonntin^'  (Viiine.  1 1  is  e;isiel'  ;in<l  inoic  ;iecni;ite  lu  niiikf;  platOH  of 
two  or  (lii"<'e  (lilntioiis  ol"  a  sample  in  order  lo  ohiaiii  a  plate  eonlainitig 
from  r)()  to  .')()()  colonies  than  it  is  to  atleinpl  to  <'<)niit  crowded  plates. 
With  special  sain|»les,  Iiowcvit,  and  willi  iho-e  llnetuaf iiiji;  widely  it  is 
not  always  possible  to  do  this,  and  the  iiaclional  ccnint  is  aji|)ropriate 
in  siKili  oases. 

Qualitative  Determination. — The  chief  interest  in  (pialitativ(;  ex- 
amination oC  drinking-water  lies  in  the  solution  of"  the  question  whetlier 
or  not  intestinal  haeteria  are  presenl.  I'lates  may  he  prepared  and 
preserve(l  in  the  same  manner  as  for  (pianl  itative  work,  except  that  the 
amonnt  of  waicr  planted  nee(ls  no  aeenrate  miiasnrenient,  but,  on 
ac(H»unt  o("  the  usual  i;reat  pri-ponderancc!  of  the  c(»mmon  liarmlesw 
bacteria,  it  is  rarely  th((  case  that  one  can  isolate  the  pathogenic  varie- 
ties without  recourse  to  special  method-^. 

The  test  for  B.  co/i,  as  carried  out  at  the  Lawrence  Experiment 
Station  of  the  State  Board  of  Healtli  of  Massachn setts, ^  may  he  divided 
into  three  steps  :  [a)  preliminary  cultivation,  {/>}  ])latin<::  out  and  is(»lati(»n 
of  the  pure  cultures,  (c)  identitieation  or  (!onfirmation  of  the  cultures. 

{(i)  The  preliminary  tests  are  of  two  kinds,  those  made  iu  fermen- 
tation tubes  and  those  made  in  bottles.  The  fermentation  tube  tests 
arc  made  by  introducing  1  cc,  or  a  fractional  part  oi'  1  cc,  of  the 
water  under  examination  into  a  fermentation  tube  containing  dextrf)se 
peptone  solution.  This  is  conveniently  done  at  the  time  that  the  water 
is  i)ipetted  into  the  plates  during  the  process  of  plating  j  tests  of  larger 
volumes  than  1  cc,  usually  100  or  1000  cc,  are  made  in  bottles,  10 
per  cent,  by  volume  of  pheuolated  dextrose  peptone  solution  being  mixed 
with  the  required  volume  of  water  iu  a  glass-stoppered  bottle.  The 
fermentation  tubes  and  bottles  are  incubated  over  night  at  40°  C.  In 
case  fermentation  occurs  in  the  tube,  it  will  be  manifest  by  a  collection 
of  gas  in  the  closed  arm.  In  case  no  gas  is  observed,  the  bacteria  of 
the  colon  type  are  not  present  and  the  test  is  com]>lete.  The  tests  in 
larger  volumes,  upon  being  removed  from  the  incubator,  are  given  one 
quick,  hard  shake  and  held  up  toward  the  light.  In  case  active  fer- 
mentation has  occurred,  the  gas  will  separate  from  the  liquid  and  rise 
slowly,  giving  the  same  a}>pearanee  as  when  a  bottle  of  highly  carbon- 
ated water  is  opened.  In  case  the  shake  test  is  negative,  it  shi^uld  be 
confirmed  by  placing  about  i  cc.  of  the  culture  in  a  fermentation  tube 
with  dextrose  peptone  solution  and  incubating  24  hours.  When  making 
the  preliminary  tests,  a  record  slip  or  day  card  is  made,  upon  which 
each  sample  tested  and  the  results  of  the  tests  are  indicated  by  plus 
and  zero  signs.  Final  record  slips,  containing  the  name  of  the  sample, 
the  date,  the  volume  of  the  test,  and  its  result  are  made  from  the  day 
^  Pei-sonal  communication  from  ^Ir.  II.  W.  Clark,  chemist  in  charge. 
30 


466  WATER. 

card  after  the  tests  are  completed,  the  volume  tested,  and  the  result 
being  placed  in  the  upper  right-hand  corner  of  the  slip,  the  date  in  the 
center  at  the  top,  and  the  sample  number  in  the  U])per  left-hand  corner. 

(6)  The  positive  tests,  either  in  fermentation  tubes  or  in  the  bottles, 
are  now  plated  out  on  litmus  lactose  agar.  The  record  slips  of  the 
positive  tests  are  arranged  on  the  plating  table,  and  sterilized  Petri 
dishes,  each  .containing  5  drops  of  litmus  solution,  are  placed  thereon. 
With  a  straight,  sterile  platinum  needle  a  minute  quantity  of  the  pre- 
liminary culture  is  transferred  to  the  litmus,  the  plates  are  poured  with 
lactose  agar,  placed  in  the  refrigerator  for  one  hour,  turned,  and  incu- 
bated 24"hours  at  40°  C. 

(c)  On  removing  the  plates  from  the  incubator  they  are  examined 
to  determine  whether  or  not  red  colonies  have  developed.  In  case  no 
red  colonies  have  developed,  the  result  is  negative,  and  is  so  recorded 
on  the  slip.  In  case  red  colonies  are  present,  two  colonies  from  each 
plate  are  transferred  with  a  sterile,  platinum  needle  to  agar  streaks,  the 
agar  streaks  being  incubated  24  hours  at  40°  C.  After  incubation  the 
characteristic  colon  streak  should  be  luxuriant,  smooth,  white,  and 
glossy,  and  should  not  be  stringy  to  the  needle.  Tubes  showing  a  very 
scanty  growth  of  small  colonies  following  the  track  of  the  needle  are 
examined  under  the  microscope  for  the  presence  of  streptococcus  forms. 
They  are  not  B.  coli.  Tubes  which  are  stringy  to  the  needle  or  which 
show  a  wrinkled  growth  are  also  not  B.  coli,  and  are  recorded  as  nega- 
tive, and  tubes  which  show  no  growth  at  all  are  so  recorded.  From 
the  tubes  which  show  the  characteristic  appearance  of  B.  coli  transfers 
are  made  with  a  loop  needle  to  a  fermentation  tube  containing  dextrose 
peptone  solution  to  tubes  of  nitrate  solution,  Dunham's  solution,  and 
with  a  straight  needle  a  stab  culture  is  made  into  a  tube  of  gelatin. 
The  fermentation  tubes  and  tubes  of  nitrate  and  Dunham's  solutions 
are  incubated  at  40°  C. — the  first  two  for  24  hours  and  the  Dunham's 
solution  for  three  days.  The  gelatin  tubes  are  incubated  at  20°  C 
for  fourteen  days.  At  the  end  of  24  hours  the  fermentation  tubes  are 
examined  for  the  presence  of  gas  in  the  closed  arm,  and  the  nitrate 
tubes  are  tested  for  the  presence  of  nitrites  with  the  usual  Griess  re- 
agents. At  the  end  of  three  days  the  Dunham's  solution  tubes  are 
tested  for  the  presence  of  indol  by  adding  1  cc.  of  1  : 1  sulphuric  acid 
and  1  cc.  of  a  solution  of  potassium  nitrite  containing  0.02  of  1  per 
cent.,  the  presence  of  indol  being  manifested  by  the  appearance  of  a 
pinkish  or  purplish  coloration.  The  gelatin  tubes  are  examined  on  the 
fourth,  seventh,  tenth,  and  fourteenth  days  for  the  occurrence  of  lique- 
faction, the  form  of  liquefaction  and  the  date  on  which  it  occurred 
being  recorded  in  case  it  is  observed.  In  recording  these  tests  no 
record  is  made  of  tests  which  are  characteristic  of  B.  coli,  i.  e.,  if  fer- 
mentation occurs,  nitrites  are  formed,  indol  is  produced,  and  no  lique- 
faction occurs,  the  culture  is  finally  recorded  as  of  the  colon  type.  In 
case  any  one  of  these  tests  is  negative,  it  is  repeated  with  the  same  cul- 
ture before  being  recorded,  and  in  case  a  second  negative  is  obtained, 
the  negative  record  is  made,  and  the  culture  is  recorded  as  not  of  the 
ColoD  type.     These  records  are  conveniently  made  in  a  book  ruled  for 


COMry\llA'l'IVI':    VALIII':   OF  ANALYSIS  OF   DiirNKINd -WATFIl.    MM 

llic  i)iir|)OHc,  (lie  hI  rc;il<  ('iilt  iiiv.-,  liciii;.,'  niimlifrcil  >ci'i;illy,  ;i  rc'Of'l  <>{ 
tlic,  s;iin|)l(',  <l;il(',  voliiiiU!,  v.U:.,  IVoiii  wliiftli  (licy  wfn;  f>hl;iitH'«l  Ixiii^ 
rc'c-oidcd  ill  (lie  Itook  ;i.f  llic  tinu!  (lie  stn';il<  (iiiltiircs  wen-  iiiMdr-,  iIk; 
tubes  of"  (',oii(ii"iii:it«)ry  nirdin  bciii*.';  carried  fliroii^di  \\\Ai-v  llif  -eri.d 
nnnihcr.  It  is  iisnal  to  rack  Uj)  llic  streak  eiilliires  in  order  and  (isli 
to  coiidrniiitory  iiiedin  !i(  convfiiiicnl  iiitcrvalH.  As  soon  as  the  fernien- 
tation,  Tiitrjilc,  and  iiidol  lesls  an;  cotiiplete,  tlu;  streak  enltnres  may  hf; 
(kfstroyod,  since  tluy  may  l»e  recovered,  if  necessary,  at  any  time  williin 
fourteen  days  IVoin  (he  <z;ela(in  stal)  cultures. 

Comparative  Value  of  Chemical  and  Bacteriological  Analysis  of 

Drinking-water. 

As  the  science  of  l)ac(('riok)i;y  he^un  to  (k^velop  and  take  tlie  posi- 
tion to  whic^ii  its  iinportaiKH'  o;a\'e  it  a  title,  its  disciples  conceive*!  a 
strong:;  j)r<>,indi(!e  against  and  contenipl  for  any  opinion  as  to  the  jiota- 
bility  of  a  particular  water  based  uj)on  chemical  analysis,  maintaining, 
quite  correctly,  that  minute  amounts  of  ammonia,  albuminoid  ammf)nia, 
and  clilovine  are  incapable  of  actinjr  as  the  excitinj^  cause  of  infective 
disease,  and  that  not  these  substances,  but  only  specific  or<ranisms  not 
demonstrable  by  eheniical  processes,  can  so  act.  It  must  Ik;  conceded 
that,  for  a  time  prior  to  tlie  discovery  of  the  nature  of  the  infective 
agents,  the  importance  of  the  results  of  chemical  analysis  was  grossly 
exaggerated,  and  that  arbitrary  standards,  such  as  were  establislied  by 
the  Rivers  Pollution  (\)miuissioners,  upon  whic^li  conclusions  were  based, 
have,  in  the  light  of  farther  experience,  been  abandoned  as  absurd  and 
untrustworthy.  But  it  must  also  be  conceded,  even  by  those  who  were 
most  caustic  in  their  criticism,  that  chemistry  is  to-day  equal,  if  not 
superior,  to  bacteriology  in  indicating  possible  danger  fi'om  the  use 
of  water  exposed  to  contaminating  influences. 

In  the  earlier  days,  much  capital  was  made  by  bacteriologists  of  the 
fact  that  a  sample  of  water,  inoculated  with  a  culture  of  the  bacillus  of 
typhoid  fever,  was  re}x>rted  by  a  chemist  of  high  standing  as  of  great 
purity  and  eminently  suitable  for  domestic  purposes.  Such  a  test, 
however,  is  unworthy  of  the  slightest  consideration,  since  under  natural 
conditions  a  water  showing  a  high  degree  of  chemical  purity  is  not 
likely  to  be  infected  with  a  })ure  culture  of  a  pathogenic  organism,  and 
the  submission  of  a  pure  water  st)  treated  is  a  mere  trap,  the  setting 
of  which  is  no  more  praiseworthy  than  Mould  be  the  sending  of  a 
sterile  solution  of  cyanide  of  potassium  or  of  sulphate  of  strychnine 
to  a  bacteriologist  Avith  a  request  for  an  opinion  from  the  standpoint 
of  his  specialty  as  to  its  desirability  as  a  beverage. 

Chemical  analysis  can  show  the  presence  of  organic  and  mineral 
impurity  such  as  accompanies  infectious  matters  from  the  intestine  and 
bladder.  It  caimot  give  grounds  for  a  positive  assertion  that  the  use 
of  a  water  thus  polluted  will  inevitably  cause  disease,  but  it  can  and 
does  serve  to  point  out  possible  danger.  It  can  detect  the  presence  of 
sewage  matters,  and  while  it  cannot  jirove  the  presence  of  infectious 
material  therein,  it  can  at  least  point  out  that  the  occurrence  of  typhoid 


468  TIM  TER. 

fever  in  the  eoiinmniity  t\irnisliini2;  the  sewage  is  likely  to  be  followed  by 
other  eases  of  the  disease  in  the  community  whieii  uses  the  polluted  water. 
It  cannot  distinguisli  typhoid  pollution  from  any  other  excremental  con- 
tamination, since  a  healtiiy  body  yields  the  same  chemical  substances 
as  one  that  is  diseased.  In  the  case  of  waters  containing  no  evidence 
of  contamination,  it  can  supply  the  basis  of  an  opinion  as  to  safety,  but 
it  cannot  furnish  any  guaranty  that  the  condition  is  pennanent. 

Bacterioloo;ic^d  analvsis  differentiates  between  ijathotienic  and  non- 
pathogenic  contamination,  but  it  is  only  rai'ely  that  it  serves  to  point 
out  danger  in  advance.  Even  when  an  outbreak  of  typhoid  fever  has 
occurred  and  attention  is  drawn  thereby  to  the  condition  of  the  water 
sup])ly,  the  results  of  bacteriological  examination  are  generally  negative. 
The  reason  for  this  is  twofold.  In  the  iirst  place,  the  examination  for 
the  detection  of  the  specific  organism  is  not  ordinarily  begun  until 
attention  is  drawn  to  its  necessity  by  an  outbreak  of  the  disease,  which 
does  not  appear  until  about  two  weeks  from  the  time  contamination 
has  occurred.  Unless  the  contamination  is  continuous,  by  the  time  the 
examination  is  instituted,  the  polluting  materials  have  either  passed  on 
or  the  specific  organisms  have  perished.  In  the  second  place,  even 
although  they  are  jiresent,  A\ith  our  present  methods  it  is  not  an  easy 
matter  to  isolate  them,  and  we  can  determine  in  most  cases  only  the 
probability  of  their  presence. 

It  should  be  borne  in  mind  that  the  organisms  are  particulate  bodies 
in  suspension  in  great  dilution,  and  that  their  distribution  .is  not  homo- 
geneous as  is  the  case  ^^•ith  substances  in  solution,  and  that,  therefore, 
the  amount  of  water  taken  for  planting  plates  may  not  contain  them. 
But  in  the  unsuccessful  search,  it  is  not  uncommon  to  find  B.  coli  com- 
munis, and  where  this  organism  lurks,  the  other  may  have  been  present. 

As  a  rule,  bacteriological  search  for  the  typhoid  bacillus  has  given 
negative  results.  Laws  and  Andrews  failed  to  find  it  in  the  sewage  of 
London,  although  it  must  have  been  present ;  and  they  had  but  slight 
success  in  the  examination  of  sewage  from  a  hospital  where  forty  cases 
of  the  disease  were  being  treated.  The  reason  for  this  may  be  that 
through  absence  of  suitable  food  material  and  favorable  temperature, 
and  bv  reason  of  the  antagonistic  influence  of  the  ordinary  sewage 
bacteria,  the  typhoid  bacilli  had  lost  their  vitality  ;  or  it  may  be  that 
they  were  so  diluted  that  the  volumes  used  for  planting  failed,  as  a 
rule,  to  contain  them.  Examination  of  the  water  supposed  to  be  con- 
cerned in  the  unusual  outbreak  at  Maidstone  yielded  absolutely  nega- 
tive results,  although  no  reasonable  doubt  can  exist  that  at  some  time 
they  had  been  present. 

Professor  Percy  Frankland,  Avho  has  had  a  large  experience  in 
dealing  with  micro-organisms  in  air  and  water,  says  :  ^  "  The  detection 
of  specific  pathogenic  bacteria  in  drinking-water  is  now  know^n  to  be 
almost  beyond  the  range  of  practical  politics,  and  the  search  for  such 
bacteria  is,  in  general,  only  carried  on  in  deference  to  the  special  request 
of  the  layman,  the  uninitiated,  or  the  hopelessly  ignorant,  whilst  it  can- 
not be  repeated  often  enough  that  any  feeling  of  security  which  may 
^  Journal  of  the  Sanitary  Institute,  October,  1899,  p.  393. 


r!OMrARA'i'fv/<:  vaijim  of  analysis  of  Dniyh'isa-WATFit.   \r,'.) 

he  jjiinilicrcd  fVotn  :iii  iirisiKTcssriil  H(!iircli  (<»r  piit  lioijcnic  h.-icfcriji  in  wliolly 
illiisoiy  jiikI  ill  llic  lii}:,li('Ml.  (Ic^rcc  (l;iii<r<i<'ii;-.  .  .  .  JJy  far  flio  niont 
iiii|)()iiii,nt  service,  wliicli  liiis  hccii  rendered  hy  l);ieteiir»l<i^y  in  flie  meniiH 
wliieli  il  udords  oC  (miiiI  I'olliti^  the  eHir-icncy  of  (ll(r;if  ion  :iiirl  otlier 
|)iirilie;il  ion  |»ro(;esses.  The  sli^htesr  irreu-nl.-u-i) y  or  defeef  in  the;  proe- 
CHS  of  (ih.i-nlion  is  ;ii  ouec  hild  l);ii'c.  iJiicti  ri.,|o;_'ic;d  purity  of  wr-ll- 
vvalcrs  e.iui  ;ilso  he  sivti^fiu^toriiy  conl  idl  l<(|." 

I'rofessor  VV.  II.  1  lornxrks,'  too,  rciiiinkinLf  on  the  (;ict  lh;it,  if  :i 
eonsidenihh'  time  h;is  el;ipsed  since  the  ocenrrenee  of  |i(»lhitioii,  the 
hiie.t<M"ioh)i;i(^d  detcelion  of  the  s;une,  es|)cci;iliy  when  \v;iters  of  {freat 
()rif>;iiial  ijurity  an;  eonccnied,  hee(»nies  more  ;ind  nioi'e  dinieult,  ad<lH  : 
"  It  is,  t!i(M-ef()re,  evident,  that  a  haeferioloiricMl  exaniination  has  its 
limits  of  usefulness,  and  a  shivish  adherene(!  to  it  under  all  eonditioDH, 
c.oinhined  with  neti'leet  of  the  hint-  to  he  ohliiincd  hy  eheinieal  means, 
may  lead  to  a  perfectly  erroneous  judgment.  Still,  there  is  one  hraiicli 
of  hygienic  study  in  which  l)acleriolo<;y  must  always  reij^n  supremo; 
it  is  now  afknowledired  on  all  sides  that  th(!  working;  of  sand  (ilt«-rs 
loi-  puhlic  water  supplies  cannot  We  properly  kept  under  control  excej)t 
hy  a])pi'alin<;"  to  hacteriolonical   methods  of  examination." 

A  positive!  result,  the  lirst  instance  in  which  the  organism  i.->olated 
responded  to  every  test,  includinu;  gi'owtli  on  gelatin,  potato,  litmu.s 
milk,  houillon  and  glucose  bouillon,  agglutination,  and  Pfeiffer's  test 
with  animals,  is  re(U)rik'd  by  Drs.  Kiibler  and  Nenfeld.-  In  tliis  case, 
the  cause  of  the  disease  lay  in  the  use  of  water  from  a  \vell  infected 
by  the  urine  of  a  person  sick  with  the  disease.  Four  weeks  from  the 
time  of  the  first  examination  when  the  bacillus  Avas  isolated,  a  .second 
analysis  was  made,  which  yieldcMl  b;icilli  which  res])onded  to  all  the 
tests  excepting  Pfeitfer's,  wdiich  excei)tion  w^as  supposedly  due  to  modi- 
fied virulence.     No  colon  bacilli  were  present  either  time. 

A  second  instance  is  recorded  by  Fischer  and  Flatau,'^  who  isolated 
the  organism  from  a  well-water  in  Ivellingen.  Similarly,  a  second 
attempt,  made  four  weeks  later,  was  unsuccessful. 

G.  Mayer  ^  claims  to  have  isolated  typhoid  bacilli  ''massenhafl" 
from  well  water.  Jackson  and  INIelia''  were  able,  by  the  use  of  lactose 
bile  media,  to  isolate  the  typhoid  bacillus  from — (1)  Grass  River,  a 
S(Hirce  of  water  supply  for  Canton,  New  York ;  ( 2)  from  a  pond  or  stream 
used  as  a  private  water  supply  at  Hastings,  New  York  ;  and  (3)  from 
two  points  in  the  Hudson  River.  Nevertheles.s,  it  still  remains  true 
that  the  isolation  of  the  typhoid  organisms  from  suspected  water  sup- 
plies is  very  rarely  accomplished. 

From  what  has  gone  before,  it  may  be  said  that  neither  chemical  nor 
bacteriological  analysis  is  infallible.  Each  has  its  uses,  and  each  may 
be  helped  by  the  other.  The  value  of  either  lies  in  the  skill  displayed 
in  interpreting  the  results,  and  this  requires  as  much  knowledge  as  the 
making  of  the  examination  itself. 

1  Bacteriological  Exaniination  of  Water.  London,  1901,  p.  3. 

2  Zeitschrift  I'iir  Hygiene  und  Infectionskranklieiten,  XXXI.,  1899,  p.  133. 

3  Centralblatt  t'iir  Bakteriolooie.  etc,  XXIX.,  p.  329. 

4  Ibid.,  1910.  Rd.  LIIL,  p.  256. 

5  Journal  of  Infectious  Diseases,  1909,  Vol.  YI.,  p.  203. 


CHAPTER  V. 
^      HABITATIONS,  SCHOOLS,  ETC. 

Section  1.     GENERAL    CONSIDERATIONS. 

It  is  essential  to  health  that  the  houses  in  which  we  dwell  shall  be 
built  upon  proper  sites,  free  from  dampness  and  organic  pollution  ; 
they  should  be  provided  with  adequate  means  for  heating,  ventilating, 
and  lighting  ;  they  should  be  well  supplied  Avith  water  for  general 
domestic  purposes,  and  provided  with  a  proper  system  of  plumbing 
for  the  removal  of  sewage ;  they  should  be  constructed  with  proper 
precautions  against  dampness  from  without  or  below.  Heating,  venti- 
lation, lighting,  and  plumbing  are  considered  below  under  their  several 
headings. 

Aspect. — It  is  commonly  directed  that  habitations  should  be  placed 
so  as  to  face  the  south  ;  but,  unfortunately,  one  is  not  always  in  a  posi- 
tion to  be  over-particular  in  the  matter  of  points  of  the  compass,  and, 
indeed,  there  seems  to  be  no  particularly  good  reason  why  that  side  of 
the  house  in  which  is  located  the  main  entrance  should  face  south  and 
the  others  respectively  north,  east,  and  west.  The  southerly  side  of  a 
hill  is  very  much  to  be  preferred  to  the  northerly,  because  of  the 
greater  amount  of  sunlight  and  of  protection  against  the  cold  winds 
from  the  north  ;  but  in  a  plain  and  elscAvhere,  whichever  wall  of  the 
house  faces  south,  there  must  be,  if  the  structure  be  rectangular,  one 
to  the  north.  Far  better  is  a  location  with  the  corners  of  the  house 
pointing  north  and  south,  for  in  that  case  every  window  must  receive 
some  direct  sunlight  at  some  part  of  the  day,  whereas  with  sides  facing 
directly  north  and  south,  the  windows  of  the  former  receive  no  direct 
sunlight  and  the  rooms  are  dull  and  cheerless.  In  large  cities,  aspect 
is  commonly  a  minor  consideration,  the  desirability  of  a  house  being 
determined  mainly  by  other  circumstances.  In  general,  it  may  be  said 
that,  when  possible,  a  house  should  be  so  situated  as  to  insure  an 
abundance  of  light  and  air  with  protection  against  the  cold  winds 
of  winter. 

Construction  and  Arrangement. — Consideration  of  building  ma- 
terials and  the  details  of  arrangement  of  rooms  and  division  of  floor- 
space  are  beyond  the  scope  of  a  work  of  this  nature,  and  it  is  necessary 
only  to  call  attention  to  the  importance  of  insuring  dryness,  light,  and 
air,  and  such  thoroughness  of  construction  as  shall  not  permit  a  too 
generous  amount  of  natural  ventilation  with  consequent  waste  of  heat. 

Of  the  very  greatest  importance  is  the  character  of  the  cellar,  that 
part  of  the  house  which  is  most  neglected  during  both  construction  and 
occupancy.  Unless  the  site  is  one  of  unusual  dryness,  the  cellar  floor 
470 


SCHOOLS.  471 

hIioiiIcI  consisl.  of  :i  ^ciicroiis  hiycr  of  (•cniciil  iinpervioiIK  U)  moiHture 
iVoin  Ixilow  ;i,ii(l  to  s<iil-;iir  ;iii<l  its  (v»iil;iiMiii;it  i'>ri,  yiicli  an  ^,'Ih  from 
l(!!i,lviii^^  niaiiis.  Tlic  (oiiiidiilJoi)  wmJIh  .-IimiiM  l>r  li;.'li(  and  <lry,  ami 
should  coiilaiii  in  llicir  n|)|)<'r  \y,\v\.  a  .'-nllicii  nl  niimlxr  ..f  u  indown  of  a 
Hi/(!  to  udniit  an  adc(|naic  sii|)j>ly  ol'  li;^lit. 

Tlio  vvuIIh  Hlionid  l)c  Miado  as  fiir  us  poHsiblc  pioof  aj^ain.st  wind  and 
wcailKir.  In  C'\|)os<!d  |)osilions,  il.  may  he  fliat  a  claplxtardcd  wall  in 
far  dri(!r  than  on(!  of  l)ri(;i<,  for  I  Ik;  latter  material,  if  very  jiorous,  Ih  not 
un(!ominonly  wet  thronfj^h  by  (lrivin<i;  rain,  and  docs  not  (piieUly  hce/mif! 
dry  a,<j^ain.  Sonuitimcs  it  beeonies  necessary  to  cover  an  entire  brick 
wall  with  a  protective  coatiiifz;  of  paint,  or  even  with  a  sheathing  of  tin 
plate.  ^^)r  proleeiion  against  dampness  and  eold,  ext<'rnal  walls  may 
l)(!  bnilt  with  an  intervening;  air  space,  wlii(!ii  acts  like  that  of  a  double 
window;  the  outer  and  inner  fac(!S  of  the  wall  are  joined  at  intervals 
by  bondin<r  bricks  or  ties  of  various  materials,  includinfr  hard  non- 
porous  bricks,  !j:;Ia/,ed  bricks,  and  iron. 

Rools  should  \)v.  tii^ht  and  protected  a<;ainst  the  backing  up  of 
water  from  lueUing  snow  and  ice  when  the  gutt<!rs  are  filled  with  ice. 
As  a  covering,  slate  is  much  to  be  preferred  to  shingles,  though  its 
initial  cost  is  much  greater  ;  it  is  permanent  in  character,  impermeiible, 
and  recpiires  but  little  repairing,  while  shingles  wear  out  in  course  of 
time,  and,  by  taking  up  moisture,  lead  to  rotting  of  the  timbers  beneath. 
Tin  is  tight  and  im|)ernicable,  but  is  very  hot  in  summer.  Tar  and 
gravel  are  well  suited  to  nearly  flat  roofs,  the  gravel  protecting  the  tar 
from  the  action  of  the  sun,  and  the  combination  being  veiy  durable. 

Care  of  Habitations. — The  ]iro]ier  care  of  a  house  and  its  surround- 
ings is  a  subject  that  can  hardly  be  taught ;  with  many,  it  is  a  natin'al 
instinct ;  with  more,  very  little  is  required  to  satisfy  the  understand- 
ing of  the  term.  A  large  class  distribute  house  sanitation  with  an 
uneven  hand,  insisting  upon  the  perfection  of  care  of  those  parts  wliich 
they  inhabit  and  in  which  the  outside  world  is  received,  and  neglect- 
ing those  where  filth  is  most  likely  to  accumulate,  but  to  which,  per- 
haps, the  general  overseeing  eye  never  penetrates.  In  a  "way,  the  most 
important  parts  of  a  house  are  the  cellar  and  the  kitchen,  and  these 
should  receive  more  careful  attention  than  the  drawing-room,  wherC; 
presumal)ly,  organic  filth  can  hardly  gain  access  in  appreciable  amounts. 
The  otherwise  careful  housekeeper,  to  whom  a  burnt  match  on  the 
hearth  of  an  open  fire  is  an  abomination,  will,  perhaps,  view  with  placid 
fiice  the  boxes,  baskets,  and  even-barrels  of  rotten  fruits  and  vegetables, 
dirty  cans,  and  other  refuse  brought  to  the  surface  from  the  cellar  once 
each  year  at  the  time  given  over  to  '^  spring  cleaning."  The  perfectly 
kept  house  knows  no  cleaning  seasons. 

SCHOOLS. 

Schools,  even  more  than  habitations,  require  the  best  of  situations 
with  reference  to  light  and  air.  A^'indows  should  be  large  and  numer- 
ous, and,  according  to  the  estimates  of  different  authorities,  then*  com- 


47-2  HABITATIONS,  SCHOOLS,  ETC 

billed  area  should  equal  from  a  tenth  to  a  fourth  of  the  totnt  floor  area. 
In  the  arrangenieDt  of  sehool  furniture,  the  maiu  consideration  lies  in 
the  direction  of  the  light.  The  desks  are  placed  best  so  that  the  light 
comes  from  the  left  of  the  pupils  ;  coming  from  the  right,  it  casts  annoy- 
ing shadows  of  pen  or  pencil  in  exercises  requiring  writing ;  cross- 
lighting  may  cause  still  greater  annoyance  by  casting  double  shadows. 
Light  from  the  front  is  exceedingly  trying,  as  may  readily  be  appre- 
ciated by  attempting  to  read  a  clock  placed  between  two  windows  ; 
from  behind,  it  casts  shadows  of  the  body  ujwu  the  work  on  the  desk. 

Cloak  rooms  should  be  spacious  and  well  ventilated,  and  provided 
with  ample  hanging  facilities  permitting  sufficient  space  betM'een  the 
individual  garments. 

Water-closets  and  urinals  demand  more  than  usual  care,  for  children 
are  prone  to  carelessness  in  their  nse  ;  and  since  they  are  commonly 
placed  in  the  basement,  they  are  very  likely,  if  not  kept  in  scrupulously 
clean  condition,  to  pollute  the  air  of  the  rooms  above. 

School  Furniture. — School  furniture  is  well  known  to  be  one  of 
the  most  important  influences  in  the  development  of  lateral  curvature, 
and  much  careful  study  has  been  pursued  in  improving  its  construc- 
tion. Desks  and  chairs  should  not  be  supplied  with  reference  to  age, 
but  according  to  the  size  of  children,  and  should  be  adjustable  to 
each  child.  Common  faults  of  chairs  include  improper  shape  of  back, 
improper  height,  too  great  depth  or  breadth  of  seat,  too  much  slope 
from  front  to  back,  and  improper  horizontal  distance  from  the  desk. 
Common  faults  of  desks  include  insufficient  or  too  great  height,  and 
improper  slope  of  the  surface. 

Chairs  should  be  of  such  a  height  that  when  the  leg  and  thigh  form 
a  right  angle  the  foot  shall  be  squarely  on  the  floor.  If  too  high,  the 
child  cannot  touch  the  floor,  and  fails  to  obtain  the  needed  assistance 
from  the  feet  and  legs  for  the  maintenance  of  an  upright  position  ;  if 
too  low,  the  position  is  cramped  and  awkward  and  the  child  is  forced 
to  extend  the  legs  in  one  direction  or  another,  and  to  contort  the  body 
accordingly.  The  seat  should  be  sufficiently  wide  to  support  both 
thighs  comfortably,  but  not  so  wide  as  to  permit  the  assumption  of  bad 
postures  in  which  the  back  is  not  well  supported.  It  should  not  be 
too  deep  from  front  to  back,  since  then  proper  attitude  is  impossible. 
It  should  slope  very  slightly  from  front  to  back,  or  be  made  slightly 
concave,  in  order  that  the  tendency  to  slip  forward  may  be  counter- 
acted. The  back  should  be  curved  forward,  so  as  to  support  the  child's 
back,  and  to  be  comfortable  in  whatever  legitimate  attitude  he  may 
assume,  for  he  requires  changes  in  position  for  the  relief  of  downward 
pressure  and  strain  of  muscle  and  ligaments,  since  any  attitude  long 
maintained  results  in  fatigue.  With  chairs  of  the  best  form  of  con- 
struction, faulty  attitudes  are  less  comfortable  than  proper  ones. 

Desks  should  be  of  such  a  height  that  the  forearms  of  the  child  may 
be  rested  without  causing,  on  the  one  hand,  stooping,  or,  on  the  other, 
raising  of  the  shoulder  and  curving  the  spine.     If  too  high  for  the 


VENTILATION   AND    IIKATISO.  4725 

(Oiild,  (lie  work  is  I)|-<)I|m|iI  loo  iH;ir,  ;iii<l  r:ni.scs  siniiiiiiij/  of  tlif  fves. 
TIk!  U)\)  should  li:iv((  !i  |>i'o|)cr  slope  (iowiiu.'ird  of  fVom  l<'ii  If)  tweiity 
(lc(i;i'('(!S,  iind  ils  cdfrc  should  projccf,  sli<.dilly  over  the  for\v;ird  (•A\rt'. 
{){'  {\\v.  cJinir,  so  lli;i,l  llic  hody  ;iiid  hciid  iii;iy  iiol  lie  iiM'liii<il  {'hvwavA 
too  \\\x. 

I'i'oncr  licl^hl  ol"  sc'ils  ;iiid  dc-ks  ;iiid  correct  hoii/ontnl  di-t;iner; 
helvvceii  (Jk;  two  ure  attjiiiied  hy  the  ;i(lo|il  ion  of  :idjii.-t;d»le  iiiniiliire, 
of  vviiieh  {\n\\\\  are  many  vari<'ties. 

Blackboards  should  !)<■  <liill  Mack,  aii<l  never  shiny,  lor  if  they  are 
shiny  tluy  rellei^t.  Ii<iht,  and  \\li;il  i-  wiitlen  thereon  is  dilVienlt  to  read 
from  certain  |)oints  in  the  room.  'I'hey  slioidd  lie  kept  well  fJr'am-il, 
in  order  Ihat^  the  ^-ontrast-  wllli  the  cli;dk  .-hall  he  sharp.  'I'lie  elialk 
should  he  white  or  yellow  ;  liinc,  likccu,  ;ind  wd  chalk  marks  an;  iniioli 
more  dillieult.  to  read.  Ulackhoiirds  should  never  he  plaex.'d  iM'twccn 
windows,  on  a<HM)unt  of  ^lare.  ( 'opyiny'  from  hiaekhoards  i.s  very  tiy- 
ing  to  the  eyes,  on  uocount  oi'  the  (Muistaiit  neees.sary  cljange  of  focus. 


Section  2.     VENTILATION  AND  HEATING. 

We  have  se(>n  how  lUH'.essary  it  is  to  life  tliat  llie  C.'fX  ^iven  off  bv 
the  blood  in  the  lnnt>;s  to  tlie  inspired  air  shall  be  disehar^(;d  eontinu- 
ously  from  the  body,  and  we  know  that  whatever  other  effects  the  im- 
purities of  vitiated  air  may  produce,  the  effect  of  undue  COj  in  the  air 
is  to  interfere  with  the  function  of  res])iration.  Therefore,  it  follows 
that  the  air  which  we  breathe  should  be  as  free  as  possible  from  the 
impurities  which  we  continually  discharixe  into  it,  and  that  this  condi- 
tion can  be  obtained  only  by  constant  dilution  of  them  by  a  constant 
supply  of  fresh  air.  In  the  open  air,  this  dilution  i^ties  on  without 
artificial  assistance  and  requires  no  consideration  ;  but  in  confined 
spaces,  Ave  have  to  a  certain  extent  a  reproduction  of  the  conditions 
that  obtain  in  the  lung ;  namely,  the  presence  of  a  volume  of  vitiated 
air,  separated  from  the  purer  surrounding  air,  and  requiring  to  be  dis- 
charged and  replaced.  In  other  words,  the  air  in  the  first  confined 
space,  the  lung,  is  discharged  into  the  second  confined  space,  the  room, 
and  thence  niust  be  removed  to  the  outside  and  replaced  by  an  equal 
amount  of  normal  air.  The  constant  dilution  and  removal  of  impuri- 
ties due  to  the  necessities  of  life,  so  that  their  amount  shall  be  so  small 
as  to  be  harmless,  are  the  function  of  ventilation,  which  may  be  re- 
garded as  the  respiration  of  a  building. 

It  is,  of  course,  not  to  be  expected  that  the  air  of  an  inhabited  room 
can  under  the  usual  conditions  be  maintained  in  a  state  of  purity  like 
that  of  the  outdoor  air,  even  though  but  one  candle  or  one  person  he 
present  to  exchange  carbon  dioxide  and  water  for  oxygen,  but  the 
impurities  can  be  reduced  to  a  mininuun  by  the  introduction  of  a  ]iro]x?r 
amount  of  fresh  air.  AMiat  shall  be  considered  a  proper  amount  of 
continuous  air  supply  depends  upon  what  we  adopt  as  a  limit  of  per- 
missible impurity,  measured  by  the  amount  of  CO.,  present. 


474  HABITATIONS,  SCHOOLS,  ETC. 

For  the  maintenance  of  a  fair  degree  of  vigor  and  stability  through 
proper  oxidation  of  the  blood  and  dilution  of  the  effete  matters  dis- 
charged, and  for  the  maintenance  of  the  fullest  and  most  perfect  func- 
tional activity,  one  requires  respectively  about  30  and  50  cubic  feet  of 
air  per  minute.  Less  than  30  will  inevitably  produce  impaired  vitality  ; 
more  than  50  can  be  productive  of  no  gain  in  improvement,  so  far  as 
the  effects  of  the  ordinary  vitiating  matters  are  concerned.  At  the 
latter  rate,  then,  an  hourly  supply  of  3,000  cubic  feet  is  necessary  for 
the  proper  dilution  of  the  respired  air  of  each  individual  present  in  a 
conhned  ypace.  Thus,  a  room  of  3,000  cubic  feet  capacity,  inhabited 
by  one  person,  should  receive  its  full  capacity  of  fresh  air  once  every 
hour.  But  this  renewal  should  be  a  continuous  process,  so  as  to 
prevent  the  accumulation  of  impurities  which  would  occur  if  the  air 
were  replaced  simply  in  bulk  by  an  hourly  aeration  by  opening  win- 
dows for  the  requisite  few  minutes.  Nor  should  it  be  supposed  that 
even  with  constant  fresh  supply  the  air  of  the  room  can  have  the  same 
composition  as  that  which  enters  from  without,  for  the  impurities  of 
each  respiration  are  not  removed  in  separate,  distinct  lots,  but  are 
mingled  in  the  general  bulk.  If  the  occupant's  head  were  in  a  conduit 
bringing  the  constant  sujDply  of  fresh  air  and  carrying  away  the 
products  of  respiration,  no  such  amount  of  air  M'ould  be  necessary, 
and  no  contamination  of  the  general  supply  would  occur.  Under 
ordinary  circumstances,  Mitli  an  hourly  supply  of  3,000  cubic  feet  per 
capita,  the  amount  of  COj  will  not  range  above  6  or  7  volumes  in 
10,000,  and  any  system  of  ventilation  that  will  keep  it  down  to  this 
may  be  called  good. 

Other  imparities  than  those  of  respiration  are  to  be  considered  in  all 
questions  of  ventilation.  The  influence  of  burning  illuminating  mate- 
rial on  the  composition  of  air  is  very  great,  both  as  to  the  consumption 
of  oxygen  and  the  production  of  COg  and  other  impurities,  and  it 
is  not  insignificant  in  its  relation  to  the  temperature.  The  impurities 
from  1  cubic  foot  of  ordinary  illuminating  gas  are  such  in  amount  as 
to  require,  according  to  various  estimates,  from  500  to  1,800  cubic  feet 
of  air  for  their  proper  dilution.  They  include  not  only  carbon  dioxide 
and  water,  but  carbon  monoxide,  sulphur  acids,  nitrogen  acids,  marsh 
gas,  ammonia  compounds,  unconsumed  carbon,  and  other  matters. 
Different  forms  of  burners  consume  different  amounts  of  gas  to  pro- 
duce the  same  illumination  ;  ordinarily  from  3  to  6  cubic  feet  are  used 
per  hour,  requiring  1,500  to  10,000  cubic  feet  of  air-supply  for  proper 
dilution  of  the  impurities  produced  by  each  burner.  Therefore,  on 
both  hygienic  and  economic  grounds,  the  burner  which  produces  the 
maximum  of  light  from  the  minimum  of  gas  is  the  best  for  use,  it  being 
understood  that  a  given  volume  of  gas  will  yield  the  same  amount  of 
impurities,  whatever  the  burner  employed. 

The  impurities  from  candles  and  lamps  are  less  in  number  and 
variety,  but,  measured  by  their  comparative  illuminating  power,  they 
are  larger  in  amount  than  from  gas.      For  example,  the  combustion  of 


AMOUNT  OF  SPACE  RKQVIIiKl)   FOli   COOl)    VENTILATION.   475 

an  aniouiit  of  ciiiidlc  or  kerosene  oil  neee.ss.'iry  to  jirodiifK;  the  Hame 
in<(!nHiiv  <>('  li<:;lit,  Jis  1  (;nl)ie  loot,  o("  |4;;is  will  [trodiiee  IVoin  40  to  HJO 
|)(!r  eeni.  more  iinpurilic^H,  iiii<l  re<jiiireH,  tlier-ef'ore,  |)roj)ortion;itt;ly  more 
iiir   (oi-   tJieii"   |)ro|)er   diliilicMi. 

'I'lie  snhjeel,  ol"  vent i!;il ion,  invoivinj;,  us  it  do(;tt,  the  e(n)tiiiurjn« 
introdnetion  oC  piiic  ;iir  to  dis|>liie(3  that  which  huH  bect^me  vitiaUjd  by 
wh:U<!V(U'  cjiiisi!  or  lie;ite(|  lo  siieh  ;i  def^nn;  as  to  b(!  in(;onsisteiit  with 
(jondbrt ;  having  to  deal  with  hidldinjrs  and  rooms  of  vnrions  hIzch, 
dosij;ned  for  different  uses  ;  and,  as  it  is  (Oiicifly  in  the  eold(!r  months 
that  its  im|)()rtanec  is  greatest,  bcinjr  intiniat<!ly  connected  with  the 
prol)Iems  and  cost  of  h(!atinui:,  is  a  very  complex  one  which  will  not 
p(M'niit  the  adoption  (»f  iidlexihle  rules  ;i|)plie;d)l<'  to  ;dl  cascH. 


Amount  of  Space  Required  for  Good  Ventilation. 

If  it  l)(i  agreed  that  foi*  the  most  ])erfe(;t  results  an  adult  retjuires  an 
hourly  su|)ply  of  o,0()()  cubic  ieet  for  the  removal  of  his  own  effete 
matters,  to  say  nothing  of  the  accessory  impurity  dependent  upon 
illumination,  the  next  question  is  as  to  the  amount  of  cubic  spa(;e 
ne(!essary  ])er  capita,  that  is  to  say,  through  how  small  a  spatie  that 
amount  of  air  can  be  drawn  hourly  without  disagreeably  j)eree|)tible 
draughts.  The  sensation  of  draught  is  governed  very  largely  by  the 
temperature  of  the  moving  air,  a  cold  slowly  moving  current  being 
more  perceptible  than  a  warm  one  moving  at  a  greater  rate  of  speed. 
Draughts  ^vhich  are  [)roductive  of  discomfort  are  more  dangerous  than 
the  ordinary  vitiation  of  the  air,  and,  therefore,  complete  ventilation 
with  draughts  is  worse  than  partial  ventilation  without  draughts. 

It  has  been  shown  by  Pettenkofer  that,  wdth  the  aid  of  delicate 
ap})aratus  and  mechanical  power,  about  2,500  cubic  feet  cxin  be  passed 
without  draughts  through  a  space  of  424  cubic  feet  in  an  hour  ;  that  is 
to  say,  through  a  room  8  feet  square  and  6.5  high,  the  air  can  be 
renewed  six  times. 

The  minimum  space  ^vithin  which  one  can  receive,  under  artificial 
conditions,  six  complete  changes  of  air  in  one  hour  is,  therefore,  424 
cubic  feet ;  but  in  order  to  get  3,000  cubic  feet  in  one  hour,  the  air 
would  have  to  be  changed  seven  times,  and  so  the  required  minimum 
space  would  be  500  cubic  feet.  In  large  spaces,  however,  it  is  possible 
to  obtain  more  frequent  changes  without  danger  from  draughts.  Thus, 
in  a  hall  40  by  20  by  15  feet,  40  persons  may  be  supplied  with  3,000 
cubic  feet  each  per  hour,  aud  each  one  will  have  300  cubic  feet  of  air 
space.  Therefore,  in  dealing  with  large  spaces,  we  may  assume  300 
cubic  feet  per  capita  rather  than  500. 

lu  the  veutilation  of  small  spaces,  there  is,  in  addition  to  the  possi- 
bility and  danger  of  draughts,  the  grave  difficulty  that  the  inlets  aud 
outlets  are  necessarily  so  near  together  that  much  of  the  air  will  pass 
directlv  from  the  one  to  the  other  without  having  mingled  with  the 


476  HABITATWXS,  SCHOOLS,  ETC. 

main  body  of  air,  ami  without,  therefore,  doing  the  slightest  service  in 
dikitiiig  tlie  impurities  present.  In  large  air  spaces,  this  objection  does 
not  apply  with  equal  foi'ce,  for  the  t)])portunity  for  diffusion  is  greater, 
the  larger  the  space,  although,  of  course,  here,  too,  the  inlets  and  out- 
lets may  be  so  placed  as  to  favor  the  formation  of  direct  currents. 

In. the  ventilation  of  large  spaces  in  which  large  nnmbers  of  people 
gather,  as  churches,  theatres,  schools,  and  lecture-rooms,  Me  are  at  once 
confronted  by  the  fact  that  300  cubic  feet  of  space  is  a  more  liberal  per 
caiMta  allowance  than  is  often  practicable,  and  that  this  space  is  incom- 
])atible  with  a  draughtless  ventilation  by  the  necessary  air  volume.  If, 
then,  the  question  be  asked,  how  to  provide  the  necessary  amount,  there 
is  but  one  answer ;  namely,  that  it  cannot  be  done.  Fortunately, 
however,  the  danger  from  impure  air  is  proportionate  to  the  length  of 
time  of  exposure,  an  occasional  short  time  spent  in  a  crowded  room  or 
public  conveyance  filled  with  bad  air  being  less  harmful  than  prolonged 
and  habitual  occupancy  of  a  room  in  which  the  air  is  less  vitiated,  but 
yet  not  good. 

In  general,  it  may  be  said  that  the  importance  of  ventilation  varies 
with  the  particular  air  spaces ;  those  which  are  used  only  at  intervals 
and  for  short  periods  have  much  less  need  of  it  than  those  which 
are  used  uninterruptedly  ;  those  which  are  not  crowded  demand  less 
than  those  that  are ;  those  used  only  for  the  moment  need  no  consid- 
eration wdmtever,  the  natural  forces  at  work  at  all  times  being  suffi- 
cient for  their  needs. 

To  insist  upon  thorough  ventilation  of  every  part  of  a  house  at  all 
times,  as  m-ost  amateur  hygienists  do,  is  to  demand  a  needless  waste  of 
energy  and  money,  for  except  in  the  warm  months  when  the  windows 
and  doors  are  left  freely  open  for  the  sake  not  alone  of  ventilation,  but 
of  general  comfort,  ventilation  goes  hand  in  hand  with  heating  and 
divides  the  expense. 

Nor  can  one  successfully  insist  upon  any  rule  that  each  person  must 
have  at  least  1,000  cubic  feet  of  air  space  with  renewal  of  the  contained 
air  once  in  twenty  minutes,  for  to  do  so  is  to  urge  in  the  case  of  the 
poor  of  large  cities  an  impossibility,  since  space  is  costly,  and,  with 
ventilation  to  the  proper  extent,  is  beyond  their  means. 

Natural  Forces  in  Ventilation. 

Before  proceeding  to  the  subject  of  systems  of  ventilation,  we  must 
consider  the  natural  forces  which  are  at  work  in  the  presence  or 
absence  of  all  schemes  and  systems.  These  forces  are  diffusion  and 
gravity. 

Diffusion  and  Gravity. — The  rate  at  which  gases  diffuse  is  by 
no  means  the  same  for  all,  the  lighter  diffusing  much  more  rapidly 
than  the  heavier.  In  fact,  the  rate  varies  inversely  as  the  square 
roots  of  their  densities.  The  province  of  diffusion  in  ventilation  is 
limited  to  bringing  the  air  to  a  condition  of  more  or  less  complete 


NA'I'UllAL    I'OnCHS    IN    V KS'I'I LA'ri< >S.  477 

li(nii(><i,'('ii(!it,y  by  ciiiisiiir^  (,li(;  l'^mkcoiis  iii;ilfcrs  (o  Ixftornc  <li-t  iiliiit<(| 
t,Iu'<)iiirli()tiM  lie  iiiiiss  ;  l)iil  in  ;iii  iiiliiiltilcl  ronm  il  f;iii  do  hut,  little 
t(»vv;ir<l  l<('('|)iiii^'  (lie  ;iii'  .'it  il-;  ihii'mkiI  c'liiiini-il  ion.  j'v'  n';i,»<»ti  rif 
tJic.  I;i\v  |L^'<»v('i'nin!j;  tlic  r;ilc  of  <lin'n,-i<in,  lliii«-  nm-l  nC  ni-ccs.silv  lu*  a 
(^oiisliiiil ,  lli(»nt;li  slow,  i-cnio\;il  of  ^ascoti-  inipniily  into  iIk;  <;xl.<'riial 
nil',  (itr  \vli('i'<'\<'i-  l\v<i  l;;iscs  ;ii'c  hroii^lit  into  cont.-ict,  fiin'll.slf»ri  will 
(XH'ur,  wlictJKU'  llic  incctinL;;  |»l;i('c  \h\  l;ir^(!  .sj);ic,c.-,  ;is  rooms,  or  sfrial! 
HpncH's,  MS  pores  in  (lie  |)l;istcrin<r,  hi'irks,  iiMtrtiir,  s('»tic  or  other 
ina,l('i"i;il  which  forms  I  lie  honmlaries  of  ihal  room.  Tlii-  f'on;<'  is, 
liovveN'cr,  \vv\  ina<lc(|iialc,  and  can  he  oC  ,-ervice  oidy  as  an  awniHt- 
ant  to  anolher.  Moreo\-er,  il  can  alleet  <inly  ^a.scoii.s  and  not  huh- 
pciided  inaMers. 

Of  vast  iin|)or(an(;e,  liowe\'er,  is  llie  oilier  force,  that  of  gravity. 
K(|iial  volumes  of  air  at  the  same  (emperiiiire  and  niuh'r  the  wamc  prcas- 
iire  will  have  the  same  speeilic;  <;ravity  ;  if  lh<!  temperature  of  one  of 
tlu'in  ho  raised,  it  expands  a  definite  amoinit  for  ea(;li  de<ri-ee,  and  thus 
has  less  speeifie  o;ravity  than  tla;  other  the  more  it  is  heated.  Jieing 
surrounded  hy  aii*  which  is  heavier  than  itself,  it  rises,  or,  more 
properly,  is  foree(l  upward  hy  the  heavier  air,  whieh  descends  to  occupy 
its  plaee  in  the  same  way  that  a  vohune  of  light  oil  in  a  cylinder  is 
forcied  u])ward  when  water  is  poured  upon  it.  If,  on  the  other  hand, 
it  is  cooled,  its  volume  eontracts,  its  specific  gravity  is  increased,  and 
it  sinks  downward  through  the  wanner  lighter  air  helow  it.  Tn  this 
way,  differences  in  temperature  cause  consttint  movements  in  bodies  of 
air,  and  currents  are  estahlished.  In  an  inhabited  room  this  force  is 
always  at  work,  for  there  must  necessarily  be  some  source  of  heat,  even 
though  it  be  only  the  body  of  the  occupant.  The  air  in  contiict  with 
the  body  becomes  heated,  and  is  then  displaced  by  the  colder  air  about 
it ;  this  in  its  tin-n  is  subjected  to  the  same  influences,  and  the  whole 
of  the  contained  air  rises  in  temperature  and  is  correspondingly  ex- 
panded. As  it  becomes  lighter  than  the  surrounding  air,  the  latter 
forces  itself  in  and  the  original  air  out  through  all  the  available 
openings,  and  thus  a  certain  amount  of  ventilation  is  accom- 
plished. 

Under  the  ordinary  conditions  of  occupancy  of  a  house  or  room,  we 
have  additional  sources  of  heat  iu  the  combustion  of  fuel  and  illumi- 
nating materials,  and  no  matter  how  imperfect  the  applied  system  of 
ventilation  may  be,  and  in  spite  of  all  etforts  to  exclude  the  external 
air,  a  very  considerable  amount  of  interchange  of  air  is  inevitable.  It 
is  only  in  a  chamber  that  is  to  all  intents  and  purposes  hermeticidly 
sealed  that  no  ventilation  will  occur  when  there  is  a  difference  be- 
tween the  internal  and  external  temperatures.  He;ited  air  will  esca|>e 
through  flues,  through  cracks  around  windows  and  doors,  between  the 
boards  of  the  floors  and  of  the  general  structure,  and  even  through  the 
interstices  of  unpainted  plastering  and  UKH'tar,  and  through  the  jx^res 
of  bricks.  That  a  large  volume  of  air  will  pass  through  cracks,  needs 
no  demonstration  ;  the  passage  of  air  through  bricks,  plaster,  and  mor- 


478 


HABITATIONS,  SCHOOLS,  ETC 


tar  may  easily  be  shown.  If  to  the  opposite  sides  of  a  brick,  we  fasten 
by  means  of  sealing  wax  two  ordinarj'^  glass  funnels,  and  then  smear  its 
entire  exposed  surface  with  a  liberal  coating  of  the  same  material,  all 
of  the  external  pores  excepting  those  within  the  spaces  covered  by  the 
funnels  are  made  impervious  to  air.  If  now  Ave  connect  by  means  of 
a  rubber  tube  the  funnel  on  one  side  with  a  bottle  in  which  air  can  be 
compressed  by  means  of  water  pressure,  and  by  the  same  means  the 


Fig.  42. 


V 


Apparatus  for  demonstrating  the  permeability  of  bricks,  etc.,  to  air. 

other  funnel  with  an  inverted  test-tube  filled  with  water,  and  apply 
pressure,  the  passage  of  air  through  the  pores  of  the  brick  will  be 
manifested  in  a  few  minutes  by  the  escape  of  bubbles  from  the  outlet 
tube  upward  through  the  water.     (See  Fig.  42.) 

The  passage  of  air  through  plastered  walls  is  much  impeded  by  wall 
paper,  and  may  be  totally  prevented  by  oil  paint  and  moisture. 

Numerous  experiments  have  proved  that  with  varying  differences 
between  the  internal  and  external  temperatures,  the  air  of  a  room  or 
building  will  be  renewed  partly,  wholly,  or  repeatedly  every  hour, 
even  when  efforts  are  made  to  prevent  as  far  as  possible  the  entrance 
of  the  outside  air.  The  results  vary  with  the  difference  in  conditions, 
the  highest  effects  being  produced  when  the  temperature  differences 
are  wide,  the  opportunities  for  leakage  great,  and  the  external  air  in 


NA  TIJllA  /.    FOnC.KH  IN    VF.STII,A  TION. 


179 


active  rnotion.      Willi  \)vy{\'ri  c'llni   ;inil   ciiii.-il    tcnijicradir*',  llic  rc-iilt 
will  l)(!  vil. 

Perflation  and  Aspiration. —  liic(|ii;illil<-  in  (.ni-idc  t(iii|.(ni(iir<« 
give  ri.sc  to  the  larger  ciirrdiits  of  air  wliicli  we  know  as  \viii<l-.  TIm'sc 
have  a  very  ^rcai  iiidiicrutf;  on  ventilation  both  by  tlicir  perflatiiif^  ar;tioii 
and  by  aH))iralion.  Tlic  liijj^lieHt  results  of  perflation  are  those  obtained 
wluMi  obstacles  to  the  ['wr  admission  and  exit  of  wind  are  n^moved,  an, 
for  inslaiiee,  by  opening  windows  in  its  path.  Thf  (piickness  and  fre- 
quency of  renewal  ol"  contained  air  by  this  means  w^ill  neries.-arily  d«'penfl 


Fio.  ^?,. 


Imu.  M. 


Fio.  4'j. 


Common  forms  of  stationary  ventilating  cowls. 


Rotarv  cowl. 


upon  the  size  of  the  openings  and  the  velocity  and  direction  of  the  wind. 
The  least  etfects  are  produced,  whatever  the  velocity  and  direction,  when 
the  obstacles  to  entrance  are  greatest. 

The  aspirating  influence  of  wind  is  shown  by  the  upward  currents 
produced  in  flues  when  the  internal  and  external  temperatures  are 
equal.  A  current  of  air,  moving  swiftly  across  the  outlet  of  a  flue,  has 
the  same  effect  on  the  contents  of  the  flue  as  that  of  a  common  hand 
atomizer  has  on  the  contents  of  the  tube.  The  air  in  the  upper  part 
is  carried  along  mechanically,  a  partial  vacuum  is  formed,  and  that 
which  is  below  rises  to  take  its  place,  and  is  in  turn  carried  away.  In 
the  case  of  the  flue,  air  from  below  is  constantly  drawn  up  and  dissi- 
pated ;  in  the  case  of  the  atomizer,  the  liquid  into  which  the  tube  dips 
is  lifted  and  blown  into  spray.  This  influence  is  utilized  and  assisted 
by  various  forms  of  cowls  placed  over  outlet  flues ;   some  of  these, 


480 


HABITATIOSS,   SCHOOLS,   ETC. 


however,  although  they  seoni  to  be  an  aid,  are  really  a  hindrance  to 
the  outtloNV,   as   may  eiit^ily   be  demonstrated. 

In  Figs.  43  and  44  are  shown  forms  of  cowls  which  offer  some 
assistance  to  the  aspiratory  inllueuce  of  winds,  and  in  Fig.  45  is  shown 
another  very  po]iular  kind,  the  rotary  cowl,  which  offers  an  obstruction 
to  the  passage  of  air.  As  the  wind  causes  the  top  to  revolve,  the  im- 
pression is  made  that  work  is  being  performed  ;  that  in  its  revolutions 
it  is  creating  a  suction  which  causes  an  upward  current  of  air.  As  a 
matter  of  fact,  however,  it  is  doing  no  such  work,  but  is,  on  the  con- 
trary, interposing  an  obstacle  to  the  passage  of  air.  This  may  easily 
be  demonstrated  by  measuring  by  means  of  an  anemometer  the  amount 

Fig.  46. 


Aspirating  cowl  with  vane. 


of  air  discharged  through  the  flue  during  a  given  period  while  the  re- 
volving top  is  in  place,  and  again  during  an  equal  period  while  it  is 
removed.  The  difference  between  the  results  obtained  will  invariably 
be  in  favor  of  the  period  during  which  the  cowl  is  absent. 

Other  forms  of  cowls,  constructed  so  that  their  outlets  are  turned  by 
means  of  a  vane  away  from  the  wind,  are  useful  in  assisting  aspiration. 
Such  a  form  is  shown  in  Fig.  46.  By  reversing  the  position  of  the 
vane,  the  mouth  of  the  cowd  is  turned  toward  the  wind  so  that  the  flue 
is  converted  into  an  inlet  for  fresh  air. 


NATUIiAL    VI':NTILATI<)N.  4X1 

Natural  Ventilation. 

V<'iiiil;iii<"i  lli!i('  |>r(iccc(ls  IVoiii  the  o|)ci;i(  ion  of"  ii;itiir:il  f'orftij.s  is 
known  iis  "  niiiiiiiil  \(iil  Ihl  ion."  I'or  (Ik;  alt;iiiiiii<  iit  of  iIh-  lar^cht 
roHulls,  f.li(!S(!  lorcrs  mil  I  hr  uHsiHtcid  to  tlic;  (!x(<'nl  of  niiioviil  of  ol>- 
stac-KiS  lo  llicir  adioii  >o  far  as  may  l)c  advisahlc  II  is  no(  well  to 
(Icjx'iid  (i|)oii  liic  cliaiirc  ci-acks  and  n|»(»n  tin;  nii;j;ialion  of  air  thron^^li 
ilic  |>oi'cs  of  laiildint;'  nialcrials,  hnl  nccrssaiy  opdnin^H,  bo(li  iidcts  and 
ontlcls,  slionld  Ix^  |)fovidcd.  'I'lic  nir.iici-  tJic  ((h.staflcs  to  (he  cscaiK'  of 
li('at(^<l  aif,  tlid  less  (lu^  oppoiluuity  ("or  sMccf'ssf"iil  natnral  ventilation. 

'V\\(\  cxircnic  ol"  ohstnid  ion  (o  llic  (•-■(•;ipc  of  eonlaincd  air  may  l>e 
illustralxid  I))'  an  licrmclicallv  scalc(|  niclallic  Lox  or  by  a  closed  ^hiHS 
bottle.  Snpposc  we  proxldc  one  small  opcniiiu'  in  the  side  of"  tlie  l>ox 
or  in  the  stopper  of  the  hotth;  to  act  as  an  onllet  and  inlet,  and  ol).-er\(; 
the  resnit.  Aceordino;  as  tlu!  eonlained  air  is  warmed  or  (tooled,  the 
openinji:;  will  act  as  an  onllet  or  as  an  inlet,  hnt  only  to  a  ]imit<Kl 
extent.  The  expansion  due  to  heatin*;;  will  ciiuse  the  escape  oi"  a 
portion  of  the  contents  ;  the  contraction  due  to  cooling  will  cause  the 
indrawini>;  of  sonu;  of  the  outer  air;  but  in  either  ease,  the  movenu'iit 
is  all  one  way,  and  there  is  no  real  interchange.  .Su[)pose,  however, 
two  openings  are  supplied  ;  then  one  may  act  as  an  outlet,  the  other 
as  an  inlet,  and  a  constant  inward  and  outward  current  may  be  main- 
tained. 

The  more  tightly  fitting  we  make  our  windows  and  dr)ors,  and  the 
more  impervious  to  air  we  make  our  walls  by  means  of  paint  and 
sheathing  paper,  the  more  do  we  oppose  natural  ventilation.  On  the 
other  hand,  the  intelligent  ])lacing  of  inlets  and  outlets  furthers  the 
object  to  be  achieved. 

In  addition  to  permanently  installed  inlet  and  outlet  flues,  temjio- 
rary  openings  may  be  ntilized  whenever  desirable.  The  most  avail- 
able of  these  is  the  opened  window,  which  may  be  utilized  so  as  to 
avoid  too  voluminous  exchange  and  unbearable  draughts.  The  area 
of  the  opening  may  be  very  simply  regulated,  and  the  air  may  be 
deflected  upward  or  the  current  may  be  broken  up  liv  the  interposition 
of  fine  wire  gauze,  flannel,  or  other  pervious  material. 

A  very  common  plan  is  to  place  a  board  lengthwise  under  the  lower 
sash,  so  as  to  fill  completely  the  opening  made  by  raising  the  window, 
and  thus  establish  an  inlet  or  outlet  where  the  sashes  overlaji  each 
other,  for  the  barrier  to  the  movement  of  air,  formed  by  the  juxtaposi- 
tion of  the  lower  border  of  the  up]5er  sash  and  the  upper  border  of  the 
lower  one,  no  longer  exists,  and  the  entering  current,  moreover,  is 
given  an  upward  direction.  Instead  of  a  board,  a  frame,  over  which 
a  diaphragm  of  flannel  is  fastened,  may  be  used.  This  arrangement 
is  pervious  to  air  but  impervious  to  dirt,  which,  therefore,  is  filtered 
out.  Movable  panes,  either  sliding  or  swinging  by  the  side  or  end, 
are  frequently  employed,  especially  in  double  windows.  There  are 
also  numerous  patented  devices  for  window  ventilation,  all  designed 
with  the  idea  of  dividing  or  deflecting  the  current  of  admitted  air. 
31 


482  HABITATIOSS,  SCHOOLS,   ETC. 

As  has  been  remarked  above,  the  most  important  force  in  natural 
ventilation  is  that  dependent  upon  unequal  temperatures  of  bodies  of 
air ;  in  a  perfect  calm  and  with  equal  temperatures,  natural  ventilation 
would  have  to  depend  wholly  on  the  force  of  diflPusion. 

The  enormous  influence  exerted  by  the  heating  and  lighting  of  a 
building  or  room  on  its  ventilatiou  becomes,  then,  self-evident,  but  it 
is  not  simply  as  a  motive  force  that  the  relation  between  heat  and  ven- 
tilation is  so  close  and  important,  for  the  incoming  air  must  be  raised 
to  an  agreeable  temperature  in  order  that  the  space  may  be  habitable. 
Thus,  a  very  large  share  of  the  cost  of  heating  is  chargeable  to  venti- 
lation, whatever  the  system  of  ventilation  be.  In  the  matter  of 
expense,  the  amount  of  leakage  through  cracks  and  other  small  open- 
ings is,  in  a  certain  class  of  cases,  of  very  great  importance.  In  our 
dwellings,  it  is  important  that  the  interchaiage  of  air  shall  proceed 
continuously  in  the  inhabited  parts,  but  in  buildings  which  are  used 
only  by  day,  and  perhaps  for  only  a  few  hours  daily  (schools,  etc.), 
it  is  not  essential  that  the  air  shall  be  renewed  constantly  at  other 
times  ;  and  here  it  is  wise  to  obstruct  the  leakage  as  much  as  possible 
by  perfect  construction  and  by  dampers  in  the  flues,  so  that  waste  of 
heat,  fuel,  and  money  may  be  prevented. 

For  the  promotion  of  the  process  of  natural  ventilation,  a  number 
of  "  systems "  have  been  devised,  many  of  which  can  be  productive 
of  no  results  other  than  incomes  for  their  promoters.  As  a  rule, 
most  of  those  noticed  in  works  of  this  character  are  either  ill-adapted 
to  the  conditions  of  our  climate  or  incompatible  with  our  methods  of 
building,  and  will,  therefore,  not  be  considered  here. 

The  only  system  of  natural  ventilation  worthy  of  advocacy  is  that 
which  provides  proper  inlets  and  outlets  and  a  suitable  means  of 
heating. 

Inlets  and  Outlets. — As  to  the  size,  location,  and  number  of  in- 
lets and  outlets,  no  hard-and-fast  rules  can  be  applied  for  all  cases, 
since  the  conditions  are  widely  varying,  and  many  different  circum- 
stances have  to  be  taken  into  account.  But  general  rules  may  be  laid 
down. 

If  several  inlets  are  to  be  provided  in  a  room,  it  is  essential  that 
they  should  be  distributed  in  such  a  manner  as  to  insure  a  thorough 
blending  of  the  admitted  air.  They  should  not  be  so  placed,  with 
reference  to  outlets,  as  to  favor  the  forming  of  direct  currents  between 
them,  Avhereby  a  large  proportion  of  the  inflowing  air  is  discharged 
without  having  fulfilled  its  function — a  not  unusual  condition,  which 
illustrates  that  the  amount  of  air  admitted  is  not  by  any  means  a 
measure  of  thoroughness  of  ventilation.  Their  location  is  not  such 
an  important  matter  as  the  placing  of  the  outlets,  but,  in  general,  an 
inlet  is  placed  best  on  an  inner  wall  where  it  shall  be  most  nearly 
central  in  relation  to  the  outside  walls. 

With  reference  to  the  floor,  if  the  incoming  air  is  heated,  inlets 
may  be  placed  high  or  low  ;  but  if  it  is  admitted  cold,  they  should 
be  at  a  higher  level  than  the  heads  of  the  occupants,  and  provided 


NA  TIJUA  L    VKS'Tll.A  TION.  483 

widi  .'irran^onKiiiiH  f'or  defied  in;^  the  emrenl  townrd  the  fxtilirij^. 
Tliis  may  he  .'iceoiiiplislied  l>y  caiisiii};;  tlie  <;iiiT«-iit,  to  impinge  n|)r)ri 
a,  siirCace  slaiiliii;;'  ii[)\vai<l.  Tlic  results  oC  lliis  <lefleetioii  are  that  tl»j 
{\vA\  air  IxiCOmcH  mixed  with  the  warmer  air,  and  that,  timre  t.il/i(;  i« 
r(H]iiin!<l  (or  it  to  nuuih  <h(!  h)sver  |»arts  of  the  room,  when  it  will  have 
boooiru!  Hn(ri(',i(!ntly  warnuMl  not  to  (^ansc  (lihcomfort.  TIm;  inf<-rj)OHi- 
tioii  ol"  the,  dedeetin*^  siM'lacc;  also  spreads  the  current  radially  and 
rc(hl(;(^s  its  Ncloeity.  The  in(;oiniuj^  air  bectotncs  mingled  with  the 
general  8uj)i)ly  and  joins  the  currentn  wliieh  are  conHhuitly  in  motion. 
That  wliich  comes  in  contact  with  cooling  Kurfac(;s,  .such  as  windowH 
and  outsider  walls,  is  (!oolcd,  and,  thcrefon;,  falls  toward  the  floor, 
and  that  whi(^h  takes  its  |)lace  as  it  falls  is  (v)oled  in  its  turn  and  fol- 
lows aftin-,  so  that  currents  are  established,  which  tend  to  keeji  the  whole 
bnik  in  more  or  less  rapid  motion.  As  these  currents  reach  the  flfK>r, 
their  natural  trend  is  across  that  surface  toward  the  inner  warmer 
walls,  where  they  become  heated  and  arc  inclined  toward  the  ceiling, 
reaching  which,  they  are  pnslKsd  by  the  force  behind  and  drawn  by 
the  one  in  front  toward  the  outer  walls  and  windows  again.  In  the 
meantime,  some  of  the  air  is  escaping  through  outlets,  and  diffusion 
of  the  impurities  is  proceeding,  so  that  a  more  or  less  even  character 
is  brought  about  throughout  the  air  of  the  room. 

Outlets  may  be  placed  at  the  level  of  the  floor,  in  the  ceiling,  or  at 
any  height  in  the  walls,  according  to  the  conditions  of  each  individual 
case.  If  the  incon)iug  air  is  not  heated,  the  outlets  should  be  placed 
high  up,  for  where  only  unheated  air  is  admitted,  the  warmest  air  must 
be  the  oldest  and  its  location  w  ill  be  in  the  upper  air  space.  If,  on  the 
other  hand,  the  air  is  heated,  the  outlets  may  be  anywhere  so  far  as 
height  is  concerned,  but  there  is  some  choice  in  locations  with  respect 
to  inner  and  outer  walls.  Outlets  placed  beneath  windows  or  near 
outer  walls  M'ill  withdraw  the  falling  currents  of  the  only  recently  in- 
troduced air  before  it  has  had  an  opportunity  to  become  well  mixed  by 
passage  across  the  floor  to  the  other  side,  and  before  it  has  in  any 
propei  degree  fulfilled  its  functions  ;  but  if  its  passage  through  the 
loAver  strata  is  not  interrupted  in  this  manner,  it  is  enabled  to  mix  with 
and  dilute  the  impurities  of  the  air  already  vitiated,  and  thus  effect  a 
large  measure  of  work,  and  so  when  it  reaches  the  other  (inner)  side 
and  finds  an  outlet  for  its  escape,  there  is  no  objection  to  its  withdrawal, 
and,  indeed,  its  removal  then  is  highly  desirable.  Hence,  and  for 
another  reason  as  will  appear,  outlets  should  be  placed  in  inner  walls 
rather  than  near  or  in  outer  cooler  ones,  and  near  the  floor  where  they 
may  intercept  the  air  before  it  may  again  become  a  part  of  the  ceiling 
currents. 

If  but  one  outlet  is  to  be  provided,  it  should  be  placed  with  reference 
to  the  most  even  movement  of  the  current  over  the  whole  area,  having 
in  mind  the  fact  that  the  air  movement  toward  it  is  convergent,  and 
the  direct  reverse  of  the  flow  from  the  deflecting  and  diffusing  surface 
at  the  inlet. 

As  to  size,  it  may  be  said,  in   general,  that  a    single  outlet,  or   the 


4.'=(4  HABITATIONS,  SCHOOLS,  ETC. 

aggregate  if  there  be  more  than  one,  should  be  of  such  size  as  to  insure 
tlio  p().>^sihi]ity  of  removal  of  such  an  hourly  air  supply  as  the  space  is 
likely  to  require  under  the  ordinary  conditions  of  its  usual  occupancy ; 
that  it  should  not  materially  exceed  this  limit;  and  that  the  final  velocity 
of  the  ontriowing  current  should  not  be  productive  of  the  sensation  of 
disagreeable  draughtiness. 

As  to  the  shape  of  inlets  and  outlets,  it  is  self-evident  that,  with 
equal  arejis,  that  which  has  the  smallest  periphery  Mill  offer  the  least 
frictioual  resistance,  and  is,  therefore,  best  adapted.  Thus,  a  circle  en- 
closing an  area  equal  to  a  square  foot  has  a  smaller  periphery  than  a 
square  enclosing  the  same  area,  and  a  square  has  a  smaller  one  than 
an  oblong  rectangle.  Take,  for  instance,  a  square  foot ;  it  may  be  in- 
cluded Avithin  boundaries  : 


12  X  12  indies,  a 

square. 

16  X    0 

18  X    8 

24  X    6 

36  X    4 

■  oblong  rectangles. 

48  X    3 

72  X    2 

144  X    1 

. 

With  these  boundaries,  the  periphery  ranges  from  4  feet  (the  smallest) 
to  24  feet  2  inches.  The  frictioual  resistance  will,  therefore,  be  greater 
in  proportion  as  the  shape  varies  from  the  circle  and  square. 

The  shafts  communicating  with  the  inlets  and  outlets  should  l)e  so 
disposed  in  the  general  plan  as  to  offer  the  least  resistance  to  the  inflow 
and  outflow  of  air.  Unless  they  are  heated  artificially,  inlet  flues 
should  not  be  located  in  outer  walls,  on  account  of  the  likelihood  of 
the  formation  of  down  draughts  due  to  cooling  of  the  air  column. 
Their  inner  surface  should  be  as  smooth  as  possible,  in  order  to  bring 
to  a  minimum  the  loss  of  movement  due  to  friction,  and  they  should 
be  cylindrical,  if  possible,  for  the  same  reason.  They  should  be  as 
free  as  possible  from  angles,  and  especially  right  angles,  because  of  the 
very  serious  loss  of  motion  which  these  cause,  each  right  angle  dimin- 
ishing the  current  about  half;  thus,  after  passing  one  right  angle,  the 
flow  would  be  half;  after  a  second  angle,  the  half  would  be  reduced 
to  a  quarter,  and  after  a  third,  to  an  eighth.  The  neglect  to  take  into 
account  the  loss  of  flow  by  friction,  l^ends,  and  angles  is  responsible 
for  the  failure  of  many  a  plan  for  ventilation. 

What  has  been  said  concerning  the  impossibility  of  making  general 
rules  for  the  sizes  of  inlets  and  outlets  applies  with  equal  force  to  the 
fixing  of  sizes  of  flues,  for  these  depend  upon  the  many  and  varied 
conditions  which,  even  under  the  best  favoring  circumstances,  affect 
the  rate  of  flow. 

In  planning  inlet  and  outlet  shafts,  it  is  to  be  borne  in  mind  that 
something  more  is  necessary  for  their  proper  -working  than  the  dictum 
that  this  one  is  for  fresh  air  and  that  one  for  foul,  for  natural  forces 
have  no  respect  for  mere  names  and  plans,  and  the  current  in  a  flue 
will  be  upward  or  downward,  inward  or  outward   according  to  natural 


A]t'ril''l('r.\L    IIKATINd    IN    ITS   llh'.LA'riOSS   TO    V I'.Sri I.ATIOS.    IH/i 

hivvH.  ()ii(l(l  sliid'tH  may  bcronir-  coiisidcmhly  roolcd  hy  low  (;xt4!rna) 
(cin|)('r;iliii'('s  ;  (JK^y  iiwiy  I)''  iii\;i(|iil  In'  r;iiii  ;iii(|  snow,  tlic  cvaporafion 
of  wliicli  cniiscs  cooling'  ;iii<l,  I licidoif,  iiici-c;isc  in  j^niv^'ty  ;  or  there 
may  \n\  an  insuni<'icii(;y  <»r  inld,  ;iii',  so  thai  a  |»ar(ial  vacmnn  is  I'ormfil 
|)y  \\h\  (Mirrcnl  of  one  lari^c  onllcl  line,  wliidi  (licrchy  ranscs  a  r<;v<;rHal 
(»r  (,li;il.  o("  a  smaller  one,  so  lli;il  one  lliif  dinws  aj^aiii.st  aiiotlu-r.  It  \n 
from  aii\'  one  ol'  (licsc  canscs  (li;it  ;i  <liiiiinfy  may  lail  to  dificharjifc; 
smoke  upward — a  (iircunistuiice  noticed  more  ol'len  in  Hiinimer  than  in 
winks  I'. 

Mechanical  Ventilation. 

M(>cliani('al  v(!ntilatioii  consists  in  flic  ))ro|)ulsion  or  (;xtraftion  (tfair 
by  means  of  blowers  or  cxhanst  fans  dri\(Mi  by  Ht<uim  or  electricity. 
That  in  w  liicli  the  air  is  ])rop('IIed  by  tla;  action  of  a  blow(;r  is  known 
as  th(!  "  plenum  "  system,  and  the  other,  in  which  it  is  w  ithdrawii  by  an 
exhaust  fan,  is  known  as  the  "vacuum  "  system. 

In  the  plenum  system,  the  air  is  drawn  into  a  box,  in  which  the 
revolving;  blades  of  a  fan  are  located,  and  it  is  then  driven  into  a  cen- 
tral (sondnit,  and  from  there  throno-h  approj)riat<'  shafts  to  the  spacxiS  for 
whicih  it  is  infendcd.  When  it  is  desired,  the;  air  may  be  received  from 
or  blown  lirst  into  a  chamber  where  it  may  be  heated.  The  air  snpj)ly 
may  be  re_<:;ulated  very  easily  by  diminishing  or  increasing  the  number 
of  revolutions  per  minute,  but  it  should  always  be  in  slight  exccsss  of 
the  real  uchhI,  in  order  to  produce  a  slight  outward  pressure,  which  will 
prevent  inward  leakage. 

In  the  vacuum  system,  the  air  is  extracted  from  the  various  rooms 
through  pipes  leading  to  a  central  shaft,  where  it  is  drawn  into  the  fan 
and  discharged  outwardly.  This  system  has  among  other  disadvan- 
tages that  of  great  inequalities  in  draught  in  the  ditfei'ent  discharge 
tubes,  aud  that  the  vacuum  condition  favors  the  inward  leakage  of  cold 
air  through  cracks,  walls,  and  about  wnndow-s,  and  tends  to  cause  cold 
floors  and  disagreeable  small  draughts  about  windows.  In  consequence, 
more  fuel  is  needed  for  the  maintenance  of  a  proper  temperature,  and 
the  system  is,  therefore,  a  source  of  greater  expense. 

The  advantages  of  mechanical  ventilation  lie  in  the  fiict  that  the 
object  sought  is  attainable  in  any  and  all  conditions  and  variations  of 
weather,  and  that  less  space  is  required  for  shafts  than  in  the  case  of 
natural  methods. 

JNIechanical  ventilation  on  a  comparatively  small  scale  is  employed 
conunonly  in  crow'ded  offices  and  other  spaces  by  means  of  small  ex- 
tracting tans  run  by  the  aid  of  electricity  (connection  being  made  with 
the  electric  light  system)  in  specially  ]irovided  locations  connecte<l  with 
outlet  flues,  or  directly  in  a  space  made  by  removing  window  panes. 

Artificial  Heating  in  Its  Relations  to  Ventilation. 

First,  for  the  proper  understanding  of  the  subject  of  heating  in  its 
bearings  on  ventilation,  it  is  necessary  to  consider  the  different  wavs 


486  HABITATIONS,   SCHOOLS,   ETC. 

in  Avhieh  heat  is  imparted.  These  are  three  in  number  :  radiation, 
conduetion,  and  conveetion. 

Radiation. — Radiant  heat  passes  from  its  source  throuiih  the  air  to 
bodies  by  which  it  may  be  absorbed,  transmitted,  or  retlected.  Air, 
being  "  transparent "  to  heat,  is  not  materially  aifected,  and  the  drier 
the  air,  the  less  heat  it  will  retain.  It  passes  dii'ectly  from  its  source 
in  waves,  like  the  waves  of  light,  to  the  object  upon  which  it  falls,  and 
the  amount  reflected  or  absorbed  varies  with  the  nature  of  the  object, 
its  color,  the  character  of  its  surface,  and  its  temperature.  Its  in- 
tensity varies  inversely  as  the  square  of  the  distance  between  the 
source  and  the  object  upon  which  it  falls  ;  thus,  the  amount  received 
by  two  objects  1  and  5  feet  respectively  distant,  will  be  inversely  as  1 
and  25  ;  at  1  and  10  feet,  inversely  as  1  and  100 ;  at  5  and  10  feet, 
inversely  as  25  and  100 ;  that  is,  the  nearer  will  receive  in  the  first  in- 
stance 25  times  ;  in  the  second,  100  times ;  and  in  the  third,  4  times 
as  much  as  the  farther  object. 

As  an  instance  of  radiant  heat,  we  may  take  that  which  proceeds 
from  an  open  fire.  The  heat  passes  in  direct  lines  through  the  air  to 
the  walls,  floor,  ceiling,  furniture,  and  other  objects  in  its  path,  and 
these  absorb  some  and  reflect  the  rest  to  other  parts  of  the  room.  It 
directly  warms  only  that  surface  of  an  object  that  is  directly  opposed 
to  it.  The  objects  by  which  it  is  opposed  then  disseminate  it  in  two 
ways  :  by  conduction  and  convection. 

Conduction. — Conducted  heat  is  that  which  passes  from  one  par- 
ticle of  matter  to  another  in  direct  contact ;  that  is,  from  one  particle  to 
another  of  the  same  object,  or  from  one  object  to  another  which  it 
touches.  Conduction  acts  through  all  solid  substances,  but  by  no 
means  to  the  same  extent,  some  being  good,  some  indifferent,  and 
others  bad  conductors.  The  best  conductors  are  metals,  and  these 
vary  within  very  wide  limits ;  copper,  for  instance,  is  a  very  much 
better  conductor  than  iron  or  zinc.  "Wood  is  a  poor  conductor,  and 
w^oven  and  felted  materials  and  asbestos  are  very  poor.  Through 
liquids  and  gases,  heat  is  conducted  to  only  a  very  limited  extent,  but 
there  is  no  substance  known  that  is  absolutely  non-conducting. 

Good  conductors  permit  a  rapid  flow  of  heat  through  their  substance  ; 
poor  ones,  only  a  slow  transmission.  Good  conductors  relinquish  their 
heat  rapidly  to  their  colder  surroundings,  whether  air  or  anything  else, 
and  withdraw  heat  from  bodies  which  are  warmer  than  themselves. 

Convection. — Convection  is  the  process  by  which  heat  is  communi- 
cated to  gases  and  liquids,  acting  through  their  mobility,  which  permits 
those  parts  that  have  been  expanded  by  reason  of  becoming  heated  to 
be  displaced  upward  by  cooler  portions,  which,  in  their  turn,  receiving 
beat,  give  way  to  others,  until  the  whole  mass  becomes  raised  in  tem- 
perature by  continued  application  of  heat  and  consequent  maintenance 
of  circulation. 

Every  warm  body  with  which  air  comes  in  contact  communicates  its 
heat  to  those  portions  in  its  immediate  vicinity  ;  these  expand  and  are 
forced  onward  by  the  cooler  heavier  parts  nearest  them  ;  these  in  their 


ARTiFiarAh  iii<:atin<;  in  its  iielatioss  to  vi'.stilatios.  -Jx7 

turn  j^iv(!  W!iy  ('»  ol  Ik  rs,  iiml  cunv-ccl  ion  (•iirccnls  arc  csbiblihlif!*!  Ut 
Hiic-li  iiii  <!xU:ii(.  iJial:  (lir  air  oCa  room  t.ikc-  on  a  Wi-vy  <;oMi))licat<;<l  htuUj 
of  activity. 

C()nv(!(!ti()ii  ciii-rcMits  ar(!  cstaldislnd  l)y  ('\'ivy  person  in  a  room  ho 
\()u\r  as  tli(!  (cnipcradirc  is  below  lliat  of  (lie  l>orly.  Tlicy  an;  cHtal)- 
lislied  l>y  tli(!  wa,rnier  walls,  floor,  fnrnilnre,  liot-wat<;r  ))i|H!H,  Hli-arn 
radiators,  close!  sloves,  and  odier  warm  objects,  and  in  this  way  tlic  air 
b(!C()meH  li(!a-t(!d.  The  air  wliieli  enters  rooms  tliroii^li  KbaCts  com- 
mnnicaiint^  with  tlu!  air  ehanibersoC  ('nrna<reH  and  "  indirect  radiation  " 
apparatuses  an;  conv(\c!tion  (Mirrenf.s  in  iIk-  largest  .s(;nsc.  'J'lic  direct 
rays  of  the  snn,  passing-  ihroii^h  windows  and  abHorbed  by  tlic  floor, 
walls,  and  other  objee^ls  which  (hey  strike,  also  cansc  upward  con- 
vection (!uri'en(s. 

Methods  of  Warming'. — TIk;  })rinci|)al  methods  of  lioatinfr  Iiousch 
and  rooms  arc:  1.  Oj)en  lircs.  2.  Stoves.  .'3.  Furnaces.  4.  Ifot- 
water  pipes.  r5.  Steam  pipes.  The  method  most  applicable  in  any 
particular  (misc  will  depend  upon  the  si/c;  of  the  room  and  the  mnnber 
of  rooms  in  the  bnildint-;.  In  general,  it  may  be  stated  that  the  smaller 
the  space,  the  more  simple  the  method.  For  a  single  room,  an  open  fire 
or  a  stove  will  be  sutiicient ;  for  a  small  house,  stoves  or  a  furnace ; 
for  a  large  one,  one  or  more  furnaces  or  hot-water  or  steam  apparatus ; 
and  for  large  buildings — office  buildings,  for  instance — "direct"  or 
"indirect"  steam. 

1.  Open  Fires. — Practically  the  whole  of  the  heat  supplied  by  an  open 
fire  is  radiant.  If  the  fuel  is  held  in  a  grate,  there  is,  of  course,  a  cer- 
tain amount  of  conduction  from  the  bars,  and  of  convection  currents 
in  the  air  in  its  immediate  vicinity.  But  this  heat  does  not  get  out 
into  the  room,  because  it  is  immediately  carried  up  the  flue  by  the 
draught  of  the  chimney.  The  radiant  heat  is  absorbed,  reflected,  and 
distributed  in  the  manner  already  described,  but  reaches  directly  only 
those  surfaces  which  are  opposed  to  its  source — which  accounts  for  the 
saying  that,  in  a  cold  room  with  an  open  fire,  "  one  side  roasts  while 
the  other  freezes."  Only  a  small  part  of  the  total  heat  of  the  fuel 
consumed  is  available  for  heating,  since  most  of  it — about  seven- 
eighths — is  carried  at  once  up  the  chimney.  An  open-fire  stove,  such 
as  the  old-fashioned  "  Franklin,"  which  stands  out  in  the  room,  and  is 
connected  Avith  the  flue  by  stove  piping,  yields  a  large  amount  of  its 
heat,  since  the  material  of  its  construction  is  heated  by  conduction  and 
then  gives  it  off"  to  the  air  by  convection. 

Open  fires  cause  the  introduction  and  removal  of  large  volumes  of 
air,  but  these  are  by  no  means  always  well  mixed  with  the  M'hole  mass 
of  contained  air.  Nevertheless,  a  large  measure  of  ventilation  is  ac- 
complished, a  cei'tain  amount  of  heat,  perhaps  sufiicient  for  immediate 
needs,  is  given  off,  and  there  is  also  an  unmeasurable  addition  to  the 
general  cheerfulness.  They  may  cause  too  much  draught,  and  they  are 
certainly  not  economical,  but  as  accessories  to  other  heating  methods 
they  may  be  most  useful. 

2.  Stoves. — Close  stoves  have  more  direct  results  in  heatiuo:  and  less 


488 


HABITATIOys,   SCHOOLS,   ETC. 


in  ventilating  than  the  open  fire,  for  more  of  the  heat  produced  is 
available,  and  they  diseharge  into  the  ehinmey  only  the  air  volumes 
that  have  passed  through  them.  The  materials  used  in  their  construc- 
tion, iron,  soapstone,  brick  and  Hreelay,  conduct  the  heat  and  give  it 
oli'  to  the  air  with  varying  rapidity  ;  cast  iron  yields  it  about  as  rapidly 
as  it  is  received,  soapstone  and  l)rick  give  it  olf  only  gradually,  but 
for  a  longer,  period. 

When  cast-iron  becomes  red  hot,  it  may  be  decidedly  objectionable 
for  two  reasons  :  first,  that  the  organic  dust  particles  in  its  immediate 
vicinity  become  charred  and  yield  odors  ;  and  second,  that  it  absorbs 
and  transmits  considerable  carbon  monoxide  from  burning  coal.  Stoves 
may  be  so  arranged  as  to  act  not  alone  as  heaters,  but  as  ventilating 
apparatuses,  and  this  fact  is  of  very  great  value  in  the  case  of  small 
school  buildings  in  country  districts.     The  stove,  standing  out  in  the 

Fig.  47. 


Jacketed  ventilating  stove. 

room,  may  be  surrounded  by  a  cylindrical  jacket  from  the  floor  up- 
ward, leaving  a  sufficient  air  space  between  the  two.  Through  the 
floor  within  the  enclosure,  is  an  opening  into  an  air  duct  communicat- 
ing with  the  outdoor  air.  The  heat  of  the  stove  is  communicated 
to  the  air  between  the  latter  and  the  jacket  and  an  upward  current  is 
formed,  which  draws  upon  the  fresh-air  conduit,  so  that  a  constant 
current  of  warmed  pure  air  is  thrown  into  the  room.  (See  Fig.  47.) 
It  goes  without  saying,  that  here,  as  elsewhere,  the  incoming  air  must 
be  taken  from  points  where  its  purity  cannot  be  interfered  with  by 
local  conditions. 

Gras  stoves  and  oil  stoves  have  the  advantage  over  others  that  they 
are  more  prompt  in  results,  more  easily  controlled,  and  more  quickly 
put  out  of  use.  They  have  the  disadvantage,  however,  that  the  prod- 
ucts of  their  fuel  combustion  are  discharged  directly  into  the  air  of  the 
room.     In  the  case  of  the  oil  stove,  this  is  not  such  a  serious  matter, 


ARTIFKUAL    III'lATINd    IN    I'I'.S   lil'H.M'IONS   V'O    VF.STI LA'IH >\.     W.) 

slli<',(!  l.lic  |)(:r("c('t,  coiiihiisl  inn  ol"  ^(kkI  oil  ic-iilt-  in  (••■iilioii  (liox  idc  ari'l 
water;  htil.  willi  ^;i,s  (Jic  ixodiK^ls  \i\v.  more  ininn  roiis  jind  varied,  ;ui<l 
iiuiliido  HoiiK!  Ilial.  ;ir(!  irriliiliii^aiid  |i()is<»ii(»ii-.  Willi  |)i-()|»cr  vfiililalion, 
llOW(!V(ir,  in  (lie  <'as('  ol"  liolli,  n<i  harm   will    ix-  done. 

'\.  Furnaces.---  I  l<>l,-air  Cnrnaccs  aic  iml  only  oC  \cry  (.ri-i  a(  iiii j»or1arif<; 
us  li(!ai(;rs,  l)iili  <>('  cnornioiis  inflncncc  in  \(iil  ilal  ion.  In  llicir  use,  tlio 
cold  outdoor  air  is  hrona.iil  In  liy  ;i  condnit,  (lu'  "cold-air  l»o,\,"  to  a 
cliiunlKT  in  [\\v.  upper  \y.\v\  of  I  lie  rnrnaee,  altove  ;iud  surroundiuj^  tlic 
"doUH!,"  where  it  <'o!nes  in  eoiila<'t  with  the  very  hot  Hurf'acc  and  is 
hciited  by  coDvee.tioii.  'riieiiei!  it,  passes  u|)\vaid  through  sf'f)!ir:it<!  tin 
tubes  to  tlu!  several  places  for  its  discliar^r(;.  In  ;i  house  wiiir-li  is 
uii])rovi(le(l  with  special  inlet  and  outlet  flu(!S  for  ventilation — aii<l  mrwt 
of  our  houses  -ayv  so  (^onsti'iicted — a  furnac^e  of  ordinary  lieatinj^ 
capacity  performs  an  amount,  of  veiiliiatinf^  woi-k  (piile  sullieient  for  all 
needs,  and  for  wliieli  it  rarely  receives  credit.  It  diseliarjros  into  the 
various  rooms  a  constant  supply  of  warmed  fresh  air.  Where  and  how 
it  all  escapes  is  a  matter  of  secondary  interest  and  importance,  for  it 
gets  out  wherever  it  may  find  its  way. 

4.  Hot-water  Pipes. — Hot-water  heating  depends  upon  the  circulation 
of  water  by  convection  currents  thi-on<jjh  a  syst<'m  of  pipes  which  may 
extend  all  through  a  large-sized  building.  The  water  is  heated  in  a 
boiler  below  and  passes  through  a  main,  leading  from  the  ui)i)er  jiart 
thereof.  As  one  portion  of  water  comes  in  contact  with  the  heating 
surface  and  expands,  it  is  moved  along,  and  the  circulation  becomes 
established  just  as  with  air.  The  "  main  "  gives  off  branches  where 
needed,  and  these  at  their  extremities  turn  back  and  become  "  returns," 
which  eventually  connect  with  each  other  and  form  the  "  main  return," 
which,  conveying  the  cooled  water,  enters  the  boiler  at  its  lowest  point. 
The  first  part  of  this  system  may  be  compared  with  the  arteries,  and 
the  "  returns,"  with  the  veins  of  the  body.  Agents  are  provided  for  the 
escape  of  dissolved  air  liberated  from  the  water,  and  "  cut-ofFs  "  are 
inserted  for  the  shutting  out  of  any  part  of  the  system  as  desired.  It 
is  very  necessary  that  air  should  not  be  allowed  to  accumulate  in  the 
pipes,  since  it  Avill  stoj^  the  flow.  In  low-pressure  systems,  a  small 
cistern  is  provided  to  allow  for  the  expansion  of  the  water  and  to  jire- 
vent  its  overflow.  The  hot- water  system  may  be  of  either  high  or  low 
pressure.  With  high  pressure,  the  pipes  are  smaller  and  necessarily 
stronger,  and  the  water  is  heated  to  a  considerably  higher  temperature 
(300°  F.),  and  hence  circulates  more  rapidly.  With  the  low-pressure 
system,  the  water  does  not  go  much,  if  any,  above  212°  F. 

With  the  hot-water  system  of  heating,  the  air  is  heated  mainly  by 
convection,  though  from  polished  pipes  a  certain  amount  of  radiation 
occurs.     With  high  pressure,  the  air  may  easily  be  overheated. 

5.  Steam  Pipes. — In  steam  heating,  the  system  is  very  like  that  of 
hot-water  heating,  except  that  steam  is  the  circulating  medium  instead 
of  water.  With  steam,  and,  indeed,  with  hot  water,  heat  may  be  dis- 
tributed by  the  "direct "  or  "  indirect  "  methods.  In  the  "direct" 
method,  the  pipes  are  distributed  withiu  the  space  to  be  heated,  and  the 


490  HABITATIONS,  SCHOOLS,  ETC. 

air  of  each  room  is  heated  separately.  In  the  "  indirect "  method,  the 
heating:  surfaces  are  all  concentrated  in  the  basement,  and  are  enclosed 
in  galvanized  irou  conduits,  which  receive  and  conduct  the  air  just  as 
in  the  case  of  the  liot-air  furnace.  The  two  methods,  it  will  be  noticed, 
vary  widely  in  the  matter  of  assisting  ventilation  ;  the  direct  brings 
in  no  air,  but  heats  that  which  is  at  hand ;  the  indirect  brings  in  large 
volumes  of  heated  fresh  air,  and  thus  insures  change  of  air. 

In  conclusion,  may  be  mentioned  the  considerable  heating  and 
circulating  influence  of  burning  illuminating  gas.  By  means  of  suit- 
able outlets  above  the  burners,  gas  may  be  made  not  only  to  discharge 
the  products  of  its  own  combustion,  but  to  send  out  large  volumes  of 
otherwise  vitiated  air  as  well.  Nor  is  the  heat  of  the  sun  so  insignifi- 
cant that  it  may  be  passed  by  without  notice  in  the  planning  of  sys- 
tems of  ventilation.  Inasmuch  as  the  difference  in  temperature  of  the 
outside  air  on  the  north  and  south  sides  of  a  house  averages  about  5, 
and  may  reach  10,  degrees  F.,  just  that  amount  of  advantage  may  be 
gained  by  taking  the  air  for  ventilation  from  the  warmer  side.  In 
gravity  ventilation,  the  inlets  should  be  where  they  may  face  the  pre- 
vailing winds. 

Regulation  of  Temperature. 

In  carrying  out  any  scheme  of  efficient  ventilation,  it  is  necessary 
to  guard  against  overheating,  which  may  not  be  noticed  until  it  be- 
comes so  marked  that  it  cannot  help  attracting  attention.  When  such 
is  the  case,  the  common  practice  is  to  cause  a  lowering  of  the  tem- 
perature to  the  desired  point  as  soon  as  possible  by  opening  windows  to 
admit  the  colder  air.  The  consequence  is  the  production  of  a  distinctly 
cold  atmosphere,  more  so  than  ordinarily  is  shown  by  the  thermometer, 
which  does  not  react  very  promptly  to  sudden  changes.  This  produces 
chilly  sensations  which  call  for  a  return  to  the  original  condition.  In 
the  meantime,  a  lot  of  heat  has  been  wasted  and  the  foundation  for  a 
cold  has,  perhaps,  been  laid.  If  windows  are  left  open  in  the  upper 
stories,  as  often  happens  in  overheated  buildings,  there  are  constant 
outflow  and  waste  of  heated  air,  with  a  corresponding  inflow  of  un- 
warmed  air  below,  which  requires  the  expenditure  of  additional  fuel  in 
order  that  the  lower  stories  shall  be  properly  warmed.  In  overheated 
buildings,  there  is  also  the  additional  loss  from  outward  leakage  through 
all  possible  outlet  channels. 

To  prevent  waste  of  heat  in  properly  heated  buildings,  we  have 
recourse  to  double  glazing  and  double  windows.  Double  glazing  is 
accomplished  by  fitting  two  panes  into  each  space,  instead  of  one,  with 
a  space  of  a  quarter  or  a  half  inch  between  them.  By  this  means, 
the  loss  of  heat  occurring  through  ordinary  windows  is  reduced 
about  one-third,  which  means  a  saving  of  considerable  fuel,  since  the 
loss  of  heat  by  conduction  through  glass  windows  is  very  considerable. 
Double  windows  are  still  more  efficient  as  heat-savers.  Here  the 
outer  window  is  made  to  fit  as  accurately  and  closely  as  possible  by 


NECESSITY   OF  I'liOVIDlNd    MOISTURE.  'V.)\ 

the  use  of  liHiin^,  -.vud  w(^  li:iv(!  l)otwccn  Ww  iwo  wirulowH  a  fairly  dcr-p 
space  fill(!(l  wifJi  iili-,  vvliirli  i.s  a  very  poor  (;oii(liif;(/)r  u['  lieaf.  It,  i.s  rin 
ilie  sairK;  principle  lJi;il,  W(!  iiH(!  loosely  wovcji  woollen  jrood.s  arifl  fiir.'^, 
wlii(!li  lioid  vvidiin  (licir  riicslics  and  hcf  wcfii  tiic  liairs  a  lar^n;  anioiint. 
of  lliiH  poor  coiidiicior.  'V\\v,  loss  o("  licat  (liroiii/li  walls  is  N'sscncd 
wluin  a  siniil.'ir  ;iir  space  exists  witliin  tlicm  ;  ;i  solid  wall  will  con- 
dwci  n,  V(^ry  larfjjc  jiriiount  of  lical,  and  waste  it,  wliile  tli<-  same  arnoiiiii 
of  l)iiil<liii^  material,  or  (MHisiderahly  less,  may  he  so  disj)r»sed  as  to 
brinj:;  tliis  loss  down  t.o  a  minimum. 

Loss  of  heat  is  caused  also  by  damjjness  of  walls,  for  a  continual 
evaporation  j^oes  on  from  their  surface,  and  this  requires  Jieat  and  pn)- 
du(;es  coolinj^j.  Evcny  ounce  of  moisture  so  vaporiz(.'d  r(!(juires  the 
consumption  of  extra  fuel. 

Necessity  of  Providing  Moisture. 

Concerninfy  the  need  of  insuring;  a  normal  amr»unt  of  moisture  in  the 
air  of  heated  huildinjj^s,  there  is  more  or  less  dilference  of  opinion,  hut 
the  weight  of  evidence  from  a  medical  standpoint  and  from  cair  own 
sensations  points  to  the  advisability  of  introducing  an  amount  of 
moisture  sufficient  to  bring  the  relative  humidity  of  the  air  to  50  or 
55  per  cent. 

The  lower  the  temperature  of  a  body  of  air,  the  less  the  amount  of 
moisture  it  can  hold,  and  what  would  be  saturation  at  a  low  tempera- 
ture would  be  but  a  very  low  relative  humidity  at  a  high  one.  For 
instance,  a  volume  of  air  at  0°  F.,  containing  its  fullest  possible  amount 
of  aqueous  vapor,  admitted  to  the  cold-air  box  of  a  furnace  and  then 
heated  to  85°  F.  before  being  conducted  to  the  rooms  of  a  house,  will 
have  at  its  new  temperature  but  a  very  small  relative  humidity.  It 
will  be  so  much  drier  than  any  outside  air,  that  that  of  the  driest 
climate  in  the  world  wall  be  moist  in  comparison.  The  great  majority 
of  U.  S.  Signal  Service  Stations  have  a  mean  relative  humidity  of  65 
to  75  per  cent. ;  only  twenty-four  show  below  60  or  over  <S0,  and  the 
very  lowest  is  in  the  hottest  part  of  Arizona,  where  newspapers  crack 
when  handled,  glued  furniture  falls  apart,  and  the  skin  becomes  hard 
and  dry.  At  this  place,  Fort  Yuma,  the  mean  relative  humidity  is  85 
per  cent. 

When  outdoor  air  is  heated  so  as  to  maintain  an  even  temperature 
of  70°  F.,  but  with  no  addition  of  watery  vapor,  its  capacity  for  ab- 
sorbing moisture  is  very  much  increased,  and  it  will  take  it  up  from 
all  moist  objects  with  which  it  comes  in  contact.  It  will  take  it  from 
the  skin,  from  the  mucous  membranes  of  the  mouth,  nose,  and  respir- 
atory tract ;  from  furniture  made  from  wood  which,  in  the  process 
of  kiln-drying,  was  never  brought  to  such  dryness ;  from  the  leather 
bindings  of  books,  causing  them  to  crack  and  fall  to  pieces  ;  and  from 
plants,  which,  in  consequence,  wither  and  die.  It  thus  causes  more  or 
less  dryness  of  the  skin,  irritation  of  the  throat,  and  cough.  It  causes 
also  need  of  a  higher  temperature  to  give  the  same  sensation  of  waraith 


492 


HABIT ATIOXS,   SCHOOLS,   ETC. 


and  comfort  than  is  the  case  with  air  containing;  a  normal  amount  of 
moisture.  It  is  ou  account  of  the  disagreeable  and  destructive  effects 
of  extreme  dryness  that  water-holders  are  attached  to  I'urnaces  and 
stoves  so  as  to  give  uioisture  to  the  heated  air.  But  even  when  atten- 
tion is  paid  to  keeping-  them  fidl,  which  is  not  often,  they  are  very 
inadequate  for  the  pin'j)ose. 

Air  at  25°  F.,  saturated  M'ith  moisture  and  then  heated  to  70°  F., 
would  need  more  than  0.5  pint  of  water  in  every  1,000  cubic  feet  to 
give  it  a  humidity  of  65  per  cent.,  and  this  is  far  in  excess  of  the 
capacity  of  the  ordinary  waterpot  of  the  furnace,  as  is  seen  when  we 
reckon  what  0.5  pint  })er  1,000  cubic  feet  means  in  the  course  of  a 
day. 

Moisture  may  be  imparted  to  the  air  by  exposing  pans  or  porous 
vessels  of  water  to  the  heated  current,  or  by  means  of  the  "  humidi- 
fier," which  exposes  to  the  air  passing  through  the  registers  a  surface 
of  cotton  wicking  communicating  wdth  the  reservoir  of  water.  (See 
Fig.   48.)     With  this  device.  Dr.  H.  J.  Barnes,  of  Boston,  reports 

Fig.  48. 


Humidifier. 


that  he  is  able  to  keep  his  office  at  53  per  cent,  relative  humidity  by 
evaporating  an  average  of  4.5  quarts  of  water  per  day.  At  the  same 
time,  he  finds  a  temperature  of  65°  to  be  perfectly  comfortable  where 
before  he  had  required  70°  or  71°. 

On  a  larger  scale,  water  may  be  vaporized  into  the  air  in  the  form 
of  steam  from  a  boiler.  In  the  building  of  the  American  Bell  Tele- 
phone Co.,  in  Boston,  a  building  having  a  capacity  of  450,000  cubic 
feet  and  a  day-time  population  of  more  than  450  persons,  the  air, 
which  is  distributed  by  the  mechanical  system,  is  drawn  into  the 
building  at  the  rate  of  26,000  cubic  feet  per  minute,  heated  to  about 
100°  F.  in  the  stack  room,  and  moistened  so  as  to  contain  about  50 
per  cent,  relative  humidity.  For  the  production  of  this  condition, 
no  less  than  675  gallons  of  water  in  the  form  of  steam  are  given  to 
the  air  in  ten  hours,  or  about  one  and  a  half  barrels  per  hour.  Certain 
parts  of  the  building  which,  before  the  adoption  of  this  process,  had 


i>i':'ri':i!.!\iiN.\'i'i()iS  of  n.\'ri:s  of  vFS'rii..\'rio.\.  \'x\ 

|)C(;ii  lic;ii-(Mi  wllli  somr  (lillii'nl  I  \  ,  ;iic  nnw  iii;ii|c  hhmc  coinC'irhililc,  ;iiii| 
in  l,li(!  vvliolf^  Ijiiildiiii;-  ."1  flc^^rccs  l(!.srt  lic;il,  arc  r<  (piircd  ('<»i-  (li<-  iii.iiiiicn- 
jiiic.(!  ()('  iiii  :ii;;i(<';il)lc  (ciniMTaliH'c.  A(H!(»r<liri;r  (<,  M  )•.  ( '.  ,|.  J  I.  \\',„,(j- 
Imrv,'  iiiidcr  whose  (lircclion  llic  )>l;iiil  VVUH  ilistiillcd,  "  am. titer  fcatiin; 
iii(li(ratiii^  IIk!  j^icater  cuiiilort  of  llie  Idiildin^  was  llu;  al>.-^<-iie«;  in  win- 
icr  of  (Jic,  conti'liin^'  hy  (li(».S(;  cniiiloyc*!  llicrc,  ;i  con^li  of"  tlio  l)rone|iial 
kind  oi'  IVdUi  IIk;  laiynx,  a,  (toiieh  wliieli  ends  willi  a  h(|neal,  wliieh  is 
so  |)r(ivalen(,  in  N<nv  l^^neland  dnrine;  the  winter,  c.sjx'eially  in  tho.sc 
(•ni|)loy(!(l    in   oni(;es," 

Filtration  of  Air. — Here  may  l»e  e;Iven  an  inst^inrf!  of  I  he  Ixnefit 
derived  Croni  dllcriiii;' laJ"_i>;(!  vohniies  of  air  int rodncred  into  a  hnihlinj^ 
for  purposes  of  \-eiililalion.  In  the  hnihlini^  above  mentioned,  the 
air  is  drawn  into  and  tln-on^li  a  system  ol"  large  (cotton  bag-s  .'iO  feet 
in  length,  in  which  all  dirl  and  dust  is  retaiiictd.  About  a  peck  per 
month  is  separat('<l  in  this  way  Irom  the  air,  which  is  drawn  not  from 
the  street  UiN'cl,  l)nt  far  above  it.  An  analysis,  cliemical  and  micro- 
seo[)ieaI,  made  in  April,  J  Si)7,  showed  22. G7  ])er  vcui.  of  organic,  ami 
77.83  of  inorganic  matter.  The  material  consisted  of  all  manner  of 
animal,  mineral,  and  vegetable  substances  ordinarily  present  in  the  dust 
of  large  cities. 

Determination  of  Rates  of  Ventilation. 

'riu>  estimation  of  the  amount  of  air  entering  and  leaving  a  room 
through  inlet  and  outlet  flues  is  a  very  simple  matter,  but  the  results 
may  not  be  accepted  as  an  indication  of  the  efficiency  of  ventilation, 
since  it  so  often  happens  that  much  of  the  efllucTit  air  has  failed  to  per- 
form its  full  duty  in  diluting  the  im])urities  arising  from  respiration 
and  combustion.  Nevertheless,  such  a  determination  may  yield  im- 
portant indications. 

In  order  to  ascertain  the  volume  of  air  passing  through  an  opening, 
whether  inlet  or  outlet,  it  is  necessary  to  knoAV  the  area  of  the  opening 
and  the  velocity  of  the  current.  The  former  is  easily  ciilciilated  arith- 
metically ;  the  latter  can  be  found  only  by  the  use  of  an  anemometer, 
an  instrument  of  very  delicate  constrnction,  which  registers  tlie  distance 
travelled  by  a  current  of  air  in  any  period  during  which  it  is  ex- 
posed. 

A  current  of  air,  passing  through  an  oi^ening,  has  not  the  same 
velocity  at  all  points  of  its  cross-section.  It  moves  in  the  same  manner 
as  a  river — faster  at  its  center,  where  it  is  least  subject  to  the  influence 
of  friction.  Therefore,  the  velocity  should  be  taken  at  different  pevints, 
and  the  mean  of  the  results  accejited  as  its  true  rate  of  movement. 
The  anemometer  is  held  for  a  given  time,  say  half  a  minute,  at  a  ]x>iut 
at  the  periphery  of  the  opening,  and  then  moved  along  a  short  distance 
and  held  for  an  equal  period,  and  so  on,  from  point  to  point,  until  the 
whole  area  has  fairly  been  traversed.  The  reading  of  the  instniment 
is  then  noted,  and  the  distance  iudicatal  is  divided  by  the  number  of 

^  Trausu'tioiis  of  the  Now  England  Col  ton  Manntaotiu-ers'  Associatiou,  Vol.  63. 


494  HABITATIONS,  SCHOOLS,  ETC. 

points  where  stops  have  been  made.  The  quotient  equals  the  distance 
travelled  by  the  whole  current  during  the  unit  of  time  employed.  It 
will  be  found  most  connuonly  that  the  movement  at  the  periphery  is 
very  slow,  and  that,  as  the  center  is  approached,  the  velocity  becomes 
greater  and  greater,  the  maximum  being  attained  at  the  center.  Know- 
ing the  average  movement  in  feet  or  meters,  the  volume  is  calculated 
by  multiplying  this  by  the  area  in  square  feet  or  square  meters,  the 
product  being  the  volume  in  cubic  feet  or  cubic  meters  passing  during 
the  unit  of  time.  From  this  result,  the  volume  per  hour  is  easily  made 
known. 

Example. — The  size  of  the  opening  is  2  by  3  feet ;  the  area  is, 
therefore,  6  square  feet.  The  anemometer,  held  at  twenty-four  points 
for  fifteen  seconds  each,  registers  228  feet.  The  mean  of  this  is  9.5 
feet,  and  the  current  is  moving,  therefore,  at  the  rate  of  38  feet  per 
minute.  The  cross-section  of  the  current  being  6  square  feet,  the 
volume  discharged  in  a  minute  equals  6  X  38,  or  228  cubic  feet,  and, 
in  an  hour,  13,680  cubic  feet. 

By  determining  the  rate  of  discharge  through  all  inlets  and  outlets 
in  this  manner,  an  idea  is  obtained  of  the  amount  of  ventilation  occur- 
ring through  means  provided,  but,  as  has  been  stated,  not  of  its  effi- 
ciency. The  sum  of  the  inlet  discharge  will  almost  never  agree  with 
that  of  the  outlet,  since  much  air  enters  and  leaves  a  room  through 
other  openmgs.  Knowing  the  capacity  of  the  room,  we  learn  from  the 
amount  of  inlet  air  the  number  of  times  the  air  of  the  room  has  been 
replaced. 

The  full  measure  of  ventilation  and  its  efficiency  may  be  determined 
very  closely  by  methods  originated  by  Pettenkofer.  One  of  these  con- 
sists in  first  creating  an  unusual  degree  of  impurity  either  through 
respiration  of  a  large  number  of  persons,  as,  for  instance,  by  children 
occupying  a  schoolroom,  or  by  burning  a  number  of  candles,  or  by 
other  chemical  processes,  then,  after  taking  a  specimen  of  the  air  for 
analysis,  keeping  the  room  closed  for  an  hour  or  two.  At  the  expira- 
tion of  the  allotted  time,  a  second  sample  is  taken,  and  from  the  results 
of  the  two  analyses,  the  rate  of  ventilation  is  ascertained  by  means  of 
Seidel's  formula,  which  is  as  follows  : 

C  =--  2.303  m.  log  ^i^^- 

in  wliicli  C  =  amount  of  air  which  has  entered. 

2.303  is  a  constant. 
m  =  capacity  of  the  room. 
Pi  =  amount  of  COj  originally  present. 
P2  =  amount  of  COj  at  the  end  of  the  experiment. 
a  =  amount  of  CO.^  in  the  external  air. 

Example. — The  air  of  a  schoolroom  of  500  cubic  meters  capacity, 
accommodating  34  children,  contains  at  the  end  of  the  session  18.5  cc. 
of  CO2  in  10,000,  or  0.00185  :  1.  At  the  end  of  an  hour,  a  second 
analysis  shows  8.5  cc.  of  CO,  in  10,000,  or  0.00085  :  1.  The  outer 
air  contains  3.5  cc.  of  CO,  in  10,000,  or  0.00035  ;  1, 


11l(^ 


LIGHTINO.  105 


=  1161.5  X  '"K       ,    - 

=  115]/)  X  !')«"' 

=  1151/)  X  0.4771  ii I.". 

—  A'lK.l  ciihic  ir)cl(TM  of  ;iir  in  ;iii  lioiir. 


Tlius,  the  Jiir  of  ilu;  room  is  n^ncwcd  but  once,  and  Ji  U-iitli  per  }iour, 
and  the  result  .shows  that  tlie  per  capita  ventilation  is  about  a  fifth  of 
what  it  should  be. 

Tlu!  other  nicdiod  (^ousisls  iii  iinj)arting  to  the  air  of  a  room  a  eoiitiii- 
uous  sup|)ly  of"  (larbou  dioxide;  by  means  of  burning  eandh'S,  and  making 
periodieal  analyses  of  the  eontained  air.  Candles  of  pure  sU^arin,  1 
gram  of  whieh  yields  1.404  liters  of  the  gas,  are  employed.  A  prelimi- 
nary analysis  of  the  air  is  mad(;,  and  then  a  mnnb(!r  of  the  eandles,  the 
combined  weij^ht  of  whieh  is  noted,  are  })laeed  about  the  room  and 
lighted.  At  stated  intervals,  the  room  is.  entered,  and  after  the  air 
has  been  well  mixed  by  vigorous  fanning,  samples  are  taken  for  anal- 
ysis. At  the  end  of  the  experiment,  the  candles  are  put  out  and  re- 
weighed,  and  from  their  loss  in  weight  and  the  results  of  the  analyses, 
the  amount  of  ventilation  is  calculated  by  means  of  a  most  complicated 
formula  devised  by  Ilagenbach. 

Other  methods  have  been  proposed  by  Recknagel,  Petri,  and  others, 
but  they  present  no  advantages,  and  are,  in  general,  so  cotn plicated 
that  in  the  hands  of  other  than  expert  physicists  they  are  quite  useless. 

Section  3.     LIGHTING. 

Natural  Lighting. — In  natural  lighting,  the  light  enters  the  room 
directly  or  by  reflection  through  the  windows,  and  is  then  reflected  to 
different  parts  of  the  interior,  which  receive  different  amounts  of  light 
according  to  circumstances.  Thus,  white  and  light-colored  walls,  floors, 
and  articles  of  furniture  reflect  and  disperse  the  light,  while  dark  walls, 
draperies,  and  other  objects  absorb  it.  Large  rooms  having  but  small 
window  area  and  all  rooms,  however  generously  provided  therewith, 
looking  on  narrow  alleys  or  streets  in  which  the  opposite  buildings  are 
so  high  that  the  sky-angle  is  small,  cannot  be  illuminated  uniformly  by 
diffused  daylight  without  some  assistance. 

The  means  employed  are  exceedingly  simple,  and  the  disco verv  of 
their  utility  for  this  purpose  was  due  to  chance.  In  order  to  obstruct 
the  view  into  factory  workrooms  from  the  outside,  and  to  lessen  the 
temptation  to  operatives  to  waste  time  in  looking  out,  ribbed  glass 
was  introduced  instead  of  ordinary  glass  for  use  in  windows,  and  it 
was  noticed  that  not  only  was  the  desired  end  attained,  but  that  the 
light  from  the  windows  was  projected  farther  into  the  rooms,  and  to  such 
an  extent  in  some  instances,  that  artificial  lights,  required  before  in 
the  brightest  part  of  the  day,  could  be  dispensed  with.  Attention 
being  thus  drawn  to  the  great  advantage  and  saving  of  expense,  a  num- 


496 


HABITATIONS,  SCHOOLS,   ETC. 


ber  of  different  kinds  of  glass  with  uneven  surface  have  been  placed 
upon  tln'  market  and  haw  come  into  very  extensive  use.  The  best  of 
these,  which  is  the  most  expensive,  is  known  as  "  i)rismatic  glass  "  from 
the  fact  that  one  surface  consists  of  a  series'  of  prisms  running  horizon- 
tally.    The  entering  light,  instead  of   falling  directly  to  the  floor,  is 


FiQ.  49. 


Fig.  50. 


Action  of  prismatic  glass  in  projecting  light. 

tipped  up  and  projected  toward  the  opposite  sides  of  the  room,  as  shown 
in  Fig.  49.  Vertical  section  of  a  sheet  of  the  glass  is  shown  at  A  in 
Fig.  50.  By  varying  the  angle  of  the  prisms,  the 
conditions  obtaining  in  any  situation  can  be  met 
and  light  may  be  projected  in  any  desired  direc- 
tion. Naturally,  the  prisms  cannot  be  used  indis- 
criminately, for  a  series  adapted  to  light  the  entire 
lower  part  of  the  room  with  a  certain  sky  angle 
might,  when  applied  to  another,  throw  the  light 
toward  the  ceiling  instead  of  to  the  parts  where 
it  is  required.  Therefore,  to  meet  all  conditions, 
the  glass  is  made  with  a  great  range  of  angles, 
and  the  particular  kind  needed  in  any  situation  is 
determined  by  measurement.  Where  the  sky  angle 
is  very  small,  canopies,  hung  at  the  proper  angle 
above  the  windoAvs,  serve  to  throw  inward  a  flood 
of  light.  The  disadvantage  of  prismatic  glass  is 
its  great  cost. 

nibbed  glass  is  very  efficient  and  much  less 
expensive.  This  is  made  with  4,  5,  7,  11,  and  12 
ribs  to  the  inch,  and  of  different  thickness  and  weight,  since  the  fewer 
the  ribs,  the  deeper  they  must  be  cut,  and  the  thicker,  therefore,  the 


Vertical  section  of  pris 
matic  and  ribbed  glass. 


^l;i-ss.       V(!rli(',;il    section    dC    ;i    sliccl    oC    lildicd    j/l.-iss  \h  hIiowii  .'it   //  in 
Vu^.  50. 

Artificial  Lig-hting.—  'riic  ni<'lli<i<l:-,  of  ;irlilirl;i|  illnniin;ition  coni- 
j)fis(!  (;l('(it,i'i(;  ii^lilin^' and  those  dependent  npon  t  he  eond)n:~l  ion  of  oils, 
^iiHCH,  iiiid  hiird  fills.  'V\\v.  oils  (•Mi|ih)yed  ;ire  r-hiefly  of  ininenil  origin, 
hilt  iiniinid  :ui(l  ve<:;el!ihh;  oils  nre  nsed  to  >onie  ixU-iit,  ;dlhoii^^h  not, 
very  much  in  this  eonntiy.  Il;ird  f;its  in  the  I'oini  (»!"  (;;iii<Jh;h  jire  used 
very  (!Xt(!n,siv<'ly  in  :dl  eonntries,  on  aeeonnt  of  Hafcty,  cluxipncHH,  and 
fTf^Kirnl  iiv;iil;thility.  The  {^uses  in  eoninion  use  iire  derived  from 
comI  iiiid  hydroeiii  l»ons.  ( )f  lat(!,  a(;etylene  ^^as,  obtained  by  the  ar-tir»M 
of  moistniH!  on  eah-enn  carbide,  has  come  into  exUinsive  use. 

Luminosity  of  Flame. —  In  the  coml)nslion  of  a  eau(ilc,  it  will  be  ob- 
served that  the  llaino  consists  of  I'onr  parts,  the  hiwest  of  which,  bhie 
in  eoh)r,  f>;ives  out  practit^dly  no  li,L;ht  ;  \\\r  middle  portion,  dark  in 
color,  consists  of  hy(b'ocai"l)on  t;as  (generated  from  the  substance  of  the 
(^andl(!;  next  is  the  luminous  yellow  portion  ;  an<l  outside  of  this,  is  an 
almost  invisible  envelo|)e.  The  atmosplierit;  oxy;i:en,  moving  toward 
tlie  inner  j)()rtion  of  the  flame,  unites  with  the  carl)on  esca])in<:;  outward 
from  the  luminous  portion,  and  forms  carbon  dioxide;  mon;  oxv^en 
passes  onward  and  inward,  meets  the  hot  <^as  from  the  central  part  of 
the  rianie,  and,  beinj^  iusulHeient  in  amount  to  unite  with  both  the 
hydrou'en  and  carbon  constituents,  comlnnes  by  reason  of  fi^rciiter  affin- 
ity with  the  hydroi!:en,  leavinii;  the  carbon  free,  but  so  nincli  raised  in 
temperature  that  it  becomes  incandescent,  thus  furnishiuLC  lii^ht  during 
the  extremely  slight  interval  elapsing  in  its  passage  to  the  outermost 
portion  of  the  fiaine,  where,  as  has  been  stated,  it  is  oxidized  to  ciirbon 
dioxide.  The  same  jn'ocess  goes  on  in  the  combusticm  of  illuminating 
gas  and  oils,  the  luminosity  of  the  flame  being  due  to  the  incandescent 
}>articles  of  carbon  in  the  l)i"(ndving  up  of  the  hydrocarbon  compoinids 
into  their  elements.  A  mixture  of  gas  and  air,  such  as  occurs  in  the 
use  of  the  Bunsen  burner,  gives  off  little  or  no  light,  since  each 
particle  of  carbon  is  provided  Avith  sufficient  oxygen  to  convert  it  at 
once  into  carbon  dioxide,  and  so  incandescence  cannot  occur.  If  the 
air  supply  to  the  interior  of  the  flame  is  shut  off,  huninosity  is  produced 
at  once. 

If  the  area  of  the  outer  surface  of  an  ordinaiy  gas  flame  is  so  small 
that  atmosj)heric  oxygen  cannot  be  taken  up  sufficiently  fast  to  unite 
with  all  the  carbon  arriving  at  the  outer  part  of  the  flame,  the  unoxi- 
dized  carbon  becomes  cooled  below  the  ignition  point  and  is  given  oft'  in 
the  form  of  smoke.  Defects  in  the  bnrner  or  excessive  richness  in 
hydrocarbons  may  cause  smoking  during  combustion,  the  supply  of  air 
being  too  sniall  to  consume  the  carbon.  The  introduction  of  a  c<x)l 
surface  into  the  luminous  ]>ortion  of  the  flame  causes  deposition  of  soot 
thereon.  If  the  area  of  the  flame  is  made  too  large  by  turning  on  a 
large  volume  of  gas  imder  high  pressure,  the  gas  is  projected  so  far  that 
it  comes  in  contact  with  sufficient  atmospheric  oxygen  to  burn  a  large 
part  of  its  carbon  and  hydrogen  simultaneously,  and,  as  a  result,  the 
excess  of  gas  is  consumed  without  luminosity  and  wasted. 
32 


498  HABITATIONS,   SCHOOLS,   ETC. 

Gas  Burners. — The  best  of  the  burners  in  most  common  use  is  known 
as  the  /xifs-iring,  from  the  shape  of  the  flame.  The  tip  is  hemispher- 
ical, and  is  provided  Avith  a  single  straight  slit,  through  which  the  gas 
emerges  in  a  thin  flat  sheet.  Another,  known  as  the  Ji.sh-tail,  contains 
in  its  tip  two  small  orifices,  through  which  the  gas  issues  and  then 
spreads  out  into  a  flat  flame,  shajied  as  the  name  indicates.  This  burner 
is  inferior  to  the  bat's-wing  in  that  its  flame  is  less  luminous  with  tlie 
same  amount  of  gas,  and  the  orifices  are  much  more  easily  fouled  and 
occluded. 

The  Argand  burner  consists  of  a  hollow  ring,  provided  with  a  circle 
of  small  holes  and  attached  by  hollow  arms,  through  which  the  gas  is 
supplied,  to  a  socket  screwed  to  the  pipe.  The  gas,  issuing  from  the 
holes,  forms  a  circular  flame,  which  is  provided  with  an  abundant  air 
supply  which  passes  upward  through  the  perforations  of  the  holder  for 
the  chimney,  which  is  an  essential  part  of  the  apparatus,  and  through 
the  central  hole  of  the  burner  as  Avell.  The  chimney  should  be  of 
proper  diameter  and  height  to  insure  an  air  supply  adequate  for  com- 
plete combustion  of  the  gas. 

The  Wekbach  burner,  which  may  be  taken  as  a  good  representative 
of  the  class  of  incandescent  lamps,  consists  of  a  modified  Bunsen  burner, 
over  which  is  suspended  a  mantle  composed  of  incombustible  material, 
which  becomes  intensely  luminous  when  heated  in  the  Bunsen  flame, 
and  thus  transforms  non-luminous  heat  energy  into  luminous  light 
radiation.  The  mantles  are  made  in  different  ways,  of  different  mate- 
rials, and  are  exceedingly  fragile.  One  of  the  most  common  and  best  sorts 
is  made  by  saturating  a  delicate  network  of  cotton  in  a  strong  solution 
of  several  earthy  oxides  (cerium,  zirconium,  lanthanum,  thorium),  then 
baking,  and  finally  heating  it  until  the  cotton  fibers  are  destroyed,  thus 
leaving  a  gauze  composed  of  the  oxides  alone.  No  single  earth  is  effi- 
cient by  itself.  The  flame  and  mantle  are  protected  by  a  cylindrical 
glass  chimney,  which  serves  also  to  steady  the  flame,  and  the  whole  is 
enclosed  commonly  in  some  form  of  globe  or  shade  to  modify  the 
intensity  of  the  light.  By  providing  a  suitable  burner  to  insure  the 
requisite  degree  of  heat,  any  kind  of  combustible  gas  or  oil  vapor  may 
be  used.  Lamps  are  made  on  the  same  principle  for  kerosene  burning. 
The  incandescent  mantle  not  only  gives  out  much  more  light  than  an 
ordinary  or  Argand  flame,  but  does  so  at  a  much  smaller  expenditure 
of  gas. 

Objection  is  often  made  that  the  Welsbach  light  is  very  trying  to 
the  eyes.  This  is  true ;  but  the  same  objection  may  be  urged  against 
the  sun  and  other  intensely  bright  objects  when  looked  at  directly. 
The  lights  should  be  so  placed  that  they  will  illuminate  those  parts 
where  light  is  needed ;  and  if  they  are  likely  to  try  the  eyes,  they 
should  be  enclosed  in  globes  designed  to  soften  the  glare  and  diffuse 
the  rays  uniformly. 


VABrETflCS   OF   ll.l.llMfSATINa   (J AS.  I-'O 

Varieties  of  Illuminating  Gas. 

Coal-gas  i.s  iii;mI('  Uy  lic;iliii^;  Wilniniiioii-  roiil  in  lii-c-clny  retorts,  in 
whi(!l>  |)i-()(!(!HH  lJi(!  coimiioiiik's  oI'  liy<l To^dii  ;iii(l  (;:irl)i»ii  ar(;  transf'orriHxl 
into  }i;iiHC'()iiH  and  oilier  |)i'o<liicls.  Tlio  ^as  i.s  condiieled  In'  Jiijx-H  to 
condcnHCirs  and  pniilicis,  w  Im  ic  i(-  is  frecid  I'roin  ammonia,  liydro^^on  Hul- 
pliid(!,  tarry  mailers,  and  oilier  im|)iirities,  and  then  i.s  carried  to  Ht')r5i^e 
tanks.  'VUr  pui-ilied  |)rodn(^t  consists  ofahont  r>()  parts  of  liydrof^en,  35 
of  marsh-^as,  (I  or  7  of  (iarhoii  monoxide,  and  llie  remaiiidt-r  of  ethylene 
and  other  hych'ociarhon.s,  and  nitrogen. 

Water-gas  is  made  from  coke  or  unthracito  (;(vd,  .stt^am,  and  petroleum. 
The  coU(!  or  coal  is  placed  in  an  air-ti^ht  cylinder  lined  with  fire  clay, 
and  tluMi  is  in;nitcd  and  blown  np  to  a  white  heat  by  ni(!an.s  of  a  bla.st 
of  air.  The  air  is  tluui  shnt  olF  and  a  current  of  .steam  is  blown 
throuo;!).  Tiiis  is  decomposed  by  the  great  heat  into  hydrogen  and 
oxygen,  the  former  ]>a.ssing  on  uncombined,  and  the  latter  uniting  with 
carbon  to  form  carbon  monoxide.  The  resulting  mixture  is  then  car- 
ried to  a  gas-holder,  from  which  it  is  conducte<l  to  the  "carburetter," 
where  it  is  enriched,  in  order  that,  when  burned,  it  shall  j)roduce  a 
luminous  flame.  This  is  a  chamber  of  fire-brick  kept  at  red  heat. 
Here,  vaporized  petroleum  is  injected  with  the  hot  gas  until  the  requis- 
ite percentage  of  carbon  in  the  mixtnre  is  attained.  The  final  product 
has  nnich  the  same  odor  as  coal-gas,  but  is  of  very  different  composi- 
tion, and  much  mOre  poisonous  in  character,  containing  about  30  per 
C(Mit.  of  carbon  monoxide,  35  of  hydrogen,  20  of  marsh-gas,  and  the 
remainder  of  ethylene  and  nitrogen.  Water-gas  may  also  be  made  by 
pumping  crude  petroleum  in  a  small  stream  into  a  red-hot  gjis  retort, 
where  it  is  converted  at  once  into  vapor,  which,  with  a  current  of 
superheated  steam,  is  then  driven  through  a  long  coil  of  pipe  heated  to 
a  high  temperature.  The  chemical  reaction  is  the  same,  the  carbon 
uniting  with  the  oxygen  of  the  steam  to  form  carb(m  monoxide,  leaving 
the  hydrogen  free. 

The  poisonous  properties  of  both  coal-gas  and  water-gas  are  due 
solely  to  the  contained  carbon  monoxide,  which,  as  shown  originally  by 
Claude  Bernard,  makes  a  definite  compound  with  the  oxygen  carrier 
of  the  blood,  the  hemoglobin,  which  then  becomes  incapable  of  per- 
forming its  function.  This  being  the  case,  the  vastly  greater  danger 
atteudino^  the  use  of  watcr-mis  is  self-evident.  The  odor  of  the  two 
gases  is  practically  the  same  in  kind,  but  not  in  degree,  so,  in  order  to 
have  the  same  value  as  a  warning  of  danger  from  leaks,  that  of  water- 
gas  should  be  much  more  pronounced,  since  so  much  less  of  the  gas  is 
required  to  bring  the  air  into  a  poisonous  condition. 

Usually  about  0.4  per  cent,  of  carbon  monoxide  in  the  air  is  required 
to  produce  fiital  results,  but  less  may  be  fatal  after  long  ex]>osure.  In 
recovery  from  poisoning,  the  carbon  monoxide  is  not  oxidized  in  the 
body,  but  is  driven  out  of  its  combination  by  the  oxygen  of  the  in- 
spired air ;  but  although  after  a  few  hours  the  blood  may  nearly  be  freed 
from  the  poison,  the  damage  already  done  to  the  brain  and  other  tissues 


500  HABn'ATIOyS,   SCHOOLS,   ETC. 

through  the  temporary  partial  ilejirivation  of  oxygen  may  be  severe  ancj 
lasting.  Recovery  is  aecompanit'd  commonly  by  severe  headache, 
persisting  for  a  long  time,  often  with  nausea  and  vomiting. 

The  increased  danger  of  gas-poisoning  when  coal-gas  is  supplanted 
by  water-giis  with  its  high  ciirbon  monoxide  content  is  well  shown  by 
the  statistics  bearing  on  the  subject  at  Boston,  jNIassachusetts.  In 
1888,  when  but  1  per  cent,  of  the  gas  sold  was  water-gas,  there  were 
no  deiiths,  suicidal  or  accidental,  from  gas-poisoning.  In  the  following 
year,  there  was  but  1.  In  1890,  the  percentage  of  water-gas  rose  to 
8,  and  there  M'ere  6  deaths,  4  accidental  and  2  suicidal.  In  1892,  as 
a  result  of  permissive  legislation,  52  per  cent,  of  the  gas  sold  was 
water-gas,  and  the  deaths  rose  to  15.  In  1897,  the  percentage  rose 
to  93,  and  the  deaths  to  47,  32  of  which  were  accidental  and  15 
suicidal.  In  the  five  years  ended  September  1,  1899,  169  deaths  had 
occurred. 

On  account  of  the  danger,  a  commission  appointed  in  England  in 
1899,  reported  adversely  on  all  illuminating  gas  containing  more  than 
20  per  cent,  of  carbon  monoxide,  which  proportion  corresponds  approxi- 
mately to  a  mixture  of  equal  volumes  of  coal-gas  and  water-gas. 

Acetylene  gas,  C2II2,  is  an  unstable  compound  of  carbon  and  hydro- 
gen. It  has  a  strong,  disagreeable  odor.  Mixed  with  air  in  the  pro- 
portion of  1  to  19,  it  is  violently  explosive.  It  is  poisonous,  but  not 
to  the  same  extent  as  ordinary  coal-gas ;  an  animal  exposed  to  an 
atmosphere  containing  it  becomes  unconscious  after  a  time,  with  no 
manifestations  of  nervous  or  respiratory  excitement,  and,  if  removed 
at  once,  recovers  in  a  very  short  time.  Prolonged  exposure  is  fatal 
Blood  will  absorb  about  0.8  per  cent,  of  its  volume  of  acetylene,  but 
the  solution  gives  no  characteristic  spectroscopic  appearance.  If  any 
compound  is  formed  with  haemoglobin,  it  must  be  very  unstable.  If  a 
high  percentage  of  oxygen  be  present,  animals  may  survive  its  action 
many  hours. 

Acetylene  is  made  from  calcium  carbide,  a  reddish-brown  or  gray 
material  prepared  by  subjecting  a  mixture  of  lime  and  coke  to  very 
intense  heat.  When  this  substance  is  wet  with  water,  a  double  decom- 
position occurs,  the  calcium  uniting  with  the  oxygen  of  the  water  to 
form  quicldime,  and  the  carbon  Math  the  hydrogen  to  form  acetylene. 
Between  four  and  five  cubic  feet  of  the  gas  are  yielded  by  a  pound  of 
the  ordinary  commercial  carbide. 

Burned  in  ordinary  gas-burners,  the  flame  cannot  secure  a  sufficient 
supply  of  oxygen  for  the  complete  combustion  of  the  carbon,  and  in 
consequence  it  smokes  and  fails  to  exert  its  full  power  of  illumination. 
By  using  a  tip  with  an  exceedingly  thin  slit,  and  forcing  the  gas 
through  under  heavy  pressure,  the  flame  is  greatly  enlarged  and  is  of 
great  brilliancy.  Its  illuminating  power  is  about  15  times  greater  than 
that  of  ordinary  gas. 

Acetylene  is  liquefied  at  a  temperature  of  64°  F.  by  a  pressure  of 
1,200  pounds  to  the  square  inch,  and  may  be  stored  in  cylinders  of 
steel.     Apjjaratus  for  its  use  should  not  be  made  of  copper  or  silver, 


VA/!.f /<:'!'/ h'S  OF   II.LinilSA'r[S(J    (IAS.  •''''''1 

since  thcHC  nuitills  arc  ;iti;ickc(|  hy  il,  ;iii(|  I  lie  rc,-iil(  iiij/  c  .)ii|)()Iiii(1m  iirc 
V('IT  explosives 

III  some  ;i,|»|);ir;iiiiscs  in  use,  I  lie  \\;it(i'  is  <li  oi)])!!!  on  lo  ()if  <-,i\\)\'\f 
by  iiii  ;iii(.oiii!i,l,ie  iiriaii^cniciil,  so  lliiil  the  yi(;l(l  ol '^as  is  rc^nilaled, 
but  tlu!  <i;as  (tonliniics  to  be  cvoIm d  adcr  (he  \vatcr-sii|i|tly  is  shut  ofl*, 
silU'X!  the  inoistcncd  carbide  eaniiol  bi-  |irc\fnl<<l  IVoni  niidcM'^oirijij 
(le(!(>in|)osilioii.  In  others,  t be  eaibide  is  iiilrodiie<d  into  lOfiiiie.sitH 
vobiiiu!  ()(■  water  in  a  vohhcI  coiiiit'ctcd  with  ii  ^as-boldir  of  Hiillieient 
(';i|)a(^ily. 

Whether  aet'tyleiie  is  bkely  to  have  a  j:;reat  Held  in  the  Cutnre, 
cannot  in  the  present  slate  ol"  dev(!h)pnieiit  l)e  pre(bete<|,  but  many 
chani2;es  an<l  improvements  are  iie(!essarv  Ix-fbre  it  can  be  h»ol<r<<l  ii|)Oii 
as  liaving  any  j2;reat  |)ractieal  vabie. 

Gasolene  gas  is  a  mixture!  or<rasoIeiie  vapor  and  air,  the  fiinelion  of 
the  latter  l)eing  to  dilute  the  Ibriner  until  the  proportion  ol"  carbon  in 
the  mixture  is  equivalent  to  that  in  eommon  t;as.  Gasolene  is  a  mixt- 
ure ol"  li<!;ht  livdi'ocarbons,  a  product  of  the  distillation  of  crude  petro- 
leum. Its  specific  (gravity  ranu;es  from  (>.()2i)  to  O.tKiT.  It  volatilizt'S 
slowly  at  low  temperatures  and  ra|)idly  at  TO*^  l'\  and  above.  It  is 
exceedingly  intlammable. 

Gasolene  gas  is  generated  and  f"orced  through  supply  pipes  to  the 
burners  by  special  forms  of  a[)paratus  which  re<|uire  but  little  atten- 
tion. It  is  well  suited  to  single  houses  and  small  groups  of  houses 
where  no  public  supply  exists. 

Impurities  Given  off  in  Lighting. — In  the  conil)ustion  of  illumi- 
nants  of  all  kinds,  considerable  amounts  of  decomposition  products 
are  given  oti'  to  the  air,  and  their  removal  1)y  means  of  eflkient  venti- 
lation is  important.  These  ]n'oducts  are  least  in  amount  and  im])or- 
tance  in  lighting  with  candles  and  oil  lamps,  being  chiefly  carbon 
dioxide  and  watery  vapor.  The  impurities  given  off  in  the  combus- 
tion of  gases  include  sulphur  dioxide,  very  variable  in  amount  accord- 
ing to  the  extent  of  juirilication  ;  carbon  monoxide,  also  variable 
according  to  the  completeness  of  combustion  ;  carbon  dioxide  ;  ammo- 
nium compounds,  and  aqueous  vapor. 

Gas  Pipes. — Street  mains  are  commonly  made  of  cast-iron  pipes  of 
rather  light  weight,  which  vary  much  in  texture  and  density,  and  not 
infreijuently  are  perforated  with  blow-holes  of  varying  diameter  or 
otherwise  defective.  On  account  of  the  dangers  of  extensive  leakage 
and  of  the  financial  loss  due  to  waste  of  gas  and  the  cost  of  making 
repairs,  all  pipes  should  be  tested  thoroughly  before  being  laid.  Pipes 
which  show  no  leaks  when  new  may  soon  be  corroded  in  the  soil  at 
points  where  bubbles  occur  in  the  walls  with  but  a  thin  layer  of  metal 
on  either  side.  A^  rought-iron  pipes  are  corroded  more  quickly  in  the 
soil,  but  are  more  uniform  in  density  and  texture  than  cast-iron  and 
require  fewer  joints  in  a  given  distance.  Both  kinds  should  be  pro- 
tected by  a  generous  coating  of  asphaltum  or  other  suitable  material. 

House  pipes  are  nmst  commonly  of  wrought  iron,  though  sometimes 
softer  materials  are  employed.      The  latter  are  more  expensive,  and 


502  HABITATIONS,  SCHOOLS,   ETC. 

possess  the  additional  disadvantage  of  being  easily  punctured  by 
nails  and  gnawed  by  rats  and  mice.  The  entire  system  of  distribut- 
ing pipes  should  be  joined  most  carefully,  in  order  that  no  leaks  shall 
occur.  A\  hen  they  do  occur,  the  search  for  their  location  should  be 
conducted  "with  all  possible  precautions  against  risk  of  explosions, 
since  mixtures  of  gas  and  air  in  the  proportion  of  about  8  per  cent,  of 
the  former  are  violently  explosive  if  brought  in  contact  with  a  flame. 
The  gas  should  be  shut  off  at  tlie  meter,  and  the  apartments  Mdiere 
the  smell  is  perceived  should  be  aired  thoroughly.  The  examination 
should  then  be  begun  at  the  meter  and  its  connections,  and  if  defects 
are  there  found,  the  meter,  if  at  fault,  should  be  removed,  or  the  con- 
nections put  in  proper  condition  with  new  Avashers.  The  fixtures 
should  next  receive  attention,  every  joint  and  cock  being  tested,  the 
gas  being  turned  on  again  at  the  meter.  Smearing  the  joints  with 
some  viscid  material,  such  as  strong  soapsuds,  will  show  small  leaks 
by  formation  of  bubbles.  The  examination  of  the  joints  of  the  dis- 
tributing pipes  is  a  matter  of  considerable  difficulty,  and  may  require 
much  disturbance  of  structural  parts. 

Fixtures  should  be  so  located  as  to  avoid  hot-air  currents  from  reg- 
isters in  the  floor  and  walls,  on  account  of  the  great  annoyance  caused 
by  flickering  of  the  flame.  Flickering  is  caused  also  by  the  presence 
of  condensed  moisture  in  sags  in  the  pipes  and  bends  in  the  fixtures, 
which  causes  the  gas  to  issue  in  a  series  of  bubbles  with  consequent  un- 
steadiness of  the  flame.  The  remedy  consists  in  interposing  drip  cups 
and  draining  off  the  water. 

The  proper  arrangement  of  fixtures  is  frequently  a  difficult  problem, 
particularly  in  large  rooms.  In  general,  it  may  be  said  that  they 
should  be  well  distributed  rather  than  clustered  in  central  chandeliers. 
Fairly  uniform  diffusion  may  be  secured  by  the  use  of  globes  of  pris- 
matic glass,  which  act  in  the  same  way  as  the  ribbed  and  prismatic 
window  glass  described  above. 

Electric  Lighting". — Incandescent  electric  lighting  possesses  cer- 
tain notable  advantages  over  all  other  systems  of  artificial  illumina- 
tion. It  requires  no  oxygen  and  produces  no  decomposition  com- 
pounds, and  hence  in  no  way  alters  the  composition  of  the  air.  It 
imparts  but  little  heat  to  the  surrounding  air,  and  hence  has  but  a 
limited  influence  in  causing  convection  currents  and  raising  room 
temperature. 

Section  4.     PLUMBING. 

Whether  we  view  the  subject  from  the  standpoint  of  possible  danger 
of  infection  through  inhalation  of  sewer  air  or  from  that  of  aesthetics, 
we  should  recognize  the  great  importance  of  the  removal  of  all  sewer 
wastes  from  the  habitation  through  a  system  of  plumbing  that  is  so 
perfect  that  it  shall  leak  neither  liquid  nor  solid  matters,  nor  foul  air 
and  smells.  For  the  attainment  of  the  best  results,  all  large  commu- 
nities adopt  plumbing  ordinances  designed  to  prevent  faulty  construc- 
tion and  the  admission  of  the  dreaded  "  sewer  gas,"  which,  to  the  lay 


rijiMiiisa.  -V)."** 

mind,  iiiid  Vi'vy  ^(^mirally  to  tin;  iJi-ofcsHiotiiil  rnind  ;is  wj-II,  Ih  51  moht 
p()t,<!iiL  (',iiiis(!  of  <liK(!;is('.  VVIiiN'  flic  wci^lil.  oC  cvidcnc*'  is  !ijr;iiiiHt  tlu; 
ji(',<H!|)t:tii(!(!  (»('  ili(Mloc.(,riii('  of  the  t  r;iiisiiiiHHi(»ii  of"  disease  flirr)ii^di  lliiH 
Ufrc'iicy,  it  Miiist  l)(^  conceded  (hat  fold  odors,  Ixisidcs  Ix.-in^  disa;;rw- 
ablc,  oxort  on    the  HCMHitiv*!    individual    a    decidedly   InjurlonH   surtion 

thron<>li   the   inia,i;i nation,  I,  more  partienhiily,  Ihroiij^h   their  el!ect« 

on  the  a,|)|)etit(!  and  digestion.  Most  oC  (he  fonl  Hinell.s  connrif^  from 
|)hnnl)in<i;  lixtni'cs  arc  not  from  the  sewer  at  all,  and  }i(,'nee  may  not 
properly  Ik;  called  sewer  ^as  or  s(;W(a-  air;  tiuiy  arc  due  U)  dccomjiosing 
or<i;ani(;  matters  within  the  jjipcs  or  traps,  or  in  some  otlier  part  of  the 
fixture!,  whieli,  with  ordinary  use,  does  not  JM^eomc!  tlioronj.ddy  eK^insed. 
Thus,  it  is  often  (ound  that  tlu;  odor  from  a  wash-hasin  is  du(!  t^) 
decomposing^  soapy  matk^rs  and  olhcr  deposits  in  lli<'  horn  leading; 
from  the  overflow  holes,  but  it  is  dillie-ult  to  convince  the  timid  that 
such  is  the  fact,  ex(!ej)t  by  ocular  and  other  demonstration. 

The  most  perfect  system  of  pluml)in«r  needs  careful  supervision,  for 
no  pipe  or  other  part  subjected  to  frecjuent  contact  with  fdthy  matters 
can  bo  kept  permanently  clean  unassisted  ;  and  any  such  surface  not 
cut  off  from  contacit  with  the  free  air  of  the  room  must  inevitably, 
under  certain  conditions,  ,2;ive  rise  to  a  certjiin  amount  of  nuisance. 
The  reduction  of  these  possibilities  for  nuisance  to  tlu;  lowest  limits  is 
one  of  the  mahi  objects  of  the  many  inj^enious  ])lumbin<:;  appliances  of 
one  kind  and  another  that  are  almost  daily  increasing  in  numlxjr  and 
variety. 

Broadly  speaking,  ])lund)ing  may  be  divided  into  two  classes  :  good 
pliniibing  and  bad  ]ilunibing.  The  former  costs  more  in  the  begin- 
ning ;  the  latter,  in  the  end ;  the  former  is  installed  by  the  capable  and 
honest  plumber ;  the  latter,  by  the  trickster  who  has  given  his  calling 
such  a  bad  name  that  he  finds  it  more  to  his  liking  to  hide  behind  the 
more  pretentious  title  of  "sanitary  plumbing  engineer,"  just  as  some 
barbers  become  "tonsorial  artists." 

The  better  class  of  plumbers,  in  undertaking  the  installation  of  a 
system  of  plumbing,  attempt  to  attain  such  a  degree  of  perfection  that 
repairs  are  only  occasionally  necessary  ;  the  other  class,  either  inten- 
tionally or  because  of  inability  to  do  good  work,  produce  a  system 
requiring  constant  repairs  and  consequent  expenditure.  This  class 
of  workmen  also  are  quick  to  take  every  advantage  of  loosely  drawn 
or  ambiguous  specifieations,  whereby  the  owner  suffers  eventually  more 
than  the  original  financial  injustice.  But  the  responsibility  for  poor 
plumbing  is  not  by  any  means  always  to  be  placed  upon  the  plumi^er, 
for  an  owner  unwilling  to  pay  the  price  of  good  work  can  hardly 
blame  the  plumber  for  unwillingness  to  provide  labor  and  first-class 
material  at  less  than  cost,  and  so  gets  cheap  material  and  cheap  work- 
manship in  return  for  his  inadequate  ap]n'opriation. 

A  good  system  of  pluml)ing  calls  for  sound  materials,  absolutely 
tight  joints,  thorough  ventilation,  and  a  plentiful  water  supply  to  in- 
sure thorough  flushing  without  wastefulness.  It  should  be  so  ]ilauned 
that  the  various  fixtures  on  each  floor  shall  be  in  relativelv  the  same 


504  ITABlTATlOys,   SCHOOLS,  ETC. 

Ideations,  thus  avoiding  unnoei'ssarv  aiul  expensive  extensions  of  waste 
and  snpply  pipes.  The  wastes  slu)uld  be  easily  aecessible,  and  are  best 
run  in  full  view,  so  that  any  leakage  may  be  detected  at  once.  When 
hidden  from  view,  leaks  may  exist  undetected  until  much  damage  has 
resulted.  Open  plumbing,  furthermore,  insures  good  workmanship, 
and  makes  repairs  simpler  and  nmch  less  expensive.  The  pipes  need 
not  be  a  distigurement  to  a  room,  for  they  may  be  neatly  painted  or 
bronzed,  and  will  then  have  no  worse  appearance  than  those  used  in 
steam  heating.  If  they  must  be  placed  in  recesses  or  within  wadls, 
thi'V  may  be  concealed  by  boards  or  panels  fastened  by  screws,  and 
easily  removable. 

The  important  fixtures,  such  as  bathtubs  and  water-closets,  should 
be  placed  where  ventilation  can  be  secured  and  where  dependence  upon 
artificial  light  is  not  altogether  necessary.  The  ideal  place  is  in  an 
outer  room  with  a  window  through  which  the  sun's  rays  and  fresh  out- 
door air  may  enter. 

The  Soil-pipe  and.  Main  Drain. — The  soil-pipe  receives  at  various 
points,  through  the  several  waste-pipes,  the  contents  of  wash-bowls, 
sinks,  bathtubs,  urinals,  water-closets,  and  other  fixtures,  and  conducts 
them  to  the  drain,  by  which  they  are  carried  on  to  the  sewer  or  cess- 
pool, as  the  case  may  be.  In  this  country,  the  material  almost  univer- 
sally used  for  soil-pipe  is  cast  iron  ;  but  in  England  lead  is  preferred. 
The  advantages  of  iron  over  lead  are  many ;  it  is  lighter,  stiffer, 
stronger,  cheaper,  and  more  durable,  and  is  not  subject  to  accidental 
perforation  by  driven  nails  and  gnawing  rats.  Lead  pipe  of  large 
diameter  sags  by  reason  of  its  weight,  and  it  is  difficult  to  secure  it 
strongly  wherever  its  weight  is  borne  by  the  fastenings.  It  is  very 
easily  corroded,  dented,  flattened,  and  perforated. 

Cast-iron  soil-pipe  is  made  in  two  grades  ;  light,  or  "  standard,"  and 
"  extra  heavy."  Only  the  latter  should  be  employed,  the  former  being 
nmch  too  thin  and  flimsy.  The  walls  of  the  extra  heavy  grade  should 
not  be  less  than  an  eighth  of  an  inch  in  thickness.  The  pipe  is  made 
in  lengths  of  five  feet,  exclusive  of  the  socket,  or  hub,  which  is  an 
enlargement  of  one  end  for  the  reception  of  the  spigot  end  of  the  next 
length,  so  that  no  irregularities  shall  be  caused  in  the  caliber  of  the 
pipe  where  joints  occur,  but,  on  the  contrary,  that  the  inner  surface  shall 
be  flush  throughout.  Each  length  should  be  of  uniform  wall  thickness 
throughout  and  free  from  flaws,  sand  holes,  and  other  imjierfections, 
and  should  be  subjected  to  strength  tests  at  the  place  of  manufacture. 
The  inner  surface  shoidd  be  perfectly  smooth. 

In  joining  the  lengths  together,  the  spigot  end  of  one  is  inserted  as 
straight  as  possible  into  the  hub  of  tlie  next,  and  a  gasket  of  oakum  is 
inserted  into  the  intervening  space  by  means  of  a  caulking  tool,  and 
rammed  hard  so  as  to  fill  about  half  the  depth  of  the  hub.  The  object 
of  the  gasket  is  to  prevent  the  entrance  to  the  bore  of  the  pipe  of  any 
of  the  molten  lead  used  in  the  next  process.  The  next  step  is  the 
filling  of  the  rest  of  the  space  with  molten  lead  from  a  ladle.  Since 
this  metal  shrinks  on  cooling,  and  since  moisture  and  dirt  prevent  its 


]'ijiMi:iN(i.  •»•>•> 

!i(lli(!r('tK',('  U)  flic  inm,  it.  is  ncccssiir-y  next  \u  expand  it  and  diivc  it 
down  by  iiH'cliaiiical  tiicans.  Tliis  |)f(tccsH  n-ijiiircs  can-  and  inv'ilv(»< 
nnic.li  risk  oC  fiaclnic,  simc  llic  Mows  of  llic  canlkinjf  tools  must  Ik; 
<(nll;(!  heavy  ;  in  ("ad,  niiidi  li(a\i<r  llian  the  li}_diler  ^rade  of  [ti|W'  eaii 
witlistand.  A^ainsl  tlii-  ('nnii  of  pipe  and  ils  jointing'-,  certain  oiijecj- 
lions  ar(!  Mr^cd,  not  llic  least  ol'  uliieli  is  the  (tpportiinity  ^iven  Cor 
l)()lcli-work  and  IVand.  Instances  of  filling  the  s|)ace  with  mortar, 
sand,  pntty,  and  other  material  liaxr  liccn  not  nneommoii.  Sojne 
nnscrnpnions  |)lnnil»erM  fii;loss  o\ir  lln'  (rand  with  a  thin  layer  <»('  lead; 
some  make  llu-  jointi  |)r()p(!rly  aixl  nr<:Iect  t<»  canik  it  ;  some  make  a.s 
perlect.  a  joint  as  |)ossil)le  in  places  where  oenlar  inspection  is  easy  and 
pi'ohahle,  and  otnit  to  canIk,  or  even  to  insert  the  oaknm,  where  the; 
joints   ai'c    hidden.  Kill   willioiil    Corf^ettin^   to    make   the   usual   charj^e, 

yVnother  ohjection  to  this  Corm  oC  joint  is  the  possiliilily  «>("  its  he- 
(lomino;  loose  throuii;!)  alternate  expansion  and  conl  lanion  dnc  fo  <-haii{;e8 
in  temp(>ratnre.  The  expansion  is  nnc(|nal,  especially  when  due  to  hot 
water  in  the  pipe,  niid  the  spi^^ot  expands  more  than  its  surrounding 
socket  and  compresses  the  interposed  lead,  which,  wiicn  ef|uilil)riuin 
becomes  reestablished,  does  not  resume  its  oi-i^inal  sha|)e,  but  renuiins 
in  its  new  form.  In  this  way,  it  is  possible,  but  not  very  probable,  that 
aminute  space  may  be  ereate<l  all  about  the  sj)i<xot,  and  that  through 
this  space,  leakage  of  licpiid,  but  more  especially  of  air,  may  occur.  In 
an  upright  pipe,  leakage  of  licpiid  is  most  unlikely  to  occur,  since  the 
hub  end  of  each   joint  is  u])permost. 

Still  another  objection  is  the  great  difficulty  encountered  in  inijoint- 
ing,  Avhen,  for  any  reason,  it  is  necessary  to  remove  a  length  of  ]iipc  in 
making  repairs  and  alterations.  The  usual  and  easiest  course  to  pursue 
in  such  a  case  is  to  break  the  pipe  and  remove  it  in  pieces. 

To  meet  the  several  objections  to  this  form  of  ]iipe,  the  Sanitas 
flanged  pipe  was  devised  by  Mr.  J.  Pickering  Putnam,  of  Boston. 
This  makes  a  joint  which  is  described  as  an  adjustable  flanged  joint 
with  lead  washers  or  gaskets  for  packing.  The  gaskets,  which  are 
star-shaped  in  cross-section,  are  squeezed  between  the  flanges  of  the  two 
adjoining  pipes  and  crushed  to  half  their  original  thickness  by  screw- 
ing up  the  bolts  set  in  square  recesses  in  the  flange  ears.  These  are 
screwed  simultaneously,  so  that  the  pressure  on  either  side  is  equalized 
and  the  gasket  is  compressed  uniformly.  The  g-asket  for  a  four-inch 
pipe  weighs  a  half  pound.  For  this  joint,  are  claimwi  cheapness  and 
security.  The  time  required  to  make  it  is  reckoned  in  seconds  as 
against  minutes,  the  amount  of  lead  consumed  is  much  less,  and  the 
unjointing  is  simple  and  involves  no  breakage. 

The  diameter  of  a  soil  pi]>e  should  ordinarily  not  exceed  four  inches, 
but  in  very  large  buildings,  in  which  are  mmierous  water-closets  and 
other  fixtures,  five-inch  pipe  is  sometimes  used. 

S(nl  pipes  should  run  as  nearly  vertically  and  with  as  few  deviations 
from  a  straight  line  as  practicable.  When  these  are  necessary-,  right- 
angled  bends,  such  as  are  shown  in  Fig.  51,  should  be  avoide<i,  and 
instead  thereof,  obtuse-angled   elbows,  as   in    Fig.  52,  should  be  em- 


506 


HABITATIONS,   SCHOOLS,   ETC. 


ployed.     Where  waste-pipes  and  branebes  connect,  tbe  junctions  should 
be  made  with  Y-branches   and   not   at    right    angles.      (See  Fig.   53.) 


FiQ.  52. 


Fio.  51 


Improper  bends  in  soil-pipe. 


Proper  bends  in  soil-pipe. 


Y-branch  to  soil-pipe. 


Fig.  54. 


These  junctions  are  made  differently  when  a  lead  pipe  is  to  be  con- 
nected with  an  iron  one.  The  lead  pipe  is  first  "  wiped "  on  to  a 
brass  ferrule  by  means  of  solder,  and  then  the  ferrule  is  caulked  into 

the  hub.  AVith  the  flanged  Sanitas  pipe,  the 
connection  is  obtained  more  easily  and 
cheaply ;  here  the  lead  pipe  is  flanged  out 
and  bolted  to  the  iron  by  means  of  cast-iron 
rings  with  ears  and  bolt-holes  corresponding 
to  those  on  the  pipe. 

Each  soil-pipe  should  be  extended  in  full 
size  through  the  roof  for  about  two  feet,  and 
its  outlet  should  not  be  obstructed  by  a  cap 
or  cowl,  as  is  commonly  done.  The  cap 
serves  no  useful  purpose,  and  the  passage 
for  air  is  so  narrow  that,  in  winter,  when  the 
warm,  moist  air  ascends,  a  coating  of  frost  is 
formed  all  over  the  inner  surface  of  the  ex- 
posed pipe,  and  this  may  grow  in  thickness 
so  as  to  occlude  the  outlet  completely,  as  is 
shown  at  A  in  Fig.  54.  In  all  cases,  one 
should  make  provision  for  the  expansion  and 
contraction  of  the  column  of  metal,  for  while 
the  movement  either  way  is  slight,  its  force  is 
very  great ;  therefore,  the  fastenings  should 
not  be  too  rigid,  but  should  allow  a  little  play. 
The  soil-pipe  should  be  very  firmly  supported  at  the  bottom,  and 


Occlusion  of  outlet  of  soil-pipe 
by  frost. 


PLJIMIUNO. 


r>()7 


itH  jiiiiclioii  wilJi  llic  iiiiiin  dniiii  .slioiilil  Ix;  in:u\t:  with  a  lend  of  a» 
largo  u  radius  as  j)(),sHil)l<;.  Tlic  Ix-hL  support  is  cilhrr  a  l.ii'k  j»ier 
or  a  wood(^u  post,  or  otli(!r  firtn  and  unyielding  Htrurtiin-.  TIk-  cori- 
ucctioii  should  under  no  cinMiinstanc-cs  \n'  at  a  right  angh-,  hut  with 
an  elbow  bend  sui)j)ort<'d  on  a  foot,  as  in  I*'ig.  55.  If  the  piix;  rnuHt 
be  carried  along  a  ec^llar  wall,  it  should  Ih;  siipportiid  cither  by  a  hUvW 
or  by  wrought-irori  pi|)(!-hookH. 

I'rorn  i]\(\  p(»int  where  th(!  soil-j)ipe  departs  IVoin  ihe  jXTiM-ndir-ular 
and  tends  toward  IIh;  s<;wer  or  (;esspool,  it  is  cornnionly  known  :ls  the; 
drain,  whether  other  soil-pip(!H  enttjr  it  or  not.  The  drain  should  c/m- 
sist  of  iron  as  far  as  a  j)oint  well  away  from  the  foundation  of  the 
house  and  from  all  danger*  of  fracture  due  to  settling.  Under  no  cir- 
cumstances should  an  eartluuiware  drain-pipe  l)e  employed  within  the 
hous(!  or  beneath  the  ioundation,  or  through  a  soil  in  whi<-h  a  well  of 
(Iriidving-water  is  situated.  The  main  drain  may  be  carri(!d  along  the 
wall  of  the  cellar  in  tlu^  manner  above  described,  or  it  may  be  HUHpondiid 
by  wrought-iron  hang(>rs  from  the  joists  of  the  floor  of  the  first  st^jry  ; 


FiQ.  55. 


Fio.  56. 


VMWMA 


'//////MMi 


Elbow  bend  and  support. 


Intercepting  trap.    (Running  trap.) 


or,  if  there  are  water-closets  or  other  fixtures  in  the  cellar,  it  may  run 
below  the  floor.     In  the  latter  case,  it  should  be  easily  acce.'ssible. 

The  drain  should  have  all  the  fall  that  can  conveniently  be  given, 
and  this  should  be  as  nearly  uniform  as  possible  thrinighout  its  length. 
No  part  of  it  should  run  flat  or  sag.  The  greater  the  pitch,  the  more 
completely  the  pipe  is  scoured  out  by  each  passage  of  water.  It  should 
have  a  fall  of  at  least  a  quarter  of  an  inch  to  the  foot,  or,  preferably, 
more. 

Before  the  drain  passes  beneath  the  foundation  wall,  or,  if  this  is 
impossible,  at  a  point  outside  in  a  manhole,  an  intercepting  trap  is 
placed,  provided  with  clean-out  holes  covered  with  air-tight  covers. 
This  trap,  known  sometimes  as  the  running  trap  and  main  trap,  is  of 
the  same  diameter  throughout  as  the  drain  itself  This  kind  of  trap 
is  manufactured  in  an  immense  variety  of  forms,  one  of  the  best  of 
which  is  shown  in  Fig.  56.  This  has  an  inlet  and  an  outlet  for  sew- 
age, an  inlet  for  fresh  air,  and  a  clean-out  and  inspection  hole  on  the 


508 


HABITATTOyS,  SCHOOLS,   ETC. 

Fig.  57. 


Objectionable  arrangement  of  intercepting  trap  and  ventilating  pipe. 

outfoll   side.      The  sewage   enters  Iw  the  inlet  at  the  left,   which  is 
slightly  higher  than  the  outfall  at  the  right.     The  uppermost  opening 

Fig.  58. 


Preferable  arrangement  of  intercepting  trap  and  ventilating  pipe. 

'\s  for  the  fresh-air  inlet.  The  latter  is  for  the  purpose  of  insuring  a 
complete  circulation  of  fresh  air  throughout  the  entire  length  of  the 
drain  and  soil-pipe,  and  communicates  with  the  external  air  by  means 


ri.iJMiiiNd. 


r,m 


of.'i  i»i|»(;  of  (Ji(!  full  (liiuiiclcr  ()(' I.Ik;  (Ir.'iiii,  r-iinniiiji  fi'iiii  lli<:  li<)ii-<-  i'lf 
of  I.Ik!  U"i{)  to  soiiir  |)<iiiil,  (iiitsido. 

Ill  l^'if^.  57  is  shown  ;ui  MrniiiL''<'iii('iil  very  coiiiiiioMly  ;i(lo|»l<'i|,  but, 
o|)(>n  (,o  si^riouM  ohjcclioiis.  Ilci-c,  llic  I'llfii  m;iy  We  flirouii  iij)  a^'aiiiHt 
tlu!  ontnuicc!  oC  (Ik!  rr(!Hli-iiir  |»i|)(!  /'':i<,  A  ;iinl  ('miih  ,iti  acrniniilation. 
Tlu!  Iloor  oC  tli(!  (Ir.'iiii  and  oC  the  outlet  /S  aic  at  the  -ainc  level,  an  in 
shown  by  tin;  two  sides  (if  the  water  Hc^al  //,  and  there  will  he,  tlnrre- 
ibre,  not  li(;ud  eiiotiti^h  to  lofee  all  lii^dil  solids  easily  henrath  the  ilip 
of  the  tfaj). 

A  nineh  Ix^ttei- a,rra,n<!;eiiient  is  that.  ;ho\\n  In  V\<^.  oH.  In  tin-,  the 
inlet  of  the  fresh-air  |)i|)(!  /''is  situated  al  a  |M,iiit  some  distance  away 
from  and  on  the  iiouse  side  of  the  tnip,  where  s|)lasliin^  jind  ruxurnu- 
latioii  of  fiHli  eaiinot  o(teur.  At  A,  the;  enteriiij^  sewaj^e  falls  through 
a,  distiinee  of  about  two  inehes  at  L,  and  (%'in  Ibrce  any  solid  matter 
under  the  dip  and  onward  throu<i;h  S.  \i  will  \h'.  not<'d  by  the  direc- 
tion of  the  arrows  in  both  Hj^ures  that  the  normal  direction  ui'  the  air 
current  is  inward,  but  under  some  conditions  of  internal  and  external 
temj)eratures,  as,  Ibr  exani|)le,  in  summer,  the  dii-eetion  is  likely  to  be 
reversed.  In  winter,  owinj^  to  the  hiijher  tcwnperaturc;  of  the  house,  the 
movement  in  the  soil-pipe  is  naturally  upward  and  outward,  and  in  the 
pij)e  F  is  dow'nward  and  inward. 

Waste-pipes. — The  pipes  connecting  fixtures  Avith  the  soil-pipe  are 
known  as  waste-i>i|)es.  They  are  made  commonly  ol"  lead,  although 
cast-iron,  wrought  iron,  and  galvanized  iron  are  employed  also.     The 

Fk).  59. 


Sags  in  an  improperly  laid  i)ipe. 

advantage  of  using  lead  is  that  it  is  more  easily  run,  especially  iu  places 
where  bends  and  angles  are  necessary,  and  requires,  therefore,  a  smaller 
number  of  joints.  The  disadvantages  are  the  liability  to  perforation 
by  nails  carelessly  driven  and  by  gnawing  rats,  and  the  ]iossil)ility  of 
the  formation  of  air-locks  through  sagging  of  a  pipe  im]iroperly  laid. 
These  occur  sometimes  when  a  pipe  is  not  properly  supported  or  where 
high  points  and  low  points  occur  in  a  crooked  run.  This  is  shown  in 
exaggerated  form  in  Fig.  59.  Here  we  see  a  series  of  low  points,  in 
which  water  will  stand  and  where  sediment  may  accumulate,  and  a  cor- 
responding number  of  high  points  containing  air.  These  impede  the 
flow  of  water  onward,  and  if  the  pressure  is  low,  a  series  of  them  in  a 
single  run  may  stop  it  altogether. 

Iron  pipes  possess  whatever  advantage  attaches  to  rigidity,  and 
while  they  are  not  so  easily  adapted  to  crooked  runs  and  require  more 
joints,  it  must  be  said  that  the  latter  are  made  quickly  and  easily 
when  screw  couplings  are  employed.     Some  joints  are  made  by  screw- 


510 


IIABITATIOSS,   SCHOOLS,   ETC. 


ing  directly  into  hubs  and  some  bv  means  of  ordinary  couplings,  the 
result  in  either  case,  as  shown  in  Fig.  60,  being  perfectly  flush 
fittings. 

Ordinarily  Avaste-pipes  need  not  be  larger  than  1.5  inches  in  diameter, 
nor  heavier  than  three  pounds  to  the  foot.  In  those  cases  where  the 
sn[)ply  pipes  deliver  a  heavy  stream  of  water  under  high  pressure,  it 
may  be  necL\ssarv  to  use  a  larger  size,  iu  order  to  insure  the  removal 
of  all  the  water  without  danger  of  overflow.     Too  large  pipes  and  too 

Ftg.  go. 


Flush  fittings  witli  screw  couplings. 

small  pipes  are  equally  bad.  If  too  small,  the  overflow  is  retarded 
and  they  are  choked  easily  ;  if  too  large  for  the  fixture  from  which 
they  lead,  they  cannot  possibly  be  flushed  thoroughly,  but  are  soon 
coated  with  grease  and  other  filth,  and  eventually  become  completely 
occluded.  Thus,  a  2-inch  waste-pipe,  attached  to  a  fixture  by  a  1.25- 
inch  joint,  would  be  quite  too  large  and  out  of  place. 

Lead  waste-pipes  may  be  joined  to  iron  soil-pipes  in  the  manner 
already  described,  and  to  wrought  iron  by  brass  screw  nipples  wiped 
on  to  the  lead  with  solder  and  screwed  with  red  lead  into  the  thread 
of  the  fitting.  Lead  should  always  be  joined  to  lead  by  wiped  solder 
joints,  and  never  by  cup  or  "copper  bit"  joints,  excepting  when  the 
operation  of  wiping  is  clearly  impossible. 

Traps. — Each  separate  fixture  connected  with  the  soil-pipe,  that  is 
to  say,  each  water-closet,  wash-bowl,  bathtub,  etc.,  should  be  provided 


Fig.  61. 


Running  trap. 


with  some  form  of  trap  situated  as  near  it  as  possible.  A  good  trap 
will  wholly  prevent  the  passage  of  all  air  or  gas  or  odor  from  the 
waste-pipe  or  soil  pipe  backward  into  the  air  of  the  house,  while  per- 


I'LUMlilNd. 


nn 


mittiri^  (lie  \'rvi'.  passuf^*!  of  liijuidH  and  hiisjxtiKlcd  nolids  (oward  the 
M('.W(!r.  \l  slioidd  \h\  of  such  coiistriirilioii  uh  will  admit  of  ntJidy 
inspccfioii  and  (ilcaiiiiij^,  and  under  ordinary  circnrnst'iiutcH  nlionld  Im: 
S('l(-(',I(!ansin^.  I  nij)r()|)(ily  Irappcd  or-  nnlrapjicd  fixtnrcs  arc  uh  innf;li 
to  be  avoided  as  leaks,  \\\v  ni.siiil-  in  cidicr  case  hciii^  iIk;  name  so  far 
as  the  passajije  of  od'cnsivc  odors  is  concerned. 

Imu.  [Vl. 


Forcing  of  .sciil  of  niniiiiiK  trap. 


The  simplest  form  of  trap,  called  runninrj  trap,  consists  of  a  down- 
ward bend  in  a,  horizontal  ])ipo,  as  shown  in  Fij^.  01.  Wh(;n  water  is 
discharg(Hl  throngh  such  a  ])ipe,  the  dej)ressed  portion  will  be  found  to 
stand  full  of  water  when  the  discharge  ceases,  and  this  body  of  water 


Fi«.  63. 


B 


Forms  of  round-pipe  traps. 


will  prevent  the  passage  of  air  in  either  direction  ;  but  if  sufficient 
pressure  is  exerted  on  either  side  to  foi'ce  the  level  of  the  water  on  that 
side  down  to  the  lowest  point  of  the  bend,  air  may  be  forced  through, 
as  is  shown  in  Fig.  62.     The  water  between  the  water  level  and  the 


512 


HABITATIOXS,   SCHOOLS,   ETC. 


Fig.  64. 


lowest  point  of  the  iij^per  internal  snrface  of  the  bond  is  known  as  the 
seal,  and  this  should  never  be  less  than  1.5  inches  in  depth.  In  Fig. 
61,  the  seal  is  that  which  lies  between  the  dotted  lines.  This  form  of 
trap  is  one  of  a  class  called  round-pipe  traps,  and  to  this  class  belong 
a  number  of  forms,  five  of  which  are  shown  in  Fig.  63.  These  are 
the  iS-trap  (A),  the  Half-S  (i>),  the  Thrcc-quarfcr  S  (('),  the  Banning 
(D)  already  described,  and  the  JJoiiblc-S  or  Huncliback  [E).  These 
several  forms  are  in  all  cases  of  the  same  size  throughout  and,  there- 
fore, will  pass  anything  that  can  gain  entrance.  A\'ith  proper  Hush- 
ing, they  are  easily  kept  clean,  but  they  are  quick  to  lose  their  seal  by 
a  sudden  How  of  water  through  them  or  l)y  disturbance  of  atmospheric 
pressure  produced  by  the  sudden  discliarge  of  water  thrc.ugh  j)i])es 
with  which  their  own  pipes  are  connected.  The  means  for  the  preven- 
tion of  this  occurrence  are  considered  below. 

Another  class  of  simple  traps  includes  all  those  known  as  Bottle  or 
Pot  traps.  In  one  form  of  the  bottle  tra}),  the  principle  of  which  is 
shown  in  Fig.  64,  the  end  of  the  inlet-pipe  dips  several  inches  into  the 
pool  of  w^ater.  In  order  to  drive  air  backward  through  the  inlet-pipe 
A,  it  would  be  necessary  to  exert  pressure  sufficient  to  force  the  water 
within  the  chamber  B  upwaixl  through  A  until  its 
level  is  brought  down  to  the  lower  end  of  A.  Under 
ordinary  circumstances,  such  a  pressure  would  be 
quite  impossible.  To  drive  air  in  the  other  direction 
through  A  into  B  is  less  difficult,  but  this  will  require 
a  pressure  sufficient  to  depress  the  water  standing 
within  A  down  to  the  outlet  of  the  ]iipe. 

In  Fig.  65  is  shown  a  traj)  of  this  kind,  in  which 
there  are  two  inlets ;  the  principal  one,  the  pipe  /, 
and  the  second,  which  connects  with  the  overflow  of 
the  fixture,  the  pipe  B.  The  arrows  indicate  the 
direction  of  movement  of  the  sewage  through  the  pot. 
As  the  level  rises,  the  excess  runs  off  through  the 
outlet  0  and  discharges  downward.  The  upper 
portion  of  the  pi])e  marked  T^  connects  with  the 
ventilating  pipe,  in  which  free  circulation  of  air  is 
maintained.  The  object  of  this  is  explained  below.  This  form  of 
trap  is  made  to  lose  its  seal  only  with  great  difficulty,  although  a  part  of 
it  may  be  lost  by  siphonage.  The  objection  to  this  form  of  trap  is  the 
likelihood  of  the  accumulation  of  filth,  for,  unlike  the  round-pipe  trap, 
they  are  not  self-cleansing,  since  the  whole  contents  are  not  set  in 
motion  each  time  the  fixture  is  used. 

Another,  simpler,  form  of  pot-trap  is  that  shown  in  Fig.  66.  Here 
the  inlet-tube  /  is  not  immersed  in  the  liquid,  but  communicates 
directly  with  the  lower  part  of  the  chamber  ;  the  outlet  0  starts  from 
the  upper  part  of  the  chamber,  and  the  communication  with  the  ven- 
tilating pipe  has  its  exit  at  the  crown.  It  will  be  observed  that  in 
both  these  forms  the  seal  is  quite  deep.  The  undue  accumulation  of 
filth  in  these  traps  should  be  guarded  against,  and  for  this  purpose 


B     A 


I'lJIMIUNd. 


5].". 


clojui-oiii.  li()l<'S,  (il(tHc<l  willi  iii(l;illi<r  ,s(!rc\v-r;i|»,s,  ;irv  pn.vidtd.  A  l;ir;.'c 
ji(!(!Uiniil;ilioii  ol"  lillli  in  <'iic  of  tlic.^c  lr:i|»s  tiiJikcs  .'-iiilioiiiif.'*'  d'  llir- 
seal  mow,  cjiMily  l)r()ii[;lil,  jiImhiI.  Tlii.s  cluss  of  liiip  is  n.scd  (miIv  iiii(l(;r 
sinks,  l):isins,  hiillis,  and  wasliliihs;  never  un(J(;r  any  circuuiHtaiKxaJ 
un<l(!r  vvalcr-(;l()S('ls. 


Fig.  Of). 


Via.  m. 


Two  forms  of  vcntiliited  bottle  traps. 


Among  the  traps  (lepcndiiig  upon  naet;hanical  dcviees  to  assist  the 
water-seal,  the  Ball-trap  may  be  taken  as  a  type.  In  this  form  (shown 
in  Fig.  67),  the  U])-cast  limb  of  the  trap  consists  of  a  chamber  con- 
siderably broader  than  the  inlet  branch,  and  contains  a  ball,  the  specific 
gravity  of  which  is  slightly  greater  than  that  of  water.     This,  when 


Fig.  67. 


r^  -.     — 

1 

B 


Ball -trap. 


the  C(Mitents  of  the  trap  are  at  rest,  rests  on  its  seat  and  makes  a  gas- 
tight  joint.  When  liquid  is  discharged  into  the  trap,  the  ball  B  is 
thrown  upward  into  the  position  indicated  by  the  dotted  line ;  and 
when  the  flow  ceases,  it  drops  into  its  original  position.  It  t^nnot 
escape  from  the  chamber,  since  there  is  not  space  enough  for  it  to 

33 


514 


HABITATIONS,  SCHOOLS,  ETC. 


pass  between  the  lip  of  the  pot  and  the  top  of  the  cover.  This  form 
of  tra))  cannot  be  siphoned  out,  because  of  the  size  of  the  pot,  but, 
Avith  disuse,  it  may  lose  its  seal  by  evaporation.  In  such  an  event, 
however,  the  ball  retains  its  seal  and  closes  the  joint.  The  great  objec- 
tion to  this  trap  is  that,  even  although  nothing  which  should  otherwise 
be  disposed  of  is  thrown  into  the  fixture,  as,  lor  instance,  matches  and 
other  objects,  the  seat  of  the  ball  is  likely  to  become  the  point  of 
deposit  for  hair,  bits  of  cotton,  linen  fiber,  and  sponge,  and  then  a  gas- 
tight  joint  cannot  be  made  with  the  ball.  As  a  matter  of  fact,  indeed, 
all  mechanical  devices  in  traps  are  much  inferior  to  the  ordinary  water- 
seal. 

Another  form  of  trap,  much  used  in  kitchen  sinks,  is  known  as  the 
Bell  trap.     (See  Fig.  68.)     In  this,  the  delivery  pipe  D  projects  for 

Fig.  68. 


Bell  trap. 


some  distance  upward  into  the  reservoir ;  the  inlet  consists  of  a 
strainer,  ^S',  to  which  is  attached  the  bell  B,  which  dips  into  the  pool 
of  water  in  the  reservoir  and  encloses  the  outlet  of  the  pipe  D.  There 
is,  it  will  be  seen,  no  direct  communication  between  the  air  contained' 
within  the  bell  and  that  above.  The  waste  reaches  the  reservoir 
through  the  holes  in  the  strainer,  and  as  the  level  of  the  liquid  rises, 
it  escapes  through  D.  This  form  of  trap  is  quite  likely  to  be  choked 
by  deposits  of  small  bits  of  food  material  and  other  substances  forced 
through  the  holes  of  the  strainer  with  the  aid  of  a  sink  brush.  It 
is  also  easily  siphoned,  and,  furthermore,  being  easily  removed,  it 
happens  very  commonly  that  the  fixture  is  utilized  by  lazy  servants 
for  the  disposal  of  waste  matters  which  should  be  deposited  else- 
where. 

Grease  traps  are  devices  for  preventing  the  choking  of  drains  by 


J'UIMIilNd. 


j^easo,  wlii(;li,  <llHc,}i;irf!;c(l  in  llic  ll<|iii(l  .sl;if«;  wifli  liol  wafxr,  holi<li(i<-H 
wlieii  i(,  coriK-H  in  (•(.iibici  wilii  lliccold  .snrlacr  of  lln'  wii.sl<;-pij)(:  ;uj(i 
jullicrcs  ili(!n!l.«)  vvilli  ^rc:i(  Icn- 
acity.  'I'Ik!  (Mtaiiiif,^  vvliidi  il 
forrriH  IxKionics  tJiifkci'  ;in<l 
iliic.Ucr  IliroiitA'li  suc<!cs,siv(;  :i|)- 
pli(;:it,i<)ns,  uiid  cvcnliiiilly  may 
occlude  the  pipe;  so  conijjlclnly 
that  the  troiihht  iniisl.  \n\  at- 
tacked f'nim  tile  outside,  tli(! 
remedy  nuniirinfi:;  soniclimes 
the  removal  and  iii('i<lcn(al  <!(;- 
struction  of  an  entin;  h'n^th 
of  j)ipe.  (jrease  traps  may  he 
h)eated  heneath  the  sink  or, 
preferably,  in  a  plaee  ])r()vi(led 
therefor  outside  the  house. 

A  common  type  of  tliis  de- 
vice is  shown  in  Fig.  69.  The 
greasy  water  runs  into  the  res-  Grease  trap, 

ervoir  through  the  inlet  /,  and 

the  liquid  grease,  being  lighter  than  the  water,  rises  to  the  surface  and 
forms  a  scum,  which,  when  cold,  solidifies  into  a  cake.  The  outlet  O 
of  the  trap  dips  far  beneath  the  surface,  and  so  discharges  none  of  the 

Fig.  70. 


Jacketed  grease  trap. 


accumulated  grease.  Air  is  admitted  through  V,  and  can  circulate 
thence  through  the  inlet  pipe  J,  as  indicated  by  the  arrows.  The  accu- 
mulated grease  should  be  removed  periodically  through  the  clean-out, 


516 


HABITATIONS,  SCHOOLS,   ETC. 


which  is  oloseil  bv  the  cover  C.  A  larger  and  more  complicated  ajipa- 
ratiis  is  slunvu  iu  Fi^^.  70.  Here  the  chamber  is  enclosed  in  a  jacket, 
A  B,  through  which  cold  water  is  allowed  to  circulate.  The  dirty 
water  enters  through  /and  discharges  from  the  upj)er  branch  O,  which 
is  vented  through  T.  The  grease  accumulates  at  G,  and  is  removed 
through  the  top,  which  is  closed  by  the  hinged  cover  C. 

There  are  many  other  forms  of  grease  interceptors,  but  none  is  per- 
fect, for  under  the  most  favoring  circumstances  some  grease  will  escape 
and  may  congeal  on  the  surface  of  the  waste-pipe  or  drain.  All  grease 
traps  should  be  attended  to  at  short  intervals,  else  they  may  become 
almost  c()m])letely  filled  with  solid  grease. 

Loss  of  Seal. — Traps  may  lose  their  seal  in  various  ways  :  by 
siphonage,  by  evaporation,  by  back  pressure,  by  leakage,  by  accumu- 
lation of  sediment,  and  by  capillary  attraction.     The  most  important 


Fig.  71. 


Effects  of  ventilation  and  non-ventilation  of  traps. 

of  these  is  siphonage,  for  the  prevention  of  which  two  methods  com- 
monlv  are  employed.  In  one,  the  up-cast  limb  of  the  trap  is  widened 
so  that  it  becomes  a  pot  or  reservoir.  A  large  reservoir  will  resist 
siphonic  action  much  more  successfully  than  a  small  one ;  an  8-inch 
pot  cannot  be  siphoned  through  a  pipe  of  ordinary  size,  a  4-inch  pot 
resists  only  when  its  seal  is  unusually  deej),  and  anything  less  than  4 
inches  is  inadequate. 

This  form  of  trap,  however,  oifers  decided  objection.  In  the  first 
place,  it  is  likely  to  accumulate  much  sediment ;  and  iu  the  second,  it 
constitutes  a  miniature  cesspool,  the  presence  of  which  in  a  system  of 
plumbing  should  not  be  countenanced,  since  sewage  matter  should  be 
discharged  in  as  fresh  a  condition  as  ])ossible,  and  not  in  a  state  of 
putrefaction,   which,    if  ces.spools   are   employed,   will    inevitably    be 


I'lJlMlllNd. 


617 


hroii^lil,  jihoiif.  NTorcovfT,  (Jiis  (orni  of  inij)  is  very  <'X|K'nHivf'  ;irt(l 
bulky.  In  llic  (itlicr  inclliod,  the.  iip-cn.st,  hrarurli  in  coimcrfiid  with  a 
veil!  ilnljii^  pipe  l»\'  :i  hiMtidi  IVoiii  ils  iip|icr  [lorlioti.  (Inlcns  on*-  or 
ili(M»(.li('r  of  llicsc  I  \vo  iiM'lliixIs  is  .■idnplcd,  (lie  confi'iit.H  of  \\u'.  trap, 
j)art;i(Milurly  in  I  he  cisc  of  ;i  nmnd  plpf  ti;ip,  an;  likely  to  Ik;  Kijilioncd 
over  wluMi  its  fixliirc  is  ms(mI  or  uIhii  ,i  liirj^c  volume  of  water  is  din- 
(!lia,i'j:;<'d  (roni  sonic  ol,li(\r  lixt-iirc  inio  iIh-  soil-|)ipf',  ;nid  in  its  dc.sc(!tit 
causes  a  parli:d  vacniun.  In  tli(;  Coi-nier  ease,  the  trap  is  Hel("-si[)lione«l  ; 
in  the  laticr,  IIk;  parliid  VMcnnin  draws  the  water  over  and  breaks  tho 
seal.  I('t.h(!  trap  eoininiini(;at(!S  with  a  venlilalin^'  pipe,  this  (JiHtnrJ>- 
anec  of  oipiilibrinni  c-innot,  oecMir,  since  the  deseendin|r  mass  of  watx;r 
cansos  a  downward  snclion  of  air  thron^h  tlu;  vent  pi[)0  to  satisfy 
what  would  otherwise*  be  a  partial  vacnnni.      In    J-'ijjj.  71,  the  diagram 


I''io.  72. 


Improper  and  proper  positions  of  vent  pipes. 

on  the  right  shows  the  condition  after  siphonage  has  occurred  ;  the 
greater  part  of  the  water  has  been  drawn  over  until  air  can  be  sucked 
through,  and  that  which  remains  has  fallen  back  into  place.  The 
result  is  that  a  free  communication  exists  between  the  fixture  above 
and  the  soil-pipe  below.  The  diagram  on  the  left  sliows  tlie  condition 
of  the  seal  if  the  trap  is  connected  with  a  ventilating  pipe  through  V. 

In  venting  traps  in  this  way,  the  position  of  the  vent  pipe  is  of 
considerable  importance.  Ordinarily,  it  is  placed  as  shown  in  the 
figure.  The  objection  to  this  procedure  and  the  proper  method  are 
shown  in  Fig.  72.  If  the  pipe  enters  in  the  middle  of  the  bend,  each 
discharge  of  sewage  into  the  trap  causes  a  projection  of  the  liquid 
upward  into  the  pipe  V,  and  after  a  time  an  accumulation  is  likely 
to  occur  at  A.  If  the  pipe  is  situated  fiirther  to  the  right,  as  in  the 
di'awing  on  the  right,  this  accumulation   is  not  likely  to  occur,  and 


518 


HABITATIONS,  SCHOOLS,  ETC. 


the  sewage  and  the  air  take  tlie  Jireetious  indicated  by  the  arrows. 
The  vent  pipe  is  more  easily  joined  to  the  trap,  however,  in  the  man- 
ner to  which  objection  is  made. 

The  ventilating  pipes  from  the  different  traps  of  a  system  of 
plumbing  connect  with  a  main  ventilating  j^ipe,  which  may  be  joined 
to  the  soil-pipe,  alongside  of  which  it  runs,  at  a  point  in  its  upper 
part,  before  its  projection  through  the  roof.     It  is  important  that  the 

junction  of  each  vent  pipe  with  the 
main  shall  be  at  a  point  above  the 
fixture,  since,  in  case  of  an  ob- 
struction in  the  soil-pipe  below,  the 
water  may  back  up  through  the 
trap  and  discharge  through  the  vent 
pipe  into  the  main  vent,  as  shown 
in  Fig.  73.     Here,  the  soil-pipe  S 

Fig.  74. 


Fig.  73. 


Improper  junction  of  vent  pipe  with  main  vent. 


Sanitas  trap  (taken  apart). 


has  been  obstructed  at  a  point  just  below  the  entrance  of  the  waste- 
pipe  from  the  fixture,  and  water  has  accumulated  throughout  the 
entire  length  of  waste-pipe  and  is  discharging  into  the  main  venti- 
lating pipe  at  V.  If  the  point  V  were  higher  than  the  upper  margin 
of  the  bowl,  this  could  not  occur,  since  the  bowl  itself  would  fill  and 
overflow  into  the  room,  and  thus  call  attention  to  the  obstruction. 

Non-siphoning  Traps. — A  number  of  traps  known  as  non-siphoning 
have  been  devised  to  obviate  the  necessity  of  back-venting.     Among 


J'LUMIifNQ. 


619 


tlicso  may  Ik;  riKMil.ioiicd  lli<;  "  Sanilas/'  iMV(:iiU;(l  hy  Mr.  .).  rickciiii^ 
Putiiiim,  Jiiid  (lie  "  IIy(lri<-.." 

TIk!  S;i,iiil;is  (r;i|),  sliowii  in  I'i^;.  7'1,  is  rriJidc  proof  ;i;^;iiii.s(,  hipliotiic 
iictioii  by  :i  <l(;ll('(;t,iiij^  |):irlitioii  williiti  IIk;  (^IiiiimIxt,  wliicli  ix-rinits  tlif; 
]);issii|j^(M)r  !iir  ;iJ)OV(;  llic  water  ami  (lirows  l)a<k  a  \ dIiiiik;  of  wut<;r 
KiillicMciiL  to  iiiaiiitaiii  ;i  .seal  over  llircc  iiiclir'S  in  »l<|)tli,  wliicli  n-HiHtrt 
(svaporation  for  a  loii^  time  and  cainiol,  l»;  destroyed  by  e,a[)ilhiry  at- 
lra<d.ioii.  Wlien  allae.lied  to  lixtnres  with  larj^e  outlets  and  (juiek  (Hh- 
eliari^Cj  it  is  also  sell-eleansin^,  even  wiicii  aslics  and  similar  unusual 
constituontH  of  sewage  an;  thrown  into  it.  In  the  figure,  the  H<;verul 
parts  are  shown  separatc^ly  :  tluj  main  strnctiire,  the  eharnher,  and  the 
defleeting  ])adition. 

The  lly(lri(;  trap,  shown  in  Fig.  75,  eontains  no  defleeting  j)artifion 
or  other  meehanical  deviee,  but  de[»ends  upon  the  a(;lionof"  the  upjM-r 
surfaec  of  the  body  of  the  trap  in  dciHeeting  and  throwing  back  the 
water  during  the  sucking  of  the  air  through  the  chamber  and  over  the 

P'lo.  75. 


Hydric  trap. 


water.  When  the  siphoning  action  is  finished,  a  sufficient  volume  of 
water  remains  to  form  a  permanent  seal. 

Evaporation  of  the  seal  does  not  commonly  occur  except  after  long 
disuse.  It  is  favored  by  trap  ventilation,  since,  when  a  current  of  air 
comes  in  constant  contact  with  a  body  of  water,  constant  absoqition 
is  in  process.  In  order  to  prevent  loss  by  evaporation  in  case  of  long 
disuse,  two  processes  are  in  vogue.  One  is  to  employ  a  trustworthy 
person  to  visit  the  premises  weekly  during  the  absence  of  the  occupants 
and  flush  each  fixture.  The  other,  and,  on  the  whole,  the  more  eco- 
nomical, is  to  pour  into  each  fixture  a  sufficient  amount  of  glvcerin, 
which,  being  hygroscopic,  will  take  water  from  rather  than  yield  it  to 
the  atmosphere,  or  of  oil,  which  will  float  on  the  surface  of  the  water 
and  prevent  its  absorption  by  the  air. 

Back  pressure  is  a  force  which  is  not  much  to  be  feared.  In  former 
times,  when  it  was  not  customary  to  ventilate  the  soil-pipe,  back  press- 
ure was  caused  not  uncommonly  by  winds  and  the  action  of  tides,  so 
that  the  air  in  the  whole  plumbing  system  was  compressed  and  the  seal 


520  HABITATIOSS,   SCHOOLS,   ETC. 

forced  backward.  Sometimes,  a  trap  situated  near  the  bottom  of  a  tall 
stiick  is  tbrced  by  back  pressure,  brought  about  by  the  descent  of  a 
cohunn  of  water  pressing  the  contained  air  ahead  of  it. 

Leakage  as  a  cause  of  loss  of  seal  is  too  evident  to  require  explana- 
tion. Accumulation  of  sediment  may  be  so  extensive  as  to  replace  the 
water  in  great  part,  and  tlnis  render  sijihoning  much  easier.  Capillary 
attraction  is  a  not  iufrc'nucnt  cause  of  loss  of  seal  when  accumulations 
of  hair,  threads,  and  other  like  substances  occur  in  a  non-scouring  trap 
at  the  outlet  and  drain  away,  little  by  little,  the  fixture  side  of  the  seid 
into  the  outfall. 

It  is  hardly  necessary  to  say  that  nothing  should  be  thrown  into 
traps  excepting  those  matters  which  are  recognized  as  constituents  of 
normal  sewage,  that  is  to  say,  neither  matches,  nor  rags,  nor  broken 
china,  nor  wads  of  newspaper,  nor  stiff  writing  paper  not  easily  dis- 
integrated by  the  action  of  water.  All  such  substances  are  likely  not 
only  to  clog  traps  and  break  the  seal,  but  also  to  form  obstructions  in 
soil-pipe,  particularly  where  bends  occur. 

The  extremists  who  cling  to  the  sewer-air  theory  of  transmission  of 
disease  are  not  always  satisfied  with  ordinary  trapping,  feeling  sure 
that  the  water  in  one  branch  of  the  trap  will  absorb  disease  germs 
from  the  sewer  air  and  discharge  them  on  the  fixture  side.  To  avoid 
this,  a  system  of  double  trapping  has  been  advocated,  with  which  assur- 
ance is  made  doubly  sure.  With  this  arrangement,  we  have  two  traps 
in  immediate  succession,  so  that  the  waste  from  the  first  must  pass 
through  the  second  ;  thus  we  have  two  seals,  and  any  poison  absorbed 
from  the  farther  one  and  disengaged  backward  will  then  meet  with  a 
second  obstruction.  Besides  the  manifest  absurdity  of  such  extreme 
precaution,  there  is  a  decided  objection  to  this  arrangement,  since  solid 
matters  are  likely  to  lodge  in  the  second  trap  and  cause  it  to  be  ob- 
structed. While  the  head  of  water  may  be  sufficient  to  drive  the  waste 
through  one  trap,  it  is  by  no  means  certain  that  it  will  be  strong 
enough  to  drive  it  through  two,  and,  as  a  matter  of  fact,  it  usually 
is  not.  Moreover,  between  the  two  traps  an  air  lock  is  likely  to 
form,  and  that  in  itself  is  a  decided  objection,  as  has  been  explained. 

Water-closets. — By  reason  of  the  fact  that  their  general  employ- 
ment is  a  matter  of  comparatively  recent  times,  it  is  believed  very  com- 
monly that  water-closets  are  the  invention  of  the  last  half  century. 
They  date  back,  however,  many  centuries,  for  in  a  somewhat  simpler 
form  they  were  in  use  in  ancient  Rome  and  Pompeii,  and  probably 
even  earlier  in  Asia  and  Africa.  These  primitive  forms,  however,  were 
devoid  of  the  mechanical  appliances,  flushing  tanks,  etc.,  of  the  closets 
of  the  present  day.  It  is  said  that  the  prototype  of  the  present  closet 
was  in  use  in  France  and  Spain  before  the  sixteenth  century,  but,  so 
far  as  is  known,  no  diagrams  of  their  construction  are  extant.  In 
England,  the  first  water-closet  with  a  flushing  apparatus  was  constructed 
under  the  direction  of  Sir  John  Harington,  at  his  country  seat  at  Kel- 
ston,  near  Bath,  and  described  by  him  in  a  satirical,  semi-political 
work,  "An  Anatomy  of  the  Metamorphosed  Ajax/'  printed  in   1596, 


I'LlJMIllSd. 


521 


from   wlii<'li    work    I'i^s.    7'!   .'mkI    77   ;iic   Inkfii.      I'ij.^,   7')   .•-liows   tlu? 
details  ol'  Uic  :i])|);ini(,UH  (Jcsctiltcil  li\   liim  ;i.-  IoIIowh: 


Fin.  70. 


te\v^\\\\v.\i.vsi^\^ASi^v:::',;  -fll. 


't 


Reduced  facsimiU'  of  the  cililest  known  (I'flro  drawing  showing  details  of  a  water-closet. 

"  Here  are  the  parts  set  clown  with  a  rate  of  the  prices,  that  a  builder 
may  guess  what  he  hath  to  pay. 


"  ^4  the  cistern  ;  stone  or  brick.      Price 6 

b,  d,  e  the  pipe  that  conies  from  the  cistern,  with  a  stopple  to 

the  washer 3 

c  a  waste-pipe 1 

/,  g  the  stem  of  the  great  stopple,  with  a  key  to  it 1 

h  the  form  of  the  upper  brim  of  the  vessel  or  stool-pot  .    .    . 

m  the  stool-pot,  of  stone 8 

n  the  great   brass  sluice,  to  which  is  three  inches  current  to 

send  it  down  a  gallop  into  the  Jax 10 

i  the  seat,  with  a  peak  devant  for  elbow-room.  The  whole 
charge  tliirty  sliillings  and  eight  pence  ;  yet  a  nia.son  of  my 
masters  was  offered  tliirty  pounds  for  the  like.  Memoran- 
dum.    The  scale  is  about  half  an  inch  to  a  foot." 


Fig.  77  shows  the  apparatus  set  up  and  during  flushing.  "  Here  is 
the  same  all  put  together  ;  that  the  workman  may  see  if  it  be  well.  A 
the  cistern.  B  the  little  washer,  c  the  waste-pipe.  D  the  seat  board. 
e  the  pipe  that  comes  from  the  cistern,  f  the  screw.  7  the  scallop 
shell,  to  cover  it  when  it  is  shut  down.  Hthe  stool  pot.  /  the  st(^pple. 
k  the  current.  I  the  sluice,  m,  Xthc  vault  into  which  it  falls  :  always 
remember  that  (  )  at  noon  and  at  night  empty  it,  and  leave  it 


522 


HABlTATIoyS,  SCHOOLS,  ETC. 


half  a  foot  deep  in  fair  water.     And  this  being  well  done,  and  orderly 
kept,  your  worst  privy  may  be  as  sweet  as  your  best  chamber." 

We  have  evidence  that  even  among  peoples  not  classed  among  the 
highly  civilized,  the  use  of  water-closets  is  by  no  means  of  recent  date. 
Thus,  Ogilby  in  bis  elaborate  work  on  Africa,  published  in  1670,  de- 
scribing the  city  of  Fez,  says,  on  page  187  :  "The  River  Fez  which 
Paulus  Jovius  calls  Rhasalme,  passes  through  the  City  in  two  Branches  ; 
one  runs  Southward  towards  New  Fez,  and  the  other  West ;  each  of 
these  subdividing  into  many  other  clear  running  Channels  through  the 
Streets,  serving  not  onely  each  private  House,  but  Churches,  Inns, 

Fig.  77. 


Companion  to  Fig.  72,  showing  parts  put  together. 

Hospitals,  and  all  other  publick  Places  to  their  great  conveniences. 
Round  about  the  Mosques  are  a  hundred  and  fifty  Common-Houses  of 
Easement,  built  Four-square  and  divided  into  Single-Stool-Rooms,  each 
furnished  with  a  Cock  and  a  Marble  Cistern,  which  scoureth  and  keeps 
all  neat  and  clean,  as  if  these  places  were  intended  for  some  sweeter 
Employment." 

The  water-closets  of  the  present  day  may  be  divided  into  two  classes  : 
those  having  movable  internal  mechanism,  and  those  having  none.  To 
the  former  class  belong  the  plunger,  or  plug,  closet,  the  pan  closet,  and 
a  number  of  others ;  to  the  latter  belong  the  hopper  closet,  the  various 
wash-out  closets,  the  siphon  closets,  and  the  siphon  jet  closets.  To 
attempt  to  describe  all  the  different  forms  on  the  market  would  be  a 
tedious  and  useless  task,  for  the  patented  devices  alone  run  up  into  the 


I'lJIMI'.INd. 


523 


ymndnsdH.  Tluircfon!,  in  tlu;  following  V-^\iy'^j  ""'y  tJ'f'Hf  wliioli  rimy 
be  tukcM  us  iyj»(;s  <»('  tli(;  worst  iiiid  Itcst,  will  he  dcsftrihcd.  I*'irsf.  will 
bo  (l(!H(',ril)(i(l  lJi«»s(!  of  (li.sliiicfly  obj(!f;l-ioii;ibl(;  f;<)ii.s(.riiclioii.  ThcHr;  iri- 
cIikKs  a  iiiirnbcT  wliic-li,  while  lli(;y  urc  no  longer  inlrodnccd  in  com- 
munities huvinfi^  mod<!rii  pliinibing  regulutif^riH,  cxihf  in  ili'.nsjindH  of 
bouses,  into  wliieli  (bey  werv;  iiid-odneed  ;it  a  time  win  ii  lli<y  w*!re  re- 
jrarded  us  ubsobilcly  \)i\v[\\v\.. 

The  Pan  Closet. — Tbe  prineiple  of  tins  uppurutus  is  sliown  in  V'\yr. 
78,  wbieb  is  u  vertieul  section  of  tb(!  working  purt  of  tbc  chi.'-et,  free 
from  tbc  cubinct  work  in  wbicb  it  is  usiiully  enclosed.  It  conHiHts  of 
u  boj)j)er  //,  provided  witb  u  flusbitig  rim  und  elos(;d  ut  its  outlet  by 
ttieans  of  a  binged  patj  P,  wbicb  is  releiis(!(l  by  a  mcciiani.srn   wJjicb  it 

Fio.  78. 


Pan  closet. 


is  unnecessary  to  illustrate  or  explain.  WTien  the  pan  is  in  the  hori- 
zontal position,  it  is  partly  filled  with  water,  into  which  the  excreta 
are  discharged,  although  ordinarily  they  come  in  contact  first  with  the 
surface  of  the  hopper  above  the  water  level.  The  closet  is  emptied 
by  pulling  a  knob  or  handle  which  releases  the  pan,  which  then  takes 
the  position  shown  in  the  figure  by  the  dotted  lines.  The  contents 
are  thus  thrown  into  the  lower  chamber,  and  fall  into  the  trap  below. 
The  mechanism  which  releases  the  pan  also  starts  a  flush  of  water 
through  the  flushing  rim  over  the  surface  of  the  hopper.  This  flush 
is  supposed  to  scour  the  interior  and  to  be  sufficiently  voluminous  to 
drive  the  excreta  over  the  bend  of  the  trap  and  forward  toward  the 
soil-pipe.  When  the  pan  is  brought  back  to  its  original  plac^,  the 
flush  continues  until  the  pan  is  filled  to  the  same  level  as  before. 

As  a  matter  of  fact,  the  flush  of  these  closets  is  ordinarily  little 


524 


HABITATIONS,   SCHOOLS,   ETC. 


bettor  than  a  more  dribble.  Tlie  front  wall  of  the  receiving;  chamber, 
against  which  the  excreta  are  thrown  by  the  pan  in  its  descent,  is 
invariably  in  a  filthy  condition,  which  cannot  be  improved  by  any 
amonnt  of  snch  flushing  as  the  a[)[)aratns  is  capable  of  giving.  The 
consequence  is  that  each  time  the  pan  is  dropped,  a  volume  of  foul 
air  is  clisplaced  upward  into  the  room.  The  inlet  side  of  the  trap  is 
commonly  a  miniature  cesspool,  since  the  flush  has  so  little  head  that 
it  is  unable  to  drive  objects  of  lighter  specific  gravity  than  that  of 
water  throngh  the  trap.  In  the  illustration,  S  represents  what  is 
known  as  a  "  safe  "  to  catch  all  drippings  from  any  source,  and  from 
this,  the  pipe  s  conducts  them  to  the  bend  of  the  trap.  This  whole 
contrivance,  formerly  the  pride  of  the  plumber's  craft,  is  now  gener- 
ally and  justly  regarded  as  an  abomination. 

The  Plunger,  or  Plug,  Closet. — This  apparatus,  shown  in  Fig.  79,  is 
far  less  objectionable  than  the  pan  closet.     It  consists  of  a  receiver  B, 

Fig.  79. 


^^r 


Plunger  closet. 

in  which  a  large  volume  of  water  can  be  retained  when  the  plunger,  or 
plug,  A,  is  in  place.  When  A  is  lifted,  the  contents  of  B  escape 
downward  into  the  trap,  which  is  vented  at  V.  The  plunger  A  not 
only  controls  the  emptying  of  the  receiver,  but  also  acts  as  a  standing 
overflow,  for  should  the  water  in  the  reservoir  rise  higher  than  the 
upper  level  of  the  ])lunger,  it  will  flow  over  into  A,  and  from  it 
through  C  into  the  trap.  This  fixture  requires  a  large  amount  of 
water  in  order  to  obtain  a  proper  flush,  for  unless  the  flush  is  gener- 
ous, bits  of  paper  and  other  material  may  adhere  to  the  edge  of  the 
outlet,  so  that  when  the  plunger  is  in  place  the  valve  is  not  tight. 
Naturally,  with  a  loose  joint,  the  contents  of  the  receiver  will  ooze 
away  and  leave  it  in  a  dry  condition. 

These  two  forms  suffice  as  illustrations  of  the  objectionable  class  of 


rijiMitisd. 


ri^n 


Vu..  80. 


closets,  ;iii(l  i(.  iriiiy  lu;  siiid,  in  ^'cncral,  tli;i(  ;ill  <;lo.-«'ts  «l<'|)<'rnliiij.^  ii|n)ii 
iiir(!rri;i,l,  inc(^liiuiic;i,l,  movuldc  purls  ■avc.  ohjcclioii.-ihlc,  uiid  :ill  of  lliciii 
arc;  likely  l.o  Ixicotiw!  <iXc.c(Mliii^ly  I'oiil. 

A    |)r()[)(!rly   c-onstriiclcd    wnlcr-clo-cl    -limild  l);i\<'  ;i    llii-li  of  water 

(lllll.     will     WJlsIl     the     wIkiIc    ()('    lllf     illlcliol-     -ll|-|';icc    of    (lie     howl     JMOHt 

tlioroii^lily,  (!iirry  oiiwjird  nil  lln'  liltli  and  other  material  l»eyond  the 
trap,  and  l(^av(!  iJie  howl  filled  to  the  proper  lii'i}xlil  with  clean  water. 
Jt  HJioiiId  !)(!  (;leaned  so  tlioronn;hly  cycvy  linK'  it  i-  used,  that  no  (iltli 
may  remain  (lej)osited  at  any  point,  and  it,  slionid  he  Irw;  I'roni  dis- 
a^rcenihlc  odor. 

Hopper  Closet. — Tiie  sini|)lest  Conn  of  non-rneehanieal  eloset.s  in 
known  as  tlu;  Hopper,  which  is  shown  in  V\yi:.  80.  The  jjhistni- 
tion  hardly  uccds  explanation,  the  d(\  ice  <'onsistinjr  of  a  hojiper  con- 
nected witii  a  simple  S-trap,  ventilated  in  (he  usual  way.  JIoj)|kth 
arc  known  variously  as  t^hori  and  Ioikj.  1  Ik  lun^r  variety  presi-nts  no 
a<Iva,ntai2;e  over  tlu*  short,  and  is  k(!pt  nuieh  k'ss  easily  in  projter  con- 
dition. The  l()n<^  hopper  has  its  tra[)  ixaieath  the  floor  ;  the  Amri  hop- 
per, above  it.  The  short  hopper  is 
less  likely  to  become  foul,  on  ac- 
count of  the  smaller  surface  pre- 
sented, and  because  the  level  of  the 
water  in  the  traj)  is  nearer  the  seat. 
The  hopper  should  be  provided  with 
a  s>;cuerous  flush  from  a  flushing  rim, 
for  otherwise  it  is  likely  to  become 
fold,  since,  from  the  shape  of  the 
receiver,  fouling  of  its  posterior 
interior  surface  is  inevitable.  This 
is  more  marked  with  the  long  than 
with  the  short  hopper.  Unless  the 
flush  is  a  generous  one,  it  is  neces- 
sary to  pour  down  an  occasional 
pailful  of  water,  and  also  to  apply  the  closet   brush  at  least  daily. 

Open  Wash-out  Closets. — The  open  wash-out  closet  is  designated 
variously  as  front  or  back  or  side  wash-out,  according  to  the  direction 
which  the  contents  of  the  bowl  take  toward  the  trap.  In  Fig.  81  is 
show^n  a  front  wash-out  in  verticiil  section.  The  bowl,  provided  with 
a  flushing  rim  i'^fed  by  the  supply  pipe  P,  holds  a  pool  of  water,  into 
which  the  excreta  are  projected.  The  greatest  depth  of  this  volume 
should  not  exceed  1.75  inches.  In  use,  the  contents  of  the  bowl  are 
swe}>t  by  the  water  from  the  flushing  rim  into  the  trap  -S',  which  is 
ventilated  at  T"in  the  usual  manner,  and  the  flow  is  sufficiently  volu- 
minous to  force  the  excreta  down  and  under  the  partition. 

If  the  volun\e  of  water  in  the  bowl  is  deej^cr  than  above  stated,  it  is 
possible  that  the  flush  may  sweep  beneath  any  floating  excreta,  which, 
in  consequence,  may  be  retained.  If  no  pool  at  all,  or  only  a  very 
nuich  shallower  one,  be  kept,  the  excreta  may  adhere  to  the  basin  with 
such  tenacitv  that  they  are  not  easilv  dislodged  bv  a  sinsrlo  flush.     For 


Hopper  closet. 


526 


HABITATIONS,  SCHOOLS,   ETC. 


the  wash-out  closet,  it  was  intended  to  secure  the  combined  advantages 
of  the  hopper  and  the  phinger  ck^sets,  that  is,  the  advautage  of  a  large 
surface  of  water  in  the  bowl  in  addition  to  that  in  the  trap,  without 
the  intervention  of  any  mechanical  contrivance.  The  objections  to  the 
wash-out  closets  are  :  (1)  that  tiie  j)rincipal  office- of  the  flush  is  the 
cleansing  of  the  basin  ;  (2)  that  after  each  using,  the  excreta  and  paper 
are  hkely  to  remain  in  the  inlet  side  of  the  trap  until  the  fixture  is 
used  again ;  and  (3)  that  the  surface  against  which  the  excreta  are 
thrown  during  the  flushing  is  likely  to  become  fouled  and  remain  so 
until  cleaned  mechanically  by  means  of  a  brush  or  other  appliance. 

Another  form  of  wash-out  closet  has  the  basin  so  constructed  as  to 
form  a  trap.     Closets  of  this  class  are  much  like  the  hopper,  but  hold 

FiQ.  81. 


Open  wash-out  closet. 

a  much  greater  depth  of  water.  They  are  known  more  commonly  as 
"wash-down"  closets.  In  both  the  wash-out  and  the  wash-down 
closets,  the  lip  of  the  trap  should  dip  not  less  than  1.5  inches  beneath 
the  water  level ;  less  than  that  increases  the  risk  of  loss  of  seal  by 
evaporation,  and  more  requires  a  larger  flush  than  is  ordinarily  obtain- 
able to  force  the  excreta,  etc.,  downward  and  onward. 

Siphon  Closets. — Another  type  of  wash-down  closet  is  known  as  the 
siphon  jet.  In  this,  the  contents  of  the  receiver  are  drawn  out  by 
siphonage,  and  at  the  same  time  are  propelled  by  a  jet  of  water  from 
the  front.  In  Fig.  82,  one  of  these  closets  is  shown.  Here  the 
chamber  is  divided  into  two  sides  of  a  trap  by  the  partition  8.  As 
the  flush  is  brought  into  play,  a  jet  of  water  comes  down  with  some 
force  through  A  and  pushes  the  contents  of  B  over  into  the  chamber 
C,  and,  as  the  flush  continues,  the  chamber  C  becomes  the  long  leg  of 


PI  JIM  It  I  NO. 


r,'27 


a  sij)lK)n,  HO  thut  wli(;ii  llic  lliisli  cciiscs  to  jict,  IIk;  Hij»lioii  f;oriLiiiU(H  to 
mvk  out  the  cAyuU^utH  of  the  receiver  iinlil  the  wnU-.r  U:v<t\  in  brought 
down  l()  tli(i  point  S,  \\\u'\\  :iir  is  adrriiUrd  and  the  Hif)}iori  hcfonicH 
th(!r(!hy  hrokcii.  'llic.  jil'tcr-liiish  rais(!M  the  vvat<;r  level  again  to  ilH 
original   poinl. 


Fkj.  82. 


Siphon  jet  closet. 


Another  form  of  siphon  closet,  which  acts  without  the  assistance  of  a 
jet  is  known  as  the  Bececo.  This  is  a  very  simple  and  efficient  fixture, 
invented  by  the  late  Colonel  George  E.  Waring,  Jr.  The  receiver  is 
very  deep,  and  maintains  several  inches  of  seal.  The  apparatus  is 
To  assist  in  charging  the  siphon,  a  weir-chamber, 


shown  in  Fig.  83. 
Fig.  83. 


Fig.  84. 


Dececo  closet. 


Sanitas  closet. 


situated  below  the  receiver  and  just  beneath  the  floor,  is  employed. 
Wlion  the  Hush  is  set  in  action,  the  water  in  the  basin  ovei'flows  and 
falls  into  the  weir-chamber  below.  This  has  a  constricted  outlet, 
which  is  closed  very  quickly  by  the  descending  water,  and  thereby  the 


528 


HABITATIOyS,   SCHOOLS,   ETC. 


entrance  of  air  from  the  soil-})ipe  side  is  prevented.  As  the  water 
rushes  into  the  long  log  of  the  siplion,  it  pushes  the  contained  air 
onward,  the  leg  is  soon  tilled  with  ^\•ater,  and  tiie  siphon  is  completed. 
AVhen  the  contents  of  the  b(,)wl  have  been  sucked  down  to  the  lower 
border  of  the  partition,  the  siphon  it  broken  by  the  admission  of  air  at 
that  ])(iint,  and  tlu'  liowl  is  then  refilled  by  the  after-flush. 

iStill  another  ellicient  form  of  closet  is  the  Sanitas,  shown  in  Fig.  84. 
In  this  apparatus,  invented  by  Mr.  J.  Pickering  Putnam,  the  flush  is 
accomplished  by  the  pressure  of  water  in  the  supply  pipe.  This  ])ipe 
enters  the  bowl  below'  the  normal  w'ater  level  and  stands  permanently 
full  through  its  entire  length  up  to  the  cistern.  The  water  is  held  in 
the  pipe  by  atmospheric  pressure.  The  upjier  end  of  the  pipe  is  closed 
by  the  cistern  valve,  and  the  lower  end  by  the  w^ater  beneath  the  water 
level  of  the  receiver.  The  lower  portion  of  the  supply  pipe  is  perfo- 
rated at  two  different  points,  through  the  first  of  which,  water  is  sup- 
plied to  the  flushing  rim,  and  through  the  second,  a  jet  is  set  in  action, 
as  in  the  ordinary  siphon  jet  closet.  When  the  flush  is  set  in  opera- 
tion, the  cistern  valve  is  opened,  and  the  water  descends  and  escapes 
through  the  two  outlets ;  through  the  upper,  the  passage  leading  to  the 
flushing  rim  is  filled,  and  through  the  lower,  the  w^ater  is  projected 
from  the  bottom  of  the  receiver  up  into  the  siphon.  The  action  is 
very  quick  and  practically  without  noise.  When  the  cistern  valve 
is  again  closed,  the  water  ceases  to  escape  through  the  openings, 
and  that  in  the  flushing  rim  and  passages  leading  thereto  falls  back 
into  the  bowl  and  restores  the  normal  level. 

Flushing  Apparatus. — The  object 
of  a  flushing  apparatus  is  the  thorough 
removal  of  all  adhering  excreta  from 
the  sides  of  the  fixture,  and  its  propul- 
sion through  and  beyond  the  trap.  The 
flushing  rim  is  connected  with  a  supply 
pipe  of  about  1.25  inches  diameter, 
connected  with  the  cistern.  Through 
this  pipe,  the  water  is  delivered  wdth  a 
rush,  and  is  spread  out  by  the  flushing 
rim  in  small  jets  against  the  sides  of 
the  bowl.  With  some  forms  of  flushing 
cisterns,  the  flush  continues  as  long  as 
the  lever  which  opens  the  valve  is  held 
down  or  until  the  cistern  is  emptied 
completely. 

Another  form  of  flushing  cistern 
is  known  as  the  siphon  tank,  the 
valve  of  which  is  shown  in  Fig.  85. 
This  consists  of  a  double  tube,  A 
and  B,  the  inner  tube  A  being  the 
longer,  and  the  two  tubes  forming  a 
siphon.       The  lower  end  of  the  long  leg  of  the  siphon  A  rests  on 


Valve  of  siphon  tank. 


rijjMitiNd. 


r/2U 


a  riiblxT  riii^;  ;ii  ^'jukI  forms  llic  vmIvc.  TIic  hiplioii  is  j^larh'd  in 
o[)(T;ition  hy  liriiii<^  Uw  v;il\'c  aiV  lis  scat  by  iricans  (if  a  diaiii  i'n^tfDi'A 
l(»  llic  riiii;'  ill  lli('c;i|)  /'J.  TIh' w  ;it<r  nislics  dowiiwanl  tliroiijrii  (Ik;  fliisli 
|)i|)(!  /'',  Slicks  I  lie  ;iir  <iii(  i»("  ,1,  .■ind  (ills  flic  siplioii  with  wafer.  'I'lic 
valv(^  is  ilicii  <lr()|i|(c(l  l);ick,  ;iiiil  I  lie  (li.-cli;ir<rc  coiiliiiiicK  flowing';  into 
t.lic  si|)lioii  al,  J>,;[\\(\  dowiiwiird  tlir(»ii<r|i  J,  as  indicated  liy  t lie  arrowH. 
'^riu!  (Iiscliai'<i;e  <'onlinncs  nntil  tlu;  level  of  liir-  w;if,cr  is  Itroiijrlit  down 
to  tlic  point.  P,  wlicn,  ;ilr  hcinj^  suclved  in,  the  .'-iplion  i-  hrok'p.  W  iti 
this  ap])aratiis,  the  ilnsh  tank  is  emptied  <\-ciy  time  tli<;  fixture  is  ij.-e<l, 
and  th(!  valve  needs  to  he  o|)ciicd  only  ion^  enoiij^h  try  nUirt  the  niplion 
in  motion,  whi(Oi  ohjcct.  is  iiecom|)iished  in  a  few  s(!eonds. 

Still  another  form  of  flushing;  aj)paratns  is  shown  in  Vifr.  80.  This 
is  emp.oycd  to  fnrnisli  a  l;ii-<i;c  flush  and  a  Miiall  aft<!r-flnsh,  by  mejinH 
of  whi(^h   the  howl   of  the   fixture   may   receive   water  after  the  main 


Flushing  tank. 

flushing  has  been  accomplished.  The  tank  is  divided  into  two  cham- 
bers, A  and  B.  The  valve  T",  worked  by  chain  and  lever,  is  4  inches 
in  diameter.  AVhen  opened,  it  discharges  water  more  rapidly  than  it 
can  flow  through  the  pipe  E,  and,  in  consequence,  the  surplus  fills  the 
chamber  B.  When  the  valve  is  closed,  the  main  flush  ceases,  and  a 
smaller  flow  continues  until  the  clnunber  B  is  emptied.  At  the  point 
0,  is  the  overflow  for  the  chamber  .1  into  B. 

A  flushing  tank  should  contain  not  less  than  4  gallons,  and,  except 
in  the  case  of  the  Sanitas  closet,  should  be  not  less  than  6  feet  above 
the  closet  bowl. 

Water-closet  Connections. — The  ordinary  method  of  connecting  a 
modern  water-closet  with  the  soil-pipe  branch  is  by  means  of  what  is 
known  as  a  brass  floor-plate  joint.  The  soil-]>ipe  branch  is  fastened  by 
means  of  solder  to  a  brass  flange,  which  is  screwed  to  the  floor.  The 
closet  flange  is  set  upon  an  intervening  rubber  gasket,  and  the  two  are 
then  screwed  or  bolted  together.  The  common  putty  joint  should  not 
34 


530 


HABITATIONS,   SCHOOLS,   ETC. 


be  used,  for  although  it  may  not  leak  water,  it  is  usually  pervious  to 
air  and  odors.  In  screwing  up  the  porcelain  branch,  great  care  should 
be  taken  to  avoid  breakage.  Some  closets  are  made  in  two  pieces,  the 
bowl  being  of  porcelain,  and  the  trap  of"  iron  or  other  metal  with  a 
porcelain  Jining.  AMth  these,  the  danger  of  breakage  is  reduced  to  a 
minimum. 

Urinals. ^-The  urinal  is  a  fixture  which  should  not  be  tolerated  in  a 
])rivato  house,  since,  with  the  best  of  care,  they  are  almost  inevitably 
offensive  and,  with  ordinary  care,  arc  sure  to  be  a  decided  nuisance. 
They  are  necessary  only  in  large  buildings,  and  there  they  require 
abundant  and  frequent  flushing  and  constant  care.  The  waste-pipe  is 
commonly  coated  on  the  interior  as  far  as  the  trap  w'ith  a  deposit  de- 
rived from  the  urine,  and  does  not  yield  it  readily  to  flowing  water. 
The  application  of  washing  soda  or  of  solution  of  ordinary  potash  is 
ineffective,  but  hydrochloric  acid  in  10  per  cent,  strength,  followed 
shortly  by  a  generous  flush  of  water,  will  remove  it.  Weak  sulphuric 
acid,  about  2.5  per  cent.,  is  also  efficient. 

Wash  Basins. — AVash  basins  are  made  of  metal,  as  copper,  enam- 
elled and  galvanized  iron,  and  of  earthenware  and  porcelain.  Most 
commonly,  they  are  of  glazed  earthenware.  In  shape,  they  are  either 
circular  or  oval.  The  latter  form  is  generally  preferred,  as  it  affords 
more  space  for  free  action  of  the  arms  than  a  circular  one  of  the  same 


Fig.  87. 


Fig.  88. 


Wash  basin  with  overflow  horn  discharging 
beneath  plug. 


Wash  basin  with  overflow 


capacity.  Some  bowls  are  made  with 
a  flushing  rim  at  the  top,  through 
which  hot  and  cold  water  are  intro- 
duced together  on  all  sides,  and  thus 
the  entire  surface  of  the  bowl  is  more 
easily  kept  clean.  In  the  upper  part  of  the  commonest  form  of  basin 
(see  Fig.  87)  a  number  of  perforations  (^S")  communicate  with  the  over- 
flow horn  {H)  connected  with  the  waste-pipe.  Ordinarly,  these  outlet 
holes  are  unable  to  deliver  water  as  rapidly  as  it  enters  through  a  faucet 
with  moderate  head,  and  consequently  too  much  dependence  should 
not  be  placed  on  them  in  the  prevention  of  overfilling  of  the  basin. 
In  some  bowls,  the  entire  overflow  horn  is  an  integral  part  of  the  fixt- 
ure, opening  just  beneath  the  plug,  as  shown  in  Fig.  88.  Where 
the  horn  does  not  so  extend,  its  junction  with  the  w^aste-pipe  is  not  in- 
frequently wrongly  made ;  sometimes,  it  is  connected  below  the  trap ; 
sometimes,  at  the  crown  of  the  trap,  into  or  near  the  vent  pipe.     The 


I'ljJMiiisa. 


ovctrflow  lioni,  cspcciMlly  willi  loiijr  use  of  \\\('.  fixtiin-,  is  very  likely  to 
bcconio  ioiil,  on  iu^coiiiil.  of  Uk;  .soup  iiiid  liltli  vvliich   becoruc  deposited 


Fin.  Hi). 


Wusli  busiii  with  standpipc  pl"K  and  overflow 


alonji;  its  inner  surfiice.  In  fact,  the  odor  wiiicli  is  ascribed  commonly 
to  "sewer  gas"  comes  from  the  horn  and  irom  tlie  waste-pipe  between 
the  bowl  and  the  trap.    Another  source  of  odor  of  much  less  importance 


Fig.  90. 


Improved  standpipe  overflow. 


is  the  chain  attached  to  the  plug.     This  gradually  collect?  within  its 
links  the  same  kind  of  dej.x>sit,  which  is  removed  completely  only  with 


532 


HABITATinyS,   SCHOOLS,   ETC. 


some  difficulty  and  imicli  scrubbiiii::  -with  a  brush.  On  aoecnint  of  the 
fouling  of  the  chain  and  the  inconvenience  of  having  it  in  the  way  of 
the  hands,  some  forms  of  basins  are  equipped  with  a  standpipe,  which 
acts  as  plug  and  ovei-flow  at  the  same  time.  In  Fig.  89.  such  an 
arrangement  is  shown  ;  the  bowl  j)resents  no  irregularities  of  surface, 
not  even  a  plug.  The  stan(l])ipe  p,  enclosed  iu  the  pipe  P,  acts  as  a 
valve  when  it  is  dro])ped  into  place,  and  the  sur])lus  water,  rising 
between  2^  and  p,  escapes  through  the  holes  iu  the  upper  extremity  of 
p.  The  device  is  lifted  by  a  knob,  and  is  kept  off  the  seat  by  means 
of  a  bayonet  catch.      In  the  illustration,  the  plug  is  off  the  scat. 

The  principal  objection  to  this  form  of  waste-valve  is  that  the  outlet 
is  situated  at  a  considerable  distance  from  the  outlet  of  the  bowl,  and 
the  entire  surface  between  these  two  points  is  certain  to  become  foul. 
Furthermore,  small  bits  of  lint  and  hair  are  likely  to  be  deposited  near 
the  seat  and  cause  it  to  leak  so  rapidly  that  the  bowl  cannot  hold  water 
for  any  length  of  time.  A  better  form  is  shown  in  Fig.  90.  Here 
the  standpipe  overflow  has  its  seat  directly  in  the  outlet  of  the  basin, 
and  may  easily  be  got  at  and  cleaned. 

Bathtubs. — Bathtubs  are  made  of  various  materials  in  a  number  of 
forms.  The  finest  grade  of  tubs  are  made  of  porcelain  or  of  fine 
earthenware  with  a  heavy  enamel  of  porcelain.  They  are  made  in 
various  shapes  and  very  commonly  are  decorated  somewhat  ornately. 
They  are  very  heavy  and  quite  expensive.  The  plainest  varieties  have 
most  commonly  the  shape  shown  in  Fig.   91.     They  are  usually  set 

Fig.  91. 


1&- 

Porcelain  or  iron  bathtub. 

upon  slabs  of  marble.  Tubs  of  iron  with  a  lining  of  porcelain  enamel 
also  are  made  in  this  form.  These  are  open  to  the  objection  that  the 
enamel  is  chipjied  off  very  easily.  Within  recent  years,  a  cheap  form 
of  tulj  in  this  shape,  made  of  ordinary  tin  plate,  has  been  introduced. 
In  spite  of  the  iron  frame  with  which  it  is  surrounded,  it  is  constructed 
very  flimsily. 

The  commonest  form  of  bathtub  used  in  this  country  is  made  of 
tinned  and  planished  copper,  weighing  from  10  to  24  ounces  to  the 
square  foot.  In  Fig.  92,  this  form  of  tub  is  shown  in  vertical  section. 
Inasmuch  as  the  copper  is  to  all  intents  and  purposes  tlie  lining  of  a 
box,  it  is  necessary,  for  the  sake  of  appearances,  to  have  an  outside 


J'LIIMIlfNa. 


casliij!;  of  c:[}>uu'i  work.  Tlu;  ordinary  liih  is  providr-d  willi  ;i  wasU* 
])Iiijr,  clmiii,  .'111(1  ovci'llow,  as  shown  in  llic  lijiiirc  Not  iinconmiotily,  flif! 
cliairi  ;tii(l  |»lii<i;  arc  .sii]i|)I:imIciI  l»y  ;m  oidiiury  |ii|f  ol'  (lie  (|c-ir<<|  lrri;.'lli, 


Kiu.  <J2. 


Vertical  section  nf  cdmnioncst  form  of  Ijathtiib. 

wliich  fits  into  tlio  onilcl  of  tlic  tub,  and  tliiis  acts  l)otli  as  pluj?  and 
overflow.  In  somo  ol"  tlic  tubs  of  more  elaborate  eonstrnetion,  a  stand- 
ing overflow  and  waste-pipe,  shown  in  Fig.  93,  is  iise<l.     In  this,  the 

Fio.  93. 


Standing  overflow  and  waste-pipe. 


overflow  passes  over  and  into  tlie  pipe  B  and  escapes  through  the 
bottom.  When  the  tub  is  to  be  em]itied,  the  tnbe  is  lifted,  and  thereby 
the  perforations  at  the  bottom  of  the  inner  tube  A  are  exposed.     Ou 


534  HABITATIONS,  SCHOOLS,  ETC. 

the  whole,  this  form  is  in  no  way  superior  to  the  ordinary  standing 
overHow,  but  possesses  certain  disadvantages  which  do  not  apply  to 
that  device,  which  can  he  removed  completely  from  the  outlet  each  time 
the  tub  is  emptied. 

Other  forms  of  baths,  including  the  sitz-bath,  foot-bath,  shower- 
bath,  douche,  and  needle-bath,  and  bidets  are  found  ordinarily  only 
in  the  very  -elaborately  litted  bath-rooms  of  the  very  wealthy.  As 
plumbing  appliances  pure  and  simple,  they  possess  no  special  hygienic 
interest,  the  matter  of  waste-pipes,  trapping,  etc.,  differing  in  no  essen- 
tial respects  from  Avhat  has  been  described  in  connection  with  other 
fixtures.  The  shower-bath,  which  consists  mainly  of  a  large  sprinkler 
from  which  water  is  delivered  downward  in  fine  streams,  is  very  com- 
monly set  above  the  ordinary  bathtub,  with  a  screen  of  wood  or  cur- 
tain of  rubber  cloth  or  other  suitable  material  to  prevent  splashing  the 
floor.  Smaller  arrangements,  consisting  of  a  sprinkler,  such  as  is  at- 
tached to  the  nozzle  of  a  watering-pot  and  a  rubber  tube  to  connect 
with  the  faucet  of  the  bathtub,  are  very  commonly  used.  If  desired, 
the  rubber  tube  may  be  attached  to  a  mixing  pipe,  which  in  its  turn  is 
attached  to  both  cold  and  hot  water  faucets,  and  thus  the  temperature 
of  the  shower  may  be  regulated. 

Sinks. — Under  sinks  are  included  pantry  sinks,  kitchen  sinks,  and 
slop  sinks.  These  are  made  of  various  metals,  including  cast-iron, 
enamelled  iron,  steel,  and  copper,  and  of  soapstone,  slate,  earthenware, 
and  porcelain. 

Cast  iron  is  easily  kept  clean  with  ordinary  care,  but  on  account  of 
danger  of  the  breaking  of  dishes  and  other  articles  which  are  washed 
or  otherwise  handled  in  them,  a  grating  of  wood  not  uncommonly  is 
laid  on  the  bottom.  This  easily  becomes  foul,  particularly  if  it  is  al- 
lowed to  stand  in  the  wet  sink  when  not  in  actual  use.  All  such  grat- 
ings should  be  kept  scrupulously  clean,  and  when  not  actually  needed 
m  the  sink,  should  be  hung  up  in  the  air. 

Enamelled  iron  is  much  more  desirable  than  plain  iron,  and  presents 
a  much  better  appearance.  Unfortunately,  however,  the  enamel  is  very 
easily  cracked  and  detached. 

Steel  sinks  are  not  so  durable  as  ordinary  cast  iron,  but  they  are 
light  and  cheap.  They  are  very  commonly  enamelled,  and  then  they 
are  necessarily  open  to  the  objection  above  mentioned. 

Tinned  and  planished  copper  is  much  used  for  pantry  sinks,  which 
are  made  commonly  with  rounded,  but,  better,  with  perfectly  flat  bot- 
toms. The  copper  should  have  a  weight  of  not  less  than  18  to  24 
ounces  per  square  foot. 

In  some  quarters,  soapstone  is  the  favorite  material  for  kitchen  sinks. 
Ordinarily,  it  is  quite  durable,  particularly  if  it  has  been  subjected  to 
a  preliminary  oiling,  but  some  specimens  show  a  tendency  to  disinte- 
grate very  rapidly,  and  to  become  so  pitted  as  to  present  a  honeycombed 
appearance. 

Earthenware  sinks  are  thick  and  heavy,  and  present  no  advantages 
over  soapstone. 


PLUMB  [NO.  636 

Porwdiiin  is  r„V|)(Mis!vf,  jiiid,  if  lliiii,  i'h  easily  hrokc;n.  It  in  not 
extoii.siviily  us(!<l  in   oidln.iry  HiiiUs, 

All  .sinks  .should  In:  |)rovid(!d  with  a  not  too  fine;  strainer  over  the 
outl(3t.  Kit(;li(!ii  iuid  |);iiil ry  sinkH  arc  conncctcMJ  h(!.st  with  a  j^r«i«e 
trap,  '^riu!  common  prjKilicc  of  constriKitinf^  cnphoardH  or  f;low;Ls  Ih;- 
ncath  sirdis  .shonid  \h\  disc^onra^cd,  since  tli(!S(;  s|)ii(;(;.s  arc  f;orninonly 
maintiuiuid  :ih  cintlci-liolcs  in  which  to  Htoro  nnwashcd  pols,  k(!ttl(;H, 
and  oth(!r  ut(!nsils,  vvhicli,  in  nin-lcan  condition,  would  not  he  toh;nitod 
in  ]K)sition.s  wlustt;  they  :ii<'  o|)(ii  to  inspection. 

House-maids'  sinks,  (tonunoniy  known  as  slop  sinks,  an;  lofatf.'<l 
fjjenernlly  in  small,  dark,  nn\'cii(ilat('d  ekhsets  in  IIk;  upper  .sfory. 
This  form  of  lixinrc  is  niad(i  rather  deeper  than  an  onh'nary  sink,  and 
is  sometimes  shaped  like  a  hopper.  'J'hey  arc  made  hest  with  a  fhish- 
ini>-  rim,  whi(Oi  will  assist  in  k-eepinj^  the  entire  surface  cle^iu  and  fn« 
from  odor.  On  Me(u)unt  of  (Ik;  nature  of  the;  refuse  jioured  into  these 
receptacles,  and  because  of  the  great  probability  of  the  occurrence  of 
splashing  when  vessels  are  emptied,  these  sinks  are  often  extremely 
foul,  and  the  closets  in  which  they  arc  placed  are  then  always  neces- 
sarily olfensive.     The  greatest  care  is  necessary  to  insure  clcaidiness. 

Laundry  Tubs. — liaundry  tul)s  are  made  of  practically  the  same 
materials  as  sinks.  The  eheajiest  kind  is  made  of  stout  planking 
with  well-fitting  joints  drawn  tight  by  iron  bolts.  This  form  is  not 
very  durable,  since  the  alternate  drying  and  wetting  .soon  ruins  the 
joints  and  causes  the  wood  to  decay.  Those  made  of  porcelain  and 
earthenware  are  heavy  and  expensive,  but  arc  very  durable  and  rciidily 
kept  clean.  The  soapstoue  tub  is  regarded  generally  as  the  most  satis- 
factory, but  it  should  be  made  of  material  of  the  best  quality,  since 
otherwise  it  is  liable  to  chip  and  crack  off  from  constant  contact  with 
hot  water.  All  enamelled  tubs  are  likely  to  lose  their  enamel,  which 
is  separated  easily  from  the  metal  and  chipped  off. 

House  Service  Tanks. — With  most  plumbing  systems,  it  is  essen- 
tial that,  in  the  upper  part  of  the  building,  above  the  highest  fixture, 
there  shall  be  a  service  tank  to  feed  the  hot-water  boiler  and  the  vari- 
ous flushing  cisterns  connected  with  water-closets  and  other  fixtures. 
These  tanks  are  commonly  placed  in  positions  where  access  to  them  is 
not  easy,  and,  in  consequence,  they  are,  as  a  rule,  examined  very  infre- 
quently. No  matter  how  carefully  they  are  covered  and  regardless  of 
the  kind  of  water  that  enters  them  for  storage,  they  accumulate  more 
or  less  dust,  dirt,  organic  matter,  and  other  sediment.  All  this  adheres 
to  and  accumulates  on  the  bottom,  forms  a  .slimy  coat  upon  the  sides, 
and  there  remains  until  removed  by  some  external  force.  It  is  hardly 
necessary  to  say  that  this  condition  should  not  be  permitted.  The  tank 
should  be  inspected  periodically  and  thoroughly  cleaned.  Fortunately, 
it  is  neither  necessary  nor  customary  in  ordinary  dwellings  to  use  water 
from  the  service  tank  either  for  drinking  or  for  cooking,  since  the  cold- 
water  service  pipes  connect  directly  with  the  street  main,  and  are  tapjied 
a.t  intervals  with  faucets  and  terminate  at  the  tank,  where  their  delivery 
is  regulated  by  means  of  ball-cocks.     Inasmuch  ;is  the  water  from  the 


oSO  HABITATIONS,  SCHOOLS,  ETC. 

tank  is  not  used  for  drinking  and  cooking,  excepting  in  houses  not  con- 
nected Avith  the  public  supply,  but  served  from  a  tank  filled  periodically 
by  pumping,  it  makes  no  very  great  difference  from  a  hygienic  stand- 
point of  what  material  the  tank  is  built.  A  very  good  tank  is  made 
of  riveted  iron  plates  lined  with  cement  of  proper  quality.  AVooden 
tanks  are  much  used,  and  give  satisfaction  if  they  are  kept  full  and 
clean.  The  tank  which,  on  the  whole,  is  most  satisfactory  is  constructed 
of  wood,  with  the  sides  secured  to  the  ends  by  long  bolts,  and  lined 
with  tinned  copper  of  good  weight.  Lead  forms  a  poor  lining,  for  it  is 
corroded  easily  by  water.  Giilvanized  iron  and  sheet  zinc  also  make 
poor  lining  material.  In  large  office  buildings  in  which  all  the  fixtures, 
including  those  from  which  w^ater  for  drinking  is  obtained,  are  supplied 
from  a  main  tank  in  the  upper  story,  it  is  advisable  that  the  lining  of 
the  tank  should  be  of  tinned  copper,  and  under  no  circumstances  should 
it  be  of  lead. 

Service  Pipes. — The  method  of  installing  the  water  service  is  of 
slight  interest  to  the  hygienist  and  requires  no  discussion,  the  nature 
of  the  pipes  having  been  considered  in  another  chapter ;  but  there  is 
one  minor  trouble  connected  with  them  which  may  be  a  cause  of 
great  annoyance,  especially  to  persons  of  nervous  or  irritable  nature. 
This  trouble  is  commonly  knowai  as  water-hammer,  and  is  something 
more  than  an  annoyance,  since  its  occurrence  has  a  w^eakening  effect 
on  the  entire  pipe  system.  This  is  the  quivering  and  rattling  that 
occur  from  end  to  end  w^hen  the  current  of  water  wdthin  them  is 
checked  suddenly  by  the  quick  closure  of  a  cock  or  valve.  In  order 
to  prevent  this,  it  is  necessary  to  make  some  provision  for  a  cushion, 
particularly  where  the  water  pressure  is  very  great.  This  not  infre- 
quently runs  as  high  as  a  hundred  pounds  to  the  square  inch,  and 
even  higher.  To  cushion  the  blow,  an  air  chamber,  commonly  made 
by  turning  the  pipe  upward  for  a  foot  or  two  above  the  cock,  is  used. 
This  extension  will  at  the  outset  contain  a  volume  of  air,  which, 
on  being  compressed  by  the  force  of  the  w-ater,  makes  an  elastic 
cushion.  Sometimes,  however,  the  air  originally  contained  becomes 
gradually  absorbed  by  the  water  wdiich  is  driven  into  the  chamber, 
and  thus  it  becomes  replaced  by  w^ater  and  the  cushion  is  destroyed. 
In  such  an  event,  it  is  well  to  shut  off  the  w^ater  and  empty  the  pipes 
so  that  air  may  again  fill  the  chamber.  Another  form  of  air  chamber 
recommended  is  made  by  extending  the  pipe  with  a  piece  of  larger 
diameter,  covered  at  the  top  wdth  a  tightly  fitting  screw  cap.  Within 
this  extension,  may  be  placed  two  or  more  rubber  balls,  upon  which 
the  force  of  the  blow  of  the  w^ater-hammer  may  be  expended. 

Water-hammer  of  a  most  annoying  and  persistent  kind  is  occasioned 
often  by  the  too  easy  movement  of  a  light  ball-cock  controlling  a 
current  of  high  pressure  in  a  small  tank.  For  example,  the  water  in 
the  tank  becomes  lowered  through  the  use  of  some  fixture  below,  the 
ball,  floating  on  the  surface,  opens  the  valve  of  the  cock,  and  water  is 
admitted  to  take  the  place  of  that  which  has  been  drawn  off.  The 
water,  entering  with  much  force,  sets  the  whole  contents  in  motion. 


viJiMinsa.  r/M 

TIk!  IkiII  is  (Jiiowii  ii|t  ;iihI  slmls  olT  I  lie  \\;ifcr  wit.li  ^rcnl  hiKMoiiiiWH 
iuid  (iills  M^jiiii  ;  ;iri<»tlici'  jcl  of  wiilcr  i-  tliioun  in,  and  iIiiih,  wifli  alf<:r- 
iiiiic  (|iiic.k  jets  iiiid  Miovcinciil,  of  (lie.  ball,  lli<:  liairiiiicriti^  (!(>litiiiii«>H, 
iiiiiil  (liially  I  Ik;  Ic^vcI  oI"  tlic  water  lias  Ixcii  restored  to  its  «»rigiiial 
point. 

Testing  Plumbing-. — 'I'i^htncss  oi'  j(»ints  lliroii|;liouL  a  syHtcm  of 
|)hMnl)in^  may  he  determined  in  H<!V(;ral  ways.  J^'or  U'stiiig  tlie  JointH 
<»r  soii-|)i|)('S  and  main  drains,  a  most-  im|)ortanl  and  seareldng  test.  \h 
that  known  as  the  water-|)ressnre  test.  This  is  applied  iiel'ore  any 
lixturtss  have  Keen  joined  lo  the  wastes  and  soil-pipe.  All  outlet-  ;ire 
(jlosed  with  appropriate  pln^s,  made  Cor  the  purpose  and  kepi  in  jilaee 
by  means  ol"  holts,  and  then  tlu;  entire  pipe  with  its  branches  is  fille*l 
with  watei'.  Should  there  be  leaks  in  any  part  ol"  the  system,  the 
fact  will  be  nKuk;  manilesl  by  tin-  sinkint^  oC  the  water,  and  the  points 
of  escape  may  easily  be  Connd  on  Inspeelion. 

The  other  methods  a|)|)li('able  to  the  entire  system  inelnde  the  smoke 
test  and  the  jx'ppermint  test.  In  the  smok<!  test,  the  system  is  fille<l 
with  smoke  by  means  of  a  device  known  as  an  asphyxiator.  It"  leaks 
exist,  tlu>  fact  will  be  made  evident  in  two  ways  :  lirst,  to  the  .sen.se  of 
smell;  se(!ond,  to  the  sense  of  sii;;ht.  JJesidcs  the  asphyxiator,  a 
nnnd)er  of  other  devices,  ineludin<2;  the  smoke  rocket,  have  been  in- 
vented. The  common  method  of  testing  plumbin<^  in  this  country 
is  known  as  the  peppermint  test.  For  this  test,  the  presence  of  two 
persons  is  necessary ;  one  to  apply  the  peppermint,  and  the  other  to 
detect  its  presence  in  the  air  of  the  building.  About  two  ounces  of 
oil  of  jiejipcrmint  are  used  for  each  stack  of  soil-pijx's.  This  verv' 
pungent  oil  should  be  carried  through  the  house  in  very  tightly  corked 
vials,  in  order  that  no  odor  shall  be  given  off  in  transit.  The  vent 
openings  are  closed  first  with  plugs,  and  the  oil  of  peppermint  is  then 
poured  into  the  soil-pipe,  and  is  followed  by  a  quart  or  two  r»f  hot 
Avater,  to  assist  its  volatilization.  The  outlet  is  then  closed  securely. 
On  account  of  the  cliugiug  quality  of  the  odor,  the  persou  who  emp- 
ties the  peppermint  should  remain  on  the  roof,  with  the  scuttle  closed, 
until  thorough  inspection  of  the  ]>remises  has  been  made.  The  vapor 
of  the  oil  permeates  all  parts  of  the  soil-pipe  and  its  connections,  and 
in  case  of  defective  seal  or  any  other  imperfection  in  the  system,  it 
escapes  and  makes  its  presence  known  in  the  rooms  through  its  effect 
on  the  sense  of  smell.  During  the  examination,  it  is  important  that 
no  water-closet  be  pulled  and  that  no  bowl,  bath,  or  sink  be  used, 
since  thereby  the  whole  of  the  peppermint  may  be  driven  out  of  the 
system  into  the  sewer. 


CHAPTER    VI. 
DISPOSAL   OF  SEWAGE. 

The  composition  of  sewage  varies  accordiDg  to  the  character  of  the 
commuuitv  by  which  it  is  produced.  To  the  lay  mind  the  word  con- 
veys the  idea  of  a  mixture  of  urine,  fseces,  and  paper,  with  the  waste 
water  from  bath-tubs,  laundries,  kitchen  sinks,  etc.  This  is  domestic 
sewage,  and  may  be  taken  as  the  type  of  that  from  purely  residential 
districts.  The  sewage  of  a  large  community,  however,  in  which  all 
manner  of  manufacturing  is  carried  on,  is  necessarily  of  a  more  com- 
plex character,  containing,  as  it  does,  in  addition  to  domestic  waste, 
that  which  is  produced  by  various  industries.  Establishments  like 
paper  mills,  tanneries,  dye  houses,  woolen  mills,  etc.,  frequently  produce 
large  volumes  of  industrial  sewage ;  in  fact,  one  industrial  plant  often 
produces  as  much  liquid  waste  as  the  residential  portion  of  a  fairly 
large  town,  and  such  manufacturing  sewage  often  contains  much  more 
organic  and  other  matters  than  does  domestic  sewage.  Where  the 
water  supply  is  abundant,  domestic  sewage  contains  but  a  small  frac- 
tion of  1  per  cent,  of  organic  matter.  It  is  this  very  small  percentage, 
however,  which  is  the  important  constituent  of  sewage,  and  which  may 
be  the  cause,  direct  or  indirect,  of  injurious  effects  upon  health.  The 
importance  of  the  quick  removal  and  disposal  or  purification  of  sewage 
is  a  matter  of  great  importance  to  thickly  settled  communities.  In 
such  communities  systems  of  sewerage,  to  which  each  house  is,  or  should 
be,  connected,  are  generally  installed,  and  sewage  from  these  sources 
should  either  be  disposed  of  by  dilution,  as  can  often  be  done  by  large 
communities  on  the  seashore  or  those  situated  upon  large  rivers  or  lakes, 
the  waters  of  which  are  not  used  for  domestic  water  supply,  or  it  can 
be  disposed  of  upon  land  or  by  more  modern  methods  of  purification, 
to  be  considered  later.  Where  residences  are  so  situated  that  connec- 
tion with  sewers  is  impossible,  as  on  country  estates,  etc.,  the  old- 
fashioned  cesspool  is  still  much  used,  and  when  properly  constructed 
and  located  can  be  used  without  danger  to  the  health  of  the  neighbor- 
hood, but  upon  large  estates,  both  in  this  country  and  abroad,  small 
installations  of  modern  purification  plants  are  growing  in  popularity. 

Before  proceeding  to  the  consideration  of  the  various  methods  of 
disposal  and  purification,  it  may  be  well  for  a  moment  to  consider  sew- 
age from  an  economic  standpoint.  Until  well  into  the  nineteenth  cen- 
tury the  sewage  problem,  as  now  known,  was  little  heard  of  or  dis- 
cussed. The  disposal  of  filth  was  a  health  problem  almost  entirely, 
needing,  of  course,  care  and  attention  in  cities  and  towns — more  care 
and  attention  probably  than  was  paid  to  it.     With  the  invention  of  the 

538 


DISPOSAL   OF  SEW  A  OK.  639 

Wiiicr-closcl.  ill  IHIO  ;iii(|  (lie  iiioR' ;rciici-;il  ill!  ro(|iH-t  ion  of  |)iil)lif  \v;it<T 
supplies,  IIm'  |)rol)l(iii  oC  llic  (iJHpoHal  of*  hirg(!  voliiriicH  oi'  jKilliitcd 
WiiHte  Wiit(;r  became  more  pressing",  aiul  sf^wajfe  fli:spo-al  Im-jt-'iii  t-o  he, 
to  u  C!OiiHi(l(!i'aJ)le  exleiil,  an  (iiij^iiieeriiifr  jjnddem.  I'rcvioiisly,  tlif; 
WiistcH  from  Immaii  lif(!  \v<!r(;  conserved  in  sneli  eoiiflition  lliat  tliey 
W(;r(!  of  fer(;ili/iii<:;  value,  lint,  witli  tlu;  intro(lucti«jn  of  piil»lie  water 
sup|)li(!S,  tl»(!  v;ilii:i,l)ie  eoiislidientH  of  sewage  were  so  diliit<'<l  in  cuor- 
inoiis  voluiiuis  of  water  that  (heir  e(;oiiomieal  recovery  beearne  an  aliiio-( 
hopeI(!Ss  task. 

Ill  tiio  minds  of  many,  liowev(!r,  the  belief  still  remains  that  tniinie- 
ipal  sewii<>^e  posscvsses  fi;reat  maiiiirial  value,  and  tjiat  disposal  of  it  with- 
out previous  troatmeiit  for  the  purpo.-e  of  nclaimiiif;  its  valuable  con- 
stitniMits  is  wasteful.  Tiiis  idea  of  its  value  has,  dc)ubfless,  never  been 
more  forcibly  (^x])ressed  than  by  Victor  irn<^o  in  tlu;  following  passaji;e:' 

"Paris  casts  twouty-tivo  millions  of  francs  annually  into  the  sea; 
and  we  assert  this  without  any  metaphor.  How  so,  and  in  what  way  ? 
By  day  and  niu^ht.  For  what  object?  For  no  object.  With  what 
thoiii^ht?  Witliout  thinivintj^.  With  what  object?  None.  By  nu/ans 
of  what  organs?  Its  int(;stines.  What  are  its  intestines?  Its  sewers. 
Twenty-live  millions  are  the  most  moderate  of  the  approximate  amounts 
given  by  the  estimates  of  modern  science.  Science,  after  groping  for 
a  long  time,  knows  now  that  the  most  fertilizing  and  effective  of 
manures  is  luiinan  manure.  The  Chinese,  let  us  say  it  to  our  shame, 
knew  this  before  we  did ;  not  a  Chinese  peasant — it  is  Eckeberg  who 
states  the  fact — who  goes  to  the  city  but  brings  at  either  end  of  his 
bamboo  a  bucket  full  of  what  we  call  filth.  Thanks  to  the  human 
manure,  the  soil  in  China  is  still  as  youthful  as  in  the  days  of  Abraham, 
and  Chinese  wheat  yields  just  one  hundred  and  twenty  fold  the  sowing. 
There  is  no  guano  comparable  in  fertility  to  the  detritus  of  a  capital, 
and  a  large  city  is  the  strongest  of  stercoraries.  To  employ  the  town 
in  mauuring  the  plain  would  be  certain  success  ;  for  if  gold  be  dung, 
on  the  other  hand,  our  dung  is  gold. 

"What  is  done  with  this  golden  dung?  It  is  swept  into  the  gulf. 
We  send  at  a  great  expense  fleets  of  ships  to  collect  at  the  southern 
pole  the  guano  of  petrels  and  penguins,  and  cast  into  the  sea  the  incal- 
culable element  of  wealth  which  we  have  under  our  hand.  All  the 
human  and  animal  mauui*e  which  the  world  loses,  if  returned  to  land 
instead  of  being  thrown  into  the  sea,  would  suffice  to  nourish  the  world. 
Do  you  know  what  those  piles  of  ordure  are,  collected  at  the  corners  of 
streets,  those  carts  of  mud  carried  off  at  night  from  the  streets,  the 
frightful  barrels  of  the  night-man,  and  the  fetid  streams  of  subter- 
ranean mud  which  the  pavement  conceals  from  you?  All  this  is  a 
flowering  field,  it  is  green  grass,  it  is  mint  and  thyme  and  sage,  it  is 
game,  it  is  cattle,  it  is  the  satisfied  lowing  of  heavy  kine  at  night,  it  is 
perfumed  hay,  it  is  gilded  wheat,  it  is  bread  on  your  table,  it  is  warm 
blood  in  your  veins,  it  is  health,  it  is  joy,  it  is  life. 

"  So  desires  that  mysterious  creation,  which  is  transformation  of  earth 
1  Les  ^liserables,  part  5,  book  2. 


540  DISPOSAL   OF  SEWAGE. 

and  transfiguration  in  heaven  ;  restore  this  to  the  great  crucible,  and 
your  abundance  will  issue  from  it,  for  the  nutrition  of  the  plains  pro- 
duces the  nourishment  of  men.  You  are  at  liberty  to  lose  this  'wealth 
and  consider  me  ridiculous  into  the  bargain  ;  it  would  be  the  master- 
piece of  your  ignorance.  Statistics  have  calculated  that  France  alone 
pours  every  year  into  the  Atlantic  a  sum  of  half  a  milliard.  Note 
this  :  with  these  five  hundred  millions,  one-quarter  of  the  expenses  of 
the  budget  would  be  paid." 

Notwithstanding  this  and  other  statements  as  to  the  fertilizing  value 
of  the  organic  matter,  the  fact  remains  that  when  these  matters  are  so 
diluted  that  they  amount  to  less  than  a  thousandth  part  of  the  whole, 
to  reclaim  them  in  concentrated  form  involves  an  expense  far  in  excess 
of  their  value.  A  fair  estimate  of  the  value  of  the  manurial  matters 
contained  in  a  ton  of  crude  sewage  of  average  composition  places  it 
somewhat  less  than  four  cents,  an  amount  so  small  as  to  make  its  re- 
coverv  from  about  two  hundred  and  fifty  gallons  of  water  highly  im- 
practicable. The  value  of  the  sewage  of  cities  with  a  large  water  con- 
sumption is  even  less  than  this.  The  sewage  of  Boston  has  been  esti- 
mated by  the  ]Massachusetts  State  Board  of  Health  to  be  worth  about 
one  cent  per  ton,  and  that  of  New  York  even  less.  To  separate  this 
small  amount  of  valuable  organic  matter  sediaientation  and  chemicals 
are  necessary.  The  resulting  body  known  as  sludge  has  a  certain  agri- 
cultural value,  but  that  value  is  not  such  as  to  warrant  generally  the 
cost  of  handling  and  transportation.  In  the  London  sewage  disposal 
scheme,  for  instance,  thousands  of  tons  of  wet  sludge  are  produced 
daily,  and  anybody  who  wishes  for  it  can  have  it  free  of  charge.  Not- 
withstanding this,  practically  none  of  it  is  taken,  and  it  is  carried  out 
to  sea  in  sludge  ships  to  Barrow  Deep,  fifty  miles  away,  and  dumped. 

The  disposal  of  the  sludge,  or  the  organic  matters  in  suspension  in 
sewage,  raises  the  chief  difficulty  in  sewage  treatment  at  the  present 
day,  for  only  an  occasional  municipality  is  able  to  give  away  or  sell 
this  sludge  for  agricultural  use.  In  considering  sewage  disposal,  it 
should  be  borne  in  mind  that  it  is  a  public  necessity  as  much  as  police 
and  fire  patrol ;  that  it  costs  money  and  that  it  cannot  be  a  source  of 
income  over  expenditure.  No  community  expects  a  pecuniary  return 
on  an  investment  for  steam  engines  or  for  police  stations,  much  as  they 
are  needed  for  the  protection  of  life  and  property ;  so,  too,  a  system  of 
sewage  and  sewage  disposal  is  necessary  for  the  protection  of  health, 
and  is  not  to  be  treated  as  if  primarily  intended  as  a  source  of  public 
revenue.  Any  return,  however,  which  may  be  possible,  either  from  the 
sale  of  sludge  or  crude  sewage,  may  be  regarded  as  a  welcome  diminu- 
tion in  the  cost  of  maintenance. 

METHODS   OF   SEWAGE   DISPOSAL. 

The  methods  of  sewage  disposal  include : 

1 .  Dilution  by  discharge  into  the  sea  or  other  bodies  of  water. 

2.  The  "  dry  method  "  or  pail  system. 


MI<:TII()I>S  Oh'  SKWAdH  JJfS/'OSAL.  541 

TL   (!li(:rin(;;i,l   I r<':iirn(!nt  followed  l»y  <liliifioi)  or  flllr;ilioti. 

4.  J  rrij^Mliori  or  "  s('\v;i;i,('  liifiiiiiiji;." 

5.  I<'il(r;il  ion  or  l)iol(ii:ic;i  I  disposnl. 

I.  Discharge  into  the  Sea.^ — In  coiiiiiiiinitics  on  and  nc-ir  the  f;r)a-t, 
i(  Is  -.v  <'oiM|);u'iiiiv('l y  (■:i.sy  tniiMcr  (o  h(|  rid  i,l'  sewage  l>y  (liHcliiirgin^  it 
into  Llic  (KtcMii  ;in<l  liMxin^  il  <;irri(d  ;i\v;iy  hy  the  <)\i{ji<>\iijs  tide.  If  it 
he  dis(rliari;'cd  in  ;i,  IVcsli  <-ondilIiin,  il  Ix'corncs  so  enoi'monsly  diluted  in 
u  very  sliorl  lime  lli;il  only  nndcr  cxeciii  ionid  i-iriMnn>laiie<;.s  can  it  ever 
hv.  a  luiisancc  in  ;uiy  way.  Tliis,  of  conr-c,  |)rc-nj)))oses  a  rea.sfniahle 
rise  and  Inll  oC  llic  lidc  :nid  the  eon>ei|n(iil  jirodnetion  of"  enrroiits  of 
eonsiderahle  veloeily.  With  slow  inoscnient,  less  than  one  and  a  half 
nules  {)er  hoiu",  deposits  are  more  than  likely  to  be  formed  and  a  inii- 
sancc  caused.  Thus  it  happens  that,  even  on  the  seahoard,  it  may  he 
necessary  to  at  least  |)artially  purily  se\\aL'"e  before  dis(!har{ring  it,  and 
the  |)i'obleni  of"  suceessl"nl  and  ecDndniiea!  |»urification  may  be  one  of 
the  most  dillleidt  and  important  in  llu;  whole  ran^c;  of  sanitary  science. 

Jn  inland  eonuuunities  situated  on  rivers  of  considerable  size,  delivery 
at  a  point  below  the  town  is  the  easiest  method  of  sewage  disjiosal  ; 
but  other  connnunities  farther  down  may  ])ropeily  object  on  more  than 
one  ground  to  such  action,  for  the  sewage  itself  may  be  a  nuisance. 

In  both  rivers  and  harl)ors,  in  order  to  ])revent  nuisance  irom  un- 
treated sewage,  the  current  should  be  suflicieutly  voluminous  and  strong 
to  afford  large  dilution  and  prevent  deposition. 

Studies  by  the  Massachusetts  State  ]}oard  of  Health,  in  regard  to  the 
volume  of  sewage  that  can  be  disposed  of  in  rivers  by  dilution,  are 
summarized  in  the  following  words  of  X.  H.  (loodnough,  Chief  P^ngi- 
ucer  to  the  Board,  in  a  report  to  the  Committee  on  the  Charles  Ki\er 
Dam, 1903: 

"  Omitting  reference  to  objections  caused  by  the  manner  of  discharge 
of  sewage  and  objections  which  may  l)e  due  to  various  other  circum- 
stances, and  considering  only  the  question  as  to  whether  olyectionable 
ct)nditions  exist  in  the  various  streams  into  which  sewage  is  discharged 
by  reason  of  the  quantity  of  sewage  discharged,  an  examination  of  all 
information  available  from  the  investigations  that  have  been  made 
shows  that  where  the  flow  of  a  stream  exceeds  (3  cubic  feet  per  second 
per  1000  persons  discharging  sewage,  objectionable  conditions  are  im- 
likely  to  result." 

2.  The  Pail  System. — This  is  limited  in  its  apj^lication  to  the  dis- 
posal of  excreta  in  }>ails  containing  dry  earth,  peat  powder,  or  other 
material,  and  although  it  is  in  operation  in  several  places  of  consider- 
able size  in  England  and  on  the  Continent,  it  is  better  adapted  to  the 
needs  of  isolated  houses  and  small  villages.  It  was  the  natural  out- 
growth of  the  very  extensive  adoption  of  the  earth-closet,  a  device  in- 
vcntcil  by  the  Rev.  Henry  ^loule,  in  which  the  solid  excreta  are  dis- 
charged into  a  receptacle  of  suitable  size  and  covei'ed  after  each  addition 
with  dry  earth,  peat  powder,  or  ashes.  As  often  as  necessary  the  pails 
arc  collected  and  emptied,  and  their  contents  are  removed  to  a  distance, 
treated  or  not  with  chemicals,  according  to  circumstances,  and  buried 


542  DISPOSAL   OF  SEWAGE. 

or  used  as  manure.  From  the  fact  that  the  collection  is  made  at  night 
arose  the  common  term  night-soil,  and  later,  from  this  one,  another  to 
designate  an  important  part  of  house  plumbing,  the  soil-pipe. 

It  is  a  primitive  sort  of  system,  but  it  has  points  in  its  favor  as  well 
as  against.  It  is  not  expensive,  there  is  no  pollution  of  streams,  and 
the  manurial  value  of  fseces  is  not  wasted.  But  it  requires  the  collec- 
tion, drying,  and  storage  of  a  large  amount  of  earth,  or  other  material, 
not  always  easy  to  obtain  ;  the  emptying  of  the  pails  is  necessarily 
accompanied  by  the  escape  of  more  or  less  odor ;  it  may  possibly  give 
rise  to  a  nuisance  at  or  near  the  place  of  final  disposal ;  and  additional 
provision  must  be  made  for  the  removal  of  liquid  refuse. 

The  materials  used  in  the  pails  are  chiefly  dry  earth  and  peat,  both 
of  which  sul)stances  are  very  absorbent.  The  earth  is  ordinarily  either 
simply  dried  or  thoroughly  baked,  but  drying  is  preferable  to  baking, 
because  the  influence  of  the  saprophytic  bacteria  of  the  soil  is  not 
destroyed. 

Sawdust  also  is  recommended  for  use  in  earth-closets,  and  as  an  ab- 
sorbent for  urinals  where  there  is  no  water  supply.  Experiments  con- 
ducted by  Dr.  G.  V.  Poore  ^  with  various  materials  proved  its  value 
for  the  latter  purpose  and  yielded  interesting  results.  A  flannel  bag, 
two  and  a  half  feet  long  and  a  foot  broad  at  the  bottom,  containing  6 
pounds  of  dry  sawdust,  received  in  the  course  of  two  months  39  pounds 
of  urine ;  after  about  a  year  45  pounds  more  were  added  during  a 
period  of  three  months.  Notwithstanding  that  the  bag  had  become  so 
rotten  as  hardly  to  hold  together,  the  contents  were  not  in  the  least 
offensive,  and  had  never  given  off  any  offensive  odor.  Of  the  84 
pounds  of  urine  added,  only  6  pounds  had  filtered  through,  while  the 
rest  had  evaporated  or  had  been  retained.  The  filtrate  was  dark  brown 
in  color,  thick,  and  of  high  specific  gravity,  but  never  offensive ;  nor 
had  it  shown,  after  lying  about  for  months,  any  tendency  to  putrefy  or 
become  offensive.  Filtration  through  earth,  old  stucco,  and  peat  moss 
gave  identical  results.  With  fresh  earth,  fresh  stucco,  and  fresh  ashes 
the  filtrate  was  almost  colorless  and  odorless,  but  the  power  of  ashes  to 
give  this  result  is  short  lived. 

The  pail  system,  whatever  may  be  said  in  its  favor,  has  had  its  day 
in  large  communities,  and  where  it  still  obtains,  it  is  being  superseded 
gradually  by  systems  more  suitable  and  satisfactory. 

3.  Sedimentation  and  Chemical  Precipitation. — As  has  been 
stated,  the  chief  difficulty  in  sewage  purification  is  proper  and  adequate 
removal  from  the  sewage  of  the  matters  in  suspension  in  it,  and  of  the 
disposal  of  the  sludge  so  formed.  Practically  every  sewage-disposal 
system  of  any  considerable  size  is  provided  with  settling  tanks  through 
which  the  sewage  passes  before  reaching  the  filters.  At  a  few  plants  in 
America,  and  at  many  plants  in  England  and  on  the  Continent,  all  the 
sewage  coming  to  these  plants  is  treated  chemically  before  passing  to 
the  filters. 

"The  reason  that  chemical  precipitation  is  employed  so  largely 
1  British  Medical  Journal,  Aug.  31,  1895. 


MK'i'iiohs  ()/''  s/':\vAfj/':  di.si'osal.  543 

wliorc  iri(»<1(!rri  (iltcrs  arc  in  use  iti  Kiij.';laii<l  i-  that  by  Hiirli  rlicniicalH 
and  siil1i('-i(!iit  scdiiiiciiLal-ioii  a  li(|iior  can  l»c  jdixjiiccd  rrnituiniiif.^  only 
about  ()iU!-Uiinl  as  iiiik^Ii  .sii,s)K'ii(I((I  maLUtr  oh  tlic  Hame  Hcwago  afu-r 
passing  ilir()M<;li  ordinary  .s('|)ti(;  or  .sclXliri^  taiikH.  To  be  Hiirc,  \\n: 
sbi(lu^(!  ))rodn(;(\d  is  ahnosi,  tbrce  timoH  that  remaining  after  HUcainHfiil 
S(^|)(ic.  tank  I r(!ainicnt,  bnt  a  clear  li(|nld  is  of  the  n(nio.-t  iniporfanec  in 
obtaining  <jjood  and  e(^»iionii('aI  resnHs  (Voin  many  Knglisli  eotita^t  and 
si)rinklin<ij  filters."  ' 

Chemical  precipitation  has,  then,  loi-  its  object  the  separation  of  the 
suspended  matters,  and  ])reeij)ita,lion  and  eonse(pient  separation  f)f  sornt; 
of  the  j)utr(W(Ml)Ie  matters  in  solution.  Whatever  |)n!eipitant  is  used, 
the  process  nMpiires  constant  and  earefid  sui)ervi-ion  in  order  that  the 
best  results  may  be  achieveil  with  a  minimum  amount  of  cliemicaJH. 
Tn  this  method  of  treatment  tlu,'  se\vag(!  is  first  screened  ordinarily,  and 
in  this  way  llie  coarser  matters  in  suspension  are  removed  ;  it  is  then 
treated  and  thoroui:;hly  mixed  with  the  (chemicals  on  its  way  to  lar^'^e 
tanks,  through  which  tanks  it  passes  slowly,  allowing  the  precipitate  to 
separate  by  subsidence.  Various  methods  are  in  vogue  for  the  treat- 
ment of  tiie  sludge  thus  ])roduced.  At  many  chemical  precif)itation 
])lauts  it  is  treated  in  hydi-aulic  presses  for  the  removal  of  water,  and 
then  dis])oscd  of  in  the  chea])est  way  possible.  In  England  it  i.-  frc- 
(jucntly  buried  or  used  for  filling  in  low  lands,  and  the  same  holds  true 
of  the  sludge  produced  at  American  precipitation  plants. 

The  chemicals  mostly  used  as  ]>recij)itants  are  alum,  lime,  and  ferrous 
sulphate.  In  England  aluminoferrie,  a  crude  sulphate  of  alumina,  is 
largely  used.  Alum  and  other  soluble  salts  of  aluminum  form,  in  the 
presence  of  lime  or  ammonia,  a  very  bulky  or  gelatinous  precipitate, 
which  carries  down  matters  suspended  in  the  sewage,  together  with  a 
large  proportion  of  the  bacteria  present,  leaving  a  fairly  clear  sujier- 
natant  fluid.  With  an  excess  of  alum  the  effluent  is  acid  in  reaction, 
but  it  does  not  form  unsightly  compounds  with  sulphur,  as  is  seen  when 
iron  and  other  substances,  which  form  black  sulphids,  are  used.  Lime 
in  the  form  of  milk  of  lime  is  used  both  alone  and  in  connection  with 
ferrous  sulphate  or  alum.  The  amount  of  precipitant  dejiends  entirely 
upon  the  character  and  strength  of  the  sewage  treated,  but  on  an  aver- 
age the  amount  required  is  about  one  ton  per  million  gallons.  The 
English  Royal  Commission  on  Sewage  Disposal  estimates  that  the 
average  cost  of  chemical  precipitation  treatment,  including  loan  charges, 
is  about  seventeen  dollars  per  million  gallons. 

At  the  Lawrence  Experiment  Station,  during  five  years  from  1893 
to  1897  incUisive,  station  sewage  was  treated  with  sulphate  of  alumina 
in  the  proportion  of  1000  pounds  per  million  gallons,  followed  by 
sedimentation  for  four  hours.  The  result  of  this  treatment  was  an 
average  removal  of  66  per  cent,  of  the  total  orgtinic  matter,  determined 
as  albuminoid  ammonia,  and  78  per  cent,  of  the  organic  matter  in  sus- 
pension, determined  as  albuminoid  ammonia ;   68  per  cent,  of  the  bac- 

1  H.  W.  Clark,  ''  Some  ObserTations  of  Methods,  Costs,  and  Results  of  Sewage  Puri- 
ficotipu  Abroad." 


644  DISPOSAL    OF  SEWAGE. 

teria  ■were  removed  and  59  per  cent.  t)f  the  fatty  matters.  These 
figures  represent  averaii,e  chemical  precipitation  results. 

4.  Sewage  Irrig-ation. — In  the  "broad  irrigation"  or  "sewage 
farming"  system,  sewage  is  utilized  in  the  growing  of  crops  which 
take  up  and  dispose  of  much  of  the  water  and  dissolved  solids,  while, 
at  the  same  time,  oxidation  2)rocesses  in  the  interstices  of  the  soil 
destroy  the  bacteria  and  convert  the  remaining  organic  matter  to  simple, 
harmless  products.  For  the  disposal  of  large  volumes  by  this  method 
very  largo  sewage  farms  are  reciuired.  The  necessary  area  will  depend 
u])on  the  nature  of  the  soil,  its  permeability  and  water  capacity,  and 
upon  the  amount  of  annual  rainfall. 

This  method  has  been  adopted  very  extensively  in  England,  where 
there  are  hundreds  of  sewage  farms,  and  in  Germany,  France,  India, 
America,  and  elsewhere ;  and  everywhere  it  has  been  found  that  no 
hard  and  fast  rules  as  to  area  per  thousand  of  po]>ulation  can  be  fol- 
lowed. In  England  the  idea  obtains  very  generally  that  every  hundred 
of  population  will  require  one  acre  of  sewage  farm  ;  but  this  varies  with 
the  composition  of  the  sewage  and  its  volume  per  capita.  The  volume 
of  sewage  ordinarily  disposed  of  upon  English  sewage  farms  varies  from 
about  2000  to  10,000  gallons  per  acre  daily;  but  in  dry  countries,  with 
a  more  sandy  or  gravelly  soil,  this  volume  may  be  increased. 

Of  the  very  first  importance  is  the  selection  of  a  suitable  tract  of 
land  f(jr  the  establishment  of  the  plant.  It  should  be  neither  too 
permeable  nor  too  close.  If  too  coarse,  it  will  permit  the  passage  of 
the  sewage  so  rapidly  that  imperfect  purification  Mall  occur,  and  the 
effluent  will  be  unfit  to  be  discharged  from  the  underdrains  into  a  water- 
course ;  if  too  close,  as  will  be  the  case  with  a  very  dense  clay,  the 
water  will  be  absorbed  so  slowly  that  it  will  fall  far  below  the  amount 
of  loss  by  evaporation.  The  best  soil  for  the  purpose  is  one  of  sandy 
loam  with  fine  interstitial  spaces,  which  will  permit  not  too  rapid  per- 
colation, and  wherein  the  processes  of  nitrification  may  go  on  most 
thoroughly.  Very  dense  clay  may  be  rendered  suitable  by  the  admix- 
ture of  sand  or  lime  and  by  tile  underdrainiug,  and  then  will  perform 
its  office  in  a  satisfactory  manner.  With  a  proper  plant  and  intelligent 
supervision  the  purified  sewage  makes  a  clear,  bright,  and  practically 
sterile  effluent. 

In  order  to  carry  out  the  scheme  so  as  to  achieve  the  best  results, 
the  farm  should  be  divided  into  sections,  not  necessarily  of  equal  area, 
but  of  equal  absorbability,  each  of  sufficient  capacity  for  the  disposal 
of  the  entire  sewage  of  a  single  day.  Each  section  should  be  worked 
in  its  turn,  but  the  capacity  of  none  should  be  overtaxed,  lest  the  soil 
become  clogged  and  the  work  of  oxidation  cease.  In  this  condition  it 
is  said  to  be  ^'  sewage  sick." 

The  farm  is  often  laid  out  in  broad  ridges  and  furrows,  the  latter 
receiving  the  sewage  at  regular  intervals  ;  the  crops  grow  on  the  broad 
ridges  between.  It  sliould  be  underdrained  naturally  or  artificially  at 
intervals  of  about  six  feet,  so  that  the  purified  filtered  water  may  be 
removed  and  allowed  to  discharge  into  any  convenient  watercourse. 


MKTIlonS   OF  SEWAdh:   lilSI'OSM..  TyXT, 

Ah  lias  heon  KtaU:<l,  IIkj  daily  '!"<<■  per  :i<-ic  will  vary  widely  accord- 
ing to  liiuajcHH  or  coarHcncHH  oC  the  -oil,  it,-^  ixrinciibility,  itn  iiunatu- 
r;i,t(id  ()[)(!ii  or  iiilcrslifiid  space,  and  iIk;  rnnkncss  of  vcj^cfati'Ui.  On  a 
(?IoS(!  Hoii,  III  a  c<»l(l  climate,  hiil,  a  lew  tlioii.saiid  gallons  j>cr  a*;r(:  can  bf; 
discharged,  \vliil<!  on  an  open  soil,  in  a  li(tt  connlry,  with  rank  vegeta- 
tion, as  in  Madras,  as  nnich  as  75, ()()()  gallons  daily  may  not.  he  ex- 
cessive. The  crops  best  grown  arc  those  which  can  hear  heavy  fIof>d- 
ing  of  the  soil. 

As  r(!gards  profit,  it  may  he  said  (li;il  this  system  is  the  only  cue 
which  (!an  j)()ssil)ly  yield  a  revenue,  dne  in  part  to  the  value  of  the 
inaiHUMal  constitu(!n(s  ol'  tlu;  sewag(^  and  |)artly  to  the  water  itself, 
which  puts  the  crops  ontside  the  danger  of  dronght  and  b(;yon(I  the 
need  of  rain.  In  sonu;  climates,  cn)p  follows  crop  the  year  rontif], 
and  the  annual  yield  is  large;  in  others,  tlu;  season  is  so  short  in 
comparison  that  the  yield  is  much  less.  At  the  Berlin  farms  a 
yearly  yield  of  25  tons  of  grass  ])cr  acre,  ecjual  to  5  of  hay,  is 
regarded  as  large  and  satisfactory,  while  at  Krishnam])ett,  in  Madras, 
wlierc  eight  cro})s  ])er  year  are  harvested,  the  output,  a«!cording  to  Dr. 
J.  N.  Cook,'  was  in  one  year  09  tons  per  acre,  ecpial  to  about  23  of 
hay,  and  worth  nearly  200  dollars.  The  city  of  Berlin  purchased  and 
set  aside  20,000  acres  of  land  for  its  sewage  farms,  and,  notwithstand- 
ing an  outlay  of  more  than  13,000,000  dollars  for  the  entire  plant,  re- 
ceives a  yearly  profit  of  60,000  dollars  from  its  operation,  the  labor 
costing  nothing  exce})t  for  maintenance  of  the  men  engaged,  these  being 
conderaued  thereto  for  various  minor  misdemeanors. 

Whether  there  be  a  profit  or  not,  this  aspect  of  the  question  should 
ever  be  kept  in  tlie  backgi'onnd  and  the  primary  olijcct  ever  in  view. 
When  the  fartns  are  let  out  to  contractors,  it  is  always  advisable,  and 
even  necessary,  that  they  be  under  the  supervision  of  municipal 
authority,  to  insure  that  the  public  good  is  not  subordinated  to  private 
gain. 

It  is  not  to  be  sup])Osed  that,  even  in  veiy  cold  weather,  the  use  of 
the  system  must  be  suspended,  for  when  vegetation  ceases,  the  soil  con- 
tinues the  process  of  purification.  At  St.  Laurent  College,  near  Mon- 
treal, for  example,  the  small  sewage  farm  was  found  to  act  efficiently 
in  disposing  of  the  usual  amount  of  sewage  in  a  January  (1898)  tem- 
perature of^ — 20°  F. 

Influence  of  Sewage  Irrigation  on  Health. — Concerning  the  influence 
of  sewage  farms  upon  the  health  of  those  dwelling  on  and  near  them, 
the  evidence  is  entirely  on  one  side,  and  in  opposition  to  what  would 
naturally  be  supposed  to  be  the  case.  It  is  the  same  from  Berlin, 
Paris,  Edinburgh,  and  the  hundreds  of  other  places  where  the  system 
is  in  use,  and  all  to  the  effect  that  in  no  way  is  it  injurious.  It  is  true 
that  not  infrequently  the  sewage  gives  rise  to  more  or  less  disagreeable 
odor,  especially  if  it  be  stored  too  long ;  but  the  fields  themselves  are 
generally  quite  free  from  nuisance,  and  even  though  odor  be  present,  it 
produces  no  harm.     At  the  Berlin  works,  in  a  population  of  more  than 

1  Indian  Medico-chirurgical  Review,  Dec,  1S95,  p.  676. 
35 


546  DISPOSAL   OF  SEWAGE. 

1,500  there  was  one  death  from  typhoid  fever  in  five  years,  the  gen- 
eral death-rate  was  very  low,  and  the  zymotic  death-rate  exceedingly 
so  ;  in  fact,  during  one  year  it  was  nil. 

Complete  freedom  from  infectious  disease  is  by  no  means  unique,  but 
is,  indeed,  a  common  condition  in  the  experience  of  sewage  farming. 
At  the. farms  at  Genncvilliers,  where  the  sewage  of  Paris  is  received, 
the  population  is  constantly  increasing,  the  general  health  is  excellent, 
and  the  general  death-rate  is  low  and  continually  decreasing.  An  ex- 
tensive epidemic  of  typhoid  fever  in  Paris  would  be  supposed  to  be  the 
forerunner  of  another  of  greater  comparative  severity  where  its  sewage, 
containing  all  the  bowel  discharges  and  urine  of  sick  and  well  alike,  is 
treated,  but  experience  has  demonstrated  that  such  is  by  no  means  the 
case,  for  in  1882,  for  instance,  when  Paris  suifered  from  an  unusually 
extensive  outbreak  of  that  disease,  there  was  not  a  single  case  at 
Gennevilliers. 

So  far  as  is  known,  there  is  as  yet  no  proof  that  sewage  irrigation 
has  ever  been  responsible  in  any  way  for  the  occurrence  of  extensive 
outbreaks  of  typhoid  fever,  dysentery,  or  cholera,  or,  indeed,  of  entozoic 
trouble.  Nor  is  there  reason  to  look  askance  upon  the  products  of 
the  farms,  despite  assertions  to  the  contrary  based  on  surmise  and 
inexperience,  for  the  facts  show  that  grass  and  other  crops  are  of  good 
quality,  make  good  fodder,  and  bring  good  results  in  milk  and  butter 
when  fed  to  cows. 

Ferre^  has,  it  is  true,  reported  an  outbreak  of  typhoid  fever  in  a  girls^ 
boarding-school  at  Juran9on,  which  was  presumably  due  to  vegetables 
from  a  garden  watered  with  the  contents  of  an  infected  cesspool ;  and 
another  localized  outbreak  of  the  same  disease  due  to  infected  celery 
has  been  reported  by  the  State  Board  of  Health  of  Massachusetts. 
This  occurred  in  September,  1899,  at  the  Insane  Asylum  at  North- 
ampton, in  which,  prior  to  September  10th  of  that  year,  but  4  cases 
had  occurred  during  ten  years.  Then  cases  began  to  appear,  and  in 
fifteen  days  the  number  had  reached  39,  and  later  a  few  more.  Inves- 
tigation proved  beyond  reasonable  doubt  that  the  outbreak  was  due  to 
celery  grown  in  beds  which  received  the  sewage  of  the  institution.  The 
method  of  banking  employed  in  the  cultivation  of  the  plants  made  them 
a  favorable  medium  for  transmitting  the  disease.  It  should  be  noted, 
however,  that  neither  of  these  outbreaks  was  due  to  produce  from  a 
large  farm  receiving  the  diluted  sewage  of  a  distant  municipality. 

Aside  from  local  considerations  of  health,  what  are  the  results  at- 
tained ?  This  question  can  be  answered  in  a  few  words.  The  organic 
matters  of  the  sewage  are  destroyed  completely  by  the  saprophytic  bac- 
teria, which  also  dispose  of  their  pathogenic  brethren  ;  the  greater  part 
of  the  water  is  taken  up  by  growing  vegetation  and  evaporated  into  the 
atmosphere,  and  the  remainder  in  practically  sterile  condition  sinks  into 
the  subsoil  or  is  carried  away  by  the  underdrains  and  discharged  into  a 
stream. 

According  to  Kinnicutt,  Winslow,  and  Pratt,^  "  the  availability  of 

1  Annales  d'Hygiene  et  de  Medecine  legale,  Jan.,  1899^  p.  23. 

2  Sewage  Disposal,  1910,  p.  219, 


mi<:ti[()I)H  of  si<:wa<iI':  disi'osai,. 


17 


broad  irrigation,  as  a,  practical  rncfJiofl  of  scwaj.'^  f n'rittiicnl,  ohvioiinly 
(|(!|)(',ii(ls  to  a  \\\\r\\  (Ic^rnH!  on  varyiii}^  local  conditions.  In  dry  (^»iin- 
trics,  whore  every  dro[)  oC  w.itci-  is  |)rccioiiH,  tliere  can  ho  no  doubt  that 
it  is  the  ideal  pnKifidiirc  In  ('alifbrnia  and  Hirnihir  rojfioiiH  of  the 
United  Statics  it  is  likely  t(»  bo  tlu!  |)rovailin^  niotliod  of  >-(!wa^e  iraxi- 
monl,.  in  India  tlu;  rice  fields  at  Madras  and  olscwlicro  are  irri^rat^-d 
with  H(!wago,  with  niarlcod  snecoss.  On  the  other  hand,  it  sr-onis  i\\\\U\ 
as  certain  that  sewap^e  farming  on  heavy  land  is  a  niistako.  The 
I<jn<j:;lish  comniunilios,  which  have  ehinp;  to  sowafrr-  farming'-  inidcr  ad- 
verse natural  conditions,  have  demonstrated  that  it  may  be  u  failure, 
and  a  (iostly  one." 

Fig.  94. 


Field  flushing  tank. 


The  Waring  System  of  Irrigation. — Irrigation  on  a  small  scale,  known 
in  this  country  as  the  "  Waring  system,"  is  resorted  to  ver^-  commonly 
for  the  treatment  of  se^vage  of  single  houses  and  small  settlements. 
As  begun  by  the  Rev.  Mr.  Moule,  the  inventor  of  the  earth-closet,  it 
was  a  scheme  for  the  disposal  of  the  liquid  wastes  which  could  not  be 
cared  for  by  earth-closets.  The  plant  consisted  of  an  open-jointed  tile 
drain  laid  a  little  below  the  surface  of  the  ground,  parallel  with  and 
close  to  a  row  of  grapevines.  It  was  next  enlarged  by  Mr.  R.  Field 
by  the  addition  of  a  reservoir  or  flushing  tank,  shown  in  Fig.  94,  by 
means  of  which  the  whole  drain  could  be  flooded  throughout  and  inter- 
mittently. Brought  to  the  notice  of  Colonel  AVaring,  he  adopted  the 
system  for  his  own  house,  and  proceeded  to  improve  it  in  several  direc- 
tions and  to  bring  it  into  common  use.  Under  him,  the  system  was 
brought  to  its  present  state  of  perfection. 

The  plant  consists  of  a  reservoir  into  which  the  sewage  runs,  a  wire 
screening  basket  to  separate  the  ]>a]ier  and  other  matters  not  easily 
oxidizabie,  an  automatic  siphon  by  which  complete  discharge  is  secured 


548  DISPOSAL   OF  SEWAGE. 

as  often  as  the  reservoir  becomes  filled,  aud  a  gatc-cliamber  by  means 
of  ^vhieh  the  flow  is  diverted  to  any  of  the  three  outlets,  which  lead  to 
a  miniature  sewage  farm.  The  drain  pipes  are  laid,  with  open  joints, 
not  more  than  ten  inches  below  the  surface,  and  the  ground  where  they 
dischari>e  mav  be  used  for  <rrassi)k)ts  or  gardens.  The  results  are  most 
satisfactory  in  every  way ;  the  organic  wastes  are  oxidized  by  the  soil 
bacteria,  and  the  water  which  sinks  into  the  subsoil  is  incapable  of 
Ciiusing  pollution  such  as  occurs  when  cesspools  with  open  bottoms  below 
the  zone  of  saprophytic  bacteria  are  employed. 

A\'ithin  recent  years,  the  tendency  has  been  to  do  away  with  the 
drains  where  sufficient  land  is  available,  and  to  discharge  the  sew^age 
directly  upon  the  surface.  Fresh  sewage  thrown  upon  grass  is  inoffensive, 
except  to  the  sight,  unless  deposited  in  such  amounts  in  the  same  place 
as  to  cause  miring  of  the  ground,  cessation  of  oxidation,  and  consequent 
putrefaction.  It  is,  of  course,  necessary  that  the  screened  matters  be 
removed  frequently  and  buried  or  burned,  and  that  the  reservoir  be 
cleansed  at  regular  intervals. 

5.  Sewage  Filtration. — The  method  of  intermittent  filtration  of 
sewage  is  the  same  in  principle  as  the  process  described  in  the  chapter 
on  Water.  Like  that,  it  is  more  than  a  mechanical  separation  of  sus- 
pended matters :  it  is  a  process  of  screening,  oxidation,  and  eventually 
almost  complete  purification,  much  like  sewage  irrigation.  As  early  as 
1836,  Bronner,  of  Heidelberg,  endeavoring  to  learn  the  reason  why 
the  constituents  of  fertilizers  in  solution  failed  to  reach  the  deeper 
layers  of  the  soil,  filled  a  bottle,  having  a  small  hole  in  the  bottom, 
with  sifted  garden  soil  and  poured  in  gradually  a  tliick  stinking  manure 
juice,  and  observed  the  character  of  the  effluent,  which  he  found  to  be 
almost  odorless  and  colorless,  and  devoid  of  fertilizing  properties. 

But  the  system  of  sewage  purification  by  means  of  filtration  had  its 
beginning  within  recent  years  at  the  Lawrence  Experiment  Station  of 
the  Massachusetts  State  Board  of  Health,  and  is  now  in  actual  use  by 
many  municipalities  in  this  country  and  abroad.  The  filter-beds  are 
made  best  of  sand,  not  finer  than  0.2  mm.  grain  size,  and  gravel. 
Ordinary  loams,  clays,  and  peat  are  practically  useless  as  filtering 
materials,  on  account  of  the  difficulty  with  which  water  passes  through 
them.  The  purifying  agents  are  the  bacteria  which  are  soon  estab- 
lished within  the  interstices,  and  these  include  both  anaerobic  and 
aerobic  varieties.  In  order  that  both  kinds  may  perform  their  office, 
the  application  of  the  sewage  should  alternate  with  thorough  aeration 
of  the  bed.  Unless  the  application  be  intermittent,  the  anaerobic 
action  alone  is  encouraged  and  the  process  fails.  Where  sand  of  the 
right  sort  is  not  obtainable,  many  other  materials,  as  coke,  burnt  clay, 
coal-dust,  and  cinders,  have  been  used  as  substitutes. 

The  essential  facts  in  regard  to  the  working  of  sand  filters  may  be 
summarized  as  follows  :^ 

''(1)  Better  effluents  can  be  obtained  by  sand  filtration  of  sewage 
than  by  any  other  method  of  sewage  treatment ;  (2)  rates  of  filtration 

\  Clark  and  Gage,  Eeport  of  Massachusetts  State  Board  of  Health  for  1908,  p.  349. 


Mi':'i'ii()i)S  oi''  si'iwAdi':  D/srosAL.  549 

rrniHi;  ])('  low  fonipjind  with  the  nitcs  tliat  cuii  he  niainlaiiK'fl  with  cou- 
Uirl  Mild  I.ficl<liiij4  (ihcrs;  (.'{)  with  scwjij^c  ;ih  hItoii^  as  thul>  at  ]>aw- 
rcncc — |)i'()l);ihly  stroiif^cr  lh;iii  average;  A iiH-riran  Hcvva^o — it  Ih  ina<l- 
visahh;  to  iitidcrtakc  to  o|)(i;ilc  ihc  hcst  saixl  filtxTH  at  a  rat<;  (;xc<;c(ling 
75,000  ji;all()ii,s  jkt  jhm'c  daily,  and  with  iiiu;  huikIh  the  rate  mtiHt  be 
niiieli  less  ;  (hat.  is,  these;  rates  eamiot,  \h'.  exceeded  if"  ahst»hife  [»enna- 
nenee  of  iJie  (ilt(;r  area  is  desired  ;  (1)  sand  lihers  properly  eared  for 
and  not,  overworked  arc  ])ractieally  [x  rniancnt ;  (5)  .sand  removal  Ih  at 
times  necessary,  espeeially  if  sysl*  inatie  care  is  not  j^iven  to  the  filterH, 
and  if  the  rate  of  ap|)li(;ation  an<l  the  (piality  or  Htren^th  of  the  Hew- 
af2;(M)V(>rloads  the  filter;  in  other  words,  if  the  rate  maintained  eanscH 
th(!  applic^ation  of  a  greater  body  of  orii;anie  matter  than  the  biological 
life  of  the  filter  can  adequately  care  for;  (0)  a  certain  portion  of  the 
sus])ende(l  organic  matter  in  sewage  retained  by  sand  filters  is  stable, 
and  resists  for  long  ]ieriods  changes  due  to  chemical  and  biological 
fbr(;(\s — it  is  ])raetieally  as  stable  as  the  organic  matter  of  soil  ;  (7j  the 
rate  of  filtration  should  be  proportioned  to  the  strength  of  tlie  sewage, 
as  shown  by  the  orgiuiic  matter  contained  in  a  given  volume  of  water, 
and  especially  the  organic  matter  in  snsjiension  ;  (8)  when  the  rate  of 
apj)lieati()n  of  sewage  goes  beyond  a  certain  normal  point,  sand  removal 
be(M)mes  necessary.  Fin*thermore,  the  amount  of  sand  that  must  be 
removed  increases  more  rapidly  than  the  rate;  (0)  preliminary  treat- 
ment of  sewage  allows  sand  filters  to  be  operated  more  or  less  satisfac- 
torily at  rates  much  greater  than  is  possible  M'ith  untreated  sewage." 

The  Lawrence  Experiment  Station  sand  filters,  from  the  o|)eration 
of  which  most  of  the  data  given  above  were  accumulated,  have  Ijcen 
in  operation  more  than  twenty  years,  and  have  produced  clear,  highly 
nitrified  efHuents,  containing  minimum  amounts  of  unoxidized  organic 
matter  and  small  numbers  of  bacteria.  IST early  thirty  municipalities  in 
Massachusetts  dispose  of  their  sewage  upon  intermittent  sand  filters, 
and  many  are  in  operation  in  other  States. 

It  should  be  borne  in  mind  that  the  sewage  of  some  kinds  of  manu- 
facturing establishments  is  not  well  purified  by  sand  filters  or  other 
processes  which  depend  for  their  eilficicney  on  micro-organisms.  Such 
sewage  contains  oftentimes  chemicals  which,  unless  removed  by  pre- 
liminary treatment,  will  destroy  the  life  of  these  necessary  agents. 
Thus,  in  tanning  at  least  two  substances  are  used  which  interfere  Avith 
bacterial  gi'owth.  In  the  first  place,  green  skins  are  frequently  pre- 
served by  moans  of  chemical  disinfectants,  and,  in  the  second  jilace, 
when  the  skins  are  soaked  preparatory  to  the  removal  of  the  hair,  large 
quantities  of  such  chemicals  as  arsenic  sulphide  and  lime,  mixed  to- 
gether, are  used  to  facilitate  the  process.  Sewage  containing  these  sub- 
stances in  suflfieiently  large  amount,  if  applied  directly  to  a  sand  filter, 
will  quickly  interfere  with  its  efticieney  by  destroying  the  nitritying 
organisms.  Sewage  from  this  industry  contains,  in  addition,  so  much 
organic  matter  in  suspension  that  if  applied  directly  to  a  sand  filter  it 
causes  clogging  very  quickly.  Industrial  sewage  of  this  objectionable 
character    should,   therefore,  be   submitted   to   sedimentation,  or  other 


550  DISPOSAL  OF  SEWAGE. 

appropriate  treatment,  as  a  preliminary  to  sand  filtration.  It  has  been 
found  that  arsenic,  Ibr  instance,  may  be  removed  completely  by  passing 
tannery  sewage  through  coke  breeze.  "  The  removal  is  probably  due 
to  a  combination  of  the  arsenic  with  the  iron  in  the  coke,  and  the  for- 
mation of  an  insoluble  double  salt  of  iron  and  arsenic,  which  is  retained 
in  the  coke."  ^  Filtration  through  coke  has  also  been  found  efficient 
in  removing  the  organic  matters,  even  when  the  sewage  is  applied  at 
the  rate  of  250,000  to  300,000  gallons  per  acre  daily.  Moreover,  in- 
dustrial sewage  may  contain  other  objectionable  substances  which  tend 
to  clog  the  filter,  such  as  grease,  soap,  and  other  materials,  and  these 
may  require  special  treatment.  The  importance  of  guarding  against 
injury  to  the  nitrifying  organisms  by  special  sewages  should  be  borne 
in  mind,  and  also  that  if  the  process  be  stopped  in  winter,  it  cannot  be 
renewed  until  the  I'eturu  of  warm  weather. 

Contact  Filtration. — While  intermittent  sand  filters  allow  a  greater 
volume  of  sewage  to  be  purified  per  acre  than  sewage  farming,  yet 
in  England,  where  sandy  soil  suitable  for  filtration  is  the  exception 
rather  than  the  rule,  some  method  was  needed  by  which  larger  volumes 
of  sewage  could  be  treated  upon  a  given  area.  This  necessity  gave 
rise  to  investigations  of  the  purification  by  coarser  materials  than  the 
sands  first  experimented  upon  at  Lawrence,  and  from  this  call  for 
hiarher  rates  arose  the  so-called  contact  filter  of  Dibdin.  This  filter 
and  the  contact  method  of  operation  had  their  origin  in  attempts  to 
pass  sewage  continuously  through  a  bed  of  coke  breeze  during  experi- 
ments on  the  treatment  of  London  sewage  made  by  Santo  Crimp  and 
Dibdin  at  Barking  from  1893  to  1895,  In  these  experiments  the 
filters  were  first  operated  continuously,  then  from  eight  to  twelve  hours 
a  day,  and  eventually  the  contact,  or  fill  and  empty  procedure  now  so 
well  known,  was  adopted.  The  filter  is  simply  a  bed  of  coke  or  other 
coarse  material,  with  retaining  walls  and  tight  bottom,  and  with  an 
outlet  which  can  be  closed.  Sewage  is  applied  in  one  or  several  doses 
until  the  filter  is  filled  and  the  sewage  stands  just  at  its  surface.  After 
a  period  of  standing,  the  sewage  is  allowed  to  drain  away  slowly.  As 
the  sewage  drains,  the  interstices  of  the  bed  become  again  filled  with 
air,  and  the  process  of  standing,  filling,  and  emptying  may  be  repeated 
several  times  daily. 

The  first  contact  filters  were  constructed  of  coke,  but  other  materials, 
such  as  burnt  ballast,  cinders,  clinkers,  broken  stone,  and  brick  are 
quite  generally  used.  By  this  method  of  treatment  of  sewage  the 
rate  depends  not  only  upon  the  superficial  area,  but  upon  the  depth  of 
the  filter  and  its  open  space.  In  contact  filtration  the  average  rate  of 
operation  can  be  about  ten  times  that  generally  obtained  with  sand 
filters  or,  perhaps,  700,000  gallons  per  acre  daily  with  a  contact  filter 
5  or  6  feet  in  depth.  Such  filters  are  in  operation  in  many  large  cities 
and  towns  in  Great  Britain,  those  at  Manchester  and  Sheffield  being 
notable  examples  of  this  type.  The  effluent  produced  by  well-con- 
structed and  well-operated  contact  filters  is  generally  purified  to  such 
1  Keport  of  the  State  Board  of  Health  of  Massachusetts  for  1896,  p.  430. 


MF/rirODS   OF  SI':WA(!K  hlSl'OSAL.  6r;l 

an  ext(!t)t  ihni  ii  is  sImMc  :iri(l  iioii-piilrcsciMc,  hii(,  very  fiir  from  l>«;in^ 
tlu!  clear,  highly  <)xi<li/<'<l  pi'ixliK-l,  seen  n.s  llic  oiit|Mit  of  ^(»o(J  int^T- 
rnittcnt  .suruJ  filtcr.M. 

A(!(!<)r(liii^'  to  ('hirk  :iii(l  ( l.i^n/  "  it  i>  cvidcnl  lliiit  lli«-  nature  of  tlic 
nmtcriul,  tlio  mkIIkkI  oC  operation,  .inil  the  (!lianiet<'r  of  the  ajjplied 
S(\WM}ji;((  have;  very  (Htiisiderabh-  elleefs  upon  (he  <|iialitv  of"  the  eflhieritH 
from  contiUit  fiUcrs.  The  lih(!rs  eomposed  of  eol<e  or  elinkers,  that  \h 
to  say,  of  roni;h  m;ileria],  gave  a(  all  times  more  .satisfactory  effiii(?iit« 
than  thos((  composed  of  smooth  imileiial.  .  .  .  This  may  have  been 
dw),  in  part,  to  the  porosity  of  the  eoke,  which  allows  an  absorption 
of  the  {u)lloidal  and  soluble  orj;ani(!  matter  witliiu  tin-  rriaterial  itself, 
when  first  started,  resulting  in  a  more  satisfaeloi-y  formation  of  a  sur- 
face coating  upon  the  material.  Another  effect  of  the  rough  material 
is  to  hold  back  the  suspended  matters  and  prevent  tlieir  free  passage 
toward  the  outlet  of  tlu^  filter.  .  .  .  Iv\|)eriments  with  briek  and 
roofing  slate  showed  that  these  materials,  though  mf)re  f)r  less  porous, 
as  in  the  case  of  brick,  were  unsatisfactory  when  so  arranged  that  the 
surfaces  were  vertical.  The  function  of  a  sewage  filter  is  to  hold  back 
the  organic  matter  to  allow  tinu;  for  tlie  biological  f)rocesses  to  take 
place,  and  this  result  was  not  accomplished  with  the  brick  and  slate 
filters. 

"The  material  should  also  be  of  such  a  character  that  it  does  not 
break  down  readily.  .  .  .  The  size  of  the  material  also  plays  a  con- 
siderable ]>art  in  the  action  of  the  filter.  If  the  material  is  too  coarse 
the  voids  are  large,  and  the  sewage  does  not  come  intimately  in  contact 
with  the  surfaces.  If,  on  the  other  hand,  the  material  is  too  fine, 
clogging  occurs,  and  the  action  within  the  filter  becomes  largely  that 
of  mechanical  straining ;  moreover,  j)utrefactive  reactions  abound,  in- 
asmuch as  the  entrance  of  oxygen  is  largely  precluded.  .  .  .  The 
question  as  to  the  proper  dei)th  of  contact  filters  ajipears  to  be  one  of 
engiueering  rather  than  of  sanitary  interest  .  .  .  and  has  xeTx  little 
relation  to  its  biological  activity.  The  difference  in  depth,  however, 
does  make,  a  great  difference  in  the  volume  of  sewage  which  can  be 
disposed  of  upon  a  given  area.  From  this  point  of  view  deep  beds 
are  better  than  shallow  ones. 

"  The  method  of  operating  contact  filters  also  has  considerable  effect 
upon  the  character  of  the  effluent.  .  .  .  The  question  of  how  long  the 
sewage  should  remain  within  the  filter  has  not  been  determined  abso- 
lutely. .  .  .  Systematic  resting  of  the  filters  for  a  period  of  one  week 
in  every  six  has  proved  to  be  beneficial  in  every  case.  .   .   . 

"  The  character  of  the  applied  sewage  also  plays  an  important  part 
in  the  quality  of  the  effluent.  The  best  effluents  and  the  best  filter 
operation  is  secured  when  the  applied  sewage  receives  some  preliminary 
treatment  to  remove  suspended  matters." 

Trickling  Filters. — The  fourth  method  of  purifying  sewage  by  the 
use  of  micro-organisms  is  purification  by  means  of  what  are  now  known 
as  trickling  filters.  These  filters  are  an  outgrowth  of  studies  in  regard 
1  Massachusetts  Suite  Board  of  Health  Report,  1908,  p.  444. 


652  DISPOSAL  OF  SEWAGE. 

to  the  bacterial  purification  of  sewage  made  at  the  Lawrence  Experi- 
ment Station  during-  the  first  three  years  of  its  operation.  In  June, 
1889,  a  filter  of  gravel  stones  was  started  there,  some  of  these  stones 
being  not  less  than  throe-fourths  of  an  inch  in  diameter  nor  more  than 
one  and  one-quarter  inches.  To  such  a  filter  sewage  was  applied  and 
good  nitrification  occurred.  In  summarizing  the  results  of  this  filter, 
it  was  stated  that  "  the  purification  of  sewage  by  nitrification  and  the 
removal  of  bacteria  is  not  to  any  essential  degree  a  mechanical  but  a 
chemical  cliange  ;  that  the  ex]>eriments  with  gravel  stones  give  us  the 
best  illustration  of  the  essential  character  of  intermittent  filtration  of 
sewage, — the  slow  movement  of  the  liquid  in  films  over  the  surface  of 
the  stones  with  air  in  contact."  Such  filters  were  operated  at  Law- 
rence as  early  as  1890  at  rates  as  high  as  200,000  gallons  per  acre 
daily,  and  the  sewage  was  applied  frequently,  often  sixty  to  seventy 
doses  a  day  being  given. 

Dr.  Dunbar,  Director  of  the  Hamburg  (Germany)  State  Hygienic 
Institute,  makes  the  following  statements  : 

*'  Of  much  more  general  importance,  however,  are  the  experiments 
which  have  been  carried  out  at  the  Experiment  Station  erected  at  Law- 
rence. By  selecting  the  most  suitable  soil  attempts  were  made  to  in- 
crease the  efficiency  of  the  method,  and  finally  such  coarse  material  was 
used  that  the  sewage  passed  straight  through  without  spreading  over 
the  filter.  Automatic  devices  had  to  be  adopted  to  distribute  the  sew- 
age. The  London  authorities  became  aware  of  these  experiments  and 
had  them  repeated.  In  1892  Santo  Crimp  prepared  experimental  fil- 
ters of  similar  coarse  material  at  Barking.  ...  It  is  not  generally 
known  that  simultaneously  and  independent  of  Dibdiu,  J.  Corbett,  the 
Borough  Surveyor  of  Salford,  worked  out  a  biological  method  of  puri- 
fication. His  method  was  likewise  based  on  the  Massachusetts  experi- 
ments, but  in  its  further  development  it  has  surpassed  the  London 
methods.  .  .  .  Corbett  attempted  to  apply  the  principle  laid  down 
by  Sir  R.  Frankland  and  recognized  to  be  correct  by  the  Massachusetts 
authorities,  viz.,  that  an  intermittent  filtration  liquid  should  always  be 
allowed  to  fl.ow  freely  away.  .  .  .  The  chief  difficulty  to  be  over- 
come was  to  obtain  a  uniform  distribution  of  the  sewage  over  the  entire 
surface  of  the  filter.  After  many  experiments  in  various  directions, 
Corbett  adopted  for  this  purpose  fixed  spray  jets  from  which  the  sew- 
age was  distributed  under  pressure  in  the  form  of  a  fountain." 

At  the  present  time  trickling  filters  are  in  use  purifying  sewage  of  a 
large  number  of  English  cities  and  towns,  and  at  least  three  good  puri- 
fication plants  of  this  type  are  in  operation  in  America,  namely,  Colum- 
bus, O.,  Reading,  Pa.,  and  Baltimore,  Md.  Such  filters,  both  in 
Europe  and  America,  are  generally  constructed  of  broken  stone,  although 
in  many  places  abroad  hard  clinker  is  used.  These  filters  are  usually 
from  five  to  ten  feet  in  depth,  and  of  material  so  coarse  that  the  sewage 
passes  through  freely,  the  open  space  in  the  filtering  material  being  so 
large  that  there  is  abundant  and  constant  supply  of  air.  By  this  method 
of  filtration  rates  from   three  to  four  times  as  great  as  those  possible 


MF/niODS   Oh'  SFAVAdl':   DISPOSAL.  5rj.'i 

with  c.ouUicA,  filtcns  can  \n:  tnuiiilaiiifd  with  the  proihidion  of  a  highly 
nitrilicd  and  noii-ittili-cscihh'  dilhicnl.  A(,  liifmiii^diarn,  lOii^laiid,  ihcn; 
is  ut  tlie  j)roH(!nl,  (imc  (he  most  ('xti.'iiHivo  j)iirilif',;iti(»t)  phint  of  this  type. 
At  this  phiiit  the  .s(!\va^c  ol' about  H(K),()()0  people  i-  piirifierl  jjy  rneaiiK 
of  septic  tanks  and  trickling  (illers. 

Two  experinienlal  lillcrs  of  this  kind  iiave  been  in  operation  at  the 
Ijawrence  Experiment  tStatioii  for  about  twelve  years  at  averaj;r;  rates 
ofmorethau  2,000,000  gaHons  per  acre  daily,  and  are  Ktill  in  gornl 
condition  and  j)racti(!ally  i'ro.c.  from  clo^r^'injr.  Jn  order  to  rjbtain  j^ood 
results  from  these  fdtxM-s,  fairly  j)erfeel  distribution  of  th(!  sewage  over 
them  is  necessary.  'I'Ik;  spray  jets  first  used  by  Corbett  liave  been 
adopted  at  many  of  the  hirj^e  j)lants  of  this  tyj)e,  but  many  other  dis- 
tribution methods  are  used.  Some  of  these  distributors,  such  as  the 
Fiddian  and  (lie  Siini)lex,  f^ive  better  distribution  results  than  can  be 
obtained  with  nozzles  or  jets  of  the  (orbett  and  allied  types,  but  jren- 
erallv  are  more  expensive,  especially  for  the  first  installations.  The 
Fiddian  distributor  is  constructed  in  the  manner  of  an  overshot  wheel 
and  is  self-propelled.  It  is  well  adaj)ted  for  circular  beds,  such  as  are 
constructed  at  scores  of  ])laees  in  FiiLrhind  and  on  the  Continent,  and 
with  the  use  of  certain  automatic  contrivances  can  be  used  upon  rec- 
tan2:ular  beds. 

"The  main  difference  between  trickling  filters  and  intermittent  sand 
filters  is  that,  owing  to  the  size  of  the  open  spaces  between  the  particles 
of  filtering  material  in  the  trickling  filters,  much  greater  rates  can  be 
maintained  and  still  allow  the  free  entrance  of  air.  Trickling  filters 
are  not  a  substitute  for  sand  filters,  which  remove  practically  all  the 
matter  in  suspension  in  sewage,  but  are  simply  devices  for  the  modifi- 
cation of  sewage,  or,  in  other  words,  the  quick  oxidation  of  the  putre- 
fying matters  present  while  allowing  the  larger  body  of  stable  matters 
and  matters  rendered  stable  by  filtration  to  pass  through.  .  .  .  The 
grade  of  filtering  material  used  may  be  varied  according  to  the  charac- 
ter of  the  applied  sewage  ;  that  is,  a  finer  material  may  be  used  with  a 
supernatant  sewage  from  sedimentation  or  chemical  precijiitation  than 
when  the  sewage  contains  much  suspended  matter.  It  follows,  of 
course,  that  the  finer  the  filtering  material  and  the  clearer  the  sewage 
the  better  the  effluent,  but  too  fine  a  material  cannot  be  used,  as  sur- 
face ]>ooling  ensues  and  air  is  excluded."  ^ 

The  type  of  filter  to  be  erected  at  any  locality  is  often  determined 
by  certain  engineering  limitations.  Contact  filters  can  be  used  at  places 
where  trickling  filter  installations  are  almost  impossible.  This  is  clearly 
described  in  the  following  paragraph  : 

"Another  distinct  advantage  of  the  contact  bed  under  certain  condi- 
tions is  the  low  head  under  which  it  can  be  operated.  A  trickling  filter 
requires  at  the  least  8  feet  of  head  for  the  bed  itself  and  for  the  dis- 
tributing apparatus  ;  while  a  double  contact  bed  could,  if  necessary,  be 
crowded  into  5  feet.  Altogether  a  contact  installation  lends  itself  to 
compact  and  inconspicuous  construction,  which  is  of  much  practical 
1  Clark  aud  Gage,  Massachusetts  State  Boai-d  of  Health  Report  for  190S,  p.  3S7. 


554  DISPOSAL  OF  SEWAGE. 

importance  in  the  design  of  small  plants  for  institutions  or  for  private 
houses.  The  contact  bed  produces  less  odor  than  the  trickling  lilter 
and  does  not  breed  liies  as  the  trickling  filter  does.  It  may,  therefore, 
safelv  be  installed  much  nearer  to  dwellings.  Another  advantage  in 
the  contact  system  for  small  disj)()sal  plants  lies  in  the  tact  that  it  adapts 
itself  more  readily  to  marked  irregularities  of  flow  than  does  the  trick- 
ling bed.  If,-  however,  plants  of  this  type  are  designed  to  work  under 
the  control  of  automatic  ajiparatus,  it  must  be  remembered  that  a  lack 
of  careful  supervision  will  mean  certain  and  inevitable  failure."  ^ 

The  Cameron  Septic  Tank. — What  is  now  known  as  the  septic-tank 
process  was  first  proposed  by  Donald  Cameron,  Borough  Engineer  of 
Exeter,  England,  where  the  first  attempt  at  preliminary  treatment  of 
a  town  sewage  by  this  system  was  installed.  A  septic  tank  is  in  a 
sense  simply  a  cesspool  on  a  large  scale,  but  more  scientifically  operated 
than  the  ordinary  cesspool.  The  process  is  one  in  which  the  anaerobic 
bacteria  are  utihzed  for  the  purpose  of  hastening  the  decomposition  of 
organic  matter  in  sewage.  By  the  process  as  proposed  by  Cameron, 
sewage  is  passed  slowly  through  large  tanks,  so  slowly  that  not  only 
does  organic  matter  in  suspension  settle  out  and  remain  in  the  tank,  to 
be  Avorked  over  by  the  bacteria  of  putrefaction,  but  the  sewage  itself 
when  passing  from  the  tank  has  also  been  submitted  to  the  work  of 
these  bacteria  for  a  considerable  period  of  time. 

The  initial  plant  at  Exeter  consisted  of  an  underground  covered 
tank,  64  feet  long,  18  feet  wide,  and  of  an  average  depth  of  a  little 
more  than  7  feet.  At  this  place  the  crude  sewage  before  entering  the 
tank  passes  first  into  a  brick  chamber,  where  the  coarser  and  heavier 
matters  settle  out.  The  sewage  is  not  strained,  but  passes  to  the  septic 
tank  proper  after  passing  through  the  brick  chamber,  and  enters  the 
tank  through  inlets  five  feet  below  the  surface.  After  this  tank  had 
been  in  operation  for  a  period  of  a  year  or  two,  it  was  stated  that  80 
per  cent,  of  the  organic  matter  in  suspension  and  retained  in  the  tank 
was  passed  into  solution  or  escaped  in  gaseous  form,  hence  did  not 
appear  in  the  tank  effluent.  At  the  present  time  such  tanks  have  been 
in  operation  upon  a  large  scale  for  a  number  of  years  at  many  places 
in  England  and  in  America,  and  it  is  now  the  general  opinion  from 
the  results  of  their  operation  that  even  under  the  best  conditions  they 
do  not  destroy  more  than  25  per  cent,  of  the  suspended  organic  matter 
retained  by  them.  At  certain  large  installations,  as  at  Hanley, 
England,  and  at  Birmingham,  England,  the  destruction  does  not  seem 
to  be  greater  than  10  per  cent.  They  are,  however,  undoubtedly  of 
considerable  value  at  certain  places  as  adjuncts  to  sewage  purification, 
and  are  well  recognized  as  one  of  the  prominent  forms  of  preliminary 
treatment  of  sewage  before  purification. 

Septic  Tanks  for  the  Digestion  of  Sludge  Only. — The  Lawrence  Tank, 

Hampton  Tank,  and  Imhoff  Tank. — A  modification  of  the  septic  tank 

for  the  concentration  and  digestion  of  sludge  only  was  first  put  into 

operation  at  the  Lawrence  Experiment  Station  in  1899.     This  modifi- 

^  Kinnicutt,  Winslow,  and  Pratt,  "  Sewage  Disposal,"  1910,  p.  313. 


MI'lTIIODS   OF  SFWAdlC    I  )ISI'()SA  I,.  666 

f!,'iiioii  consisted  of  ;i  t:uik  witli  two  coiiijKirt iikiiIh,  tlif  lowor  compart- 
iriciil  nitainiiif^  the  scUlcd  hIikIj^c;  for  wplif!  lu'lion  or  (li;r<'.stion,  while 
tlic  iriuiri  body  ol'llic  scwjij^c  vv;is  not  rctiiiiutd.  (\{(\)i)r\  oC  Mjihh.  S<at<', 
PxKird  of  IlcaliJi  for  !«!)!),  j).  422.)  This  tank,  Jiidj.dn}r  from  jtrcscnt 
knowledge,  was  sii(!(!cssful  in  a(r(V)rnj)lishin}.''  :dl  that  conid  he  <-\\)C(:U-(\ 
of  it  in  slnd^<!  (H^cistion.  Since  lli<!  ojicration  of  that  tank,  tlur 'J'ravJH 
tank  at  Ifainpton,  En^kirid,  and  (ho  GcTnian  rnodifioution,  known  aw 
the  linliofT'  tank,  have  l)eeoine  well  known,  and  are,  apparently,  of  nnieh 
promise.  I>oth  an;  hased  npon  the  priiu-iph;  of"  the  Lawnnee  tank  'tf 
1<S!)!),  namely,  tlie  retention  of  slud^'e  only  for  di|rcHtioii,  uhih-  th«; 
main  body  of"  sciwaf^e  pass(!s  (juickly  to  the  jxirificiation  area. 

Dr.  Travis  inak(^s  the  f"ollowinfr  statement:' 

"The  conception  of"  tlu;  '  Ilydrolitic  Tank  and  ()xi<liziii^'-  I>eds  '  \h 
the  result  of  a  clos(^  study  of"  the  numerous  experiments  conducted  at 
Lawrence  under  the  State  lioard  of  Health  of"  Massachusetts,  etc.  .  ,  . 
This  beinji;  so,  an  acknowledg;ment  of  the  source  from  wlience  the  ideas 
were  derived  and  a  recital  of  the  conclusions  having  special  referenw 
thereto  are,  as  a  matter  of  common  honesty  as  well  as  of  courtesy, 
equally  desirable." 

The  Imhotf  tank  is  based  upon  the  Travis  tank,  and  consists  gen- 
erally of  two  cylinders  with  conical  bottoms  connected  with  an  upper 
rectangular  tank  through  which  the  sewage  flows.  As  the  sewage 
passes  through  this  taid'C  at  a  slow  rate  the  solid  particles  settle,  slide 
along  the  sloping  walls,  and  are  deposited  finally  in  the  cylindrical 
liquefying  chambers,  reaching  perhaps  thirty  feet  below  the  surface  of 
the  sewage  in  the  tank.  In  these  lower  chambers  the  sludge  undergoes 
putrefaction,  but  the  gas  evolved  is  prevented  by  an  arrangement  of 
bafilles  from  ]>assiug  up  through  the  sewage  in  the  upper  tank.  The 
sludge  is  held  in  these  lower  chambers  for  a  series  of  months,  and  is 
forced  out  from  time  to  time  through  pipes  connected  with  the  bottom 
of  these  chambers,  pressure  of  the  sewage  in  the  upper  tank  being 
utilized  for  this  purpose.  The  sludge  is  spread  upon  suitable  sludge 
beds,  where  it  dries  (|uickly  and  can  be  removed  easily  to  the  place  of 
final  disposal.  The  advantage  of  this  type  of  tank  is  that  the  sludge 
is  very  concentrated  and  practically  free  from  odor. 

1 "  British  Sewage  Works,"  M.  X.  Baker. 


CHAPTER    YII. 
DISPOSAL  OF  GARBAGE. 

Garbage  eomprisos  all  manner  of  waste  material,  and  its  disposal 
is  of  very  great  economic  and  sanitary  importance.  The  daily  accumu- 
lation in  towns  and  cities  is  enormous,  and  its  removal  at  regular 
intervals  is  a  matter  of  great  concern  to  municipal  administration. 
From  a  hygienic  standpoint,  the  proper  disposal  of  kitchen  waste  and 
other  decomposable  material  far  outweighs  in  importance  the  removal 
of  such  matters  as  waste  paper,  ashes,  discarded  boots  and  shoes,  tin 
cans,  bottles,  and  other  rubbish,  which  in  no  way  can  affect  the  public 
health,  but  which  for  various  reasons,  may  not  be  allowed  to  accumulate 
in  the  household.  In  rural  districts,  the  disposal  of  garbage  in  general 
is  exceedingly  simple ;  but  in  crowded  communities  it  entails  great  ex- 
pense, and  is  usually  a  very  complicated  problem.  Since  this  work  is 
concerned  solely  in  matters  of  sanitary  interest,  and  not  in  economics, 
the  consideration  of  this  subject  will  be  restricted  to  the  methods  of 
disposal  of  those  matters,  the  retention  of  which  on  occupied  premises 
may  be  regarded  as  detrimental  to  health,  namely,  those  known  as 
kitchen  refuse,  or  swill. 

The  methods  of  disposal  of  these  matters  comprise  those  Avhich 
may  be  carried  out  by  the  individual  householder  on  the  spot, 
and  those  adopted  by  municipal  authority  after  house-to-house  col- 
lection. 

In  many  households,  refuse  is  disposed  of  by  burning  in  the  kitchen 
fire  Math  or  without  a  preliminary  process  of  drying,  for  which  a  num- 
ber of  simple  apparatuses  have  been  devised.  A  very  efficient  arrange- 
ment in  common  use  consists  of  an  enlargement  in  the  lower  part  of  the 
stovepipe,  forming  a  chamber  into  which,  through  a  doorway  in  the  end  or 
side,  the  refuse,  in  a  suitable  metallic  holder  with  perforated  sides  and 
bottom,  is  introduced.  Through  this  the  hot  air,  gases,  and  smoke 
from  the  fire  pass  on  their  way  to  the  chimney  flue,  and  thus  complete 
drying  and  partial  carbonization  are  brought  about.  The  dried  residue 
is  disposed  of  finally  by  burning  in  the  stove,  where  it  serves  a  useful 
purpose  as  fuel. 

lu  country  and  suburban  districts,  kitchen  waste  is  advantageously 
disposed  of  by  feeding  it  in  a  fresh  and  sweet  condition  to  swine  and 
poultry,  and  depositing  in  the  soil  such  matters  as  they  will  not  eat. 
Burying  in  the  soil  is  a  simple  and  eflPective  method  of  disposal,  entail- 
ing but  little  labor,  since  it  is  best  not  to  deposit  it  very  deeply.  Near 
the  surface,  decomposition  occurs  rapidly,  and  so  a  covering  of  earth 
a  few  inches  in  depth  is  sufficient  to  prevent  contamination  of  the 
atmosphere  with  noisome  odors. 

Very  recently  small  household  incinerators  have  been  devised  for  use 

556 


DISPOSAL    OF  (J  Aim  AGE.  557 

in  btiildiii^s  :i]r(!a<ly  |)i|)('(l  for  ^as  oonsiirn})tif)n.  The  ^rutx;  uhchI  in 
tills  iiuiiiicrnior  is  of  ;i  special  type;  \viii<;li,  alllioiif^li  it  |)r(;V(;nt.s  the 
li(|iii(l  por-tions  of  the  i^arbat^c  from  passiii}.^  ihroii^'li,  allows  the  wjist« 
iiial('i-ial  to  l)(i  cxposc^d  to  ^^rcat  heat  from  a  lar^c  liniisr-ii  {^as  flarrir;. 
'V\\{\  iiioisliiic  of  llir  fijiirhafjje  is  driven  olT  hy  the  heat  and  the  remain- 
ini;-  malerial  is  then  rediice<i  (piicUly  to  the  condition  of  dry  as}).  Smoke 
and  s((!am  an;  n-moved  tliron<fli  a  connection  with  a  cliimn(;y  fine. 

'I'Ik!  iuetIio<Is  adopled  l)V  niiinicipal  aiif liorilies  comprise  dnm[)- 
inu;'  inio  the  sea,  disposal  (o  (ariiiers  for  -wiiie-fcedin^r,  utili/ation 
as  food  for  herds  of  swine  kept  [ny  the  purpose,  and  redncljon  ;iiid 
incineration  in  fnrnac(ss  ol"  special  const  rnet  ion,  known  as  dest  rnetors. 

Duinpint;'  into  th(;  sea.  is  open  to  tli((  ohjection  that,,  nnder  fav«»rin^ 
conditions  of  winds,  tides,  and  ciu'rents,  mnch  material  may  h<-  washed 
ashore,  and  bcconu;  a  nuisance  and  eyesore  to  the  immediate  neigh- 
borhood. 

I)is|)osal  to  farmei's  involves  cartag(!  over  miles  f)f  road  in  wagons, 
which,  if  not.  leaky  for  li(piid  matters,  at  l(;ast  permit  the  csca])e  of 
nauseous  odoi's,  to  the  annoyance  of  dwellers  and  travellers  along  the 
I'outc.  It  involves,  also,  storage  for  at  least  a  short  time  after  collec- 
tion, unless  the  garbage  wagons  can  themselves  be  sent  into  the  c^mn- 
try — a  proceeding  which  can  hai'dly  be  regarded  by  taxpayers  as 
consistent  with  the  pr()|)er  management  of  mnnicij)al  revenues.  This 
period  of  storage  is,  in  elfect,  a  continuation  of  that  which  has,  perhaps, 
extended  already  through  several  days  or  a  week  before  collection, 
during  which  time,  various  fermentative  processes  have  been  active  in 
the  prodiu'tion  of  conijiounds  of  offensive  character. 

Incineration  at  sjiecial  stations  for  the  destruction  of  swill  and  all 
other  combustible  rubbish  is  being  widely  adopted  by  large  communi- 
ties, and,  in  many  ])laces,  has  proved  to  be  not  only  the  most  econom- 
ical method  of  disposal,  but  even  a  source  of  gain.  To  such  a  station 
are  brought  the  daily  collections  of  garbage,  which  at  once  undei'go  a 
process  of  sorting.  Paper  and  pasteboard  are  utilized  in  the  furnaces 
as  fuel  or  are  sold  to  be  used  in  the  manufacture  of  the  cheaper  grades 
of  papcH"  and  cardboard  ;  old  shoes  and  boots  are  disposed  of  to  makers 
of  artificial  leather,  and  rubbers  and  overshoes  to  manufacturers  of 
rubber  goods  ;  tiu  cans  are  heated  to  recover  the  solder  ;  ]Meces  of  un- 
consumed  coal  are  collected  and  used  or  sold  for  fuel ;  broken  furni- 
ture, boxes,  barrels,  and  other  wooden  objects  are  split  up  into  kindling, 
and  excelsior  stuffing  is  utilized  in  the  furnaces.  In  short,  almost 
every  kind  of  rubbish  may  be  utilized  in  some  way  to  advantage. 
The  late  Colonel  George  E.  Waring,  Jr.,  experimenting  in  Xew  York 
with  a  long  travelling  belt,  on  which  the  combustible  waste  from  a 
district  containing  200,000  people  was  deposited  and  picked  over, 
found  that  90  per  cent,  of  it  was  salable,  and  but  10  per  cent,  remained 
to  be  destroyed  by  fire.  In  some  establishments  now  in  operation,  a 
long,  travelling,  endless  belt  of  steel  plates  is  employed,  the  carts 
dumping  upou  it  at  oue  place.  As  the  material  passes  along,  it  is 
sorted  over  quickly  by  men  on  either  side,  and  what  is  left  is  conveyed 


558  DISPOSAL    OF  GARBAGE. 

onward  to  a  bin,  from  whicli,  in  time,  it  passes  to  the  furnace,  to  serve 
to  destroy  the  kitchen  waste. 

It  wouhi  be  impossible,  even  if  it  were  not  unnecessary,  to  give 
in  detail  a  description  of  the  many  \arieties  of  machines  and  fur- 
naces which  have  been  invented  for  the  incineration  of  refuse.  In 
general,,  it  may  be  said  that  a  destructor  consists  of  a  furnace  with  a 
chamber,  provided  with  grate-bars,  in  which  the  dry  or  partially  dried 
offal  is  burned  ;  and  a  second  chamber,  in  which  it  is  subjected  to  a 
preliminary  process  of  drying.  This  second  chamber  is  placed  behind 
the  front  compartment,  Avhich  receives  the  dried  garbage  and  other 
combustible  material  serving  as  fuel.  In  the  best  forms,  two  fires  are 
maintained  :  one  at  the  forward  end,  and  the  second  at  the  stack  end 
of  the  furnace,  the  latter  being  designed  to  insure  complete  combustion 
of  vapors  and  dust  before  entrance  to  the  chimney,  from  which,  other- 
wise, they  miglit  issue  in  such  a  form  as  to  create  serious  nuisance,  not 
alone  to  the  immediate  neighborhood,  but  even  at  considerable  dis- 
tances. 

The  burning  of  the  smoke  and  fumes  is  very  essential,  and  failure 
to  provide  therefor,  or  the  unsuccessful  operation  of  the  fume  cremator, 
has  caused  the  abandonment  of  many  plants,  which,  with  better  instal- 
lation, should  have  worked  successfully  and  to  public  satisfaction. 
In  many  English  cities,  destructor  furnaces  have  been  in  operation  for 
years  in  close  proximity  to  dwellings,  schools,  and  hospitals  without 
causing  offence.  At  Ealing,  for  example,  the  furnace  is  located  at  a 
distance  of  180  yards  from  two  hospitals;  in  Whitechapel,  within  a 
very  few  yards  of  dwelling  houses  in  the  midst  of  a  very  populous 
district ;  at  Leicester,  but  a  very  few  yards  from  a  large  school  and 
immediately  adjoining  a  considerable  number  of  dwellings. 

The  fume  cremator  consists  of  a  reverberatory  arch  with  rings  of 
firebrick,  placed  in  the  direction  taken  by  the  gases.  Projecting  ribs 
deflect  the  vapors  to  the  top  of  an  intensely  hot  fire,  in  which  they  are 
destroyed.  Provision  is  made  for  rapid  removal  of  ashes,  and  for 
drafts  of  air  at  needed  points  to  maintain  a  continuous  temperature 
above  2.000°  F.  The  heat  produced  is  commonly  utilized  in  the  pro- 
duction of  steam  for  the  engine  which  does  the  necessary  hoisting  and 
other  work,  and  drives  the  shafting  connected  with  the  endless  belt  and 
other  appliances.  Another  most  useful  and  economical  application  is 
the  utilization  of  the  great  store  of  energy  for  maintaining  electric- 
light  plants  for  lighting  the  premises,  and  even  the  public  streets.  In 
New  York  and  Boston,  the  surplus  energy  is  utilized,  but  at  most 
other  plants  in  the  54  cities  and  towns  of  this  country  which,  in  1899, 
were  using  the  process,  the  heat  is  wasted. 

At  the  beginning  of  1899,  81  communities  in  Great  Britain  were 
employing  incineration  as  the  chief  means  of  disposal  of  refuse,  and  76 
of  them  turned  the  developed  heat  to  some  useful  purpose.  About  a 
third  of  the  number  use  the  power  for  electric  lights  for  the  works  or 
streets,  or  both  together;  nearly  two-thirds  maintain  mills  for  grinding 
rnaterials  for  mortar  and  clinkers  for  pathways ;  six  employ  the  steam 


DIHl'OSAI,   Oh'  (lAlli:y\(iK  559 

for  t,ho  purpose  of  pnl)Ii<;  disliifictioii;  hcvcnil,  lor  j)iuiipiji}^  h(;vv:i|(c,  and 
others,  Cor  various  useful  purposes.  In  oik;  city,  ;'>,(K)0,()(JO  gallons  of 
s(!wu<;'e  are  puiii|)e(l  tlirounli  a.  tweiity-foot  lift,  flie  works  arc;  lighted 
l)y  (ileetrieity,  the  sh(»|)s  and  Corfres  of  the  tnuniei|)al  servifu;  are  su})- 
plied  with  power,  and  olhcr  work  also  is  performed. 

Reduction. — In  the  reducHion  process,  the  kitchen  pirha^'c;  is  stored 
ill  tanks  which  p(!nnit  the  draining  away  of  most  f»f  the  water,  wdiicli 
is  c()n<hieted  direelly  to  a  sewer.  Next  it  is  dried  in  cylindrir-al 
.stc!am-ja(^k('ted  ehandters,  into  which  hot  air  and  siiperheati-d  stejini  arc 
conducted,  the  process  requirinu;  al)oul  six  hours.  'I'h(;  material  1oh(.'8 
about  three-fourths  of  its  weight,  which  j)asses  of]'  in  the  form  fjf  aque- 
ous vapor  and  is  (condensed  and  discharged  into  th(!  sewer;  the  rion- 
cond(nisiWle  stinkinu:;  vapors  are  disposed  of  in  the  vajjor  cremator 
(5onnected  with  tlie  boiUirs  in  which  the  s(<'aiii  is  ireiieraled.  TJic  clri(;d 
residue  is  next  introduced  into  tanks  of  naphiha,an<l  llif  whole  is  heated 
by  steam  coils  until  all  <:;reas(!  has  been  I'emoveil,  when  the  naphtha 
solution  is  separated.  This  is  tluMi  distillcfl,  the  naphtha  |)assin^  <»ver 
and  beint;'  reclaimed  for  re{)eated  use,  and  the  fat  n^mainin^  behind  as 
a  valuable  j)ro(luet.  The  extracted  residue  is  dried  again  and  wftrked 
up  into  fertilizer. 

Reduction  methods  are  a])pli(^al)le  only  to  large  cities,  and  since  it  i.s 
almost  inqwssible  to  conduct  the  works  without  creating  a  nui.-ance, 
these  should  be  located  at  such  a  distance  from  a  community  that  the 
value  of  property  may  not  be  impaired,  and  the  daily  enjoyment  of 
life  may  be  in  no  way  sensibly  abridged.  If  the  amount  of  collectable 
kitchen  waste  is  suificiently  large,  say  that  from  a  ])opulation  of  at 
least  150,000,  aiid  if  the  works  can  be  so  placed  as  to  cause  no  nuisance 
and,  at  the  same  time,  not  to  necessitate  a  long  and  expensive  haul  of 
the  material,  reduction  has  been  found  to  fulfil  both  the  sanitiir}-  and 
the  economic  requirements,  the  yield  of  grease  and  fertilizer  having 
considerable  value,  thus  reducing  materially  the  cost  of  disposal.  But, 
as  in  the  case  of  sewage,  it  should  be  borne  in  mind  tliat  the  removal 
and  divSposal  of  waste  are  sanitary  measures,  and  should  not  be  viewed 
too  much  from  the  standpoint  of  profit-making. 

If  the  quantity  of  garbage  collected  is  too  small  to  warrant  treatment 
by  reduction  processes,  it  may  be  burned  to  advantage  in  destructors. 
A  combination  of  the  two  methods,  reduction  and  cremation,  would 
seem  to  be  the  most  advantageous  for  communities  producing  a  very 
large  daily  amount  of  general  w^astes.  But  the  possibility  of  nuisance 
from  all  reduction  works,  a  nuisance  which  has  caused  the  abandon- 
ment of  the  great  majority  of  the  plants  which  have  been  installed  in 
this  country,  shouki  ever  be  borne  in  mind,  even  though  the  nuisance 
be  limited  to  a  small  percentage  of  the  population,  who,  if  they  com- 
plain, are  regarded  by  the  rest  as  unduly  sensitive,  ]n'one  to  magnify 
small  discomforts  and  give  them  a  factitious  importance,  aud  incon- 
siderate of  the  general  welfare,  which,  even  if  true,  can  not  deprive 
them  of  their  right  to  ajipeal  to  the  courts  for  the  abatement  of  the 
cause  of  their  disconifort. 


CHAPTEK    VIII. 

DISINFECTANTS  AND  DISINFECTION. 

Disinfectants,  ov  germicides,  are  agents  which  bring  about  the 
destruction  of  bacteria  in  general,  and,  more  particularly,  of  those  that 
act  as  the  exciting  causes  of  disease.  While  they  are  all  to  be  classed 
as  antiseptics,  the  latter,  as  a  class,  are  by  no  means  necessarily  disin- 
fectants, since  many  of  them  act  simply  to  delay  or  prcN'ont  the  action 
of  fermentative  agents,  ^vithout  exerting  any  destructive  influence  upon 
them.  Cold,  for  example,  is  a  most  efficient  antiseptic ;  but  ^vhile  it 
may  inhibit  growth  and  activity  of  micro-organisms,  it  does  not  neces- 
sarily deprive  them  of  vitality. 

Deodorants  are  agents  which  remove  or  mask  disagreeable  odors,  but 
they  are  not  necessarily  disinfectants.  Some  deodorants  are  efficient 
disinfectants,  but  not  all  disinfectants  are  efficient  deodorants.  The 
latter  are  largely  substances  Avhich,  being  of  strong,  peculiar  odor,  are 
used  to  overcome  or  supersede  disagreeable  odors,  but  without  exerting 
any  influence  upon  the  causes  thereof.  Odors  may  or  may  not  be  a 
concomitant  of  infectious  matter  according  to  circumstances  ;  and  ^vhen 
so,  the  mere  fact  of  their  being  overwhelmed  by  a  more  powerful  rival 
smell  has  no  influence  on  the  vitality  of  the  bacteria  present.  Some 
deodorants  remove  smells  without  the  creation  of  another,  and  without 
exerting  any  action  upon  their  causes  ;  such  are  charcoal  and  ordinary 
earth. 

The  function  of  disinfectants  is  the  destruction  of  morbific  agents  so 
that  they  shall  not  spread  infective  diseases.  They  are  not  curative  of 
the  infected  person,  but  are  }>reventive  of  the  spread  of  the  disease 
from  that  person  to  others.  An  efficient  disinfectant  for  general  pur- 
poses should  possess  the  property  of  killing  not  this  and  that  species  of 
bacteria,  but  one  and  all,  and  their  spores  as  well.  Some  pathogenic 
bacteria  have  a  tolerance  for  certain  disinfectants,  and  may  acquire  one 
gradually  for  certain  others.  Such  agents  cannot,  therefore,  be  in- 
cluded among  the  efficient  class  for  general  use.  For  special  work  in 
destroying  the  infective  agents  of  certain  diseases,  disinfectants  which 
have  been  proved  to  exert  a  destructive  influence  on  the  particular  or- 
ganisms may  be  used,  although  they  have  failed  to  show  an  equal  poAver 
against  other,  more  resistant,  varieties.  Disinfectants  may  be  divided 
into  two  classes,  namely  :  1.  Physical  agents.     2.  Chemical  agents. 

PHYSICAL  AGENTS. 

The  physical  agents  are  :   1.   Light.     2.  Heat. 

Light. — Direct  sunlight  is  one  of  the  most  important  disinfectants 
known.      It  retards  the  gro^vth  of  many  organisms,  and,  after  a  vary- 
560 


ril  YSICA  L   A  (J  h\\  TS.  Tj  C,  \ 

\n^  iiiinih(!r  of  hours  of  exposure,  fiomplft/ily  <lf!sfroys  flir-  vitality  of 
;i  iiiiiiiIm'I'  of  t\n'.  rriosi  itiiporlnni,  jml  lio<.'('iiic  iKu-.tcria,  iiirliHlinjr  sorru- 
j^ciuMvilly  r('(;o<^iii/('(l  as  lil;i;lily  rcsislanl.  I  )i(T'iis('(|  dayli^lit  and  ch-ctrif; 
light  also  ;in!  ciYvA'Xwc,  hut  in  a  niiicli  (liiiiiiii.^hcd  dcj/n-c. 

Tho  destructive  eflect  of  Hiinli^lit  on  l>ar(cria  was  dctnon'-tiatfd  first 
by  Downos  and  Blunt,'  in  1.S77.  Tlicy  inocnlat<'d  flasks  of  broth  with 
bactisria  and  exposed  |)art  of  (lieni  to  .~nnliji;lit  and  kept  the  ftthers  in 
(larkn(!ss;  tlu;  Ibrrner  retnained  clear,  while  the  lalt(;r  bef:atne  turbid  by 
reason  of  l)a(!t(!rial  (null i plication. 

Mit(!holl  and  C/rouch  ^  cxpos(!d  tuberculous  s|)ntiiin  to  direel  snnliLdit 
for  varying  periods  up  to  25,  ,'U),  oTj,  lo,  and  oo  hours  and  then  inoe- 
ulat(Hl  it  into  guinea-pigs,  with  the  result  that  those  whi('h  received 
sputum  exi)osed  longer  than  25  hours  remained  healthy,  while  the 
others  became  infected. 

Koch''  announced,  in  1890,  that  the  bacillus  of  tuberculosis  is  killed 
by  <lirect  sunlight  in  from  a  few  minutes  to  several  hours,  according  to 
the  thickness  of  the  layer  of  material  in  which  it  is  containtHJ,  and  by 
diffused  light  in  from  5  to  7  days.  Migneco  *  exposed  tuberculous 
sputum  on  linen  and  woolen  fabrics  to  direct  sunlight,  and  found  that, 
])rovided  the  layer  was  not  too  thick,  the  bacilli  could  not  resist  longer 
than  from  24  to  30  hours.  The  virulence  was  observed  to  diminish 
gradually  after  10  to  15  hours,  and  to  disappear  com])letely  after  24  to 
30  hours, 

Jousset^  found  that  tuberculous  sputum  containing  virulent  bacilli 
was  rendered  innocuous  by  4  hours'  exposure  to  diffused  sunlight  and 
after  drying  and  exposure  to  direct  sunlight  for  1  hour. 

Janowski,*'  experimenting  with  B.  typhosus,  discovered  that  that 
organism  failed  to  grow  wdien  planted  in  bouillon  and  exposed  for  6 
hours  to  direct  sunlight ;  and  that,  in  bouillon,  exposed  8  hours  out  of 
every  day  to  diffused  light  and  kept  in  the  dark  the  rest  of  the  time, 
its  development  was  much  delayed,  but  in  the  same  medium,  kept 
wholly  in  the  dark,  cloudiness  was  observed  in  from  16  to  20  hours. 
That  this  action  is  not  due  to  increase  in  temperature  was  shown  first 
by  Saverio,^  who  exposed  gelatin  cultures  of  the  organisms  of  typhoid 
fever,  anthrax,  and  cholera,  and  Staphj/Iococnis pyor/cncs  aureus,  to  sun- 
light and  electric  light  for  from  2  to  47  hours,  and  made  careful  obser- 
vations of  the  temperatures  within  the  tubes.  He  discovered  that  the 
most  energetic  action  was  not  coincident  with  high  temperatures, 
although  the  latter  hastened  the  beginning  of  the  process.  Anthrax 
spores  were  destroyed  almost  as  quickly  as  the  bacilli,  and  after  a  cer- 
tain length  of  time  their  virulence  progressively  diminished.  The  red 
and  infra-violet  rays  appeared  to  exert  no  bactericidal  properties. 

1  Proceedings  of  the  Royal  Society,  XXVI.,  p.  488;  XXVIII.,  p.  199;  XL.,  p.  14. 

^  Journal  of  Pathology  and  Bacteriolo£ry,  ^lay,  1899,  p.  14. 

3  Vortrag  auf  dan  zehnten  internationalen  medicinischen  Congresse,  1890. 

*  Archiv  fiir  Hygiene,  XXV..  p.  361. 

*  Coraptos  rendns  de  la  Societe  de  Biologic,  Nov.  2,  1900,  p.  884. 

*  Oentralblatt  fiir  Baktcriologie,  VIII..  p.  6. 

^  Annali  dell'  istituto  d'igiene  sperimentale  della  reale  universita  di  Koma,  II., 
Serie  2,  p.  121. 

36 


562  mSIXFECTAyTS  AXD  DISINFECTION. 

Geissler  ^  found  that  direct  sunlight  exerts  a  more  powerful  influence 
on  cultures  of  the  bacillus  of  typhoid  fever  than  an  electric  light  of  a 
hundred-caudle  power  at  a  distance  of  a  meter,  and  advanced  the  prop- 
osition that  the  effects  ou  the  bacteria  are  due  in  part  to  changes 
bn)Ught  about  in  the  character  of  the  culture  media.  That  the  action 
of  sunlight  is  chemical  is  shown  by  the  differences  in  the  capacity  of 
the  different  rays  for  producing  results,  the  ultra-violet  being  endowed 
with  the  greatest  power. 

This  change  in  the  character  of  the  culture  media  has  been  noted  also 
by  Kruse,-  who  found  that  liquid  media,  containing  complex  nitrogenous 
substances,  are  so  altered  by  the  influence  of  light  that  they  acquire 
antiseptic  properties  against  the  bacteria  and  that  the  change  is  propor- 
tionate to  the  intensity  of  the  light  and  the  duration  of  the  exposure. 
But  it  is  not  alone  through  changes  in  the  media  that  bacteria  are 
killed,  but  through  changes  brought  about  within  themselves  as  well. 
And,  indeed,  it  has  been  demonstrated  that  not  alone  bacteria,  but 
their  toxins  also,  are  affected.  According  to  Fermi  and  Celli,^  the 
toxin  of  tetanus,  diluted  with  distilled  water  and  exposed  to  direct 
sunlight  at  temperatures  between  40°  and  50°  C,  is  rendered  inert  in 
8  hours,  and  at  37°  C.  in  15  hours.  In  dried  condition  it  loses  its 
power  after  4  hours.  Rattlesnake  venom,  however,  is  not  injured  by 
sunlight,  even  by  14  days'  exposure. 

Moisture  and  access  of  air  are  also  important  factors,  as  has  been 
shown  by  Moment,''  who  found  that  anthrax  bacilli  in  a  moist  state 
were  killed  in  2.5  hours  with  free  access  of  air,  and  survived  more 
than  50  hours  when  air  was  excluded.  Dry  bacilli  were  killed  with 
access  of  air  in  5  hours ;  dry  spores,  exposed  in  glass  without  air,  were 
virulent  after  110  hours,  and  proved  to  be  more  resistant  than  others 
in  a  moist  state. 

The  rapidity  of  action  of  sunlight  is  influenced  also  by  the  number 
of  bacteria  present — the  greater  the  number,  the  longer  the  time  re- 
quired for  the  bactericidal  effect  to  be  instituted. 

Weinziel  ^  asserts  that  the  methods  employed  in  older  recorded  exper- 
iments were  defective,  not  only  with  regard  to  the  bacilli  of  tuberculosis, 
but  with  other  non-sporing  bacteria,  in  that  the  medium  employed 
absorbed  considerable  sunlight  and  that  the  glass  covers  both  reflected 
and  absorbed  it.  Direct  exposure  of  bacteria  on  paper  or  glass  to  sun- 
light sufficed  to  destroy  B.  tuberculosis  in  about  10  minutes,  and  B.  coli, 
B.  typhosus,  B.  prodigiosus,  and  others  in  less  time ;  but  if  the  bacteria 
were  clumped,  they  resisted  longer. 

The  sterilizing  influence  of  sunlight  on  the  bacteria  of  drinking-water 
and  sewage  has  been  demonstrated  by  Procaccini,  Buchner  and  Minck, 
and  others  to  be  very  considerable,  especially  at  and  near  the  surface. 

1  Centralblatt  fiir  Bacteriologie,  XI.,  Nos.  6  and  7. 

2  Zeitschrift  fiir  Hygiene  und  Tnfectionskrankheiten,  XIX.,  p.  313. 

3  Centralblatt  fiir  Bacteriologie,  XII.,  No.  18. 
*  Annales  de  I'Institut  Pasteur,  1892,  p.  28. 

5  Journal  of  Infectious  Diseases,  Suppl.,  Vol,  HI.,  May,  1907,  p.  128. 


I'lIYSlCAIj  AdKNTS.  ',(',?, 

Procuccini '  ohtjiincd  posifivc  n^siilts  at.  a  dcpfh  of  frnrii  20  to  .'50  cftn- 
tiiruilcrs.  Mituik  and  liiiclincr  ^  foiMxl  that  wafer  containiiij^  100,000 
/)'.  voli  roni'iii'iniin  jo  tlic  (tiihic,  cciitinu'lcr  was  rciidfred  hUtIK;  in  an  li'*ijr. 
'J'Ik;  bacilli  oi'  typlioicj  i'vvv.r  and  clioltTa,  and  Ji.  jryocyancuH  al.so  w^to 
found  to  be  dcHtroycd.  ('ulturoH  of  B.  ti/jjlioms,  cxpoHcd  at  a  d<'[)tli 
of  ab(»nt  5  feet,  wen;  stcrili/i^d  in  ■IJ  hours,  but  at  twice  fhat  disfance 
beneath  the  snrfa(!(;  the  ac^tion  virtually  (;eased,  I'uehner''  friiind,  further, 
that  dilTused  liujht  has  a  stron}^  influence,  even  an  hite  in  tlie  year  as 
November,  on  II.  co/i  coiinniuiis  and  />.  pyocyancuH.  'J'he  action  of  lijrht 
is  considerably  interfered  with  l)y  particles  in  Kuspension,  but  with  fairly 
clear  water  tlu;  efleets  are  |ierceptil)lc!  at  a  de|)t]i  of  ay)ont  0  feet,  'i'he 
action  of  sunlight  on  bacteria  in  the  [)rcsenc(!  of  water  is  believe<l  by 
niaiiy  to  l)c  due  to  th(>  production  of  hydrf)gen  peroxide.  Thiel  and 
Wolf,*  liowever,  investigating  this  question,  found  no  evidence  what- 
ever that  this  agent  plays  any  part. 

The  relation  of  sunshine  to  the  well-known  resistance  of  tlie  natives 
of  tropical  Africa  to  ordinary  infections  has  been  studied  by  Martin,' 
whose  experiments  were  carried  on  in  a  district  wliere  the  summer  tem- 
perature in  the  open  averages  77°  F.  in  the  early  morning  and  at  night 
and  144°  F.  at  noon.  Bacteriological  examinations  of  indoor  and  out- 
door air  and  of  the  soil  showed  an  abundance  of  non-pathogenic  and  a 
scarcity  of  ])athogenic  bacteria  ;  and  exjiosure  of  pure  and  mixed  cul- 
tures of  pathogenic  bacteria  to  the  action  of  the  sun  convinced  him 
that  while  the  sun's  heat  played  a  considerable  part,  much  influence  is 
exerted  by  the  bactericidal  action  of  the  light  rays. 

The  obvious  disadvantages  of  relying  upon  sunlight  for  practical 
disinfection  are  that  its  supply  is  beyond  control,  and  that,  even  on 
the  brightest  days,  it  is  impossible  to  apply  it  to  all  parts  of  a  house. 
Nevertheless,  its  beneficent  action  may,  under  favoring  conditions,  be 
taken  advantage  of  in  the  treatment  of  furniture,  hangings,  and  deco- 
rations, often  the  most  troublesome  objects  to  disinfect,  especially  in  a 
country  practice. 

Heat. — For  purposes  of  disinfection,  heat  is  employed  as  "  dry 
heat,"  /.  c,  hot  air,  and  "  moist  heat,"  /.  e.,  steam  and  boiling  water. 
Steam  is  employed  under  various  pressures  in  both  the  saturated  and 
superheated  conditions.  In  both  conditions  it  is  actually  dry,  although, 
as  very  commonly  understood,  saturated  steam  is  associated  with  the 
idea  of  moisture.  "  Wet "  steam  is  partially  condensed  saturated 
steam,  and  contains  suspended  particles  of  water.  The  temperature  at 
which  steam  is  formed  depends  upon  the  pressure  ;  and  whatever  the 
temperature  and  pressure,  as  ebullition  begins  and  proceeds,  the  water 
is  maintained  at  that  temperature,  and  is  converted  constantly  into 
steam,    in   which   the   heat  employed   becomes  latent.     Until  all   the 

1  Annali  dell'  istituto  d'is^iene  sneriraentale  della  reale  universita  di  Roma.  Ill .  d 
437.  ^ 

"  Centralblatt  fiir  Bacteriologie,  etc.,  XL,  p.  781. 
3  Arcliiv  fill-  Hygiene,  XYII.,  p.  177. 
*Ibid.,  LYII.,"p- 2P. 
-  Miinchener  medizinische  "Wochenschrift,  December  IS,  1906. 


564  DISIXFECTAXTS  AND  DISiyFECTION. 

water  has  become  converted,  the  resultine:  steam  is  said  to  be  safurated, 
since  any  vapor  in  the  presence  of  the  liquid  from  whicli  it  oripnates 
and  in  thermal  equilibrium  is  necessarily  saturated.  In  the  saturated 
state,  it  can  neither  do  work  by  expansion  nor  be  cooled  without 
undergoing  partial  condensation. 

When  saturated  steam  is  farther  heated,  its  temperature  rises,  and  it 
is  then  known,  as  sujjcrlicafcd ;  and  then,  having  a  temperature  higher 
than  the  condensing  point  corresponding  to  its  actual  density  and 
volume,  it  may  be  cooled  and  can  do  work  by  expansion  without  being 
condensed.  When  very  much  superheated,  it  behaves  more  and  more 
like  a  perfect  gas,  Avhile  saturated  steam  differs,  as  a  rule,  considerably. 
If  water  at  the  temperature  of  superheated  steam  be  mixed  with  the 
latter,  some  of  it  will  be  vaporized  and  taken  up ;  but  mixed  with 
saturated  steam  at  the  same  temperature,  no  such  action  will  occur. 

According  to  Rideal,^  the  tirst  recorded  experiments  in  the  sterilizing 
of  organic  matter  by  the  application  of  heat  were  those  of  Needham, 
made  prior  to  and  during  the  year  1743,  and  the  first  application  of 
this  agent  to  disinfection  on  a  large  scale  was  made  in  1831  by  Dr. 
Henry,  F.R.S.,  who  treated  infected  clothing  with  hot  air,  and  showed 
that  the  clothing  of  scarlet  fever  patients,  subjected  to  a  temperature 
of  200°  F.  for  two  to  four  hours,  would  not  propagate  the  disease  if 
worn  by  healthy  persons.  The  first  use  of  direct  steam  as  a  dis- 
infectant was  made  under  the  direction  of  Dr.  A.  N.  Bell,  U.S.N., 
in  the  case  of  the  steamer  Vixen  and  schooner  3fahone.s,  which  were 
infected  with  yellow  fever  while  on  service  in  the  Mexican  war  in 
1848.  Knowing  of  this  use  and  its  observed  results,  at  the  Quaran- 
tine and  Sanitary  Convention  held  in  Boston,  Mass.,  in  June,  1860, 
the  committee  recommended  that  "  steam  generators  and  steam  jackets 
or  vats  be  provided  for  the  disinfection  of  all  personal,  hospital,  and 
ship's  clothing  and  bedding,  together  with  such  other  infected  goods  or 
things  as  may  properly  be  subjected  to  high  steam  heat."  ^ 

In  1862,  according  to  Dr.  Bell,  the  U.  S.  Transport  Delaware  was 
disinfected  by  steam  at  the  New  York  Quarantine  Station  on  account 
of  yellow  fever,  this  being  the  first  disinfection  of  a  vessel  at  that 
station,  and  probably  the  first  at  any  of  the  port  quarantines.  Accord- 
ing to  the  same  authority.  Commander  Ralph  Chandler,  of  the  U.  S.  S. 
Don,  from  Santa  Cruz,  W.  I.,  reported  to  the  Navy  Department  that 
his  vessel  had  been  infected  with  yellow  fever  in  its  woi-st  form  (23 
cases  with  7  deaths),  and  that  he  had  disinfected  the  ward  room  and 
berth  deck  successfully  by  means  of  steam.  He  recommended  that 
vessels  destined  for  service  in  the  West  Indies  be  provided  with  means 
of  steaming  the  lower  decks  and  holds. 

Dry  Heat. — Dry  heat  is  much  less  effective  than  moist  heat,  even  at 
much  higher  temperatures  and  with  longer  exposure.  Thus,  air  at 
300°  F.  requires  three  or  four  times  as  long  to  accomplish  the  same 
work  as  steam  at  212°,  and  possesses  the  additional  disadvantage  of 

'  Disinfection  and  Disinfectants,  London,  1898,  p.  20, 
*  The  Sanitarian,  June,  lS97s 


rilVSK'AL   AdllNTH.  r)f>5 

injiiriiif^  f';i,l)ri(!,s  niid  oflicr  <(I)J(!c|,h  r-x posed  U)  it.  Mo.st  fahrir-s  of  voi- 
ton,  lliusii,  ainl  silk  will  vviliislaiid  an  <'X|»oHiir(!  of  Hivcral  lioiirn  f,o  dry 
heat  at  2.'>()"  l'\,  Imi(,  IxvoihI  this  |»i(iiil,  iw'uh'.wcx-,  of  irnj)air<'(j  ti^tiHile 
stnitif^th  1h  soon  niani(c,->lc(l,  Jwcn  at  002*^  ¥.  (150'^  C.j,  dry  lur-'it  wsw 
found  by  Koc-li  and  \Volll"lnin;('l  lo  he  not  always  cWi-cXw't',  even  after 
two  hours,  wliilc  l)oilin<r  water  and  strcaniinj^  sleatn  at  2\2''  V.  were 
focnid  to  produce  tlie  dcjsired  residts  in  a  v<!ry  sliort  time.  JJiit  Seliurn- 
bnrg^  has  shown  that  air  heated  to  212°  F.  will  d(!Htroy  the  common 
non-sj)orino;  pathot^cMiic,  haeteria  if  it  eonfains  55  to  05  relative  liurnid- 
ity.  '^riiis  condilion  can  he  secinv-d  hy  plaeiri}^  pans  of"  wat(T  within 
th(^  spacH!  wlu^re  the  iideelcd  (thjcels  ai'e  treated. 

Steam. — Althouj^h  steam  had  been  recommend(;d  and  used  for  pur- 
poses of  disinfection  us  early  as  1848,  and  althouj^h  Pasteur,  Tyndall, 
Cohn,  and  others  had  demonstrated  in  a  iniml)er  of  extensive  scientific 
invest iji;ati()ns  the  steriliziniz;  acition  of"  moist  lieat  on  ])Utref"active  bac- 
teria and  other  miero-or<2;anisms,  and  Tyndall  had  shown  the  necessity 
of  discontinuous  boilini^  for  the  sterilization  of  spore-hearers,  the  first 
investigation  of  the  action  of  steam  on  the  vitality  of  the  haeteria  as.so- 
ciated  with  infective  diseases  was  that  conducted  by  Kocli,  M'olff hiigel, 
and  their  associates,  the  results  of  which  were  published  in  1881, 
They  demonstrated  the  very  great  superiority  of  steam  over  much 
hotter  air,  and  showed  that  the  most  resistant  spores  are  destroyed 
within  a  few  minutes.  They  studied  its  effects  on  the  different  kinds 
of  articles,  such  as  clothing,  bedding,  furniture,  and  other  objects, 
which  in  sanitary  practice  may  require  to  be  disinfected,  showed  its 
applicability  to  all  excepting  a  limited  number,  such  as  furs,  leather, 
and  veneered  furniture,  and  led  the  way  to  the  installation  of  public 
disinfecting  plants  for  municipalities,  hospitals,  and  quarantine  station.s. 

A  variety  of  apparatuses,  botli  fixed  and  portable,  have  been  devised, 
and  their  use  is  steadily  on  the  increase,  not  alone  in  large  communities, 
but,  especially  in  Europe,  in  thinly  settled  districts  as  well.  For  the 
latter,  the  portable  apparatus  on  wheels  is  especially  adapted,  for  it  is 
beyond  the  limits  of  reason  to  expect  small  towns  in  which,  perhaps, 
infective  diseases  of  the  kinds  that  call  for  thorough  disinfection  are 
only  occasional  visitors,  to  establish  and  maintain  public  stations, 
whereas  a  number  of  such  communities  may  have  joint  ownership  in  a 
portable  machine  which  may  be  despatched  on  demand  to  the  point 
where  its  services  are  required. 

The  general  plan  of  the  stationary  and  portable  machines  is  essen- 
tially the  same.  They  consist  of  one  or  more  chambers  of  sufticient 
size  to  admit  objects  as  large  as  or  larger  than  a  rolled  mattress  ;  and 
a  boiler  for  the  generation  of  steam,  which  is  admitted  through  pipes 
controlled  by  valves.  The  most  approved  machines  are  so  constructed 
that,  after  the  objects  have  been  introduced  and  the  doors  closed,  the  con- 
tained air  may  be  withdrawn  and  a  partial  vacuum  of  about  20  inches 
produced,  the  object  of  which  will  be  explained  later.     This  is  pro- 

^  ]\liulioilungoti  aus  doni  kaiserliohen  Gesunilheits;iiuie,  I.,  p.  301. 
-  ijeitschiift  fiir  Hygiene  umi  lufeotionskraukheiten,  XLI.,  p.  167. 


566 


DJSJyFECTAXTS  AND  DISINFECTION. 


duced  best  through  the  agency  of  a  steam  jet  rather  than  by  a  pump, 
since  the  latter  is  much  slower  in  achieving  the  same  results  and  exerts 
no  disinfecting  action  on  the  germs  that  are  contained  in  the  air  with- 
drawn. The  best  machines  are  provided  also  with  a  steam  jacket, 
which  assures  a  more  uniform  diffusion  of  heat  in  the  chamber  walls 
and  a  lessened  opportunity  for  condensation,  and  a  non-conducting 
outside  casing  of  asbestos  or  asbestos-magnesia  composition,  to  prevent 
loss  of  heat. 

Stationary  apparatus  is  usually  so  placed  that  the  receiving  and  dis- 
charging ends  of  the  chamber  open  respectively  into  rooms  having  no 
direct  communication  ^vith  each  other,  as  shown  in  Fig.  95,^  which  is 
the  ground  plan  of  the  first  public  station  installed  in  Berlin,  G^  being  the 

Fig.  95. 


Ground  plan  of  public  disinfecting  station. 

room  into  which  infected  material  is  brought  from  the  receiving  platform 
L  or  store-room  J"  and  loaded  into  the  trucks  6,  6,  6.  These  are  pushed 
into  the  steam  chambers  a,  a,  a,  the  doors  of  which  are  then  securely 
closed.  After  the  operation  of  steaming  is  completed  the  trucks  are 
drawn  into  the  room  G^,  from  which  the  materials  may  be  taken  to  the 
discharging  platform  if  or  store-room  H.  A  is  a  repair  shop  and  store- 
room for  coal;  B,  the  boiler-room;  Cand  D  are  bath-rooms  and  water- 
closets  for  the  employees;  ^  is  a  store-room  for  chemicals  ;  and  K  is 
the  office,  from  which  the  work  can  be  directed  by  tele])hone,  being 
completely  shut  off  from  iJand  K,  a  full  view  of  which  is  possible 
through  hermetically  sealed  windows. 

In  operating  the  machines  of  the  latest  design,  as  soon  as  the  articles 
are  in  place  and  the  doors  fastened  (usually  by  turn-buckles),  the  air  is 

*  Merke-Vierteljahrschrift  fiir  gerichtliche  Medizin  und  iiffentliches  Sanitatswesen, 
XLV.,  p.  137. 


rilYSKlAI,   Ad H NTS.  667 

removed  from  IIk;  cliiuiilx!!-  by  mcuiis  ol"  a  ht<;um  jet,  wliidi  |»ro(liu;<jH  a 
Viioiiiitrj  of  iiboul;  20  iiwilics,  jiiid  tlicii  llio  Ht(;!irn,  iiikI'T  nliout  10-15 
pounds'  |n-(!s.surc  Ih  iidmil.lcd  very  nipldly.  Aflcr  I  .'<  tiiiimlcH' cxpfj- 
siin;  ili(!  s((^'i,m  jet  is  JiL^'iiii  ciuijloycd  to  scciiri'  n.  viu'iiiiin  of  20 
inchoH,  mikI  IIk^u  IIm'  !Vcsli-;iir'  iiilfl  is  opfiicd  ;iiid  ;i  ciirniiit  of  air  \h 
drawn  tliroii<;li  Liu;  <;iiiiml)(;r  foi-  about  10  miinitoH,  ai't(;r  which  tlie 
arl,i(ilcs  can  be  romovwl  and  (ixposod  to  the  :iir  to  cool  and  dry,  for 
wliieh  but  a  (cw  miniifcs  arc  rctjuin-d. 

Jj^rom  a  cliamber  not  provided  with  a  Mteam-jfit,  tiie  air  ean  be  re- 
moved in  great  part  by  turninj^  on  the  Hteam  and  allowing  tlie  air  to 
blow  off  from  time  to  tinu;  through  a  valve  open(;d  for  a  few  secoridH 
for  the  })urp()se. 

The  vahu!  of  the  removal  of  the  air  fi-om  tin;  eliamber  lies  in  the 
I'aet  that  the  confined  air  causes  great  delay  in  bringing  the  infected 
articles  to  the  desired  temperature,  and  interferes  much  with  the  pene- 
trating action  of  the  steam.  The  influence  of  air  was  overlooked  by 
Koch  '  when  he  asserted,  because  a  litei-flask  of  water,  exj)osed  for  '30 
minutes  to  steam  under  about  15  pounds'  pressure,  attained  a  tempera- 
ture of  but  85°  C,  instead  of  120°  C,  that  steaming  steam  was 
superior  to  steam  under  pressure.  The  necessity  of  removing  the  air 
was  demonstrated  first,  in  1(SS7,  by  ITeydenrei(;h,  who,  in  a  similar  ex- 
periment, but  with  the  air  removed  in  jKirt,  succeeded  in  attaining  the 
desired  result  in  5  minutes,  whereas  Koch's  specimen  was  o5  degrees 
away  at  the  end  of  30  minutes.  In  experiments  with  and  without  the 
assistance  of  the  vacuum,  reported  by  Doty ,2  self-registering  thermom- 
eters, placed  within  packages  of  newspapers,  sheets,  blankets,  and  rugs, 
showed  differences  ranging  from  nothing  to  a  100  degrees  (F.)  after  3 
minutes'  exposure,  the  higher  temperature  in  each  case  being  reached 
in  the  experiment  with  vacuum,  and  the  smaller  differences  occurring 
when  the  articles  were  loosely  wrapped.  With  longer  exposure,  the 
differences  were  considerably  smaller. 

Another  point  in  favor  of  the  vacuum  is  the  lessened  opportunity 
for  condensation  of  the  steam  in  the  interior  of  bundles  and  in  the 
interstices  of  fabrics.  It  has  been  found  to  be  advantageous  to  fill  the 
chamber  several  times  at  short  intervals  with  a  fresh  charge  of  steam, 
and  when  the  vacuum  appliance  is  at  hand,  the  time  required  for  this 
series  of  operations  is  lessened  materially. 

The  penetrating  power  of  steam  is  greatly  dependent  upon  the 
amount  of  pressure ;  the  lower  the  pressure,  the  less  the  penetration. 
With  machines  in  which  low-pressure  steam — a  pound  or  two,  for 
instance — is  employed,  penetration  is,  therefore,  very  slow  and  un- 
certain ;  and  when  bulky  articles,  such  as  rolled  carpets  and  bedding, 
are  treated,  the  results  are  likely  to  be  unsatisfactory.  For  such 
articles  it  is  agreed  generally  that  a  pressure  of  at  least  20  pounds  is 
none  too  great ;  but  for  smaller  articles,  such  as  clothing,  towels,  dress- 
ings, and  sponges,  a  pressure  of  10  pounds  is  ample.  But  whatever 
the  pressure  employed,  penetration  may  be  much  assisted  by  arranging 
1  Loc.  cit.  -  Xew  York  Assembly  Document  No.  58. 


568  DISiyFECTANTS  AND  DISlXFECTION. 

the  contents  of  the  ebauibcr  so  that  too  solid  })aeknig  is  avoided.  This 
is  secured  by  the  iuterpositiou  of  wooden  shits  and  gratings,  which 
leave  spaces  between  the  difiereut  layers,  through  which  the  steam  is 
distributed  more  readily. 

With  low-pressure  steam,  condensation  is  much  more  likely  to  be 
troublesome  than  when  high  pressures  are  employed  ;  but  ordinarily 
even  then  but  little,  if  any,  injury  is  suffered  by  the  most  delicate 
fabrics  beyond  a  slight  impairment  of  gloss  or  the  acquirement  of  a 
slight  yellowish  tinge  ;  but  woolen  garments  undergo  a  material  shrink- 
age in  size,  and  for  this  reason  the  method  of  exposure  to  air  heated  to 
212°  F.  and  containing  55  to  65  degrees  of  humidity  is  preferable. 

The  relation  of  pressure  to  temperature  is  shown  in  the  following 
table: 

Temperature. 
Pressure  (pounds).  Fahrenheit.  Centigrade. 

0  212  100 

5  228  109 

10  240  115.5 

15  251  121.5 

20  260  126.5 

40  287  141.5 

Steam  disinfectors  are  used  extensively  for  purposes  other  than  the 
destruction  of  disease  germs ;  they  are  most  useful  for  renovating  bed- 
ding and  in  the  treatment  of  clothing  infested  with  lice,  which  with 
their  eggs  are  killed  quickly  by  steam  at  any  pressure. 

Boiling  Water. — Articles  not  injuriously  affected  by  boiling  water 
may  be  disinfected  most  conveniently  in  the  hou.sehold  by  being  boiled 
for  a  few  minutes.  This  suffices  to  kill  all  varieties  of  bacteria  and 
the  most  resistant  spores  of  pathogenic  bacteria ;  in  fact,  all  organisms 
excepting  the  spores  of  a  number  of  non-pathogenic  bacteria  which  are 
not  destroyed  even  after  several  hours'  boiling.  This  method  is  adapted 
particularly  to  bed-linen  and  body-linen  and,  in  short,  to  all  washable 
fabrics  except  woolens.  It  has  the  disadvantage  of  fixing  stains,  so 
that  they  become  permanent ;  therefore,  sheets,  night-dresses,  and  other 
articles  stained  with  blood  or  excreta,  should  have  a  preliminary  soak- 
ing in  cold  water,  so  that  the  spots  may  be  removed. 

Although  but  a  few  minutes'  exposure  to  the  boiling  temperature  is 
quite  sufficient  to  destroy  all  pathogenic  organisms,  it  is  common 
through  abundant  caution  or  through  ignorance  of  the  thermal  death- 
points  of  these  bacteria  to  continue  the  boiling  for  a  half  hour  or 
longer.  One  who  recommends  pasteurization  of  milk  at  160°  F.  as  a 
certain  means  of  ensuring  the  consumer  against  all  danger  from  strep- 
tococci and  other  pus  organisms  and  the  exciting  causes  of  tuberculosis, 
typhoid  fever,  epidemic  diarrhoea,  diphtheria,  and  other  diseases,  is  not 
unlikely  to  insist  that  on  surgical  instruments  these  same  organisms 
require  for  their  destruction  much  higher  temperature  and  more  pro- 
longed exposure.  Yet,  the  most  resistant  pathogenic  organisms  known 
— anthrax  spores — have  been  proved  by  Sternberg  ^  to  be  incapable  of 
1  Infection  and  Immunity,  New  York,  1903,  p.  44. 


rilYSICAL    AdHNTS.  609 

r(!,slsf.ln^  1  riiimilcs'  boiling;  mid  :ill  kiiosvn  Moii-h-poririjr  piif liojr^-iiir! 
I)a(;l('i'i;i  pciisli  iil  KiO"  l'\,  oi' .-ihovc,  willilii  10  iriiiiiit<-s.  I'i.\|)cciiiiciit- 
iiifj;'  witli  ;i,  iiiiiiilxr  oC  .sli'aiiis  ofllw  iii'>  I  nv-i-tniil  oC  (lie,  |)yoj.'-ciiic  baf;- 
t(!ri;i — Hihi,j>liiili)r(icfi(H  aiircn.-:  —  I  lie  ihiiIidi-  (oiiiifl  not  one  that,  f,oijl'l  r«'- 
.si.st  l)()ilin<^  more  IIimii  a   iniiiiilc  ;iii(i  ;i   li;ili. 

Fit;'.  !)()  shows  a  sicfili/iii;;  liopjMr  devised  \>y  V.  A.  Wasliljiirii, 
M.  I).,  Sii|)eiMiit('iiden(<)('  (Ik;  Massacliiisetts  (leiiei'al  Hospital.  'I'liis 
h()p|)Cl' is  used  instead  o("  clieniieal  a<:;enl>  ('oi-  I  lif  disinfeet  ion  <((' typlioiil 
stools  and  urines. 

In  (M)ininon  daily  use  tlu;  ^ate  valve  of  (lie  liopper  i-;  open,  tlie  eover 
is  up,  and  the  steam,  of  course,  is  not  turneil  on,  WIm-u  it  is  to  Ix;  uwd 
for  sterili/in|L!;  juirposes  tlu;  nate  valv(!  is  closed,  the  l»(;<lpun  i.s  WJLshed 
out  hy  means  of  walei'  tJironL;;Ii  llie  niMici-  hose  attached  to  the  fau(!<.*t 
and  water  is  allowed  to  entcM-  ihe  hopper  to  the  line  marked  "li." 
ExperieiKH!  has  siiowii  that  this  is  the  lino  of  safety;  that  if  water  is 
intro(hieed  above  this  line;  v(!ry  viu^orous  boiliiijr  may  (;ause  the  eontetits 
to  overflow.  Steam  is  then  inti'odueed  into  the  double  jaekf.'t  by  oj)en- 
iui;-  the  valve  of  the  steam  pipe  inlet,  tlu?  cover  is  closed,  and,  with 
70  pounds'  ])ressure  of  steam,  boilini;;  is  almost  instantaneous.  When 
five  minutes  have  elapsed,  the  <:;ate  valve  is  opened,  the  cover  is  raised, 
and  the  liopper  is  flushed  out  by  means  of  the  hose  attached  to  the 
faucet. 

Bedpans  and  urinals  are  also  boiled  in  a  small  copper  tank  with  a 
steam  coil  iu  the  bttom. 

The  following  is  a  copy  of  the  sign  which  hangs  over  the  sterilizing 
hopper : 

''To  use  sterilizing  hopper,  close  valve  at  bottom  bv 
pushing  lever  toward  hopper  and  fill  with  water  to  level 
of  ring  painted  on  outside.  Open  steam  valve  and  heat 
for  five  minutes.     Flush  hopper  thoroughly  after  using." 

There  is  uo  obnoxious  odor  connected  with  the  use  of  this  apparatus, 
provided  the  cover  is  shut  from  the  time  boiling  is  started  until  a  short 
time  after  the  sterilized  contents   have  been  discharged  into  the  sewer. 

It  is  not  necessary  to  use  nearly  as  much  steam  j^ressure,  although 
a  lower  pressure  means  a  longer  wait  before  boiling  occurs. 

Cold. — Although  cold  is  a  very  efficient  antiseptic,  but  not  commoulv 
classed  as  a  disinfectant,  it  appears  to  have  destructive  power  over 
certain  pathogenic  bacteria,  but  none  whatever  over  certain  others,  even 
when  extremely  low  temperatures  are  employed.  During  the  cholera 
epidemic  in  Germany,  in  the  winter  of  1892-93,  Uffelmann,'  experi- 
menting with  cholera  germs,  concluded  that  they  have  considerable 
power  to  withstand  cold  for  periods  varying  with  the  temperature. 
Renk-  placed  the  limit  of  endurance  in  ice  at  8  days.  Inoculated 
\vater,  containing  620,000  per  cc,  was  frozen  at  — 9.6°  C.  and  kept  at 
that  temperature  for  39  hours  ;  the  ice  was  then  melted  and  tested,  and 

1  Berlinor  kliniscbe  "Woclienj^orift,  180.>,  Xo.  7. 
■•^  Fortsclu-itte  der  Mediciu,  May  15,  1893. 


570 


DISINFECTANTS  AND  DISINFECTION. 

Fig.  96. 


ja 


/CALCOFiKiCHCX 


LEGEND.  <; 

"A"=JTEAM   PIPE, 
INLET  ^- OUTLET. 
B"-  >5EWER.Te.AP 
'C'=  dATE  VALVE. 
'D'"-- FLEXIBLE  TUBE 
•E''=  WATEB  J-UPPLY. 
T'=VAPOB  VtNT. 
'G'  =  TtiAP  VENT. 
"l-l"-  PAINTED   LINE. 
"I"-  3EWER,  PIPE. 
;j'^  VALVE   HANDLE. 
'K  ■  COVEC. 

"U-  TI^,AP   CLEANOUT 
"M'-IilM  OF  WATE5^J"EAL 

DETAlLOPJ'EALj 


DRIP. 

RIM  ^  ^-pocicEr 


"TT 


COVtH, 


ELEVATION. 

'°"      '5.       r^.      nc  /  5AJE 

J-CALE  or  INCHEwT.  ^ 


sterilizing  hopper  used  at  Massachusetts  General  Hospital. 


CIIKMWAL  AdlCNTS.  571 

tho  r(!HiiliH  wen;  nc^ufivc  In  oilier  cxjxTirrKtiitK  in  wliittli  frcfzin^  \sn^ 
int('i-iMi|)t(;(l,  no  ora;aMisrns  were  found  wWcr  0  and  7  dayH.  Hut  W'lik- 
now  '  l<(^|)i  tli(!tn  alive  nior-e  llian  a  nionlli  af  — .'52.5'^  (J.,  and  ChrJH- 
lian  ■"  liUH  .shown  thai,  iuid<T  (livoiahle  eondilions  fliey  ean  live  longer 
than  4  niontliH. 

Th(!  typhoid  or<:;anisin,  as  is  well  known,  may  survive  the  aefion  f>f 
cold  for  a  loufj^  time.  'I'liis  was  well  shown  in  the  (txperienr-e  of  I'ly- 
moiit.h,  I*a.,  wiicre,  in  l.SSf),  a  most  d(!vastaling  epidemic  occurred  after 
the  thawing  out  of  an  actcuniiilatioii  of  tyj)hoid  e-xcrcta  situated  near  a 
brook  which  supplied  tlic  town  witii  drinking-water,  and  at  Ogdens- 
l)in-g,  N.  Y.,  where  an  oulhn^ak  was  traced  to  ic(!  that  had  heen  housed 
9  months  before. 

The  bacilli  of  diphtli(!na  have  been  proved  to  hv.  virulent  after  G 
months'  continuous  freezing,  sometimes  at — 25°  C.,  and  those  of  plague 
have  been  found  to  be  about  equally  resistiuit. 

The  ex(H'edingly  low  temperature  of  lifpiid  air,  — 312°  F.,  a[)pears 
to  have  no  elTecit  on  organisms  exposed  to  it  for  slu)rt  or  long  perio<ls. 
MacFadyen  and  Rowland  •' subjected  broth  emulsions  of  Ji.  lyphosim, 
B.  coll  communis,  B.  (Jiphthcri<v.,  B.  proteus  vulgaris,  B.  acidi  lactici, 
Sp.  cholcrcB  Asiaticcc,  >Sf.<ij)liiflococcus  pyogenes  aureus,  B.  anihracis 
(sporulating),  />.  j>/i()sj>h(>i-csc(')L!<,  a  sarcina,  a  saccharomyces,  and  unster- 
ilized  milk,  hermetically  sealed  in  fine  quills,  to  the  refrigerating  in- 
fluence of  liquid  air  for  7  days,  and  at  the  end  of  this  time  the  quills 
were  withdrawn  and  allowed  to  thaw.  Culture  experiments  proved 
that  the  vitality  of  the  various  micro-organisms  was  in  no  way  imjiaired. 
Every  species  grew  well,  the  ])hotogenic  bacteria  grew  and  emitted 
light,  and  the  milk  became  curdled.  Later,  Macfadyen  ^  exposed  the 
organisms  for  6  months,  and  in  no  case  was  there  any  appreciable  eflfect 
upon  their  vitality. 

CHEMICAL  AGENTS. 

The  list  of  substances  falling  under  the  head  of  chemical  disinfect- 
ants is  very  long,  and  includes  a  wide  variety  of  organic  and  inorg-anic 
compounds,  some  of  which  are  gases,  some  liquids,  and  others  soluble 
salts.  While  it  is  very  long — for  almost  any  chemical  substance  pos- 
sesses under  one  condition  or  another  a  certain  degree  of  bactericidal 
power — the  number  of  agents  which  may  be  regarded  as  trustworthy  in 
actual  general  practice  is  exceeding  small.  Many  substances  which 
have  a  high  reputation  for  efficiency  are  found  to  be  actually  worthless 
when  subjected  to  modern  methods  of  testing,  and  others  which  yield 
promising  results  in  the  laboratory  are  found  often  to  fail  when  used 
under  the  conditions  which  obtain  in  practice. 

The  undeserved  reputation  of  many  preparations  is  based  wholly 
upon  the  apparent  influence  which  they  have  exerted  in  limiting  the 
spread  of  infectious  diseases,  and  it  has  not  been  impaired  by  unex- 

iWratsch,  1S93.  Xo.  8. 

*  Aichiv  fiir  Hvsjiene,  LX.,  1909.  No.  1. 
3  The  Lancet,  April  ;21,  1900. 

*  Proceedings  of  the  Eoyal  Society,  LXXI.,  1902,  p.  76. 


572  DISINFECTANTS  AND  DISINFECTION. 

plainable  failure  to  accomplish  the  same  result  at  other  times.  Au  out- 
break of  au  iufectious  disease  occurs,  for  example,  in  a  boartliiig-school, 
aud  duriug  its  coutiuuance  a  number  of  bottles  of  some  proprietary- 
preparation  are  used  ;  no  further  cases  are  rei)orted,  and  the  credit  is 
given  to  the  disinfectant.  Six  montlis  later,  perhaps,  another  outbreak 
occurs,  and,  in  spite  of  the  use  of  the  same  agent,  it  spreads  and  the 
school  is  closed ;  this  result  is  not  charged  on  the  other  side  of  the 
account,  but  to  the  inscrutable  ways  of  Providence,  and  the  fame  of  the 
disinfectant  is  in  no  way  injured.  In  many  iustauces,  strength  and 
peculiarity  of  odor  are  the  only  qualities  necessary  for  the  building  up 
of  a  reputation  for  efficiency,  for  man  is  wont  to  attribute  potent  prop- 
erties to  unusual  things. 

]\Ianv  substances  have  undoubted  germicidal  power  over  certain 
forms  of  bacteria,  and  are  quite  inert  against  others  ;  some  will  kill 
every  known  form  under  some  conditions,  and  yet  may  wholly  fail  to 
affijct  bacteria  of  slight  resisting  power  protected  by  mucus  or  other 
matter,  or  may  even  be  rendered  inert  almost  immediately  by  chemical 
union  with  some  other  substance  accidentally  })resent. 

Chemical  disinfectants  act  in  various  ways  to  bring  about  the  de- 
struction of  bacteria.  Some  act  directly  upon  the  bacterial  protoplasm 
and  cause  its  coagulation ;  some  bring  about  changes  in  reaction  favor- 
able to  life  and  growth  ;  some  destroy  nutritive  material  by  chemical 
change  ;  some  take  up  all  the  available  oxygen,  thus  becoming  them- 
selves changed  in  character  while  depriving  the  bacteria  of  an  essential 
element ;  and  others  bring  in  such  an  excess  of  this  same  element 
that  the  bacteria  cannot  withstand  its  action.  Some  even  stinudate 
multiplication,  and  thus  act  only  indirectly  by  promoting  the  formation 
of  organic  compounds  which  exert  a  destructive  influence  upon  the 
organisms  by  which  they  have  been  produced.  The  disinfectant  power 
of  many  of  the  metallic  salts  depends  partly  upon  the  nature  of  the 
solvent. 

DifTerent  agents  produce  their  best  results  in  different  degrees  of  con- 
centration ;  thus,  while  one  may  be  efficient  in  5  per  cent,  solution, 
another  may  act  equally  well  or  better  in  0.10  per  cent,  or  even  weaker 
solution.  Some  agents,  as,  for  instance,  alcohol,  are  most  bactericidal 
at  some  one  point  of  concentration,  and  above  and  below  this  the  prop- 
erty progressively  diminishes.  In  applying  any  agent  whose  best  work- 
ing strength  is  known,  it  should  be  borne  in  mind  that  it  is  not  suf- 
ficient to  use  a  small  volume  of  solution  of  that  particular  strength,  but 
that  the  substance  itself  must  be  employed  in  such  an  amouut  that  it 
shall  be  present  throughout  the  whole  mass  in  the  proportion  required. 
Thus,  au  agent  which  is  effective  in  2  per  cent,  solution  cannot  be  used 
in  that  strength  to  disinfect  an  equal  bulk  of  infective  material,  since 
the  mixture  would  then  contain  but  1  per  cent. 

Non-metallic  Elements  and  Their  Compounds. 

Oxygen. — The  disinfectant  property  of  pure  air  is  due  to  its 
oxygen,  which  attacks  organic  matter  under  favorable  conditions  and 


NON-Mh'/rAI.LK!  KLI'.MKNTS  AND   'I'll Kill   COM fony DS.       573 

convcfis  il,  ill  <^rc:il  |»;iii  lo  ciiilxni  (lidxiilc  ;iii(l  \\;it<r.  \'yi>\i<\\^i-i\ 
aenitioii  is  ri^lilly  rc<;;ii'(lc(l  ;is  ;i  \;ilii;il)lc  ;i:-:-i-l;iiit  in  (li-iii("(<'li<iii,  lint 
it,  hIioiiM  iKil  he  ovci'lookcfl  lli;il  wlifii  iiil'icicil  irliji  (■(  -  jn-c  ex  |»o>«'(l  to 
moving  (MIITciiIm  oCoiildiidi-  ;iii',  llir\  ;iic  -iilij' 'led  ;i|  o  to  (lie  jtowcrCiil 
iiiMiiciK'c  (•("  ( lie  clicniiciil  r;i\-.s  dl"  siinlinlil  ;iii(l  In  the  jxtssihilil y  of  doic- 
catioii.  ().\Nncii  :icls  inosi  puw  (•rCiilly  in  tin'  iKiscciif  stale,  iiH  wlicii 
liborutcd  (Voiii  coniixiiiiKls  w  lidsc  (l<<'.,hi|i()>ili(tn  n'-nlt-  in  tlu;  CHrsijJC  <»f* 
the  ^!is  in  tJic  (Vcc  coiMlilion.  AinnnL;  lli<-f  r(iin|ionii(ls,  o/.tiiic,  (lie 
allotropic/  lurni  o("  oxygen,  (•ftntainin;^  in  ladi  inolcciilc  tlircc  atoriiH 
instead  of  two,  and  liydroo(Mi  peroxide,  may  lie  inentiftiied  as  eoiispir-ii- 
<)US  ('Xaniples  o("  oxi<li/inn'  aj^cnts  wliicli  pail  very  readily  witli  flif 
loosely  held  elenieiil. 

Ozone,  in  the  niiniile  aiiioiinls  in  which  it  exists  nornially  in  air, 
oan  hardly  he  refiarded  as  an  important  infliieiiee  in  practical  disinfec- 
tion. Prodnced  ai'tificially  by  means  o("  the  silent  electric  discharge,  it 
is  Ibund  to  he  possessed  of"  marked  haetei-icidjil  power,  and  has  heen 
reeomnicnded  highly  for  special  \vorl<,  particnlaily  in  ihe  sterilization 
of  drinkinjj^-water.  The  researches  of  a  niinii)er  of  investijratf»rs  have 
<lemonstrat('d  that  dry  bacteria  are  not  much  ailected  by  dry  ozone, 
but  that  in  a  moist  condition  they  ari'  '[iiickly  d(~ti-()ycd  by  >iiiall 
amounts. 

Krukowitsch,  quoted  by  Kowalkowsky,'  experimentintr,  in  1882, 
with  putrefactive  bacteria,  found  that  -'>  milliu:i'ams  of  ozone  jier  cubic 
meter  of  air  killed  fresh  l)acteria,  exposed  on  pa})er,  within  an  honr, 
and  8  milligraius  ])er  cubic  meter  sufficed  to  destroy  the  dried  organ- 
isms. Later  (1888),  Lukaschewitsch,  experimenting  with  B.  stihti/is, 
B.  anthraeis,  Sp.  cholei^ce  Asiatica;,  and  certain  putrefactive  bacteria, 
olitained  results  which  were  less  favoi-able,  luit  in  agreement  in  so  far 
as  they  demonstrated  the  relatively  slower  action  exerted  on  dry  bacteria. 
Spores  of  B.  sr(btilh  and  B.  anthraci'i  in  a  dry  state  were  unaffected  by 
1.50  grams  of  ozone  per  cubic  meter,  and  the  comma  bacillus,  in  a 
moist  condition,  was  not  afiected  until  after  15  hours'  exposure  to  the 
same  atmosphere. 

Ohlmiiller^  employed  a  much  greater  strength,  namely,  15  grams 
to  the  cubic  meter,  and  conducted  the  air  through  distilled  water,  in 
which  bacteria  were  suspended.  Water  containing  anthrax  spores  was 
sterilized  in  10  minutes  by  89.9  milligrams  of  ozone;  and  contain- 
ing millions  of  typhoid  and  cholera  germs  to  the  cubic  centimeter, 
in  2  minutes  by  less  than  20  milligrams.  River-water  and  sewage 
were  found  to  be  much  less  aftected,  but  with  only  moderate  pol- 
lution it  appeared  probable  that  in  ozone  might  be  found  a  cheap  and 
efficient  means  of  purifying  drinking-water.  Later  on,  a  number  of 
processes  were  devised  for  this  })urpose  and  carried  out  on  a  large  scale. 

In  the  hope  of  arriving  at  some  definite  conclusion  as  to  the  avail- 
ability of  ozone  as  a  room  disinfectant,  Kansome  and  Foulerton  ^  coa- 

1  Zeit^chrift  fiir  Hygiene,  IX..  p.  89. 

2  Arbeiten  aus  dem  kaiserliohen  Ge;<undheitsamte,  YUL,  1892,  p.  229. 

3  Public  Health,  July,  1901,  p.  6S-1. 


574  niSIXFECTAXTS  AND  DISINFECTION. 

ducted  a  series  of  experiments  in  whieli  large  quantities  were  used,  mixed 
with  air  or  with  pure  oxygen.  The  organisms  employed  as  tests  in- 
cluded B.  tuberculosis,  B.  mallei,  B.  cUplitherke,  B.  anthmck  (sporing), 
B.  typhosus,  B.  col'i  communis,  B.pijocyaneus,  ^.jL)neit??io7ii«;(Friedldnder), 
B,  prodigiosus,  Staph,  pt/or/cnes  aureus.  Strep,  pyogenes,  Micr.  candicans, 
Saccharomyccs  n/hicaiis,  Sarcina.  ventriculi,  and  an  anaerobic,  sporing, 
butyric-acid-Jbrmiug  bacillus.  The  results  demonstrated  that  dry  ozone 
has  no  appreciable  action  on  the  vitality  of  these  organisms ;  that  pro- 
longed exposure  does  not  diminish  the  pathogenic  virulence  of  B.  tuber- 
culosis in  sputum,  B.  mallei  or  B.  anthracis  ;  that  ozone  passed  through  a 
fluid  medium  containing  bacteria  has  germicidal  power  :  "  that  any  puri- 
fying action  which  ozone  may  have  in  the  economy  of  nature  is  due  to 
the  direct  chemical  oxidation  of  putrescible  matter  ;  and  that  it  does  not 
in  any  way  hinder  the  action  of  bacteria,  which  latter  are,  indeed,  in 
their  o^vn  ^vay,  working  toward  the  same  end  as  the  ozone  itself  in 
resolving  dead  organic  matter  to  simpler  non-putrescible  substances." 

Hydrogen  peroxide,  H2O2,  is  quite  stable  in  the  presence  of  some 
substances,  but  gives  up  its  loosely  combined  atom  of  oxygen  very 
readilv  to  others.  It  is  a  powerful,  odorless  oxidizing  agent,  prepared 
by  the  action  of  dilute  sulphuric  acid  on  barium  peroxide.  It  is  de- 
structive of  bacteria,  but  has  no  action  on  the  enzymes  of  the  digestive 
juices,  and  in  dilute  form  is  neither  poisonous  nor  irritant  in  the  human 
system. 

According  to  Alteh5fer,^  in  the  proportion  of  1  part  in  1,000  of 
water  containing  the  organisms  of  cholera  and  typhoid  fever,  it  pro- 
duces sterility  within  24  hours.  In  1  per  cent,  solution,  according  to 
Traugott,^  the  bacilli  of  diphtheria  and  typhoid  fever  are  killed  in  5 
minutes,  the  organisms  of  erysipelas  and  cholera  in  2  minutes.  Strepto- 
coccus pyogenes  in  10  minutes,  and  Staphylococcus  pyogenes  am-eus  in 
from  15  to  30  minutes.  With  half  this  strength,  the  typhoid  organism 
and  Streptococcus  pyogenes  are  destroyed  with  equal  promptness,  the 
cholera  and  erysipelas  organisms  in  5  minutes,  the  bacillus  of  diph- 
theria in  15,  and  Staphylococcus  pyogenes  aureuft  in  an  hour.  It  is 
believed  by  many  that  the  bactericidal  eifect  of  sunlight  on  organisms 
in  surface  waters  is  due  to  the  hydrogen  peroxide  produced  through  its 
influence,  but  the  experiments  of  Thrill  and  Wolf^  indicate  that  this  is 
not  true,  and  that  no  peroxide  is  formed. 

Chlorine,  botii  in  the  free  gaseous  condition  and  in  solution  in  water, 
has  very  powerful  disinfectant  and  deodorant  properties.  It  decom- 
poses the  offensive  gaseous  products  of  putrefaction,  such  as  ammonia 
and  sulphuretted  hydrogen,  and  in  the  presence  of  moisture  unites  with 
hydrogen,  thus  liberating  oxygen  in  the  nascent  state,  which  is  far  more 
active  than  atmospheric  oxygen  against  organic  matter.  In  the  dry 
state  the  action  of  chlorine  upon  dry  matter  is  slight  and  unreliable  ;  its 
disinfectant  action  on  dry  matter  is  but  slight  and  unreliable ;  but  in 

1  Centralblatt  fiir  Bakteriologie,  VIII.,  p.  129. 

"^  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XIV.,  p.  427. 

*  Archiv  fiir  Hygiene,  LVII.,  p.  29, 


(JIIICMIdAlj   AdKNTS.  576 

the,  |)r(!H(WU!(!  of  ii  niodfT.'ilc  ih'\ryiH'.  of  ;ilrno.'-|»li<Tifr  nioistiin',  its  fW\-('X  Ih 
c()iisi(l('i";il)l(',  its  Ih  hIiovvii  hy  its  hhs'icliinj^  .'ictioii  on  (ivfd  f';il)rif:.M.  TIk; 
('xli;uis(iv(!  rcsoiu'cli  of"  T'lsclicr  ;ui<l  I'rvtskuiicr  '  (htriKMotnitcd,  lio\vr;v«'r, 
tluit  (ililoi'iiK!  as  a  riiiiii<i;ii(,iiij^  uj;(!iit  is  iiiitni.stwortliy,  ancJ  that  its  apj)li- 
CJitioii  is  iitt(!ii(l(!(I  hy  serious  {iJHadvantagoH.  Tlio  tcHt-objcctH  (trnploycd 
(MiihraccMl  a  soincwiiat  widc^  variety  of  |)a(lio^f'iiir'  and  non-patlio^^r-nic 
of^aiiisMiH,  and  \wv.\\\  ('X|)os(!d  inidcr  dilfcrcnt  c/Miditions  of  moistun- and 
<lryn(!ss  for  varyinji^  |)('rio(ls  and  to  diffident  jx-rcenlaf^es  of  tli»:  ^as. 
The  results,  as  a  whole,  wen*  highly  unsatisfactory  from  a  practifjid 
standpoint,  on  acxioinit  <tf  I  he  ini|)ossibility  of  properly  regulating  ail 
tlu!  neo(!Ssary  conditions,  the  aliscnce  of  pcnefrating  power,  the  dctstriu;- 
tive  action  of  fahriiis  and  other  articles,  and  the  uneertainty  in  aehir^v- 
inu;  the  ohjecit  sou<i;lit. 

"  Chloride  of  Lime,"  Bleaching  Powder,  Chlorinated  Lime,  which 
is  a  combination  of  calcium  chlorid<!  and  hyj)oehlorite,  the  residt  of 
passing  (ihlorine  oyvx  dry  slaked  lime,  was  in  ns(;  as  a  disinfectant  and 
deodorant  for  a  long  tim(!  beibre  the  (levelo[)n]ent  of  the  science  of  l)ac- 
teriology.  In  1881,  in  the  course  of  the  first  real  investigatif)n  of  the 
properties  of  what  were  commonly  regarded  as  disinfectants,  Koch  ob- 
tained very  unsatisfactory  results  from  his  tests  with  this  agent,  which 
thereupon  to  a  great  extent  was  discarded.  In  188r>j  Sternberg,  then 
chairman  of  the  committee  of  the  Am(a-ican  Pui)lic  Health  Association, 
to  which,  in  1884,  the  subject  of  disinfectants  had  been  referred,  took 
very  different  ground  regarding  this  and  other  hypochlorites,  and  as- 
serted their  efficiency  in  no  uncertain  terms.  Since  then  the  matter 
has  been  the  subject  of  many  investigations  by  competent  observers, 
and  while  in  some  hands  the  results  have  failed  to  be  uniformly  favor- 
able, the  work,  as  a  whole,  has  sustained  the  position  taken  by  Stern- 
berg as  a  result  of  his  own  experiments. 

Woronzoff,  Winogradoff,  and  Kolesnikoff^  demonstrated  that 
anthrax  spores  were  killed  in  1  minute  by  a  5  per  cent,  solution, 
although  in  Koch's  experiments  they  had  been  found  still  active  at  the 
expiration  of  2  days.  Jaeger,^  in  1889,  concluded,  after  a  series  of 
tests  with  a  number  of  species  of  pathogenic  bacteria,  that  it  is  a  very 
efficient  disinfectant,  even  in  weak  solutions.  Nissen,*  in  1890,  after 
a  series  of  careful  experiments,  reported  that  the  organisms  of  cholera 
and  typhoid  fever  were  destroyed  in  5  minutes  when  the  material  in 
which  they  were  present  contained  0.12  per  cent,  of  the  agent,  and  in 
10  minutes  by  half  that  amount.  Anthrax  bacilli  were  killed  in  1 
minute  by  0.10  per  cent.  ;  Staphi/lococcus  pyogenes  aureus  and  Strepto- 
coccus erijsipelatis  in  5  minutes  by  0.12  and  0.15  per  cent.,  respectively, 
and  in  1  minute  by  0.20.  Anthrax  spores  of  low  resistance  were  de- 
stroyed in  15  minutes  by  5  per  cent,  and  in  70  minutes  by  1  per  cent. 
Very  resistant  spores,  capable  of  surviving  4  hours'  immersion  in  0.10 

1  Mittlieiliingen  aus  dein  kaiserlichen  Gesundheitsarate,  II.,  p.  228. 
'CentralblaU  fiir  Bakteriologie,  18S7,  p.  (i41. 
3  Ai'beiten  aus  dem  kaiserlichen  Gesundlieitsamte,  V.,  p.  247. 
*  Zeitschrift  fiir  Hygiene,  YIIL,  p.  62. 


5" 6  DTSIXFECTAXTS  ASD  DISIXFECTION. 

per  cent,  corrosive  subliinnto  aiul  10  mimites'  exj)()sure  to  streaming 
steam,  were  killed  in  4.5  luuirs  hy  5  per  cent. 

Klein,'  experimenting  with  sodinni  hypochlorite  in  10  per  cent,  so- 
lution (1.0  per  cent,  chlorine)  on  the  colon  bacillus,  anthrax  spores, 
Staphylococcus  pyogenes  aureus,  B.  enteriUdis  sporogenes,  and  tlic  bacteria 
of  tvphoid  fever,  cholera,  and  s\vine  fever,  found  that  all  \\-ere  killed  in 
20  minutes,  and  the  non-spore-bcarers  in  10.  In  one-tcntli  as  strong 
solution,  all  but  the  two  kinds  of  spores  were  destroyed  within  20 
minutes.  Duggan,-  working  according  to  Sternberg's  method,  reported, 
in  1885,  that  his  experiments  had  shown  "that  a  solution  containing 
0.25  per  cent,  of  chlorine  as  hypochlorite  is  an  effective  germicide,  even 
when  allowed  to  act  for  only  1  or  2  minutes,  while  O.OG  per  cent,  will 
kill  spores  of  B.  anthracis  and  B.  subtilis  in  2  hours." 

The  composition  of  "chloride  of  lime,"  or,  more  properly,  chlorinated 
lime,  and  its  mode  of  action,  are  matters  concerning  which  there  is  con- 
siderable disagreement.  The  substance  is  held  variously  to  be  :  (1)  a 
mixture  of  calcium  chloride  and  hypochlorite  ;  (2)  calcium  hyjiochlorite 
in  which  one  CIO  is  replaced  by  CI,  that  is,  Ca(C10)Cl,  which,  in  con- 
tact with  water,  is  broken  up  into  calcium  chloride  and  hypochlorite ; 
(3)  a  compound  of  calcium  hypochlorite  and  oxychloride  with  4H2O, 
formed  according  to  the  equation 

4Ca02H2  +  2CI2  =  CaO^Cl.,.  Ca302C].,4H,,0, 

which  is  split  up  in  water  into  calcium  chloride,  hypochlorite,  and 
hydroxide ;  and  (4)  a  compound  of  calcium  chloride  with  hydroxide,  of 
which  one  H  is  replaced  by  CI.  It  is  white  or  whitish  in  color,  and 
occurs  as  a  powder  or  as  friable  lumps ;  it  should  be  dry  or  nearly  so, 
and  should  have  no  more  than  a  faint  odor  of  chlorine,  which  element 
should  be  present  in  available  form  to  the  extent  of  not  less  than  35 
per  cent,  to  conform  to  the  requirements  of  the  U.  S.  P.  (British 
standard  =  33  per  cent.,  German  standard  =  25  per  cent.). 

AVith  keeping,  under  vai'ious  conditions,  chlorinated  lime  may  undergo 
decomposition  in  a  number  of  ways.  A  pasty  condition  or  a  strong 
odor  of  chlorine  is  evidence  of  partial  decomposition.  It  is  only  par- 
tially soluble  in  water,  and  its  aqueous  preparations  are  made  best  by 
triturating  the  requisite  amount  with  water  to  th(i  consistency  of  cream, 
and  then  diluting  to  the  desired  volume.  The  addition  of  acids  to  the 
solution  causes  evolution  of  chlorine,  but  the  carbon  dioxide  naturally 
present  in  the  water  or  absorbed  from  th«  air  decomposes  the  hypo- 
chlorite, yielding  calcium  carbonate  and  hypochlorous  acid,  the  latter 
of  which  breaks  up  into  active  oxygen  and  free  hydrochloric  acid.  (See 
Hypochlorous  Acid,  p.  577.) 

The  solution  known  as  the  "American  standard"  contains  6  ounces 
of  the  powder  to  the  gallon.  It  is  used  largely  in  the  disinfection  of 
discharges,  and  for  scrubbing  floors  and  other  woodwork.     A  weaker 

1  The  Lancet,  Nov.  26, 1896,  p.  509. 

2  Report  of  the  Committee  on  Disinfectanf?  of  the  American  Public  Health  Associ- 
ation :  Baltimore,  1885,  p.  12. 


NON-MKTM.I.K:  hLKMh'NTS  AND    Til  Kill   COM  I'OfJSDS.        577 

Koliii.ioii  is  ciiipldycd  (or  llic  I  icil  incut  nl'  inrcclcd  hcd-lincii  and  Wiiwli- 
;il)l(!  (;l()tliin^,  bill  i»ii  .iccoiinl  of  its  dcsl  iiic(iv(!  action,  flx-Hc  articlcH 
slioiild,  iillcr  ;t  not,  loo  lon^j  iinnni-ion,  l)c  wii-li'd  f lioroiijriily  in  plcnfy 
of  (Vdsli    vvaicif. 

Sodium  hypochlorite  solution,  otlicrwisc!  known  mh  fliloririatfKl 
Koda,  Lal)aria(|n('s  solntion,  ami  li(|nor  sochc  (tlilorata;,  i.s  "an  afjUcoUH 
solulion  <)('  scNcial  clilorinc  conipoiMidH  of"  Hodinm,  cliicfly  NaClO  and 
NaX'I,  and  conlainin}^  at  least  U.H  per  cent.  In'  wcMTrlit  f)f  availahlf; 
(^liloiinc, "  (U.S.  P.).  It  is  used,  hnt  not  so  extensively,  for  tlie  same 
pni'poses  as  clilorinaU^d  linic. 

Hypochlorous  Acid. — It  Ixinj^  not  iin|)rol)aljlo  tliat  <'liIorine  in 
solntion  in  water  exerts  its  disinCcetant  action  as  iiypoeiilorous  acid, 
Andi-ews  and  Orhon  '  tested  the  hacterit^idal  |)ropcrties  of"  preparations 
of"  the  pure  acid  and  found  tliein  to  be  of  the.  most  intense  character, 
anthrax  spores  Ixmiij^  very  (piickly  destroyed  hy  the  acid  in  extreme 
dilution,  wiien  they  were  suspended  in  pure  water.  Tiie  presence  of 
organic  matter,  however,  causes  the  very  unstable  acid  to  decompose 
very  rapidly,  so  that  whereas  l^fdjtlnjIiK-occnH  j)i/of/nifN  aurcua  in  dis- 
tilled water  was  killed  inniiediately  by  1  :  100,000,  in  veal  brotli  it 
was  killed  only  within  30  minutes  by  1  :  3000.  But  it  was  found  that 
the  germicidal  power  of  l)leaching  pc'iwder  solution  is  increased  by  the 
addition  of  a  weak  acid  (acetic  or  carbonic)  to  liberate  free  hypochlor- 
ous acid  (a  strong  acid  liberates  free  chlorine).  Thus,  a  saturated 
solution  containing  5  per  cent,  of  calcium  hypochlorite  required 
between  7  and  10  minutes  to  destroy  dried  anthrax  spores,  while  the 
same  solution  diluted  with  two  volumes  of  1.25  per  cent,  acetic  acid 
killed  them  in  less  than  1  minute. 

Iodine  has  powerful  disinf"ectant  properties,  but  is  more  suited  to 
the  purposes  of  the  operating  room  than  to  general  disinfection.  The 
experiments  of  Kinnamou  -  indicate  that  in  solutions  of  0.2  to  1  per 
cent,  it  is  far  superior  to  corrosive  sublimate — 1  :  1000.  The  latter 
required  15  minutes  for  the  destruction  of  streptococci,  while  iodine 
(2  :  1000)  killed  them  in  2  minutes.  Iodine  possesses  the  advantage 
over  corrosive  sublimate  that  it  neither  coagulates  albumin  nor  forms 
inert  comjiounds  M'ith  the  tissues,  and  in  effective  strength  is  non-toxic 
and  non-irritating.  Dannreuthcr  ^  considers  the  tincture  the  best 
means  of  sterilizing  a  dirty  wound,  and  an  excellent  agent  for  sterilizing 
the  skin  before  incision  and  for  limiting  the  extension  of  the  erysip- 
elatous rash. 

Bromine. — While  bromine  has  marked  disinfectant  properties,  it  is 
disagreeable  and  dangerous  to  handle,  and,  according  to  Kinnamon,^  is 
much  inferior  to  iodine  in  all  respects.  Its  use  in  the  puriticatiou  of 
water  has  not  been  markedly  successful.      (See  chapter  on  Water.) 

Sulphur  dioxide  easily  outranks  all  other  disinfectants  in  point  of 

1  Centralblatt  fiiv  Rakteriologie,  etc.,  I.  Abth.,  Originale,  1P04,  XXXV.,  p.  645. 

2  Journal  of  the  American  Medical  Association,  Aug.  26  and  Sept.  2,  1905. 

3  Medical  Eecord,  January  25.  1908. 

*  Journal  of  the  American  Medical  Association,  February  1,  190S,  p.  345. 

?7 


578  DISINFECTANTS  AND   DISINFECTION. 

\eT\gih  of  service,  its  use  dating  liack  to  very  ancient  times.  While  it 
has  undoubted  bactericidal  properties,  it  has  been  demonstrated  by- 
Koch,  AA'olffhiioel,  and  their  associates,  and  many  others,  to  be  wholly 
untrustworthy  lor  general  use,  and  although  still  very  extensively 
employed  by  public  sanitary  authorities,  is  rapidly  being  abandoned  in 
favor  of  more  efficient  and  reliable  agents.  It  is  purely  a  surflice  dis- 
infectant un(ler  conditions  nuxst  favorable  to  its  action,  and  even  then 
is  effective  against  only  a  somewhat  limited  number  of  species  of  patho- 
genic-bacteria. 

Sulphur  dioxide  is  a  colorless  irrespirable  gas,  produced  by  burn- 
ing roll  sulphur  or  "  flowers  "  in  an  iron  vessel,  ])laced  as  a  precaution 
against  fire  in  a  pan  of  water,  or  by  burning  sulphur  candles  or  carbon 
disulphide,  the  latter  in  a  lamp.  The  amount  of  sulphur  employed 
varies,  according  to  the  custom  of  the  operator,  from  1  to  6  pounds 
per  1,000  cubic  feet  of  air  space  ;  but  the  whole  amount  is  never  con- 
sumed, and,  indeed,  under  ordinary  circumstances,  combustion  ceases 
before  a  half  or  even  a  third  has  been  burned.  In  order  to  avoid  the 
necessity  of  burning  sulphur,  the  liquefied  gas,  contained  in  cylinders, 
is  employed  to  some  extent. 

In  the  absence  of  moisture,  the  action  of  sulphur  dioxide  on  even 
the  least  resistant  bacteria  is  practically  nil,  and  even  when  water  is 
evaporated  in  the  room  beforehand  or  at  the  same  time,  and  the  gas 
is  present  in  the  highest  percentage  possible,  the  exposed  organisms, 
whether  of  low  or  high  resistance,  are  likely  to  retain  their  vitality 
unimpaired.  It  is  true  that  some  experimenters  have  reported  great 
success  in  the  destruction  of  pathogenic  organisms  by  means  of  this 
agent,  but  the  adverse  reports  are  so  numerous  that  it  must  be  clear 
that  much  official  disinfection  by  means  of  it  is  worse  than  an 
empty  form  and,  by  reason  of  causing  a  false  sense  of  security,  a  posi- 
tive danger.  Even  were  it  an  efficient  disinfectant,  the  many  disad- 
vantages which  attend  its  use  would  suffice  to  make  it  undesirable  for 
general  purposes,  especially  in  view  of  the  fact  that  the  same  disad- 
vantages are  wholly  absent  in  other  processes.  In  the  presence  of 
moisture  and  air,  it  is  to  some  extent  oxidized  to  sulphuric  acid,  which 
corrodes  fabrics  and  other  objects ;  it  reduces  organic  matters  and 
destroys  organic  colors  ;  it  tarnishes  brass  and  silver  ware,  gilt  frames, 
and  other  objects  ;  it  leaves  a  disagreeable  odor  which  persists  for  days 
and  even  weeks  after  thorough  aeration  ;  bedding  and  other  articles 
become  impregnated  with  a  peculiar  highly  offensive  odor  which  renders 
their  use  unpleasant  and  even  impossible ;  and  it  has  such  little  power 
of  penetration  that  only  such  organisms  as  are  exposed  openly  are  likely 
to  be  affected. 

Where  sulphur  dioxide  is  the  official  disinfectant,  it  is  commonly 
enjoined  that  the  room  shall  be  cleansed  thoroughly  and  air  freely  ad- 
mitted for  some  days  after  fumigation.  The  necessity  of  this  supple- 
mentary process  is  in  itself  an  admission  of  the  inadequacy  of  the  main 
operation,  for  if  sulphur  is  an  efficient  disinfectant,  the  application  of 
soft  soap,  carbolic  acid,  hypochlorites,  and  other  agents  by  means  of 


SODIUM  CM: IK )\' ATI':.  579 

tho  Hf!rul)})iii<^-bniHli  mikI  cIoIIi.'^,  I  Ik-  removal  and  vc\)\:v'\u\r  of  wall- 
j)a,|)(!r,s,  ili(!  |)r(»<;(!,ss  oC  wliilc-waKliiiifr,  and  other  means  oC  renovation 
rc'eoiiiiriciidcd,  aro  attackH  aj^ainsl,  an  ima^dnary  evil,  (irant^-d  that 
th(!M(!  processes  are  nwiessary,  the  claims  of  snlj)hnr  dioxide  an  a  prae- 
t.ieai  disin(e(U;ant,  must,  (ail  to  tlie  gronnd  ;  if  n(*t  riocoHHary,  thf;y  hhould 
not  he  enjoiiu'd. 

Althongh  not  an  enicicnt  di.sinfeclanl,  snlpimr  dioxido  is  an  exceed- 
ingly valuable  .-ifj^cnt  for  i\\v.  destrnetioii  oC  mosquit^jes  in  houses  where 
malaria  and  yellow  fever  an?  rife  (see  eha|)ter  on  Tlie  Relation  of 
Insects  to  Human  Diseases)  and  of  rats  in  ships'  liolds  (see  chapter  on 
Naval  and  Marine  Hygiene). 

Sodium  Carbonate. 

Sodium  Carbonate,  or  "  Washing  Soda,"  used  in  every  household 
as  a  cleaning  a<i;eni.,  because  it  sa))onifies  grease  and  dissolves  albumin- 
ous substances,  is  a  substance  wlii(;h  |)ossesses  none  of  the  flisadvantages 
that  belong,  one  or  another,  to  almost  all  other  chemical  disinfectants. 
These  are — 1,  disagreeable  odor;  2,  poisonous  properties;  3,  high 
cost ;  4,  corrosive  action.  Simon,'  mindful  of  the  fact  that  the  hotter 
a  disinfectant  is  applied  the  better  the  results,  investig-.ited  the  action 
of  hot  solutions  of  this  substance  upon  some  of  the  commf)n  pathogenic 
organisms,  the  maximum  teuiperature  employed  being  140°  F.,  wliich 
marks  the  limit  which  the  hands  of  a  scrubwoman  can  endure.  He 
employed  the  agent  in  solutions  of  2,  5,  10,  and  20  per  cent,  in 
water  at  from  72°  to  140°  F.  against  staphylococci,  streptococci,  B. 
dlphthcrice  and  B.  tuberculosis  in  sputum,  dried  on  threads,  and  on 
articles  of  furniture  and  other  objects  likely  to  be  contaminated  with 
infective  matter. 

Below  132°  F.  none  of  the  solutions  exerted  any  immediate  destruc- 
tive action  against  B.  diphtheriw,  but  at  that  temperature  the  2  per 
cent,  solution  killed  it  in  2  minutes,  and  the  5  per  cent,  solution  in  1 
minute,  controls  in  distilled  water  kept  at  the  same  temperature  being 
still  capable  of  growth  after  15  minutes.  Staphylococci  were  resistant 
to  all  solutions  up  to  140°  F.,  atwdiich  temperature  they  were  killed  in 
5  minutes.  Streptococci  were  killed  more  quickly,  and  dried  tuber- 
culous sputum  Avas  sterilized  by  the  2  per  cent,  solution  in  5  minutes 
and  by  the  10  per  cent,  solution  in  1  minute.  Kurpjuweit^  employed 
2  and  5  per  cent,  solutions  against  colon,  typhoid  fever,  and  dysentery 
bacilli  at  75°,  95°,  and  122°  F.,  with  the'following  results  :  Typhoid 
fever  bacilli  were  killed  by  the  2  per  cent,  solution  in  1  minute  at 
122°  F.  and  in  5  minutes  at  95°  F.,  and  by  the  5  per  cent,  solution  in 
15  minutes  at  75°  F.  The  colon  bacilli  were  more  resistant,  the  2 
per  cent.Golution  requiring  5  minutes  at  122°  F.  and  1  hour  at  95°  F. 
The  dysentery  organism  was  killed  almost  immediately  by  the  2  per 
cent,  solution  at  122°  F.  and  in  30  minutes  at  95°  F. 

The  substance  does  not  injm-e  ordinary  woodwork,  furniture,  or 
linoleum  carpets. 

1  &itscluift  fiir  Hygiene  und  Infectionskrankheiten,  XLIII.,  1903,  p.  348. 
•  Ibid.,  p.  367. 


580  DISINFECTANTS  ylND  DISINFECTION. 

Lime. 

Lime,  quicklime,  or  calcimn  oxide,  has  long  been  knoAvii  as  an 
agent  possessing  great  power  in  destroying  organie  niattcM",  and  has 
been  used  extensively  from  very  early  times  in  conneetion  with  dis- 
posal of.  the  dead.  Treated  with  half  its  weight  of  water,  it  is  slaked 
to  a  dry  powder,  the  hydrate,  which,  mixed  with  sufficient  Avater, 
forms  the  well-known  '^  white  wash  "  commonly  used  for  disinfecting, 
sweetening,  and  brightening  the  walls  of  cellars,  rooms,  barracks, 
barns,  poultry-houses,  and  other  outbuildings.  Slaked  lime,  mixed 
with  four  volumes  of  water  to  the  consistency  of  cream,  forms  what 
is  commonly  known  as  "  milk  of  lime,"  which  is  used  extensively  in 
the  disinfection  of  excreta  and  privy  vaults. 

The  scientific  investigation  of  the  disinfectant  properties  of  lime  by 
Liborius,'  undertaken  at  the  instance  of  Koch,  demonstrated  its  value 
in  the  destruction  of  the  bacteria  of  typhoid  fever  and  cholera,  the 
former  of  which  were  found  to  be  destroyed  in  a  few  hours  by  lime- 
water  containing  0.0074  per  cent.,  and  the  latter  within  the  same  time 
by  0.024(3  per  cent.  Cholera  bouillon  cultures,  containing  munerous 
coagula  of  albumin,  such  as  would  be  present  in  cholera  discharges, 
thus  oifering  unfavorable  conditions  for  the  action  of  the  disinfectant, 
were  completely  disinfected  within  the  course  of  a  few  hours  by  0.40 
per  cent,  of  pure  lime  or  by  2  per  cent,  of  ordinary  crude  lime.  He 
recommended  the  employment  of  the  pure  dry  powder  or  of  milk  of 
lime  containing  20  per  cent,  thereof. 

Favorable  results  were  obtained  also  by  Kitasato,^  who  found  that 
the  same  two  species  Avere  destroyed  by  about  0.10  per  cent,  in  from 
four  to  five  hours.  Pfuhl,'^  carrying  the  experiments  somewhat  farther, 
recommended  the  use  of  milk  of  lime  of  20  per  cent,  strength,  freshly 
prepared  from  lime  of  good  quality,  for  the  disinfection  of  loose  dejec- 
tions, prescribing  that  it  should  be  added  in  sufficient  quantity,  with 
thorough  mixing,  until  the  whole  mass  is  strongly  alkaline  in  every 
part,  as  shown  by  testing  with  red  litmus-paper.  AVith  such  treatment, 
he  asserted  that  complete  sterilization  is  accomplished  within  an  hour. 
Extensive  researches  by  numerous  other  scientists,  although  diffisring 
somewhat  in  results  in  certain  unimportant  particulars,  have  confirmed 
the  conclusions  of  these  earlier  investigators  as  to  the  great  practical 
value  of  this  agent.  As  to  its  value  in  comparison  with  chlorinated 
lime,  there  is  disagreement,  some  authorities  favoring  the  one  and  some 
the  other,  but  practically  all  unite  in  the  opinion  that,  whichever  is  the 
more  efficient,  the  difference  is  slight. 

Of  great  practical  importance  in  the  use  of  any  disinfectant  on  a 
large  scale  is  the  item  of  expense.  It  happens,  fortunately,  that  this 
valuable  aid  is  exceedingly  cheap,  and  that  its  use  with  a  liberal  hand 
in  excess  of  the  recommended  amount  may  be  urged  without  promoting 
lavish  expenditure  of  money.     In  the  disinfection  of  stools  it  is  com- 

•■  Zeitschrift  fiir  Hygiene,  II.,  p.  15. 

*  Ibidem,  III.,  p.  404.  *  Ibidem,  VI.,  p.  97. 


ME'IWLIJC  SM/rs.  581 

monly  julviscd  <<>  iidd  :il,  K-.-isI;  im  c;fjii;il  volume  of"  llw  milk,  or  ^•v^'^\ 
twice  ;is  iniicli,  :iii<l  lo  ;ill<i\\  llic  iiiixdire  to  k(;iii<I  f'oi-  two  lioiirs  «ir 
loiiti;'er  l)e(oi"e  dual  <lis|)os:il.  In  iaiii|)  .'^aiiitaf ion,  il  is  iiiiieli  iiscil  wifji 
l!X(!(!iI('iit  results;  hut,  (or  llicir  allaiiiinent,  eoiistaiit  watelifiil  sujier- 
viHJoii  is  necessai'v. 

It  should  lie  Ixirne  in  mind  dial  air-slaked  lime  sliould  not  Ik* 
employed  in  I  lie  |)re|iaial  ion  of  the  milk,  and  that  the  latt<'r  on  stand- 
ing- loses  its  homogeneous  character,  which  should  he  restored  by 
stirrini;-  or  shakintr;  each  time  the  material  is  \\T-fi\.  'V\u'  milk  is 
most  powerful  when  (Veslily  prepared,  and  should  noi  he  used  wh<;Ii 
older  than  a  (ew  da\s,  unless  nmsl  earernlly  |irotee|((|  from  contact 
with  iiir. 

Metallic  Salts. 

Ferrous  sulphate  and  other  salts  of  iron  have  lonj;  been  used  ex- 
tensively, both  as  i2^('rmicides  and  deodorants.  AH  scientific  investi- 
<»;a,tions  of  the  disinfectant  properties  of  ferrous  sulphate  by  Kf)ch, 
Sternberg',  and  others  have  demonstrated  the  utter  w«)rthlessness  of  this 
agent.  Not  only  does  it  fail  as  a  germicide,  Init,  as  has  been  ])ointed 
out  by  Foote,'  it  has  also  no  claim  to  be  considered  as  a  deodonmt. 
Its  employment  in  this  capacity  not  infrequently  makes  a  bad  odor 
worse,  through  chemical  action  on  organic^  comjiounds  produced  in  the 
process  of  putrefac^tion. 

Ferric  sulphate  has  been  shown  by  lliecke  -  to  have  very  marked 
action  against  the  bacteria  of  typhoid  fever  and  cholera  in  acid  and 
alkaline  excreta,  wdien  added  in  an  equal  volume  of  5  per  cent,  solu- 
tion. The  disadvantages  attending  its  use,  however,  more  than  out- 
weigh any  considerations  which  may  be  urged  in  favor  of  its  employment 
in  place  of  other  more  efficient  and,  on  all  accounts,  less  objectionable 
agents. 

Ferric  chloride,  also,  has  some  claim  to  be  regarded  as  a  germicide, 
but  it  is  inferior  to  the  sulphate  and  is  open  to  the  same  objections. 

On  the  whole,  therefore,  the  iron  compounds  may  safely  be  passed 
by  in  the  practice  of  disinfection. 

Zinc  chloride,  like  ferrous  sulphate,  was,  until  subjected  to  the 
rigid  test  of  bacteriological  proof,  regarded  as  a  most  efficient  disin- 
fectant, and  to-day,  although  the  original  adverse  findings  of  Koch,  in 
1881,  have  been  confirmed  by  many  careful  experimenters,  it  is  still 
very  extensively  em])loyed,  and  in  many  places  is  prescribed  officially 
by  the  local  health  authorities.  Under  some  conditions,  it  does  succeed 
occasionally  in  destroying  some  forms  of  bacterial  life,  but  its  place  in 
the  list  of  actual  and  supposed  disinfectants  is  well  down  toward  the 
very  bottom.  It  is,  however,  somewhat  efficient  as  a  deodorant.  The 
sulphate  and  other  salts  are  equally  inefficient  as  disinfectants. 

Aluminum  chloride  is  the  chief  soluble  constituent  of  a  number  of 
extremely  popular  proprietary  disinfectants,  prescribed  by  practising 

'  Ainorioan  Joi;rnal  of  the  Meilioal  Sciences,  XCVIII.,  p.  o'29. 

-  Zeitsohrift  fiii-  Hygiene  und  Infeetionskrankheiten,  XXIV.,  p.  303. 


582  DISINFECTAyTS  AND  BISiyFECTION. 

physicians  and  bought  with  and  without  advice  by  the  laity.  Like 
other  ahiminum  compounds,  the  sulpiiate  and  the  ahims,  for  example, 
it  is  po\Yerfully  astringent,  even  in  dilute  form.  It  is  cheap,  has  no 
action  on  metallic  substances,  and  docs  not  stain  nor  otherwise  injure 
fabrics.  Its  disinfectant  action  is  slight,  and  herein  it  agrees  farther 
Avith  other  aluminum  compounds.  A  number  of  proprietary  prepara- 
tions, in  which  it  is  present  either  as  principal  or  auxiliary  ingredient, 
examined  by  the  author  with  Dr.  R.  M.  Pearce,^  were  found  to  be 
inefficient.  The  test-objects  included  cultures  of  B.  anthracis  and  B. 
typhosus,  typhoid  dejecta,  diphtheritic  membranes,  and  tuberculous 
sputa.  Each  of  five  preparations,  in  the  strength  recommended,  was 
subjected  to  10  tests,  and  their  proportions  of  successful  disinfection 
varied  from  20  to  70  per  cent.  Anthrax  bacilli  were  destroyed  by 
one ;  one  culture  of  B.  ti/phosus  was  killed  by  one,  another  by  all,  a 
third  by  two ;  one  typhoid  stool  was  unaffected  by  all,  a  second  was 
sterilized  by  all,  and  a  third  by  three ;  one  specimen  of  diphtheritic 
membrane  was  sterilized  by  four,  and  another  by  only  one ;  tubercu- 
lous sputum  was  affected  by  none. 

Potassium  permanganate,  well  known  as  a  powerful  oxidizing 
agent,  is  much  used  in  surgical  practice  and  in  other  lines  of  special 
work.  In  the  process  of  sterilization  of  the  hands,  however,  it  is  in- 
capable, as  the  author  has  shown,^  of  producing  the  results  for  which 
it  is  employed.  In  contact  with  organic  matter  and  oxidizable  mineral 
substances,  it  parts  very  readily  with  its  available  oxygen,  and  it  is  to 
this  element  that  whatever  disinfectant  property  it  has,  is  due.  It 
cannot  be  used  in  the  treatment  of  excreta,  because  of  the  very  large 
amount  which  would  be  required  to  produce  complete  sterility  of  even 
a  single  ounce  of  faeces ;  nor  can  it  be  employed  in  the  treatment  of 
clothing,  because  of  the  permanent  stains  which  it  produces. 

Copper  sulphate  in  weak  solutions  destroys  sporeless  bacteria  in 
great  variety  within  a  short  time,  but  in  practical  work  its  use  is  rather 
limited.  Although  it  appears  to  be  of  considerable  value  in  the  destruc- 
tion of  certain  forms  of  algal  growth  in  public  water  supplies,  the 
assertions  made  concerning  its  germicidal  value  in  the  treatment  of 
infected  waters  have  not  as  yet  been  substantiated,  and  in  the  light  of 
a  number  of  recent  investigations  it  would  seem  probable  that  they 
must  fall  to  the  ground.  It  has  been  recommended  strongly  for  the 
sterilization  of  faeces,  but  its  cost  and  other  disadvantages,  not  to 
mention  its  inferiority  as  a  germicide  to  other  cheaper  and  more  avail- 
able substances,  make  it  improbable  that  its  employment  will  ever 
become  very  extensive. 

Mercuric  chloride  or  corrosive  sublimate  is,  beyond  question,  the 
most  powerful  of  all  the  metallic  salts  as  a  disinfectant,  but  at  the 
same  time  it  enjoys  a  reputation  for  practical  efficiency  that  is  not 
wholly  deserved.  A  number  of  the  earlier  experiments  which  gave  it 
its  standing  led  to  conclusions  which  could  not  be  justified  by  later 

1  Journal  of  the  Boston  .Society  of  Medical  Sciences,  March,  1899. 

2  Annals  of  Surgery,  October,  1904. 


META  L  /.  I<;  SA  I.  TS.  683 

work  (iondiictcd  on  lines  of" f^i'cuLcr  uccu racy  and  with  improvr^d  Icclinic; 
but  wliilo  Kooli  and  otlions  hmw  fit  to  modify  tlicir  (»ri^inal  OKtirnattj  of 
its  f^ciKiral  (idicicncy,  it  wonM  appear  fliat  a  larfr''  propf»rfion  of  lliOHe 
wlio  liav(!  occasion  to  cni|)loy  ^crrnic.idcs  arc  iidlncnr-cd  more  hy  the 
original  tiian  by  tlu;  lat(!r  invcsti;^ations.  In  testing  its  disinfection 
pr()p(!rti(!H  against  anthrax  sponis  an<l  oilier  highly  nisistiint  organiHms, 
widely  different  resnlts  have  been  oldained  and  recorded  by  diffcTent 
ol)S(n'V(Ts,  but  th(!S(\  arc  explained  by  didV^renctes  in  nutrient  media, 
in  tcchnic,  and  in  viridence;  and  although  it  has  been  y)rov(Kl 
that  the  original  findings  were  fur  too  favorable,  it  also  has  been 
proved  that  as  a  germicide  it  stands  far  abf)ve  all  otlier  metal) io 
compounds.  But  it  should  be  understood  that,  under  conditions  wliich 
obtain  in  practice,  the  same  resnlts  as  are  obtained  in  laboratory'  experi- 
ments, made  with  broth  cnllni-es  and  spores  dried  on  silk  threads,  are 
not  always  to  be  expected.  In  the  treatment  of  tuberculous  s[)utiim, 
for  example,  the  innermost  bacilli  are  proteetx^d  from  contjiet  with  the 
disiid'cctant  by  the  coagulum  wlii(;h  forms  on  the  surface  of  each  sepa- 
rate mass.  Again,  in  the  treatment  of  other  organic  matter,  the  pos- 
sibility of  precipitation  as  albuminate  or  sulphide  or  other  insoluble 
compound  of  mercury  should  be  kept  in  mind. 

Precipitation  as  albuminate  may  be  prevented  by  the  addition  of 
about  5  parts  of  sulphuric,  hydrochloric,  or  tartaric  acid,  or  of  10  parts 
of  connuon  salt,  for  each  part  of  sublimate  in  1,000,  but  conversion  to 
sulphide  canuot  be  prevented,  if  the  conditions  necessary  for  its  forma- 
tion are  present.  In  the  disinfection  of  faces,  for  which  purpose  cor- 
rosive sublimate  is  sometimes  used,  it  is  evident  that,  with  the  usual 
strength  of  solution  employed,  the  whole  of  the  salt  must  frequently 
be  precipitated  in  one  form  or  another  very  early  in  the  process.  In 
household  disinfection,  its  corrosive  action  on  plumbing  must  be  con- 
sidered as  a  serious  drawback. 

Its  chief  use  in  surgical  practice  is  as  a  sterilizing  agent  for  the  skin, 
ligatures,  etc.,  the  strength  used  being  commonly  1  part  in  1000;  but 
weaker  solutions,  even  1  in  10,000,  are  also  employed.  Unfortunately 
the  element  of  time  seems  not  to  be  generally  regarded  in  the  practice 
of  disinfection,  and  instantaneous  germicidal  action  appears  to  be 
assumed  as  the  result  of  contact  of  the  agent  with  pathogenic  bacteria. 
In  order  to  determine  the  length  of  time  required  for  solutions  of  dif- 
ferent strengths  to  destroy  some  of  the  commoner  pathogenic  organisms, 
the  author  ^  conducted,  with  Dr.  Harold  AValker,  a  series  of  experi- 
ments which  led  to  the  following  conclusions  : 

(1)  Different  species  of  pathogenic  bacteria,  and  different  cultures 
of  the  same  species,  vary  very  greatly  in  their  resistance  to  the  action 
of  corrosive  sublimate.  (2)  With  some  species  resistance  is  diminished 
in  a  remarkable  degree  by  a  condition  of  dryness,  so  that  even  the 
1  :  10,000  solution  can  bring  about  sterility  in  a  very  short  time.  But 
some  species  are  not  materially  affected  in  this  respect  by  dryness. 
(3)  Corrosive  sublimate  in  as  weak  solution  as  1  :  5000  is  iuefi'ective 
^  Boston  Medical  and  Surgical  Journal,  April  23,  1903. 


584  DISINFECTANTS  AND  DISINFECTION. 

agiiinst  the  common  pathogeuie  bacteria,  iucludiuo-  the  pus  organisms 
when  they  arc  moist,  excepting  after  prolonged  contact.  Since  fifteen 
minutes'  contact  is  not  sufficient  for  the  destruction  of  JB.  coli  communis, 
B.  pyocyaneus,  and  Staph,  jyyogencs  albus,  in  the  moist  state,  or  of  Staph, 
pyogenes  aureus  whether  moist  or  dry,  the  use  of  this  and  of  weaker 
preparations  in  surgical  work  and  for  irrigation  and  similar  purposes 
should  be  abandoned.  (4)  The  1  :  1000  solution  is  very  slow  in  its 
action  on  some  of  the  commonest  of  the  skin  bacteria,  and  since  under  the 
most  favorable  conditions  more  than  ten  minutes'  contact  may  be  nec- 
essary for  it  to  kill  Staphylococcus  pyoc/cnes  albns,  it  should  not  be  relied 
upon  to  any  great  extent  to  ensure  sterility  of  the  hands  or  of  instru- 
ments. The  mere  dipping  of  the  hands  for  a  few  seconds  into  solutions 
of  this  strength  can  serve  no  useful  purpose,  but,  on  the  contrary,  can 
lead  to  much  harm  by  inducing  a  false  sense  of  security.  (5)  Corrosive 
sublimate  in  any  of  the  strengths  commonly  employed  is  a  much  over- 
rated disinfectant,  and,  under  the  best  of  conditions,  is  so  uncertain  in 
its  action  that  it  would  be  of  advantage  to  abandon  its  use  altogether 
in  surfer v. 

Mercuric  cyanide,  much  praised  by  some,  has  been  proved  by  the 
author^  to  be  far  inferior  to  the  chloride.  In  solution  of  1  :  1000  it 
fails  to  kill  Staphylococcus  pyogenes  aur-eus  in  3  hours,  but  is  far  more 
eifective  iignm&t  St.  pyogenes  albus,  B.  pyocyaneus,  and  B.  coli.  Tablets 
containing  2  parts  by  weight  of  borax  to  1  part  of  the  cyanide,  recom- 
mended for  use  in  the  proportion  of  1  tablet  to  a  quart  of  water,  were 
found  to  be  ineffective  against  St.  pyogenes  aweus  in  30  minutes, 
even  when  employed  in  4  times  the  amount  above  stated. 

Sublamin,  or  ethylenediamine-sulphate  of  mercury,  possesses  several 
advantages  over  corrosive  sublimate  in  that  it  is  non-irritating  to  the 
skin,  even  in  2  per  cent,  solution  ;  forms  no  precipitate  in  the  presence 
of  albuminous  material  or  soap  solution,  and,  when  used  in  the  pro- 
portion 3  :  1000,  acts  with  considerably  greater  rapidity  against  pyo- 
genic organisms  than  sublimate — 1  :  1000.  In  a  series  of  experiments 
conducted  by  the  author,^  while  a  3  :  1000  solution  failed  to  destroy 
Staphylococcus  pyogenes  aureus  in  10  minutes,  >S'^.  pyogenes  albus,  B. 
pyocyaneus,  and  B.  coli  were  killed  in  less  than  a  minute  and  a  half. 

Silver  Compounds. — In  addition  to  the  familiar  fluoride  and 
nitrate  a  considerable  number  of  organic  compounds  of  silver  have 
within  recent  years  come  into  use  in  various  special  fields  of  medical 
practice,  and  for  them  are  claimed  great  bactericidal  efficiency.  Ac- 
cording to  Marshall  and  Neave,^  those  which  are  powerfully  bacteri- 
cidal include  the  nitrate,  the  fluoride,  actol,  itrol,  argentamine,  albar- 
gin,  argonin,  ichthargan,  largin,  novargan,  and  protargol  ;  nargol  is 
much  inferior ;  and  argyrol  and  collargol  are  practically  inert.  With 
these  findings,  those  of  Derby  ^  are  in  substantial  agreement.     Argyrol 

1  Boston  Medical  and  Surgical  Journal,  January  14,  1904. 

^  Annals  of  Surgery,  Octolaer,  1904. 

3  British  Medical  Journal,  August  18,  1906,  p.  362. 

*  Transactions  of  the  American  Ophthalmological  Society,  1906. 


MI'lTALLK!  SALTS.  685 

and  (U)lliir^ol  wen;  foiiiHl  lo  Ix'  very  weak  in  action  ;  thf;  nitraU-  in  0.5 
to  2  IXT  (;<!iil,.  soliilioii  killed  Shii)/ii//()cor<:ii»  jji/of/rurM  (inrciiH  in  2  t«»  5 
niimilcs  ;  pivjiarijol,  "1  to  I  |i<r  ccul.,  in  :',  l<.  '.,  niinnlc^- ;  ailiarj.'-in,  10 
to  20  |)ci'  ccnl.,  in  2  lo  •')  niiniilc.s  ;  idit  liai^'aii,  0.1  to  1  jH;r  cent.,  in 
I  to  I  ininnlcs  ;  lar.^in,  10  to  20  per  (•••ril.,  in  2  t(»  o  niiinitcH  ;  arjijonin, 
5  j)(T  ('(Mit.,  in  .')  to  ()  rninnlcs.  Tlic  proportion  of  rnclallif:  hilvcr  in 
tIi('-S(u',oniponn<ls  appears  lo  hear  no  rekition  to  tlie  haeterieidal  elli<-ieney. 
Sodium  Aurate.  According'-  lo  V'erlioelT,'  this  eomjxHind  of  jrold, 
re(V)ni mended  lor  use  in  llu;  treatment  of  gonorrluud  oplitlialtnia,  lia.s 
remarkable  nvmiieidal  properties.  In  liis  hands  a  Holntion  repre- 
senting 0.5  per  (U'nt.  of  (chloride  of  gohl  destroyed  S/nj,Jii//ororruH  pif- 
(H/cufs  (inreuii  and  various  less  resistent  bacteria  within  J  minute,  and 
anthrax  spores  in  less  thai.i  -'>  minnt(!S. 

Mineral  Acids. 

The  minei'al  aeids  ])ossess,  in  dill'erent  degrees  of  dilnti(jn,  var^'ing 
disiideetaut  power  against  all  species  of  bacteria.  Jn  any  effective 
working  strength,  they  eorrod('  the  eominon  metals  and  destroy  the 
tensile  strength  of  all  kinds  of  fabrics. 

The  bactericidal  effect  of  gastric  juice  on  the  bacteria  of  cliolera,  dis- 
covered by  Koch,  was  ascribed  by  him  to  the  contained  hydrocliloric 
acid;  and  experimenting  with  bouillon  cultures  of  this  organism,  Kita- 
sato^  showed  that  0.1  o2  ]ier  cent,  of  hydrochloric  or  0.04!J  of  sulj>hnrie 
acid  produced  sterility  within  a  few  hours.  This  result,  so  far  as  it 
concerns  sulphuric  aeid,  was  confirmed  by  Stutzcr,^  who  found  that 
0.05  per  cent,  killed  in  15  minutes  the  organisms  suspended  in  dis- 
tilled Mater. 

The  experiments  of  Boer  '  showed  that  the  l)aeillus  of  tyjthoid  fever 
in  bouillon  cultures  was  destroyed  in  2  hours  by  0.07  per  cent,  of  hy- 
drochloric acid,  and  in  the  same  time  by  0.12  per  cent,  of  suli>huric 
acid.  The  cholera  organism  was  killed  by  smaller  amounts,  0.02  per 
cent,  of  each,  within  the  same  time  ;  the  bacilli  of  anthrax  were  but 
slightly  more  resistant  than  the  cholera  germ  ;  and  those  of  diphtheria 
succumbed  to  the  same  amounts  as  were  fiital  to  those  of  typhoid 
fever.  Ivanoff^  determined  the  amount  of  sulphuric  acid  necessary 
to  sterilize  sewage.  That  of  Potsdam,  three  times  as  foul  as  that 
of  Berlin  and  slightly  alkaline  in  reaction,  impregnated  with  cholera 
germs,  was  disinfected  by  0.08  per  cent,  in  15  minutes.  A  proprietary 
preparation,  containing  0.76  per  cent,  of  sulphuric  acid  and  nothing 
else,  tested  by  the  author,  sterilized  one  of  two  bouillon  cultures  of 
ty])hoid  bacilli  and  one  of  two  typhoid  dejecta  in  2  hours,  but  had 
no  effect  whatever  on  diphtheritic  membrane  and  tuberculous  sputum. 

1  Journal  of  the  American  ^redical  Association,  Januarv  27,  1906,  p.  270. 
»  Zeitscbrift  fiir  Hvdene,  III.,  ISSS,  p.  404. 
3  Ibid.,  XIV.,  1893,^ p.  9. 
*  Ibid.,  IX.,  1890,  p.  479. 
5  Ibid.,  XV.,  1893,  p.  86. 


586  DISINFECTANTS  AND  DISINFECTION. 

Carbolic  Acid  and  Cresol  Preparations. 

Carbolic  acid,  phenol,  phenic  acid,  obtained  chiefly  from  coal,  is 
a  substance  of  varying  degrees  of  purity  and  disinfectant  power.  The 
highest  grade  is  practically  pure  phenol,  but  the  commoner  qualities 
contain  variable  amounts  of  cresols,  xylol,  and  other  higher  homo- 
logues,  all  of  which  have  marked  bactericidal  properties,  and  tar  oils 
which  have  none.  In  the  opinion  of  many  authorities,  the  crude  acid 
is  superior  to  the  highest  grades  in  disinfecting  power  by  reason  of  the 
presence  of  the  cresols. 

Prior  to  Koch's  work  on  disinfectants  in  1881,  carbolic  acid  was 
believed  generally  to  be  one  of  the  most  powerful  of  germicides,  a  belief 
which  was  due  doubtless,  in  part  at  least,  to  its  peculiar  and  power- 
ful odor.  Koch's  experiments  with  anthrax  spores  led  him  to  the 
conclusion  that,  even  in  5  per  cent,  solution,  it  was  an  inefficient  agent 
against  highly  resistant  organisms.  Then  followed  a  number  of  in- 
vestigations by  others,  whose  conclusions  were  by  no  means  in  agree- 
ment. It  was  found  by  some  to  be  a  very  efficient  general  disinfectant, 
by  others  to  be  very  unreliable,  and  by  still  others  to  be  well  suited  to 
some  lines  of  work  and  not  to  others.  It  was  conceded  very  generally 
that  in  certain  respects  its  use  has  many  advantages  over  that  of  cor- 
rosive sublimate  and  other  metallic  salts  ;  that  it  is  not  destroyed  or 
precipitated  by  contact  with  albumin,  acids,  salts,  and  other  com- 
pounds ;  and  that,  even  in  weak  dilution,  it  destroys  many  of  the  com- 
mon pathogenic  organisms  very  quickly. 

Behring,  Sternberg,  and  others  found  it  effective  against  the  bacilli  of 
typhoid  fever  and  cholera  in  1  per  cent,  solution,  but  opposite  conclu- 
sions have  been  reported  as  to  its  action  against  the  former,  which  organ- 
ism is  said  to  flourish  in  mixed  cultures  in  the  presence  of  even  as  much 
as  5  per  cent.,  the  accompanying  species  being  destroyed.  For  the 
disinfection  of  tuberculous  sputum,  Schill  and  Fischer  ^  found  it  to  be 
reliable  in  5  per  cent,  solution  within  24  hours.  An  experiment  by 
the  author  and  Dr.  R.  M.  Pearce,^  in  which  this  material  was  treated 
with  17  different  preparations,  proprietary  and  otherwise,  including  a 
5  per  cent,  solution  of  carbolic  acid,  was  successful  with  this  agent  and 
4  others  after  a  2  hours'  exposure.  With  typhoid  stools,  diphtheritic 
membrane,  and  bouillon  cultures  of  the  typhoid  organism,  disinfection 
was  not  accomplished. 

Against  pus  cocci  and  B.  pyocyaneus,  the  1  :  20  and  1  :  40  solutions 
act  with  considerable  rapidity.  In  a  series  of  experiments  with  differ- 
ent strains  of  Staphylococcus  pyogenes  aureus  and  albus,  B.  pyocyaneus, 
and  B.  coli,  conducted  by  the  author,^  the  organism  first  mentioned, 
which  is  the  most  resistant  of  all  the  common  pathogenic  bacteria  to 
most  chemical  disinfectants,  was  killed  uniformly  v/ithin  2  minutes  by 
the  1  :  20  solution  and  within  4  minutes  by  the  weaker  preparation. 
All  of  the  other  organisms  succumbed  even  more  quickly.     That  the 

'  Mittheilungen  aus  dem  kaiserlichen  Gesundheitsamke,  II.,  1884,  p.  145. 
^  Loc.  cit.  3  Annals  of  Surgery,  October,  1904. 


t'AIiliOIJC  A<!ll)   AND    (niKSOL    I'llKI'A  liATIONS.  hHl 

t,yj)}i()i(l  l);u;illiis,  wliidi  is  oik;  oC  the  least  resistant,  of  tlie  ftonmion 
palJiogdiiic  l)ac.t(  ria  to  (dictiiieal  a^';<'nts,  can  vvillistarid  ]>r()\<)i\^c<l  <;oii- 
tact  with  5  \x'X  cA'ui.  carlxilic  ;Mi(|,  indicates  that  ccrf^iin  spcrjcH  rnay 
poKSOHH  cxc(3i)ti(>nal  rcsisti/if,^  power  against  atrtaiii  hactcriciclal  aj^critw, 
and  eni[)lia8izos  the;  importance  of  employing  in  experimental  wrjrk  the 
witlesL  |)ossil)l<'  variety  of"  haeterial  speeies  undctr  like  eonditions  before 
forming  un  opinion  ol'  tlie  value  oi"  a  given  snhstanee  for  gr-neral  dis- 
infe(!tant  purposes. 

The  j)resene(;  of  small  amounts  of  min(!ral  aeids  in  solutions  of  ear- 
bolic  acid  is  shown  by  Frilnkel  and  Laplace  to  he  very  lielpfiil,  hut  it 
is  to  he  home  in  mind  that  th(!  fornwr,  unassisted,  are  hy  no  means 
without  a  very  considerable  degree  of  germicidal  j)ower.  Jioth  authori- 
ties, however,  have  proved  that  mixtures  of  carbolic  and  mineral  acids 
are  more  bactericidal  than  either  ingredient  in  the  proportions  used,  and 
both,  and  No(;lit  as  well,  have  d(;monstratcd  also  the  superir)rity  of 
mixtures  of  the  crude  acid  with  mineral  acids  over  combinations  of  the 
pure  phenol  with  mineral  acids  in  the  same  proportions.  According  t.o 
Epstein,^  carbolic  acid  in  alcoholic  solution  is  more  powerful  in  the 
same  amount  than  in  a(pieous  solution,  which  finding  is  endorscnl  by 
Mincrvini.^  On  the  other  hand,  in  solution  in  oil,  according  to  Koch, 
it  loses  its  germicidal  property  completely.  This  is  because,  being 
more  soluble  in  oils  than  in  water,  it  does  not  leave  the  oil  to  penetrate 
the  bacterial  cell. 

The  experiments  of  Heller''  with  mixtures  of  carbolic  acid  and  the 
green  soap  of  the  German  Pharniacopfcia,  using  cultures  of  B.  typhosus 
as  tests,  indicate  that  the  soap,  which  possesses  but  slight  bactericidal 
power,  increases  that  of  phenol  in  a  marked  degree,  especially  when 
the  two  substances  are  present  in  equal  parts.  While  the  organisms 
were  killed  in  20  minutes  by  the  carbolic  acid  in  5  per  cent,  solution, 
they  were  destroyed  in  the  same  time  by  a  4  per  cent.  sf)lution  of  the 
two  agents  in  equal  parts  ;  that  is  to  say,  by  less  than  half  the  required 
amount  of  the  acid  alone.  The  reason  for  this  increase  in  power  may 
be  that  a  new  complex  compound  of  greater  bactericidal  power  is 
formed,  or  that  the  presence  of  the  soaji  increases  the  rate  of  dissocia- 
tion of  the  acid.  The  so-called  carbolic  powders  are,  as  a  rule,  inert 
mixtures  of  mineral  matter  and  waste  products  of  coal-tar  distillation. 
Their  strong  odor  appeals  to  the  imagination  and  promotes  their  sale. 

Cresols  (meta-cresol,  ortho-cresol,  and  para-cresol),  which  occur  as 
impurities  of  carbolic  acid,  and,  according  to  many  authorities,  are 
more  powerful  as  germicides  and  less  poisonous  to  higher  organisms, 
are  constituents  of  a  large  number  of  preparations  which,  within 
recent  years,  have  come  into  extensive  use.  The  cresols  are  closely 
related  to  phenol,  from  which  they  differ  in  that  CH^  replaces  one  H 
in  the  benzol  ring,  and  according  to  the  position  of  CHg,  we  have 
meta-cresol,  ortho-cresol,  or  para-cresol.  The  latter  may  be  made 
synthetically  from  pure  para-toluidin.     Cresols   are  practically  insol- 

1  Zeitscbrift  fiir  Hvsjiene  und  Infectionskranklieiten,  XXIA'.,  1S97,  p.  1. 

»  Ibid.,  XXIX.,  1898,  p.  117.  3  Archiv  fiir  Hygiene,  XLVII.,  p.  213. 


588  DISINFECTANTS  AND  DISINFECTION. 

uble  in  water,  but  solution  is  brought  about  by  soaps  auJ  by  cresol 
salts. 

Laplace  ^  was  the  first  to  dra\v  attention  to  the  fact  that  crude  car- 
bolic acid  and  strong-  sulphuric  acid,  mixed  together,  tbrni  a  c(Mn])ound 
soluble  in  water  and  of  high  disinfectant  po\ver.  He  reported  that 
the  mixture  in  4  per  cent,  solution  destroyed  anthrax  sj^ores  within  24 
hours,  while  pure  carbolic  acid  in  2  per  cent,  solution  had  no  effect 
wliatever.  The  first  extensive  study  of  tlie  action  of  cresol  was  made 
by  Friinkel,^  who  showed  that  the  mixture  of  suljihuric  acid  and 
crude  cresols  is  not  of  the  nature  of  a  new  compound,  but  that  each 
ingredient  exists  by  itself  and  exerts  its  own  action,  and  that  the  acid 
keeps  the  cresols  in  solution.  Hammer^  investigated  the  j^roperties 
of  cresols  dissolved  in  sodium  meta-cresotinate ;  here,  also,  no  double 
compound  is  formed,  the  salt  acting  merely  as  a  solvent.  Sodium 
salicylate  acts  equally  well  as  a  solvent.  The  various  preparations 
containing  cresols  and  solvents  of  the  same  are  recommended  highly  as 
substitutes  for  phenol,  on  the  ground  of  higher  bactericidal  power, 
lower  toxicity,  and  of  being  less  irritating  in  surgical  M^ork.  They 
may  be  diluted  at  will  with  water,  some  forming  milky  emulsions,  some 
clear  solutions. 

From  a  study  of  the  comparative  disinfectant  action  of  the  several 
cresols  and  of  several  other  preparations,  including  tri-cresol  (prepared 
synthetically  from  toluene)  and  phenol,  Seybold  *  concluded  that  of  the 
three  isomers,  meta-cresol  is  the  most  powerful,  and  that  the  cresols 
are  all  superior  to  phenol.  Tri-cresol,  which  is  40  per  cent,  meta-,  35 
per  cent,  ortho-,  and  25  ])er  cent,  para-cresol,  proved  to  have  double 
the  bactericidal  power  of  phenol  against  B.  pyocy emeus,  B.  jirodigiosus, 
and  Staphylococcus  pyogenes  aureus.  Another  preparation  of  cresol, 
made  by  another  manufacturer  and  examined  by  Schiirmayer,^  also 
proved  to  be  far  superior  to  phenol  and  to  a  number  of  the  more  com- 
monly known  cresol  compounds.  Experiraeuts  with  tri-cresol,  con- 
ducted by  the  author,  demonstrated  considerably  greater  bactericidal 
efficiency  than  is  possessed  by  phenol  or  any  of  the  cresol  preparations 
obtainable. 

Among  the  more  commonly  used  cresol  preparations  may  be  men- 
tioned the  following  : 

Liquor  Cresolis  Compositus  (U.  S.  P.). — This  is  a  liquid  soap  con- 
taining 50  per  cent,  of  cresols.  It  is  a  thick,  dark-brown  liquid,  mis- 
cible  with  water,  and  is  made  by  adding  350  grams  of  linseed  oil  to 
80  of  caustic  potash  in  50  of  water,  mixing  thoroughly,  and  then  add- 
ing 500  of  cresol,  and  finally  enough  water  to  make  1000  grams.  The 
experiments  of  McBryde^  show  that  it  is  very  considerably  superior  in 

1  Deutsche  medicinische  Wochenschrift,  1887,  No.  40. 
^  Zeitschrift  fur  Hygiene,  VI.,  1889,  p.  521. 
3  Archiv  fur  Hygiene,  XH.,  1891,  p.  359;  XIV.,  1892,  p.  116. 
*  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXIX.,  1898,  p.  377. 
5  Archiv  fur  Hygiene,  XXV.,  1896,  p.  328. 

®  Bureau  of  Animal  Industry,  United  States  Department  of  Agriculture,  Bulletin 
No.  100,  May  31,  1907. 


(JAni'.OLKI  ACID    AND   CILESOL    I'lLia'A  ILATIOSS.  r,80 

tlu!  <J(!.slriictioii  ol"  />'.  I.1JJ//1JMUH,  SbijiliijIdcorrtiH  'fyjiof/nwH  aumiH,  II.  jfi/'>- 
cjldncm,  and  />'.  ch.olr.nv.  hum  U)  cjirlxdic  arid  cm  ployed  in  tlu;  Kinu; 
(lihil-ioii.  iLs  j^crnil(ri(lal  (•(licicncy  is  j(rc:if<:i-  flu-  lii^^licr  tlic  hr.ilin^- 
poinl,  of  (li(!  ci-csol  it  (!(>iil;iins,  and  licncc  is  lowcsl.  wlicii  tlic  prepara- 
tion Ih  mad(;  wil.li  (»i'l:li()-crc,-,ol  ;  ;iiid  even  tlicn  ii  is  n<,'arly  oik;  .-ukI  oih;- 
lialf  tiin<\s  <i;r(!at(;r  iJian  tliiil,  ol"  c'lrholic  .-icid. 

Creolin. — TliiH  1,4  a  darU-hrow  n,  tliick,  alKaiinc;  li(piid,  said  fo  fontiiin 
about.  10  per  rent,  of  (M'csoIs,  held  in  solution  by  soap,  and  a  -rriiill 
amount  of  piicnol.  Ac(!ordin^  to  liidcal/  j>n'parati(jns  bearing  tlii.s 
name!  vary  greatly  in  composition  ;ind  properties,  even  when  coming 
from  tlu!  same  manufaeturor.  Mixed  with  water,  ereolin  forms  a  tur- 
bid, wliilisli  emulsion.  Specimens  examined  by  Jtideal  varied  gr(r:itly 
in  germicidal  (!ni(MeucA%  but  were  uniformly  su])erior  to  carbolic;  aeid  in 
equal  strength.  That  (sxamined  by  I  liinerman  ^  proved  t<j  be  inferior 
to  carbolic  acid  against  anthrax  bacilli  and  pus  cocci ;  but  Van 
Ermengem  •■'  found  it  very  (ill'ective  in  0  per  cent.  soluti<»n  against  the 
latter  and  typhoid  and  (;h()lera  organisms;  and  Laser  '  found  that  in 
the  same  strength  it  disinfects  dejectii  cora])Ietely.  Tlu;  results  obtained 
by  various  experimenters  arc,  on  the  wiiole,  very  conflicting;  but  the 
|)roduct  of  diiferent  makers  varies  greatly  in  chemical  composition,  and 
herein  lies  prol)ably  the  cause.  According  to  Rideal,''  its  bacterici<lal 
efficiency  does  not  dej)end  upon  its  content  of  phenol  and  its  homo- 
logues,  and  this  appears  to  be  most  probable,  since  the  favorable  results 
reported  for  5  per  cent,  solutions  can  hardly  be  due  to  the  fraction  f>f 
1  per  cent,  of  these  substances  present  in  this  dilution. 

On  account  of  the  variability  in  the  composition  and  bactericidal 
properties,  one  manutacturing  company  has  abandoned  the  name  and 
adopted  for  its  pi'oduct  the  name  Cyllin,  which  substance  is  said  by 
Klein  ^  to  be  more  than  twenty-seven  tiiiies  as  efficient  as  phenol. 

Lysol  is  a  brown  oily  liquid  containing  about  50  per  cent,  of  cresols 
with  neutral  potash  soap,  miscil>le  with  water  in  all  ]iroportions,  form- 
ing a  soapy,  frothing  liquid,  and  with  alcohol  and  glycerin.  Gruber^ 
found  a  2  per  cent,  solution  more  effective  against  pus  cocci  than  a  3 
per  cent,  solution  of  phenol.  Buttcrsack's  *  experiments  led  to  the 
same  conclusion,  and  demonstrated  also  its  suitability  for  the  treatment 
of  sputum.  In  the  hands  of  the  author,''  iiowever,  it  acted  less  quickly 
against  Staphylococcus  pi/ogcnes  aureus  and  albus  than  carbolic  acid  and 
tricresol  in  the  same  dilutions — 2.5  and  5  per  cent.  Vincent  ^°  found 
it  to  be  a  valuable  agent  for  the  disinfection  of  faeces  and  vault  con- 
tents. In  surgical  practice,  in  which  it  is  used  exclusively,  instances 
of  poisoning  through   absorption,   sometimes  with  fatal   results,   have 

1  Public  llealtli.  December,  1903,  p.  156. 

2  Centralhl-.itt  fiir  Pxikteriolosiie,  Y.,  1889,  p.  650. 

3  Ibid.,  VI I.,  1S90,  p.  75.       ^  ♦  Ibid.,  XII.,  1S92,  p.  232. 
s  Journal  of  tbe  Sanitary  Institute,  Nov.,  1903,  p.  425. 

6  Public  Health,  June,  190-i,  p.  566. 
^  Centralblatt  fiir  Bakterio''.02;ie,  XL,  1892,  p.  117. 
8  Arbeiten  aus  deni  kaiserlichen  Gesuniiheitsamte,  VIII.,  1892,  p.  369. 
^  Annals  of  Surpery,  October,  1904. 
10  Annales  de  I'lnstitut  Pasteur,  IX.,  1895,  p.  26. 


590  DISINFECTANTS  AND  DISINFECTION. 

been  numerously  reported.  Its  use  in  Berlin,  and  elsewhere  in  Ger- 
many, for  suicidal  purposes  has  become  so  widespread  as  to  cause  grave 
concern. 

Bacillol  is  a  product  of  the  distillation  of  tar,  and  contains  variable 
amounts  of  cresols  according-  to  source,  but  should  contain  not  less  than 
50  per  cent.  It  is  very  cheap  and,  as  may  be  inferred  from  its  content 
of  cresols,  is  very  efficient  in  5  per  cent,  solution, 

Saprol, — This  is  a  liquid  containing  20  per  cent,  of  mineral  oil  and 
80  per  cent,  of  crude  carbolic  acid.  It  is  lighter  than  water,  and  when 
thrown  into  it  diffuses  over  the  surface  in  a  thin  layer,  which  gradually 
yields  its  active  ingredients  to  the  strata  below,  which,  in  the  course 
of  a  day,  become  impregnated  to  the  extent  of  about  0.34  per  cent. 
In  this  strength,  according  to  Scheurlen,^  it  destroys  cholera  bacteria 
in  1  hour.  For  the  disinfection  of  privy  vaults,  Keller  ^  determined 
that  it  must  be  added  to  the  extent  of  1  per  cent,  of  the  entire  contents. 
In  mixtures  containing  5  per  cent.,  the  same  observer  showed  that  the 
typhoid  fever  bacillus  is  destroyed  within  a  few  minutes.  Pfuhl  ^ 
found  it  to  be  much  superior  as  a  general  disinfectant  and  deodorant 
to  carbolic  acid,  but  not  suited  to  the  treatment  of  vault  contents. 
Laser,^  however,  found  that  1  per  cent,  will  disinfect  faeces  and  urine ; 
and  Scheurlen  ^  reported  that  for  the  disinfection  of  vault  contents  but 
two  other  agents  are  comparable  with  it,  namely,  milk  of  lime  and  crude 
carbolic  acid. 

Solveol  is  a  concentrated  aqueous  solution  of  cresols  with  sodium 
cresotinate,  containing  more  than  25  per  cent,  of  cresols.  It  is  highly 
recommended  for  use  in  surgical  practice,  being  unirritating  and  much 
less  toxic  than  carbolic  acid.  According  to  Hammer,^  it  is  more  power- 
ful in  2  per  cent,  solution  than  creolin,  lysol,  and  carbolic  acid  in  2.5 
per  cent,  strength.  Hammerl  ^  also  found  it  superior  to  carbolic  acid 
and  the  other  cresol  preparations.  A  specimen  tested  by  the  author, 
however,  was  found  to  be  markedly  inferior  to  carbolic  acid,  tricresol, 
lysol,  and  bacillol  in  the  same  dilution,  requiring  15  minutes'  contact 
to  kill  pus  cocci,  whereas  none  of  the  others  failed  to  do  so  in  the  5  per 
cent,  solution  in  less  than  5  minutes. 

Sulfonaphtol. — This  is  a  coal-tar  product  of  variable  composition, 
widely  employed  in  surgical  practice  and  in  general  disinfection.  One 
specimen  tested  by  the  author^  failed,  in  5  per  cent,  dilution,  to  ster- 
ilize 2  typhoid  stools  and  2  typhoid  cultures  in  2  hours ;  and  another  ^ 
in  the  same  dilution  required  between  30  and  45  minutes  to  destroy 
Stajjhylococcus  pyogenes  aureus. 

1  Archiv  fiir  Hygiene,  XVIII.,  1893,  p.  35. 

2Ibid.  XYIII.,1893,  p.  57. 

3  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XV.,  1893,  p.  192. 

*  Centralblatt  fiir  Bakteriologie,  XII.,  1892,  p.  234. 

5  Archiv  fiir  Hygiene,  XIX.,  1893,  p.  347. 

6  Ibid.,  XII.,  1891,  p.  359. 

7  Ibid.,  XXI.,  1894,  p.  198. 

*  .Journal  of  the  Boston  Society  of  Medical  Sciences,  March,  1899. 
^  Annals  of  Surgery,  October,  1904. 


ALCOHOL.  691 


Alcohol. 


OnliiKuy  ;i1(v»1k)1  Iimm  lon^  Ix-cii  used  ,'ih  a  y^rnsorvativo  of  or^^'lnic 
inatcri.'ils  and  as  a  (lisiiifccfjiiit  in  .siir^rical  yr-.u-Ucc.  Its  fJisiiifc-r-tant 
projMirticis  were  slii<lic(l  lii-hl  l)V  Ivodi  ;iii(l  hi-  assooialx-H ;  and  in  liin 
olaboratn  n.'jxtrl,  Iki  sjx'aks  incitlcntnlly  oC  ;il)-<)|ii(c  mIcoIimI  and  Hh'rilizcl 
w;i,l,(ir  ;i,s  in  i\u\  saiiuf  class  ("  iiidincrciit  li(|iii<l- "j.  I  lis  (;x[K!riin(!nt,H 
s1i(»vv(hI  tliat  aiidirax  spon^s  wcn^  not  .'dlcfitcd  by  nearly  4  rnontlis' 
cxpostu'o  to  ;tl)soliil('  nlcoliol,  and  to  50  and  .'>.'*  per  cent,  alfoliol. 
Sonu!  years  after  l<'iirl)rin<!;er  reeotnrnended  tlie  u.se  of  aleoliol  for  tlio 
removal  of  fattv  matters  from  the  skin  in  j)roparin^  tlie  hands  for  Ki]r- 
fijical  work.  lieinieke'  announced  tliat  it  was  useful,  nf)t  only  in  this 
dire(d,Iou,  but  as  a  f2j(!rmieide  ;  and  1^'trusc'hky  ^  reported  that  in  his 
studies  of  infection  of  the  skin  by  pyogenic  coccii  he  had  found  it  wtsy 
to  produce  sterility  by  means  of  ether  and  alcohol.  Kronig,  ^  in  the 
same  year,  failiiii:;  to  destroy  dried  Staph j/Iocomus  pj/or/r.noi  av^reuH  with  00 
percent,  of  alcohol  in  5  iniuut(^s,  although  successful  in  less  time  with  moist 
organisms,  attributiul  the  difference  in  action  to  the;  astringent  influence 
of  absolute  alcohol  in  abstracting  the  moisture  of  the  skin  and  locking 
up  the  bacteria  in  the  shrunken  particles.  The  first  important  investi- 
gation of  alcohol  as  a  germicide  was  conducted  by  Epstein,  *  who,  work- 
ing with  /).  pi/oci/anriis,  B.  prodif/iosas,  and  Sfajjln/lococcus  pi/or/rnes 
aweufi,  dried  for  a  long  time  on  silk  threads,  and  then  exposed  to  six 
different  concentrations  of  alcohol  for  periods  of  3,  5,  and  10  minutes, 
was  led  to  the  conclusion  that  absolute  alcohol  is  devoid  of  germicidal 
properties,  and  that  considerably  stronger  and  weaker  solutions  than 
50  per  cent,  are  less  powerfully  germicidal  than  alcohol  of  that  per- 
centage dilution.  He  noted,  however,  that  a  preliminary  wetting  of 
the  threads  with  water  was  essential  to  favorable  results,  which,  how- 
ever, were  by  no  means  constant.  This  had  already  been  reported  by 
Ahlfeld  and  Vahle,''  who  found  that,  although  they  failed  to  destroy 
Staph ijhcoeem  pi/o(jcnes  aureus  with  strong  alcohol  in  o  minutes,  when 
the  threads  were  given  a  preliminary  wetting  in  water,  the  organisms 
were  killed  in  2  minutes.  Miuervini  ^  found  that  at  ordinary  temper- 
atures alcohol  and  its  aqueous  dilutions  are  powerless  against  s])ore- 
bearers,  even  with  long  exposure,  and  that  against  others  the  action  is 
variable,  according  to  the  amount  of  water  present.  The  best  results 
Avere  obtained  using  50  to  70  per  cent,  alcohol.  Bertarelli,^  employing 
25,  50,  70,  80,  and  99  per  cent,  alcohol  against  B.  p7-odiffiosus,  B. 
pi/oci/aneus,  Staphylococcus  pyogenes  aurcxi-s,  Sp.  cholera,  B.  pestis, 
B.  typhosus,  and  anthrax  spores,  all  dried  on  silk  threads,  concluded 
that  the  most  effective   strength  is  50  per  cent.  ;  and  Salzmedel  and 

*  Centralblatt  fiir  Gyniikologie,  1894.  No.  47.^ 

-  Zeitschrift  fiir  Ilvgiene  und  Infectionskrankheiten,  XVII.,  1894.  p.  59. 
3  Oentralblatt  fiir  Gynakologie,  1894. 

*  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXIV.,  1897,  p.  1. 
^  Deutsche  medizinische  Wochenschrift.  1896,  No.  6. 

^  Zeitschrift  fiir  Hvgiene  und  Infectionskrankheiten,  XXIX..  1898.  p.  117, 
7  II  PoUclinico,  October  1,  1900,  p.  4SS. 


592  BISiyFECTAXTS  AXD   DISINFECTION. 

Eisner '  placed  it  at  55  per  cent.  Yon  Brunn  -  found  that,  while  the 
vapors  of  51  and  74  per  cent,  alcohol  at  167°  F.  were  very  effec- 
tive against  sporulating  agar  cultures  of  anthrax  within  a  few  min- 
utes, those  of  95  per  cent,  alcohol  produced  no  result  at  the  end  of  an 
hour ;  and  he  concluded  that  the  water  present  must  play  an  important 
part.  Frauk,^  too,  found  that  the  vapors  of  90  to  99  per  cent,  alcohol 
and  of  dilutions  below  40  per  cent,  to  be  ineffective.  The  experiments 
of  Weigl,^  in  which  bouillon  cultures  of  cholera  bacteria  and  pus  cocci 
were  mixed  directly  with  different  amounts  of  absolut^i  alcohol,  and 
threads  impregnated  with  Staphylococcus  pyor/enrs  aurpuR  or  pus  were 
treated,  yielded  conflicting  results,  unfavorable  to  the  use  of  alcohol  in 
surgical  work. 

The  discrepant  results  of  the  above-mentioned  experimenters  and 
others  whose  work  has  not  been  cited  are  evidently  due  to  differences 
in  conditions,  both  of  the  agent  and  the  test-objects,  and  this  fact  led  the 
author  and  AValker^  to  test  the  resistance  of  B.  coll  communis,  B. 
pyocyaneus,  Staphylococcus  pyogenes  albus,  Staphylococcus  pyogenes 
aureus,  B.  typhosus,  and  B.  cUplitheria',  in  both  dry  and  moist  condi- 
tions, to  14  different  strengths  from  15  per  cent,  to  absolute  alcohol,  the 
periods  of  contact  ranging  from  1  minute  to  24  hours  (1,  2,  3,  4,  5,  10, 
15,  30,  and  45  minutes,  1,  2,  7,  and  24  hours).  The  results  of  these 
experiments  led  to  the  following  conclusions  : 

Against  dry  bacteria,  absolute  alcohol  and  ordinary  commercial  alco- 
hol are  wholly  devoid  of  bactericidal  power,  even  with  24  hours'  direct 
contact,  and  other  preparations  of  alcohol  containing  more  than  70  per 
cent,  by  volume,  are  weak  in  this  regard,  according  to  their  content  of 
alcohol — the  stronger  in  alcohol,  the  weaker  in  action.  Against  the 
commoner,  non-sporing,  pathogenic  bacteria  in  a  moist  condition, 
any  strength  of  alcohol  above  40  per  cent,  by  volume  is  effective  within 
five  minutes,  and  certain  preparations  within  1  minute.  Alcohol  of 
less  than  40  per  cent,  strength  is  too  slow  in  action  or  too  uncertain  in 
results  against  pathogenic  bacteria,  whether  moist  or  dry.  The  most 
effective  dilutions  of  alcohol  against  the  strongly  resistant  (non-sporing) 
bacteria,  such  as  the  pus  organisms,  in  the  dry  state,  are  those  contain- 
ing from  60  to  70  per  cent,  by  volujue,  which  strengths  are  equally 
efficient  asrainst  the  same  oro;anisms  in  a  moist  condition.  Unless  the 
bacterial  envelope  contains  a  certain  amount  of  moisture,  it  is  imper- 
vious to  strong  alcohol  ;  but  dried  bacteria,  when  brought  into  contact 
with  dilute  alcohol  containing  from  30  to  60  per  cent,  of  water  by  vol- 
ume, will  absorb  the  necessary  amount  of  water  therefrom  very  quickly, 
and  then  the  alcohol  itself  can  reach  the  cell  protoplasm  and  destroy  it. 
The  stronger  preparations  of  alcohol  possess  no  advantage  over  60  to 
70  per  cent,  preparations,  even  when  the  bacteria  are  moist ;  therefore, 
and  since  they  are  inert  against  dry  bacteria,  they  should  not  be  em- 

1  Berliner  klinische  Woclienschrift,  1900,  No.  23,  p.  496. 
HJentralblatt  fiir  Eakteriologie,  etc.,  XXVIII.,  1900,  p.  309. 
^Munehener  mcdizinische  Wochenschrift,  1901,  No.  4,  p.  134. 
*  Archiv  fiir  IIvKiene,  XLIV.,  1902,  p.  27.'',. 
^Boston  Medical  and  Surgical  Journal,  May  21,  1903. 


ESSENTIAL    OILS.  593 

[»Ioy(Ml  iit  ;ill  iiH  ;i  inciuiH  of  sffMiriii^^  ;iti  jiscpllc  coiidilion  of"  tluf  skin. 
Pr()vi(I(!(l  ilic,  sUin  huctcri;!  in  llic  (Iccim  r  parts  ran  he  hroiij^ht  into  roii- 
laci  wilJi  (liHiiiCcclaiils,  alcohol  (»('  (iO  to  70  jxt  ffiil.  sfrciij.'-lli  may  bo 
<l(;|)(',n<l('<l  upon  nsiiall\',  \)\\\  not  always,  tcxlcstroy  tlicm  within  o  rninijt<«. 

Witli  rojjjafd  lo  mixlni'c^  oC  njcohol  ;iii'l  <itli<r  <li-inf('<;t{intH,  the  evi- 
(h'n(^(!  is  sonicvvhat  conlliclin;^.  Mincixini  li.iinil  thai  .'»  per  ffiit.  of 
carholic  a^jid  in  stroiif^  alcohol  acted  wilh  nndiniini-lic<l  cncrL'v,  hut 
thai  (!orrosiv(!  suhliniatc,  nitrate  o("  silver,  and  olh(;r  aj^cnts  acted  with 
;j;rcat('r  power  the  less  the  amount  of  alcohol  present.  According  to 
Kj)stcin,  not.  oidv  carbolic  acid,  hut  al-u  corrosive  siihlimatc,  lysr*!,  and 
thyinol  anMnoi'e  powerlnl  in  50  percent,  alcohol,  hut  oi  her  a|:rcnts  .ire 
weaker.  Lenti  '  re|)orte(|  that,  while  0.1  j)er  cent,  of  corrosive  sub- 
limate in  absolute  alcohol  had  no  elTect  on  anthrax  spores  in  18  hours, 
0.1  percent,  in  i).S  ])er  cent,  alcohol  destroyed  them  in  half"  the  time. 
Similar  results  were  obtained  with  in  [nr  cent,  of  carbolic  acid  ;  in 
absolute  alcohol  it  was  powerless,  but  in  .'50  jxr  cent,  alcohol  it 
killed   them    in   4(S    hours. 

EndeavoriniLr;  to  find  a  preparation  which  would  kill  pus  org'anisms 
not  in  minutes  but  in  seconds,  the  author-  found  that  a  mixture  of 
640  cc.  of  commercial  alcohol,  60  cc.  of  hydrochloric  acid,  0.8  gram 
of  corrosive  sublimate,  and  300  cc.  of  water  w'ould  kill  Sfaphi/lorocats 
j)i/o(/en.cs  aureus,  (ilhus,  and  ciireus,  and  B.  pj/ori/nvrus  within  10 
seconds,  and  sterilized  ]mis  from  a  carbuncle  in  .30  to  60  seconds,  and 
2  other  specimens  of  pus  in  less  than  30  seconds.  Not  one  of  these 
active  agents  alone  in  the  same  percentage  strength  is  capable  of  pro- 
ducing these  results  with  such  rajiidity,  a  stronger  preparation  of  cor- 
rosive sublimate  requiring  not  less  than  15  minutes  to  destrf)y  the  most 
resistant  of  the  pus  cocci,  and  alcohol  in  its  most  effective  working 
strength  requiring  from  1  to  5  minutes.  Attempts  to  reduce  the  pro- 
])ortion  of  any  one  of  the  active  ingredients  of  the  mixture  and  retain 
the  same  rajiidity  of  action  were  unsuccessful,  but  reports  from  many 
who  have  employed  the  mixture  as  a  skin  disinfectant  agree  that,  in 
spite  of  the  amount  of  free  acid  present,  it  is  not  likely  to  cause  irri- 
tation. 

Essential  Oils. 

The  volatile  oils  have  long  been  known  to  possess  a  certain 
degree  of  antiseptic  power,  but  bacteriological  experimentation  has 
failed  to  demonstrate  that  they  are  very  active  as  germicides.  Those 
highest  in  favor  are  the  oils  of  peppermint,  eucalyptus,  and  thyme, 
which  contain,  respectively,  menthol,  eucalyptol,  and  fhi/mol.  The  latter 
was  in  somewhat  extensive  use  in  surgical  practice  prior  to  1870, 
It  is  only  slightly  soluble  in  alcohol,  ether,  chloroform,  and  fixed 
and  volatile  oils.  By  many  it  has  been  regarded  as  superior  to 
phenol.      Spencer  Wells  much  preferred  it  in  his  extensive  experience 

1  Annali  dell'istituto  d'Isjiene  sperimentale  della  reale Universita  di  Boma,  III.,  1893, 
p,  515. 

2  Annals  of  Surgery,  October,  190-i. 

38 


594  DISiyFECTANTS  AND  DISINFECTION. 

iu  ovariotomy.  According;  to  Behring/  however,  it  is  only  about  a 
fourth  as  powerful,  and  Sauter'-'  ranks  it  even  below  salicylic  acid. 
Eucalypiol  is  practically  insoluble  in  Mater,  but  soluble  in  alcohol  and 
other  solvents.  Concerning-  this  agent,  too,  there  is  much  diversity  of 
opinion,  some  regarding  it  as  vastly  superior  to  phenol,  others  as  much 
inferior.  Lister  jiraised  it  higlily.  Behring  found  it  to  be  about  equal 
to  thymol.  Jlcufhol  is  sparingly  soluble  in  water,  but  freely  in  alcohol 
and  other  solvents.  It  has  been  highly  praised  as  a  surgical  antisejitic, 
and  as  freely  criticised.  Omeltschenko^  ranks  the  oil  of  peppermint 
above  that  of  eucalyptus,  but  below  that  of  thyme.  All  three  are 
placed  by  liim  below  the  oils  of  cinnamon  and  cloves. 

Aside  from  the  conflicting  evidence  as  to  the  power  of  the  various 
volatile  oils,  their  cost  alone  would  be  sufficient  to  restrict  their  gen- 
eral use  as  disinfectants.  They  are  employed  considerably  in  various 
combinations  in  mouth  washes  and  in  a  number  of  decidedly  expensive 
proprietary  disinfectants,  one  at  least  of  which,  tested  by  the  author, 
was  found  to  be  efficient  in  the  sterilization  of  tuberculous  sputum,  one 
of  the  few  uses  for  which  its  manufacturers  made  no  claims. 

Soaps. 

The  evidence  concerning  the  bactericidal  influence  of  soaps  is  ex- 
ceedingly conflicting.  It  was  investigated  first  by  Koch,  who  asserted 
that  potash  soap  in  the  proportion  of  1  to  5000  has  a  distinct  inhibitory 
effect  upon  the  growth  of  anthrax  bacilli,  and  in  five  times  that  strength 
prevented  it  altogether.  In  1885,  Knisl,*  while  admitting  that  this  is 
true,  asserted  that  against  other  bacteria,  B.  typhosus,  for  example,  it  is 
inert.  In  1890,  Behring,^  experimenting  with  40  different  soaps, 
announced  that  their  disinfectant  power  Avas  found  to  be  considerable, 
and  concluded  that  it  is  dependent  upon  their  alkalinity  ;  but  Serafini « 
has  pointed  out  that  the  free  alkali  present,  even  in  concentrated  soap 
solutions,  is  too  small  to  exert  any  disinfectant  action  whatever.  He 
believed  that  neither  the  alkali  nor  the  fatty  acid,  but  the  combination 
of  the  two,  is  the  effective  agent;  but  it  must  be  remembered  that 
even  a  neutral  soap  is  decomposed  in  contact  with  ordinary  water  con- 
taining lime  and  magnesium  salts,  with  consequent  setting  free  of  the 
alkali  with  which  the  fatty  acid  was  combined.  Konradi  ^  believed 
that  the  majority  of  soaps  possess  a  fairly  strong  bactericidal  power, 
quite  independent  of  free  alkali  or  fatty  acid,  but  dependent  alone  upon 
the  added  perfumes.  He  tested  a  soap  in  the  various  stages  of  manu- 
facture and  found  that  the  bactericidal  power  did  not  show  itself  until 
the  perfume  had  been  added.     In  a  later  communication  ^  he  asserted 

1  Zeitschrift  fiir  Hygiene,  IX.,  1890,  p.  395. 
'■'  Centralblatt  fiir  gesammte  Therapie,  VI.,  p.  376. 
3  Centralblalt  fur  Bakteriologie,  IX.,  1891,  p.  813. 
*  Inaugural  Thesis,  Munich,  1885. 

5  Zeitschrift  fiir  Hygiene,  IX.,  1890,  p.  395. 

6  Archiv  fiir  Hygiene,  XXXIII.,  1899,  p.  369. 

7  Ibid.,  XLIV.,  1902,  p.  101. 

8  Centralblatt  fur  Bakteriologie,  etc,  XXXVII.,  Orjg.,  April  27,  1904. 


Sf)A  I'S.  606 

that  a  10  \)(\v  (^-ni.  solution  of  a  certain  pcrfMrticfl  HO'.vy  provf!<l  to  poK- 
Hess  a  germicidal  j)owc'r  equal  to  a  1  :  1000  .--oJution  of  corrohivc  Hiih- 
limate.  Kodct/  experimenting  willi  I  .iml  o  per  fcnf.  Holutionn  of  lianl 
Mars(^ill<'S  soap  (ion tain irifi;  no  free  :ill<:ili  wliatevcr,  with  ntaphylococri 
and  typlioid  haxriiii  a.s  tcsl-ohjccis,  ohiainrd  very  [)o.sitive  haclf-rial 
rcsiilis,  a  I  jx-r  (Mjnt.  solnlion  killing;  llu;  typhoid  hruiilli  within  a  few 
iniiuitcs,  a]thoM<>;h  against  staphylococci  the  acli(»n  was  very  hIow. 

Nijland,'"'  experitnenting  with  a  potash  soap  containing  47.2  per  cent. 
of  wat(!r  and  a  hard  so;i])  containing  1  ^.5  per  cent.,  found  (hat  the 
former  in  0.2  1  per  cent,  sohilion  kill(Ml  cholera  haciteria  in  10  minutes, 
and  the  latter  in  the  sam<'  str(Migth  was  not  wholly  elfective  in  1  o^  f)nt 
in  {)..'}0  ])er  cent,  solution  dcsstroyiid  th(;ni  within  I  mimile.  'J'he 
cholera  organism  was  used  by  Jollcs"  in  testing  iive  soaj)s,  all  of  which 
proved  to  he  in(>fTicient.  By  10  per  c(mt.  solutions,  th(!  bacteria  were 
destroyed  within  1  minute;  by  4  j)er  cent,  in  10  minutes;  by  2  \)vt 
cent.,  and  in  three  instances  by  1  per  cent.,  in  .'JO  minut<js. 

In  a  later  scries  of  tests  with  typhoid  fever  bacilli,  Jones'*  tried  an 
almost  neutral  soap,  containing  but  0.041  per  cent,  of  free  alkali,  and 
with  1  percent.,  sterilized  a  bouillon  culture  within  12  hours,  with  '.\ 
per  cent,  within  2  hours,  and  with  (J  per  cent,  in  lo  mimites.  lie 
showed  that  the  action  was  much  influenced  by  temperature.  The 
above  results  were  brought  about  at  temperatures  between  4°  and  8*^ 
C,  but  at  18°  C,  the  time  which  elapsed  before  complete  sterilization 
was  accomplished  was  about  double.  This  result  is  not  in  accordance 
witli  the  general  rule  that  disinfectants  are  more  active  with  incrwised 
temperature.  He  obtained  practically  the  same  results  \\\i\\  other 
varieties  of  bacteria,  and  reported  that,  because  of  its  action  on  the 
most  common  pathogenic  forms,  soap  is  especially  valuable  and  adapt- 
able for  precisely  the  kind  of  work  in  which  it  is  the  most  natural 
agent ;  that  is,  in  washing  dirty  and  infected  clothing. 

Serafini,^  however,  is  of  the  opinion  that,  in  the  ordinary  washing  of 
clothes,  soaps  exert  but  little  disinfection,  because  of  the  many  influ- 
ences, hardness  of  the  water,  for  example,  which  cause  a  diminution 
of  their  power.  He  recommends  the  avoidance  of  soft  soaps,  on 
account  of  the  presence  of  all  of  the  impurities  of  the  fats  and  alkali 
from  wdiich  they  are  made,  and  advises  one  to  distrust  the  ordiuar\^ 
colored  soaps,  which  are  likely  to  contain  rosin.  If  soap  is  the  sole 
reliance,  he  recomniends  using  it  in  strong  solution  at  80°  to  40°  C. 
(86°  to  104°  F.),  and  immersing  therein  for  a  number  of  hours  the 
articles  to  be  treated.  Even  with  long  soaking,  Beyer®  reports  unvary- 
ing failure  of  soap  against  pus  cocci  and  the  bacilli  of  cholera  and 
typhoid  fever  on  clothing  in  hospital  practice. 

Reithotfer,'  experimenting  with  common  soft  soap  containing  traces 

1  Revue  d" Hygiene,  April  20,  1905. 

^  Aieliiv  fiir  Hygiene,  XVIII.,  1893,  p.  335. 

3  Zeitschrift  fiir  Hvgiene  und  Infeotionskrankheiten,  XV.,  1893,  p.  460. 

<  Ibid.,  XIX.,  lS9o,^p.  130.  5  Loc.  cit 

6  Fortsohritte  der  Medicin,  1897,  No.  1. 

7  Archiv  fiir  Hygiene,  XXVII.,  1896,  p.  350. 


596  DISINFECTANTS  AND  DISINFECTION. 

of  free  alkali  aud  2.55  per  cent,  of  potassium  carboDate,  a  white 
almoud-oil  soap  perfumed  with  nitrobouzol  aud  coutaiuing  0.062  per 
cent,  of  free  alkali,  and  a  patented  potash  soap  containing  0.031  per 
cent,  of  free  alkali,  found  that  all  three,  even  in  1  per  cent,  solution, 
were  highly  efficient  against  cholera  germs  within  very  few  minutes, 
and,  therefore,  recommends  soap  as  a  practical  disiufectaut  for  clothing, 
furniture,  etc;,  during  epidemics  of  that  disease.  For  washing  body- 
and  bed-linc'U,  furniture,  wood-Avork,  floors,  etc.,  he  recommends  a  4  to 
5  per  cent,  soa]-)  solution  as  pr(^)bably  efficient  under  all  conditions  after 
fr(Mn  5  to  10  minutes'  contact,  but  suggests  cai'e  in  avoiding  the  com- 
mon commercial  soft  soaps,  Avhich  are  frequently  of  poor  quality. 
Experimenting  Avith  B.  typhosus  and  B.  coll,  he  proved  that  here  again 
the  soaps  possessed  a  high  degree  of  power,  though  much  larger 
amounts  were  necessary  than  in  the  case  of  B.  cJiokrce.  He  demon- 
strated that  a  10  per  cent,  solution  was  necessary  for  the  destruction 
of  the  typhoid  germs  within  1  minute,  and  that  a  5  per  cent,  solution 
required  from  3  to  10  minutes  according  to  the  kind  of  soap,  the  soft 
soap  being  slowest  in  action,  as  was  true  also  against  the  cholera  germs. 
Against  the  colon  bacillus,  the  action  was  still  slower  :  5  per  cent,  of 
the  almond  soap  required  15  minutes,  and  the  same  strength  of 
potash  soap  failed  to  accomplish  complete  sterilization  in  20  minutes. 
The  superiority  of  the  almond  soap  suggested  the  possibility  that  its 
increased  power  might  be  due  to  the  nitrobenzol  with  which  it  was 
perfumed,  and  experiment  showed  this  to  be  true.  Against  pus  cocci, 
all  three  agents  failed  completely  ;  Staphylococcus  pyogenes  aureus  was 
unaffected  by  20  per  cent,  solutions  at  the  expiration  of  more  than  an 
hour.  For  the  disinfection  of  the  hands,  5  per  cent,  solutions  were 
found  to  be  almost  immediately  effective  against  cholera  germs,  but 
longer  and  more  thorough  washing  is  recommended  in  typhoid  infec- 
tion. 

According  to  Mikulicz,^  tincture  of  green  soap,  the  German  officinal 
Spiritus  sapouatus,  containing  10.2  parts  of  potash  soap,  0.8  of  olive 
oil,  1  of  glycerin,  43  of  alcohol,  and  45  of  water,  is  admirable  in  undi- 
luted form  for  sterilizing  the  hands  in  surgical  work.  They  should  be 
scrubbed  for  5  minutes  with  the  preparation  in  its  full  strength.  In 
his  experiments,  Staphylococcus  pyogenes  aureus  was  killed  in  a  half 
minute  and  >S'.  p.  albus  in  a  minute. 

From  all  the  evidence,  conflicting  though  it  be  in  certain  respects,  it 
must  be  evident  that  in  soap  we  have  an  agent  which,  with  all  its  limi- 
tations, is  entitled  to  very  serious  consideration,  at  least  as  an  auxiliary 
in  complete  disinfection. 

Medicated  Soaps. — In  order  to  increase  the  disinfectant  properties 
of  ordinary  soaps,  various  agents,  including  mercury  compounds,  car- 
bolic acid,  and  the  cresol  preparations,  are  incorporated  in  them.  Com- 
pared with  ordinary  soaps,  these  preparations  appear  to  be  of  doubtful 
utility,  although  in  the  hands  of  some  experimenters  they  have  yielded 

1  Deutsche  medicinishe  Wochensclinft,  June  15,  1899. 


SOAI'S.  'i'M 

^()()(1  rcsiills.  Vnnu  ;iii  cxtcii-ivc  invest i^utioii  <»('  llifw;  ho;i|)H,  SyriicH  ' 
concJiidcd  lJi;ii,  foi'  ;ill  |»r;icli<',il  |)iir|)()scs,  imm.-(  oC  llicrii  pdSHChH  no 
ii(l(I(!(l  vmIik',  I)|iI.  Ili.it  III''  MMTciiry  hom^s  arc  ii-cCnl  in  (li-infl-<-tion 
of  tlid  li:ui<ls.  A  I  |»crcciil.  .^olnfioii  of  tlif  liiniodiflc  -o;i|)  killed  piis 
(!()<',ci  in  1  niinnlc,  while  iIk'  oilier  .m);i|.~  Kiijed  to  <|..  -o  in  •".  lioiir.H. 
Nljlniid '"  found  iluit  tli(!  iiddilioii  oC  disinleelants  to  soajts  inercji-mr.s 
(Jieir  nation  in  some  eiis(!S  and  diiuiiiislies  if  in  ollicr.s,  tlio  hifter  <;HjK;ci- 
mIIv  wlien  Ihe  added  siib.staiice  combinoH  with  the  ordinary  constitiiciibi. 
Aeeordinn'  (o  his  expeiirnentH,  tlu!  most  ])owei  In!  of  all  is  the  r/)rrosive 
snhlimale  soap,  which,  however,  has  less  power  than  tlu!  eorrespondinjr 
anionnt  of  suhlimatc  ah)ne.  In  O.OO;',  per  cent,  solution  it  kill«-<l 
(ihohu-a  bacilli  in  water  within  10  minntes.  Rideal ''  asserts  that  the 
(loiibl(!  iodide  of  potassiimi  and  niereiiry  has  stronger  gcrrnici(Jal 
])owcrs  than  corrosivt;  sublimate,  and  is  easily  incorporated  in  the  s*»ap 
sto(^k.  lie  recommends  the  admixture  of  1  to  '■)  parts  eat^li  of  mer- 
curic and  potassic  iodide  in  100  of  soaj).  "  Potassio-tncircuric  iodide 
has  the  advantage  of  being  comi)atible  with  strong  alkalies.  .  .  . 
Moreover,  it  does  not  prccij)itatc  albumin,  and  is  not  easily  reduced." 
Mc(-lintock  '  tried  to  make  an  antiseptic  s(Kip  in  which  th(j  mercury  salt 
should  exist  unchanged  and  active,  and  found  tlu;  doubh;  iodide  to  be 
the  most  available  agent  in  the  ])roportion  (jf  0.5  to  2.0  per  cent.  A 
solution  containing  1  per  cent,  of  the  soa])  was  found  to  be  fatal  to  pus 
cocci  and  cholera,  diphtheria,  and  typhoid  fever  bacilli  in  1  minute.  The 
soap  attacked  neither  nickel,  silver,  aluminum,  nor  steel  instruments, 
nor  lead-pipes,  and  did  not  coagulate  all)umin. 

Concerning  carbolic  acid  and  cresol  soaps,  the  weight  of  evidence  is 
clearly  in  su])port  of  the  assertion  that  they  are  in  no  way  superior  to 
common  soaps.  Many  contain  no  more  than  sufficient  to  make  them 
])ONverful  in  odor,  which  is  not  sufficient  to  confer  any  marked  bacteri- 
cidal powder.  Nocht  ^  calls  attention  to  the  solvent  property'  of  soap  on 
carbolic  acid,  showing  that  at  60°  C.  a  3  per  cent,  solution  of  soap 
will  dissolve  6  per  cent.,  and  double  that  strength  will  dissolve  12  \^QV 
cent,  of  carbolic  acid.  He  found  that  a  cold  solution  of  soap  containing 
1.5  per  cent,  of  carbolic  acid  was  fatal  to  pns  cocci  and  non-sporing 
bacteria  in  half  an  hour,  but  recommends  the  employment  of  3  per 
cent,  solution  of  a  5  per  cent,  soap  for  the  treatment  of  clothing, 
leather  articles,  and  other  objects.  Reithoflfer^  found  that  carbolic  acid 
is  weakened  by  the  presence  of  soap,  and  that  a  soft  soap  containing  4<'i 
per  cent,  of  lysol  was  no  more  effective  ag-aiust  pus  cocci,  B.  coli  and 
B.  typhosus^  than  ordinary  soaps,  and  was  much  weaker  than  a  solu- 
tion of  lysol  alone  in  the  same  lysol  strength.  Touzig ''  found  that 
various  creoliu  soaps  were  ineffective,  like  other  soa}>s  ctrntaining  cor- 
rosive sublimates  and  other  disinfectants,  because  new  compouuds  ai'e 

^  Bristol  Medico-Chirurgical  Journal,  Sept.,  1S99. 

'^  Loc.  cit. 

3  Disinfection  and  Disinfectants,  London,  1898,  p.  485. 

<  ]\Iedioal  News,  April  17,  1897,  p.  4S5. 

s  Zeitsohrift  fiir  Hygiene,  ^'II.,  1889.  \\  o'21.  ^  Loc.  cit. 

^  Gazetta  degli  ospedali  e  delle  cliniche,  1900,  ^o.  6. 


598  DISINFECTANTS  AND  DISINFECTION. 

formed   with   the  ordinary   coustitueuts   of  the  soap,  and  the  natural 
disinfeetaut  properties  of  the  same  are  thereby  diminished. 

Lysoform  is  a  liquid  perfumed  soap,  containing  about  8  per  cent,  of 
formaldehyde,  miscible  with  water  and  alcohol,  and  somewhat  expen- 
sive. AVhile  it  has  a  marked  deodorant  action,  by  virtue  of  its  formal- 
dehyde content,  its  bactericidal  effect  is  decidedly  slow.  Symanski  ^ 
found  that  a  2  per  cent,  solution  required  5  hours'  contact  to  destroy 
staphylococci  in  pus ;  but  Scydewitz,-  working  with  pure  cultures  of 
staphylococci,  streptococci,  B.  typhosu.'i,  B.  coli,  B.  dipldlierkc,  and 
other  bacteria,  found  that  a  3  per  cent,  solution  killed  them  in  less  than 
3  minutes,  and  a  4  per  cent,  solution  required  but  1  minute.  Anthrax 
spores  were  killed  by  a  5  per  cent,  solution  in  4  hours.  On  the  other 
hand,  Galli-Valerio  ^  found  that  a  5  per  cent,  solution  required  4  hours' 
contact  to  destroy  Staphylococcus  pyogenes  aureus,  and  a  3  per  cent, 
solution  was  ineffective  against  B.  coli  in  less  than  45  minutes.  It  is 
asserted  and  denied  that  it  is  non-irritant  to  the  skin  and  mucous  mem- 
branes. Weyl  '^  asserts  that  it  is  poisonous,  even  in  small  doses,  and 
that  to  the  gastric  mucous  membrane  it  is  corrosive. 

Paralysol  is  a  solid  cresol  soap,  said  by  JNieter  ^  to  be  able  to  destroy, 
in  3  per  cent,  solution,  staphylococci  in  less  than  1  minute,  and  in  1  per 
cent,  solution,  streptococci  and  B.  typhosus  in  less  than  2  minutes,  and  B. 
pyocyaneus,  B.  diphtherice,  and  Sp.  cJiolerce  Asiaticce  within  3  minutes. 

Metakaline,  a  compound  of  hard  soap  and  potassium  metacresolate, 
is  said  by  Wesenberg  ^  to  possess  such  germicidal  power  that  a  0. 5 
per  cent,  solution  will  destroy  the  common  pathogenic  bacteria  within 
a  few  minutes. 

In  the  disinfection  of  hands  by  means  of  medicated  soaps  it  should 
be  borne  in  mind  that  the  added  disinfectant  is  commonly  present  in  in- 
sufficient amounts,  and  that,  as  used,  the  soaps  form  a  very  weak  solu- 
tion, which,  in  the  time  ordinarily  given,  can  have  but  little,  if  any, 
effect. 

Formaldehyde. 

The  germicidal  properties  of  formaldehyde,  otherwise  known  as 
methyl  aldehyde  and  oxymethylen,  the  simplest  known  compound  of 
carbon,  hydrogen,  and  oxygen,  were  not  recognized  until  1886,  and 
were  not  put  to  practical  use  until  1891.  Formaldehyde  is  a  gaseous 
product  of  oxidation  of  wood  alcohol,  made  most  simply  by  passing  a 
current  of  the  alcohol  vapor  over  platinum  sponge  previously  heated  ; 
as  the  vapor  comes  in  contact  with  the  incandescent  platinum,  it  is 
oxidized  to  aldehyde  and  water.  (CH^OH  +  O  =  CHp  +  HjO). 
The  continuous  current  maintains  the  incandescence.  On  a  large  scale, 
it  is  produced  by  treating  the  alcohol  in  copper  tubes  containing  incan- 
descent coke. 

'  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXXVII.,  1901,  p.  393. 

'-'  Centralblatl  fur  Bakteriologie,  etc.,  I  Abt.,  XXXII.,  1902,  Orig.,  No.  3,  p.  222. 

3Therapeutisclie  Monatshefte,  XVII.,  1903,  p.  452. 

*  Miinchener  medizinische  Wochenschrift,  1905,  No.  27. 

^  Hygienische  Rundschau,  April  15,  1907,  p.  451. 

«  Centralblatt  fur  Bakteriologie,  Abt.  I.,  XXXVIII.,  No.  5,  p.  612. 


FORMA  iJ)/':in'nh\  699 

ForiMJildcliydc  is  .soliiMc  in  w.ilcr  ii|i  to  10  |)cr  cciif .,  ;iii(|  (rivets  a 
IKilltrul  Kollll.ioii,  Itiil  llii'  (•oiiiiiicici.il  |ii  (  |);ii;i(ioii-  ;iic  ii-ii;illy  KlJj^Jitly 
aciid  in  rvnvi'iow  (Vdin  liviccsoC  (oiinif  ;ni(|.  Ii  i-olniion  cannot  Im; 
H(,r()n^((r  llian  '10  per  cent.,  and  iiltcnipis  to  cone*  iil rale  il  or  fo  condonfiff 
tli(!  vapor  (',ans(!  il.  to  polynici'i/c  lo  a  wliilc  indi>linctly  rry.-tallinr-  holid, 
trioxymdliylcn  or  paiafoi  iniddrliydc  (( ';(n,;0.,j,  wliicli  is  almost  inw)lu- 
l)l<!  in  water,  nicHs  al.  171'  ( '.,  wlicn  ignited,  lairns  willi  a  liiiu-  flarnr;, 
bnt  wluMi  ^cnily  licah^d  in  an  open  dish,  is  conNcrtcd  a^'ain  to  tlir^  ^ih- 
oons  fornialdcliydc.  VVlicii  I  lie  solution  is  healed  in  a  closed  vessel 
nnd(U'  |)ressiire,  j)olyineri/ation  is  ])revented  hy  the  j)resence  of  borax 
or  of  neutral  Sidtw,  as  chloride  of  caleiinn. 

Formaldehyde  vapor  is  exceedingly  ])nngent  and  vei-y  irritating  to 
the  eyes  and  nose.  It  has  a  strong  ailinity  for  many  orgjinic  sni)- 
slan('(>s,  and  coinhines  with  nearly  all  fonl-snuilling  j)rodncts  of  (h-com- 
position,  forming  odorless  compoinids,  thus  acting  as  a  deodorant. 
It  transforms  gelatin  in  solution  to  a  tough  transparent  substance  in- 
soluble in  boiling  water,  causes  blood  serum  to  lose  its  coagidability  by 
heat,  combines  with  the  ])roto))lasm  of  bacteria,  and  converts  egg  albu- 
min into  a  substance  insoluble  in  water  and  indigcstilile.  A\'ith  am- 
monia, it  forms  an  inert  compound,  hexamethylentetramin,  which  has 
the  odor  of  neither  substance  (4NH3  -f-  GCHp  =  (CH2)6N^  -f  6H,0). 
It  has  no  action  on  copjK-r,  brass,  zinc,  nic^kcl,  silver,  iron,  steel,  or 
other  metallic  substanc(>s,  causes  no  diminuti(»n  in  the  tensile  strength 
of  fal)rics,  and  has  no  bleaching  or  other  effect  on  colors,  excepting  to 
intensify  the  effect  of  certain  of  the  coal-tar  dyes  (fuchsin,  saflrauin, 
and  perhaps  others).  It  may,  however,  fix  blood,  pus,  and  fgecal  stains 
on  clothing.  It  has  no  injurious  action  on  clothing  and  other  woven 
fabrics,  furs,  articles  of  rubber,  leather,  and  paper,  pliotographs,  paint- 
ings, woodwork,  and  furniture. 

The  antiseptic  properties  of  formaldehyde  were  note<l  first  in  1886 
by  Loew  and  Fischer,^  but  its  value  as  a  practical  disinfectant  -was 
made  known  first  by  Trillat"  in  a  communication  to  the  French  Acad- 
emy of  Science  in  1892,  and  since  that  time  it  has  been  the  subject 
of  very  extensive  investigation,  which  has  demonstrated  conclusively 
that  formaldehyde  is  by  far  the  most  powerful  and  practical  chemical 
disinfectant  known.  In  general,  it  is  used  in  the  form  of  gas  gener- 
ated in  different  Avays  from  methyl  alcohol  oi*  from  the  aqueous  40  j>er 
cent,  solution,  commonly  known  by  the  commercial  name  Formalin,  or 
from  the  solid  polymer  trioxymethylen,  otherwise  known  as  paraformal- 
dehyde and  by  the  trade  name  Paraform.  In  some  processes  of  disin- 
fection and  deodorization,  it  is  applied  directly  in  the  form  of  aqueous 
solution. 

Methods  of  Use,  and  Apparatus. — At  first  the  gas  was  generated 
directly  from  methyl  alcohol  by  means  of  lamps  specially  constructed 
for  the  purpose.  The  first  of  these  was  devised  by  Trillat,  who  was 
followed   by  Gambier,  Barthel,  Dieudonne,  Krell,   Tolleus,  Robinson, 

^  Journal  fiir  praktisohe  Chemie,  XXXIII..  p.  221. 
^  Comptes  rendus,  CXIY.,  p.  127S. 


600 


DISINFECTANTS  AND  DISINFECTION. 


and  others,  Avbo  presented  various  modifications  and  improvements,  but 
all  of  the  lamps  thus  far  devised  are  open  to  several  objections,  among 
which  may  be  mentioned  the  fact  that  a  large,  if  not  the  greater,  part 
of  the  alcohol  is  converted  to  carbon  monoxide  and  dioxide,  and  the 
possibility  of  fire. 

Trillat,  recognizing  the  defects  of  his  own  and  other  lamps,  and  being 
convinced  of  tiie  futility  of  attempting  to  disengage  the  gas  by  evap- 
orating the  aqueous  solution  from  open  vessels,  whereby  polymerization 
is  caused,  attempted  to  devise  an  apparatus  in  which  the  aqueous  solu- 
tion could  be  employed  without  the  occurrence  of  this  undesirable 
phenomenon.  The  outcome  of  his  study  was  the  autoclave  which  bears 
his  name. 


Fig.  97. 


Fig.  98. 


Trillat's  autoclave. 


Sauitary  Construction  Company's 
regenerator. 


Trillat's  autoclave,  shown  in  Fig.  97,  consists  of  a  cylindrical  silver- 
lined  pot  of  heavy  copper,  of  about  a  gallon  capacity,  with  a  cover  rest- 
ing on  a  rubber  gasket  and  secured  by  means  of  turn-buckles.  The 
cover  carries  a  pressure  gauge,  a  thermometer,  and  an  outlet  controlled 
by  a  valve  and  terminating  in  a  narrow  brass  tube.  The  pot  is  sup- 
ported on  a  tripod,  and  beneath  it  is  a  Swedish  lamp,  the  flame  of 
which  is  fed  by  vapors  from  kerosene  oil  forced  out  by  compressed  air. 
In  the  pot  is  placed  not  more  than  three-fourths  nor  less  than  one- 
fourth  of  its  capacity  of  a  mixture  of  the  40  per  cent,  solution  of 


FORMALI>i:iIYI)l':. 


OOl 


f()rm;il(l('hy(](!  ;ui(l  chloride  of  calfMiim,  (If  hiff'T  for  tlio  j)nrf>oHf  of 
])rov('iil,iii}i;  polviiicri/.-dioii  iiihKt  prcssinf.  'I  liis  niixfiin-,  wliifli  fori- 
tiiiiis  150  {j^nuiiM  of  tlic  chloride  to  the  liter,  is  known  eh  Formf)chlorol. 
'V\u\  (oriiiMldcliydc  soiiilioii  iiHcd  slionld  he  |)r;iflic,;dly  fn-c  from  niflhyl 
.mIcoIioI,  vvhifih,  while  of  ii(»  |)r;iclic;d  iiitcrcsf,  under  ordinary  eireiim- 
HliiiKtes,  Ih  ail  oI))eelioiial)le  iiiipiirily  when  fli<"  solution  is  lu-aled  nnder 
))i'(!ssnre,  since  \\\v\\  if.  nniles  with  a  eorresponrjin^  arnonnl  of  fr»rnial- 
(lohyde  io  form  inert  metli\  l;il.  The  cover  is  (irndy  fixed  hv  the  tnrn- 
l)nc.I<les,  and  then  the  laiu|)  is  put  in  operation.  When  the  franjre  showH 
a.  |)ressnn!  of  three;  atmospheres,  the  f)ntlet,  (uhe  is  introdnecd  into  the 
keyhole  of  the  door  of  th(!  room  to  be  disinfeetc<l,  and  the  valvf!  Ih  ojK^ncfl 
gradually  so  as  to  release  the  vapor.     The  disenga^eni(;nt  of  the  ga.s  Ih 

Fio.  90. 


Lentz's  reffcncrator. 


continued  until  a  sufficient  amount  of  the  liquid,  based  upon  the  amount 
of  air  space  treated,  is  consumed.  According  to  Trillat,  in  the  case  of 
a  room  of  ordinary  size,  say  1 8  feet  square  and  1 0  from  floor  to  ceiling, 
the  operation  should  require  about  an  hour.  The  objections  urged 
against  this  form  of  apparatus  are  its  cost,  the  want  of  uniformitv  in 
the  amount  of  gas  delivered  within  a  given  time,  and  the  danger  of 


602 


DISINFECTANTS  AND  DISINFECTION. 


Fig.  100. 


explosion  from  the  possibility  of  the  uon-working  of  the  valve,  or  from 
obstructiou  by  one  cause  or  another  of  the  outlet  tube. 

A  number  of  other  apparatuses  for  the  same  purpose  have  been 
devised,  and  to  several  of  them  these  oljjections  no  not  apply.  One  of 
these  is  the  regenerator  made  by  the  Sanitary  Construction  Company, 
and  used  extensively  by  public  authorities,  (See  Fig.  98.)  It  consists 
of  a  copper  reservoir,  holding  about  3  quarts,  from  the  bottom  of  which 
leads  a  quarter-inch  copper  tube,  Avhich  forms  a  coil  2  inches  below, 
and  then  turns  upward  and  extends  above  the  top  of  the  apparatus, 
where  it  is  fitted  with  a  rubber  tube  carrying  a  fine  copper  nozzle, 
through  which  the  gas  is  delivei'ed.  Beneath  the  coil  is  a  Swedish 
lamp  similar  to  that  used  with  the  Trillat  autoclave.  The  formaldehyde 
solution  is  admitted  to  the  heated  coil  through  a  valve,  and  is  trans- 
formed to  vapor,  which  escapes  through  the  nozzle.  Neither  pressure 
nor  the  presence  of  calcium  chloride  is  necessary,  and  the  rapidity  of 
action  and  amount  of  solution  used  can  be  determined  by  observing 
the  height  of  the  liquid  in  the  glass  gauge  on  the  side  of  the  reservoir. 
The  apparatus  is  very  much  cheaper  than  the  Trillat  and  similar  auto- 
claves. 

Another  regenerator  which  meets  with  favor  is  that  of  Lentz  (see 
Fig.  99),  in  which  the  formaldehyde  solution  is  heated  in  a  retort  by 

means  of  a  Swedish  lamp,  the  gas 
emerging  through  the  metallic  deliv- 
ery tube  connected  by  rubber  tubing 
with  the  nozzle,  which  is  inserted 
through  a  keyhole. 

In  order  to  avoid  the  use  of  the 
liquid  preparation,  and  to  employ  in 
its  place  the  solid  polymer  trioxyme- 
thylen,  or  paraform,  the  Schering 
lamp  was  devised,  and  in  1897  was 
brought  into  notice  by  Aronson,^ 
after  he  had  made  a  series  of  tests 
w^hich  yielded  good  results.  This 
very  simple  and  inexpensive  appa- 
ratus, shown  in  Fig.  100,  consists 
essentially  of  a  metallic  shell,  not 
unlike  an  open  piece  of  stove-pipe, 
supported  on  legs,  and  carrying  in  its 
upper  part  a  basket  made  of  sheet- 
iron  and  wire  gauze,  and  an  alcohol 
lamp  carrying  6  or  more  wicks.  For 
convenience,  the  paraform  is  supplied 
in  pastilles  weighing  a  gram  each, 
and  these  are  placed  in  the  basket  to 
the  number  of  2  for  every  35  cubic  feet  of  air  space  to  be  disinfected. 
The  lamp  is  supplied  with  alcohol  to  the  extent  of  2  cc.  for  each  pas- 
^  Zeitschrift  fiir  Hygiene  imd  Infectionskrankheiten,  XXV.,  1897,  p.  186, 


Schering  paraform  lamp. 


FOllMM.DKtJYDK. 


603 


tille.  Tlio  winks  should  project  not  iiion;  lliuii  nitoiit,  :i  twflftli  of  an 
incli,  wliic.li  is  siinici<'iil  to  {^ivc  a.  flame  \vlii<'li  will  lu-at  tii«'  basket  aiifl 
its  e()iit(!iits  siinicieiiily  In  ciiiise  \'olat ili/.atioii  of  tlic  aj^ciit,  with  ahso- 
lutcly  no  (laiit^(!r  ol'  its  taking  lire  and  thus  yieldiiij.'  no  forrnaldcliydc; 
j2;as.  \\y  i\\v  time  the  alcohol  is  eonsinned,  tlu;  jiastilh-s  will  have  been 
volatilized  eoinpletc^ly  or  nearly  so.      If  thf  space  to  be  treated   be  of 

Fi(i.  101. 


Druslau  rogunL-rator  iiml  hiinp. 

such  size  that  the  requisite  number  of  pastilles  cannot  be  placed  in  the 
basket,  more  than  on*:-  apparatus  should  be  used.  This  ])rocess  has  the 
advantai>:e  of  simplicity  and  economy  of  time,  for  when  the  apparatus 
is  placed  in  jwsition  with  its  lamp  burninij,  it  requires  no  further  atten- 
tion on  the  part  of  the  operator,  who  then,  Avith  other  lamps,  is  enabled 
to  start  the  process  elsewhere,  and  thus  accomplish  much  more  than 

Fig.  102. 


Vertical  soot  ion  of  Breslau  regenerator.    (Lamp  in  position.) 

another  Nvho,  operating  an  autoclave,  or  similar  apparatus,  is  obligee!  to 
give  it  constant  attention  as  long  as  the  gas  is  being  generated. 

Still  another  apparatus  is  that  used  in  what  is  known  as  the  "  Bres- 


604  DISINFECTANTS  AND  DISINFECTION. 

lau  method,"  in  which  the  gas  is  disengaged  in  company  with  an 
abundance  of  steam,  by  boiling  dikite  formaldehyde  solution.  The 
apparatus  shown  in  Figs.  101  and  102,  taken  from  the  description  of 
the  method  by  von  Brunn,i  consists  of  a  copper  boiler  about  14  inches 
in  diauieter  and  3  in  depth  at  the  periphery,  with  an  immovable  cover 
slightly  domed,  in  the  centre  of  which  is  an  outlet  tube,  to  which  a 
stout  rubber  tube  can  be  attached.  The  cover  is  provided  also  with 
two  handles  and  an  orifice  closed  by  a  screw  cap.  A  flange  around 
the  upper  border  of  the  boiler  keeps  the  latter  in  place  when  it  is  put 
on  its  support,  which  is  a  cylinder  of  enameled  sheet  iron  about  14 
inches  in  height,  provided  in  its  loAver  half  with  slits  for  the  free  en- 
trance of  air,  and  on  its  iuner  side  with  three  supports  for  an  alcohol 
lamp.  The  lamp  is  an  open  dish,  through  the  bottom  of  which,  in  two 
concentric  rings,  20  tubes  project  upward  as  high  as  the  sides  of  the 
vessel.  With  this  apparatus,  3.5  liters  (nearly  4  quarts)  of  fluid  can 
be  brought  to  boil  in  10  minutes,  and  nearly  the  whole  can  be  evapo- 
rated in  an  hour.  The  amount  of  alcohol  placed  in  the  lamp  should 
be  about  one-fourth  of  the  volume  of  the  solution  in  the  boiler,  and 
this  will  be  consumed  before  the  boiler  is  empty.  Like  the  Sobering 
lamp,  the  apparatus  may  be  left  in  the  room  or  it  may  be  used  outside 
with  a  delivery  tube  passing  through  the  keyhole.  In  order  to  achieve 
the  best  results,  a  dilution  of  1  part  of  the  40  per  cent,  solution  of 
formaldehyde  with  4  of  water  is  recommended.  With  this  dilution, 
one  avoids  the  polymerization  observed  when  the  undiluted  solution  is 
heated,  which  is  due  to  the  fact  that  the  water  is  driven  ofi'  faster  than 
the  formaldehyde. 

A  somewhat  similar  apparatus  has  been  devised  for  the  generation 
of  steam  in  connection  with  the  use  of  the  Schering  lamp.  It  consists 
essentially  of  a  circular  copper  boiler,  surrounding  the  Schering  lamp 
and  heated  by  a  circular  open  alcohol  lamp  which  is  really  a  sort  of 
gutter  into  which  a  measured  amount  of  alcohol  is  poured. 

Various  methods  have  been  devised  for  spraying  the  solution  of  for- 
maldehyde itself,  but  they  have  had  their  day  and  have  fallen  into  disuse. 

In  many  municipalities  the  public  health  authorities  suspend,  in  the 
space  to  be  disinfected,  sheets  wet  with  the  requisite  amount  of  for- 
malin, which  is  thus  allowed  to  evaporate  into  the  atmosphere. 

A  method  of  generating  the  gas  which  does  away  with  special  appa- 
ratus and  also  the  need  of  a  flame  is  that  of  Evans  and  Ilussell,^ 
•which  depends  upon  the  fact  that  when  formalin  and  potassium  per- 
manganate are  brought  together,  a  violent  reaction  occurs,  with  the 
evolution  of  much  heat  and  rapid  liberation  of  the  gas,  and  also 
vaporization  of  the  water.  Numerous  experiments  demonstrated  that, 
for  the  attainment  of  the  best  results,  6.5  ounces  of  the  permanganate 
in  the  form  of  powder  or  very  small  crystals  should  be  employed  with 
each  pint  of  formalin.  In  any  given  case,  the  necessary  amount  of 
each  having  been  determined,  the  permanganate  is  placed  in  a  suitable 

1  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXX.,  p.  201. 

^  Thirteenth  Report  of  the  State  Board  of  Health  of  Maine,  1904,  p.  234. 


FOIlMM.hlHIVni':.  fJ05 

V(!ss(^l  ntul  ilic  forrnalin  is  pounid  upon  it.  'I'lic  cvolulioii  of  tlu;  ^;iH 
hciii^  Viwy  Tiipid,  it  is  iicrcssiiry  for  I  lie  op(  i;ilor  lo  Ic.'ivf:  the  room  ',in 
(jiiickly  iiH  |)OKsil)l('.  ( )n  .iccdiinf  of  llic  frotliiiif^  uliirli  occiirn  in  cuu- 
,s{!(pi(!iK;(!  of  I.Ik!  violence  of  the  icaclJ**!)  v<!ry  lull  V(!S^cls  .'irc  n'f|iiin'(l, 
Ex])oricMeo  has  shown  that  thcsn  are  best  niado  of  tin  and  with  fiaririj^ 
tops.  It  is  rccoinnicndcd  that  they  have  a  dianicfi-r  of  10  inclu-s  at 
tli(!  holtoni  and  a  h('i<;lil  of  17  inchos,  the  sides  liavinj;  a  perpr-ndienlar 
hei<2,hl  of  H  inclies  ;iii(l  llii  ii  flariiiic  al   an  anijie  of  about  oO  de^n-CH. 

(^nanl  ilal  I\('  (l(l('i'niln;il  ions  pr()\-e(|  tli;it  ihe  \'ield  of  ^;\^  averapcts 
<S  I  per  cenl.  of  llic  annmnl  preseni  in  the  :-o|iili(in,  and  that  abf»iit 
foni'-liftlis  of  lhisar(!  set  \.Wv  within  O  minutes,  the  remainder  beinjj^ 
given   oir  in    rapidly  diminishinti;  amount   during   the   next    12   liourH. 

To  avoid  the  violent  ebullition,  foanung  and  spattering,  and  to 
retard  tlu;  evolution  of  the  gas,  Jloughton  and  (.'lark  '  j)ro|)ose  mixing 
the  ery.stals  ol"  })ernuiuganate  with  lo  per  eent.  of  Portland  eement  and 
enough  water  to  j)erniit  the  making  of  small  bloeks,  each  containing  XO 
grains  of  tin;  crystals.  They  recommend  the  use  of  3  of  such  blocks  to 
about  a  pint  of  formalin.  The  formalin  is  j)laccd  in  a  pail  of  abr)ut  3  gal- 
lons' capacity,  and  the  blocks  are  then  dropped  into  it.  The  reaction 
is  slower  and  less  violent  than  that  whi(di  occurs  in  the  original  process. 

Another,  somewhat  similar,  mcjthod  is  that  proi)ose(l  by  Kichengriin,* 
in  which  a  mixture  of  paraformaldehyde  and  metallic  peroxides  (barium 
and  strontium),  called  Autan,  is  employed.  This  preparation,  which 
is  presented  in  the  form  of  powder  and  in  tal)lets,  on  being  thrr>wn  into 
water,  gives  off  formaldehyde  gas  with  a  ra])idity  which  varies  accord- 
ing to  the  relative  pro])ortioiis  of  the  ingredients.  Equal  weights  f»f 
the  peroxides  and  paraformaldehyde  mixed  with  twice  their  volume  of 
water  cause  a  violent  explosion,  but  the  preparation  in  the  proportions 
presented  gives  off  the  gas  very  quickly  without  explosion.  Selter^ 
reported  that  the  action  is  so  ra])id  and  the  room  is  filled  with  the  gas 
so  quickly  that  the  usual  precautious  of  sealing  minor  apertures  are 
unnecessary.  Using  as  test-objects  anthrax  spores,  staphylococci,  and 
fresh  tuberculous  sputum,  he  reported  favorable  results,  as  did  AVesen- 
berg,^  who  used  the  same  and  additional  test-objects.  But  Nieter^  dis- 
agrees with  Selter  as  to  the  necessitv  of  sealins;  the  room,  and  while 
conceding  the  advantages  of  simplicity,  freedom  from  danger  of  fire, 
and  the  possibility  of  a  number  of  disinfections  simultaneously  under 
control  of  a  single  individual,  jioints  out  a  very  material  disadvantage 
in  the  high  price  of  the  compouud.  Unfavorable  results  are  reported 
by  Ingcltinger,"  Bock,^  Kirehg-aesser  and  Hilgermann,"  Proskauer  and 
Schneider,'-'  and  also  by  Christian  ^^  and  Hammer!. ^^ 

1  Tlierapeutic  Gazette,  July,  1907. 

'  Zeitsi.'lirift  iTu-  aiigewandte  Chemie,  XIX.,  1906.  No.  3.S,  p.  1412. 

3  ^[ulu•l^ene^•  niedizinische  Woohenschrift,  1906,  p.  24'2-5. 

4  lIvLrienisohe  Rnndscliau,  Xovember  15,  1906,  p.  1241. 

5  Ibid.,  February  1,  1907.  p.  151. 

6  Klinisches  Jahrbuch,  XVIII.,  1907,  No.  1. 

7  Ibid.  8  Ibid.  9  Ibid. 
1'^  Ilygieni^olie  Eundscliau,  ^lay  15,  1907,  p.  571. 

^1  Munchener  me<.Uzinisclie  Woclienschrift,  1907,  No.  23. 


606  DISINFECTANTS  AND  DISINFECTION. 

Dieiidonne'  advocates  the  evaporation  of  diluted  formalin  with  the 
aid  of  heated  bricks,  the  liquid  being  poured  over  them,  or  of  red- 
hot  steel  bolts,  weighing  about  7  pounds,  held  in  a  sheet-iron  pocket 
in  the  vessel  in  which  the  liquid  is  contained.  A  perforated  cover  is 
em})loyed  to  minimize  the  amount  of  loss  of  liquid  by  spurting. 

Another  simple  method  of  generating  the  gas  and  steam  at  the  same 
time  is  that  of  Schering,-  in  which  pastilles  of  paraform  and  unslaked 
lime  are  employed.  These  are  wet  with  warm  water,  and  the  heat 
which  is  produced  in  tiie  process  of  slaking  the  lime  is  sufficiently 
intense  to  cause  the  volatilization  of  formaldehyde  from  the  paraform 
and  the  formation  of  steam  at  the  same  time.  One  may  use  also 
unslaked  lime  and  diluted  formalin,  dropping  the  former  into  the  latter. 
This  process  has  the  disadvantage  that  part  of  the  formaldehyde  released 
is  decomposed.  To  avoid  this  the  addition  of  oxalic  acid  or  of  sul- 
phuric acid  is  proposed,  but  the  process  is  patented. 

Another  method  of  generating  the  gas  consists  in  the  application  of 
formalin  to  unslaked  lime,  the  heat  produced  thereby  liberating  the  gas 
with  considerable  rapidity.  An  improvement  upon  this  method  is 
offered  by  Huber  and  Bickel,^  who  report  very  satisfactory  results  with 
a  mixture  of  about  2  quarts  of  formalin,  4  pounds  of  quicklime,  and 
about  6  quarts  of  boiling  water  for  each  1000  cubic  feet  of  air  space. 
The  lime  is  placed  in  a  large  wash-tub,  the  water  is  poured  over  it,  and 
then  the  formalin  is  added.  The  gas  and  generous  volumes  of  steam 
are  given  off  very  rapidly,  and  the  space  to  be  disinfected  is  soon  filled 
with  the  vapors. 

The  method  of  Elb,  with  "carboformal  Gliihblocks,"  yields  results 
which  do  not  warrant  commendation. 

Germicidal  Properties. — The  first  to  note  the  antiseptic  effect  of 
formaldehyde  were  Loew  and  Fischer  in  1886,  but  although  Loew 
continued  his  ol)servations  for  some  months,  and  Buchner  and  Segall 
made  a  study  of  its  antiseptic  action  in  1889,  Trillat,  in  1892,  was  the 
first  to  draw  attention  to  the  importance  of  the  agent  as  a  disinfectant. 
Almost  at  the  same  time  came  a  publication  by  Aronson,*  and  since 
then  the  germicidal  properties  of  this  substance  have  been  the  subject 
of  more  numerous  investigations  than  have  been  made  of  those  of  all 
other  disinfectants  combined.  So  many  have  been  the  favorable  reports 
and  so  well  has  been  established  its  claim  to  first  place  as  a  gaseous  dis- 
infectant that  it  is  hardly  necessary  to  present  the  evidence  in  detail. 
It  is  sufficient  to  state  that,  provided  the  gas  can  reach  them  in  suf- 
ficient concentration  under  favorable  conditions  of  temperature  and 
moisture  and  with  a  reasonable  period  of  contact,  no  pathogenic  organ- 
isms can  withstand  its  influence. 

Although  certain  experimenters  have  claimed  for  formaldehyde  a 
much  greater  penetrating  power  than  can  be  explained  by  any  law  of 

1  Die  arztliche  Praxis,  1901,  No.  2. 

2  Hygienische  Rundschau,  1900,  p.  708. 

3  Miinchener  medizinische  Wochenschrift,  September  3,  1907. 

4  Berliner  klinische  Wochenschrift,  1892,  No.  30. 


F(HiMM.i>i:iiYi>i<:.  607 

pliysi(!S,  ii  is  v(!ry  ^cncrully  ;i^n'C(l  lliat,  in  tlu'  ^'aHfoiiK  form  it  i.'-  rucn-iy 
ii  siirlac,*!  (lisiiifiM-fjuil,  unless  I  lie  olijc*-!  cxposr-fl  is  casilv  pr-rnKiiMr-  hy 
any  gas  or  inixtiici'  of"  ^.'i^e,-,  siidi  ;i-  :\\r.  W'liilr  il  '•;iiiii<it  |.(iK'tratf;  to 
the  interior  of  a  closely  rolle<l  hiindle  oi'  elotliinj^,  lor  exa/ii|»|r',  it  ean 
rc!a(!li  all  parls  o(  a  iooHiiiy  rniii|(l<(|  nias>  of  elieese-cjotli  ;  and,  altliou^li 
it  may  he  ahle  to  sleriliz(!  test-ohjects  placed  inside  a  pillr»\v  or  inattr*-"- 
the  (!overin|^  of  which  is  laid  o|)en,  it  cannot  ordinarily  ix-  depen<l«'d 
npon  to  do  so,  il'the  c()V(!riiig  is  intact,  any  more  than  it  can  he  eonntt-d 
upon  to  <lisinfeet  the  paf^es  of"  a  tightly  closed  hook.  For  Hiipfirfieial 
(lisiid"e(!tion  of"  walls,  f'lirnitiire,  clothing,  and  fiihrics  freely  Hj»read  out 
and  <'Xposed,  it  is  ellieient  in  tlu;  highest  degree.  J^ong  ago,  I'fidd  ' 
warned  against  expecting  too  mnch  in  perl"ornianee,  saying  that  it  will 
always  be  merely  a  surface  disinf"ec.tant,  not  to  he  relied  nj)on  to  in- 
fluence bacteria  oidy  slightly  covered  or  on  <lus(  w  hich  lie;^  in  measurable 
thickness,  and  in  cracks  of  floors  and  walls. 

Jt  is  inijiortant  to  bear  in  mind  the  lack  of  jKiietrating  jtower  <if 
formaldehyde  gas,  since  a  disregaid  of  this  fiict  will  cause  much  suj)- 
posed  disinfection  to  be  a  positive  danger,  because  of  overconfidencc  in 
the  results  actually  achieved.  Therefore,  in  practice,  all  obstacles  to 
thorough  dissemination  nuist  be  removed  as  far  as  is  ])ossible. 

Conditions  Favoring-  Action. — Concerning  the  influence  of  moisture 
on  the  efliciency  of"  formaldehyde  gas  there  "was  at  one  time  a  decided 
difference  of  opinion,  but  it  is  generally  agreed  that  unless  the  air  of 
the  space  acted  upon  has  a  relative  humidity  of  at  least  65,  the  rc^^ults 
are  likely  to  be  unsatisfactory.  But  if  the  objects  exposed  are  actually 
wet,  so  that  the  gas  is  taken  up  virtually  in  solution,  it  has  been  shown 
by  the  author  -  that  penetration  of  a  loose  mass  of  fabric  is  prevented, 
and  by  Rubner  and  Peerenboom  ^  that  the  concentration  of  the  formal- 
dehyde solution,  formed  by  absorption,  is  too  weak  to  be  effective. 
\A  ith  regard  to  temperature,  it  is  agreed  that  tlie  greater  the  degree  of 
heat,  the  surer  the  action,  and  that  below  60°  F.  favorable  results 
cannot  be  expected. 

Toxicity. — It  has  been  asserted  by  a  number  of  experimenters,  in- 
cluding Aronson,  Trillat,  Robert,  Pfuhl,*  and  others,  that  the  gas  is 
non-toxic  to  animals,  but  the  experiments  of  Pottevin  ^  with  guinea- 
pigs,  of  the  author  ^  with  rabbits,  and  the  experience  of  Brough '  and 
others  engaged  in  the  work  of  public  disinfection,  demonstrate  that  this 
is  untrue.  Dogs  and  cats,  accidentally  overlooked  in  rooms  under- 
going disinfection,  have  repeatedly  been  found  dead  by  public  disinfec- 
tors,  as  well  as  flies  aud  other  insects,  including  roaches  and  bedbugs. 
Against  mosquitoes,  Rosenau*  finds  formaldehyde  to  be  far  inferior  to 
sulphur  dioxide. 

1  Zeitsohrift  fiir  Hygiene  und  Infectionskrankheiten,  XXIV.,  1897,  p.  289. 
'^  American  Journal  of  the  Medical  Sciences,  January,  1898. 
3  Hygienische  Rundscluiu,  1899,  p.  2(35. 

*  Berliner  klinische  Wochenschrift,  1892,  No.  30,  and  Zeitscbirft  fur  Hygiene  und 
Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXV.,  1897,  p.  68. 
5  Annales  de  d'Institut  Pasteur,  Xoveniber  2o,  1894. 

®  Loc.  eit.  '  Transiictions  of  the  Massachusetts  Medical  Society,  1898, 

^Bulletin  No.  6,  of  the  Hygienic  Laboratory,  Washington,  September,  1901. 


608  DISINFECTANTS  AND  DISINFECTION. 

The  solution,  taken  internally  throngh  mistake  or  with  suieidal  in- 
tent, has  caused  many  tleaths.  The  most  rapidly  fatal  case  known  is 
that  reported  by  Levison.^  The  amount  taken  was  estimated  at  2  or 
3  ounces,  and  death  occurred  in  '20  minutes,  after  intense  suffering. 

Amount  Necessary  for  Room  Disinfection. — The  amount  of  for- 
maldehyde necessary  to  disinfect  any  given  air  space  depends  very  much 
uptui  the  thoroughness  with  which  the  escape  of  the  gas  is  prevented 
during  the  time  given  for  action.  Under  ordinary  conditions  and  with 
the  observance  of  all  reasonable  precautious,  it  is  generally  agreed  that 
for  each  1,000  cubic  feet,  a  pint  of  formalin,  or  about  60  pastilles  of 
paraform,  ought  to  sufiice.  Striiver^  would  use  45  pastilles  per  1,000 
cubic  feet  ag-ainst  sporeless  bacteria,  but  in  practical  disinfection  one 
cannot  always  discriminate.  Fliigge^  advises  that,  in  small  rooms 
containing  the  usual  amount  of  furniture,  the  number  of  pastilles  be 
increased  from  2  to  2.5  per  cubic  meter,  or  to  72  per  1,000  cubic 
feet. 

With  the  Breslau  method,  it  is  claimed  that  less  than  half  a  pint  of 
formalin  (190  cc.)  will  suffice  for  1,000  cubic  feet  with  7  hours'  ex- 
posure. ISTovy  *  also  is  of  the  opinion  that  in  the  presence  of  sufficient 
moisture,  even  less  will  be  found  adequate;  namely,  150.  Provided 
the  gas  is  prevented  from  escaping,  there  can  be  no  doubt  that  the 
smaller  amounts  are  effective  within  much  less  time  than  that  usually 
given  in  practical  M^ork.  In  a  series  of  experiments  in  a  practically 
air-tight  glass  cabinet,  using  as  test-objects  smears  of  anthrax  spores, 
Staphylococcus  pyogenes  aureus,  a  highly  resistent  non-pathogenic  spore- 
bearer,  and  the  bacilli  of  diphtheria  and  typhoid  fever,  the  author  found 
evers^thing  sterile  after  two  and  a  half  hours'  exposure  to  an  atmosphere 
containing  the  equivalent  of  110  cc.  formalin  in  1,000  cubic  feet. 
Using  it  to  the  extent  of  about  a  pint  to  the  1,000  cubic  feet,  the  same 
result  was  attained  in  less  than  a  half  hour. 

Disadvantages. — The  principal  disadvantage  observed  in  disinfec- 
tion by  formaldehyde,  aside  from  its  cost,  which  is  considerable,  is  the 
odor,  which  is  sometimes  very  persistent,  especially  when  ranch  moisture 
is  present,  and  which,  except  under  very  unusual  conditions,  is  plainly 
perceptible  outside  the  room  in  which  the  gas  is  disengaged.  Usually, 
however,  this  is  a  transient  trouble,  and  is  met  by  thorough  aeration. 
If  deemed  advisable  on  the  score  of  saving  time,  and  when  the  gas  has 
been  absorbed  by  the  condensed  moisture  on  the  walls  and  furniture,  it 
may  be  neutralized  by  means  of  ammonia  water,  which  may  be  exposed 
in  the  room  in  shallow  dishes  or  vaporized  from  a  flask  or  other  appa- 
ratus and  conducted  into  the  room  by  means  of  an  outlet  tube  through 
the  keyhole  of  the  door.  Flugge  recommends  the  latter  method,  and 
advises  the  use  of  about  120  cc.  of  the  25  per  cent,  solution  to  each 
100  cc.  of  formalin,  and  320  cc.  to  each  100  pastilles  of  paraform  used. 

^  .Journal  of  the  American  Medical  Association,  June  4,  1904. 

^  Loc.  cit. 

3  Zeitschrift  fiir  Hygiene undlnfectionskranklieiten.  XXIX.,  1898,  p.  276. 

*  Medical  Kews,  1898,  p.  641. 


piiAdrrcAL  DisiNFi'/rnoM.  i',{)\) 

Art'i(!l(fH  of  clolliiiij^',  KtiidJ'd  fiirnitiirc,  .'uhI   IIic   like  rniif-(.  ollicrwihc  rc- 
qiiirc  soniclJtiics  Mcvcnil  (lay.s  of"  niriii^. 

Technic  of  Room  Disinfection. — Sec  uikK  i-  ri;irii(;il  I)iHnf(fiioii, 

Other  Applications  of  Formaldehyde. — Jk-sidos  its  \m-  \u  \\\c  \<ra»- 
coiiH  sliiUi  ior  lioiisc  (lisiiilrc.tioii,  (orMi.'iKlcliydc;  in  tlu;  I'orm  ui'  its  afjiifouH 
Bohilioii  is  well  ii<la|»l('(|  lo  (lie  sIciili/aliDii  oC  urine,  ('a;c/!S,  spntntri,  and 
otluir  waste  products,  (iirnil  iiif,  wood-work,  toilet  articles,  and  other 
ohjecits,  and  it  is  also  Naliiablc  as  a  (Uiodoi'ant.  Jn  the  disinfection  of 
urine,  the  addition  oC  one-twentieth  of  its  volume  of  formalin  will  Ik; 
found  to  prodtKH'  sterility  within  an  hour,  'ruherculous  sputum  and 
di[)htheritie  meinhranes,  covered  hy  ;i  sulficient  volume  of  a  mixture  of 
about  two  and  a  half  tahh^spoonf'uls  of  formalin  in  a  quart  of"  water, 
are  sterilized  within  2  hours.  Li(|uid  stools  j)lus  and  equal  volume  of 
the  same  mixture  are  disinfected  completely  within  the  same  period. 

A  mixture  of  1  part  of  formalin  and  20  of  water  is  very 
efTici(nit  as  a  wash  for  furniture,  wood-work,  and  other  objeets,  for 
sprayinii;  carpets  and  woollen  clothing,  etc.,  and  for  soaking  bed-linen 
and  other  washable  fabrics.  A  tablcspoonful  to  a  quart  of  water  will 
remove  all  odor  from  the  hands  after  autopsies,  and  will  deodorrze  other 
parts  of  the  body  to  which  it  may  be  applied. 

Prevention  of  Dissemination  of  Infectious  Material;  Practical 

Disinfection. 

Even  with  the  best  disinfectants  available,  and  with  the  exercise  of 
the  greatest  care  in  their  application,  practical  disinfection  is  by  no 
means  always  eflcctivc  in  ]ireventing  the  transmission  of  infective  ma- 
terial to  new  fertile  ground.  Hence  it  is  advisable  and  necessary  to 
keep  the  infected  area  as  small  as  possible  and  to  prevent  the  accumu- 
lation of  infective  material  by  destroying  it  continnonsly  and  as  quickly 
as  possible  after  it  is  thrown  off  by  the  body.  ^Vith  the  exercise  of 
due  care,  the  waste  products  which  act  as  vehicles  for  the  infective 
agents  of  (mu*  common  and  occasional  scourges  may  be  so  effectively 
dealt  with  from  hour  to  hour  and  from  day  to  day  as  to  make  the  after- 
treatment  of  the  room  and  its  contents  somewhat  of  a  mere  form,  car- 
ried out  as  a  matter  of  routine  practice,  or  in  order  to  make  assurance 
doubly  sure. 

Accordiug  to  the  nature  of  the  disease,  these  agents  reside  iu  dis- 
charges from  the  mouth,  nose,  aud  throat  (diphtheria  and  pertussis), 
in  sputum  (pulmonary  tuberculosis,  influenza,  and  pneumonia),  iu  dis- 
charges from  the  bowels  (typhoid  fever,  cholera,  dysentery,  and  tuber- 
culosis), in  the  urine  (typhoid  fever),  aud  iu  mattere  thrown  off  by  the 
skin  (acute  exanthemata).  Therefore,  the  course  to  be  pursued  during 
the  continuance  of  a  sickness  or  convalescence  varies  accoixliug  to  the 
nature  of  the  disease. 

The  limitation  of  the  infected  area  and  of  the  amount  of  material 
which  may  require  disiufection  on  the  termination  of  the  disease  should 
39 


610  DISINFECTANTS  AND  DISINFECTION. 

be  a  matter  for  immediate  action  on  the  discovery  of  the  existence  of 
the  disease.  The  patient,  especially  in  the  case  of  the  acute  exanthe- 
mata, should  be  placed  in  a  room  which,  if  possible,  may  be  isolated 
from  the  rest  of  the  house,  and  from  which  all  unnecessary  furniture, 
especially  of  the  upholstered  kind,  hangings,  carpets,  and  rugs  have 
been  removed.  Disinfectants  for  the  prompt  treatment  of  infective 
matter  should  be  kept  near  at  hand,  together  with  a  sufficient  number 
of  appropriate  vessels  and  utensils. 

In  order  to  prevent  or  restrict  the  carriage  of  living  organisms  from 
the  room,  ingress  should  be  denied  to  all  whose  presence  is  unneces- 
sary ;  the  wearing  of  other  than  cotton  and  linen  dresses,  that  is, 
smooth-surfaced  and  washable,  by  the  attendants  should  be  interdicted; 
no  food  remainder  should  be  taken  away  to  be  consumed  by  others ;  no 
used  bed-linen  or  body-linen  removed  until  after  immersion  in  disin- 
fectant solutions,  and  no  discharges  finally  disposed  of  until  after 
appropriate  treatment.  If  it  be  necessary  to  use  the  broom,  the  dust 
should  be  kept  down  by  the  use  of  wet  sawdust  or  tea  leaves,  which, 
with  the  gathered  dirt  and  dust,  should  be  treated  with  disinfectant 
and  burned. 

Under  no  circumstances  should  the  process  known  as  "dusting," 
which  is  merely  the  scattering  of  dust  through  the  air  from  surfaces 
where  it  was  at  rest  and  upon  which  and  elsewhere  it  will  again  be 
deposited,  be  allowed,  but  such  surfaces  should  be  wiped  with  cloths 
moistened  with  or  wrung  out  in  disinfectant  solution  and  afterward 
soaked  and  boiled.  According  to  season,  the  windows  should  be  pro- 
vided with  ware  screens  to  keep  out  flies,  which  not  only  are  an  annoy- 
ance, but,  through  their  habit  of  visiting  all  manner  of  excreta  and 
other  filth,  act  as  carriers  of  infection. 

Disinfection  of  Faeces.  —  The  discharges  from  the  bowels  in 
typhoid  fever,  dysentery,  cholera,  and  intestinal  tuberculosis,  should 
be  received  in  vessels  containing  an  amount  of  disinfectant  solu- 
tion equal  to,  or,  better,  larger  than,  the  probable  volume  of  the 
discharges.  Whatever  the  agent  used,  it  should  be  brought  into  imme- 
diate contact  with  the  entire  mass  of  the  discharge  by  thorough  mixing, 
and  the  whole  should  stand  under  cover  for  about  an  hour  before  final 
disposition.  Milk  of  lime,  although  efficient,  leaves  a  bulky  residue 
which  cannot  be  conveniently  disposed  of  through  the  usual  channels. 
Chlorinated  lime  is  also  efficient,  but  is  disagreeable  in  odor.  Cor- 
rosive sublimate  is  unsuitable  for  reasons  elsewhere  stated.  Phenol, 
in  5  per  cent,  solution,  with  or  without  the  addition  of  mineral  acids  or 
common  salt,  and  the  various  cresol  disinfectants,  may  be  employed, 
but  their  odor  is  not  always  tolerable  to  the  patient.  Dilute  formalin 
presents  no  objections,  and  is  very  efficient  and  rapid  in  action. 

Urine. — In  typhoid  fever  and  tuberculosis  of  the  urinary  tract,  the 
urine  should  be  sterilized  by  the  addition  of  an  equal  volume  of  a  5 
per  cent,  solution  of  chlorinated  Kme,  carbolic  acid,  or  one  of  the  cresol 
compounds,  Ijut  better  by  the  addition  of  about  a  twentieth  of  its 
volume  of  formalin. 


I'IIA(!TI<!AI.    IHSINFI'lCriON.  611 

Sputum. — Til  pncunioMiu  ;iii<l  |)iilinoii;iry  tiihr-n-iilosiH,  tin;  >-|)iifijrfi 
wlioiild  l)(!  r(i(^('ivc<l  ill  s|»il--(;ii[)S  [t.'irfly  (illcd  wifli  «li,-iiif"r:ctanl,  Holii(ir»ri, 
and  kept  cov<  r<d  wIhh  nol  in  ;i<lii;ii  ii-<'.  It  iiiuy  1)0  tnjiif^d  with  5 
per  cent,  ciubolic;  acid,  or  ahoiil  •")  jxr  ••(•iit.  of"  any  of"  tlic  cnwol  fom- 
pouiidH,  or  with  4  p(!r  cent,  of  lorriialiii.  Miii<(>f'  lime  and  clilorinaUid 
lime  are  also  eHifMetit.  (V)rrosive  siihliiiiati!  i.s  very  nneerbiin.  V>y 
r(!a,soii  (»r  its  eonsislciHn'  and  adhesive  properties,  s|)iitiim  is  one  f»f'  the 
most  diniciih.  iiialcrials  to  sterilize  It  is  es|)eeially  dan^rcroiis,  as  it 
may  eoiitaiii  iar^-e  immhers  of  eiitaiif^led  hiieteria,  wliieh,  on  flryin^, 
mjiy  be  disseminated  hy  air  enrrents. 

Discharges  from  Mouth,  etc. — In  diphtiieria  and  jjertuHsis,  all 
dis('ha-rii:;es  (Voin  the  month  and  throat  should  he  reeeiv(!d  r)n  piee^-.s 
of  rag,  which  should  he  hmned.  The  di|)htheria  organism  retainH 
its  vitality  a,  long  time  in  the  dry  state,  and  .so  may  exist  in  the 
air  of  the  room,  if  particles  of  false  mciinbrant^  whifth  ha|)pen  to  i)e 
thrown  ont  in  coughing  or  sneezing  are  allowed  to  dry  on  walls,  fnr- 
nitnn^,  and  elsewhci'e. 

Eating  Utensils,  etc. — All  eating  ntcnsils  u.scd  by  patients  with 
pneumonia,  diphtheria,  pertussis,  the  exanthemata,  and  tuberculosi.s 
should  be  well  scalded.  All  napkins  should  be  treated  in  tlir*  same 
manner  as  infected  bed-linen.  All  remains  of  meals  should  be  de- 
stroyed. 

Bed-linen  and  Clothing. — In  any  case  of  sickness  in  which  isola- 
tion is  advisable  or  in  which  the  morbific  agent  is  known  to  exist  in 
the  bowel  ilischarges,  all  used  body-linen,  bed-linen,  towels,  napkins, 
wash-cloths,  handkerchiefs,  etc.,  even  if  not  obviously  soiled,  should 
be  immersed  for  an  hour  in  disinfectant  solutions,  and  then  conveyed 
under  cover  to  the  laundry  or  other  suitable  place,  and  boiled  for  an 
hour.  Should  the  organism  survive  the  first  treatment,  which  event 
with  proper  care  is  unlikely,  it  will  perish  in  the  second.  Should  there 
be  no  focal  or  other  stains,  the  boiling  may  be  carried  out  without  the 
preliminary  soaking ;  but  in  no  case  should  the  articles  in  a  dr^-  state 
be  removed  from  the  room  except  under  cover  or  wrapped  in  a  sheet 
wetted  with  an  efficient  disinfectant. 

In  scarlet  fever,  for  example,  the  morbific  agent,  whatever  it  may 
be,  is  exceedingly  tenacious  of  life,  and  resides  in  the  fine  particles  of 
epidermis  wdiich  are  continually  cast  off  by  the  skin,  and  it  is  easily 
conceivable  that  an  armful  of  linen  from  a  case  of  this  disease  might 
shed,  in  its  journey  to  the  laundry,  a  number  of  dust  particles  capable 
of  nuich  mischief.  Neither  lime  nor  chlorinated  lime  may  be  used  on 
clothing,  on  account  of  probable  injury.  Corrosive  sublimate  1  : 1 ,000, 
phenols  and  cresols  in  5  per  cent,  solution,  and  formalin  in  4  or  5  per 
cent,  solutiou,  may  be  advised.  Colored  goods  are  sometime?  aflfected 
by  some  of  the  cresol  compounds,  but  to  no  greater  extent  than  may 
be  caused  by  ordinary  laundry  soap. 

Hands. — In  the  nursing  of  cases  of  infectious  disease,  the  soiKng 
and  infection  of  the  hands  are  frequently  unavoidable.  After  every 
use  of  the  bed-pan,  every  wiping  away  of   discharges,  every  handling 


612  DISINFECTANTS  AND  DISINFECTION. 

of  the  patient's  body,  aud,  in  short,  after  every  act  by  which  the 
hands  may  become  infected,  they  shoukl  be  washed  immediately  and 
thoroughly,  although  not  necessarily  with  that  thoroughness  which  is  so 
essential  in  surgical  practice.  Ordinary  soap-and-water  treatment 
should  be  supplemented  by  the  application  of  some  more  power!  ul 
disinfectant.  Carbolic  acid  and  the  cresols  may  serve,  but  they  leave 
a  disagreeable  smell,  and  have  sometimes  an  unpleasant  eflPect  on  the 
skin.  Formaldehyde  in  3  per  cent,  solution  is  efficient,  but  when 
applied  frequently,  causes  a  hardening  of  the  epidermis  M'hich  is  far 
from  agreeable.  Corrosive  sublimate  1  :  1000  is  not  so  efficient,  and 
its  use  is  often  followed  by  dermatitis.  Schenk  and  Zaufal  ^  recommend 
the  use  of  sand  soap  followed  by  immersion  in  corrosive  sublimate 
1  :   1000,  as  hot  as  the  hands  can  bear. 

Air. — All  attempts  to  disinfect  the  air  of  the  sick-room  in  the 
presence  of  the  patient  are  futile,  for  the  presence  of  sufficient  of  any 
chemical  disinfectant  to  have  any  effect  on  the  bacteria  present  would 
cause  the  air  to  be  irrespirable.  It  is  a  common  practice  to  place 
about  the  room  dishes  containing  carbolic  acid,  permanganate  solution, 
chlorinated  lime,  iodine,  and  other  agents,  and  to  suspend  sheets  wrung 
out  in  all  kinds  of  active  and  inert  solutions,  in  the  vain  hope  that 
thereby  the  air  is  made  better  for  the  patient  and  incapable  of  trans- 
ferring infection  to  others.  Whether  the  agent  used  is  a  true  disin- 
fectant in  any  strength  ^vhatever,  and  whether  the  sheet  is  continuously 
or  only  intermittently  wet,  do  not  appear  to  enter  in  any  way  into  the 
question  of  efficiency.  Ordinarily,  anything  sold  in  the  shops  at  a 
high  price  and  under  a  label  alleging  not  infrequently  the  impossible, 
will  be  accepted  without  question.  But  it  may  safely  be  asserted  that 
no  disinfectant  known  can  be  of  the  slightest  service  when  used  in  this 
way,  and  if  this  is  true  of  the  disinfectant,  it  must  be  of  the  sheet. 

Much  can  be  done  to  remove  the  well-known  disagreeable  sick-room 
smell,  due  to  the  excreta  and  to  matters  eliminated  by  the  lungs  and 
skin,  but  all  hope  of  producing  sterility  of  the  air  should  be  aban- 
doned. If  pathogenic  organisms  are  present  in  the  air,  a  much  easier 
and  more  reasonable  method  of  dealing  with  them  is  that  of  thorough 
aeration,  and  this  is  one  of  the  most  important  parts  of  treatment  in 
general.  The  germicidal  properties  of  sunlight  should  also  not  be 
overlooked  when  it  is  possible  to  make  use  of  this  important  aid.  If 
good  ventilation  is  not  sufficient  to  keep  the  air  sweet,  the  old-fashioned 
pastilles,  containing  benzoin,  may  be  employed  as  occasion  demands, 
or  one  or  two  paraform  pastilles  may  be  volatilized  slowly  in  a  small 
lamp  for  the  purpose.  In  very  small  amounts  in  the  air,  the  gas  is  in 
no  way  disagreeable  or  irritating,  and  acts  very  powerfully  as  a  de- 
odorant, not  by  supplanting  the  smell,  but  by  destroying  it  by  chemical 
union. 

Room  Disinfection. — Net  until  the  termination  of  the  disease  or  the 
removal  of  tlie  patient  should  the  disinfection  of  the  sick-room  and  its 
contents  be  attemptod.  This  is  not  such  an  easy  matter  as  is  com- 
'  Miinchener  medicinisclie  Wochenschrift,  April  10,  1900. 


f>nA  (ITfdA  L   l>ISTNFK(;TIf>N.  C 1  ."> 

monly  Ixil'uivcd,  uikJ  miicli  Hiij)|>*).sr;(l  (liHiiir(;c(,i(»n  is,  l>y  rcahon  of  a 
lack  (»r  Mioroiijz^liiKiSs,  no  \h'\,{v.v  lliaii  iioiio  at  all,  or,  iii<l(;('(l,  \vorH<;,  bc- 
ciuisd  ol"  iiii<l('S(!rv(!(l  (;oijli(l<!ii(!(!  and  unConndcd  s'-nsc  of  safely.  Kveri 
willi  (lie  nlinoHf,  ciu'c!.  one  can  hardly  ('X|»('ct  altsoliito  jx-rferiion  of  rr- 
smIIs,  althoufrl:  in  idcial  (llsinCcrtion  every  niic'i-o-or^ani.sin  j)r(;s(jiit  hIiomM 
l)(!  <lestroy(!d.  Fiii}!;<;'e,'  w)h)  lias  devoted  nineJi  iinuj  and  study  U)  tlic 
(|n('st,ion  of  lionse  disinfection,  avers  that  with  any  proeess  hy  whieh 
!)()  |)(>r  (!(',nt.  of  the  |)athoii;eni<!  I)aet(!i"ia  presentare  destroyed,  on(!  should 
he  eontenl,  and  that  no  proeess  |)rae.tieahlc  will  kill  all  of  them. 

The  |)i()(H'sses  employed  n|>  to  within  very  recent  years  are  not^>ri- 
ously  inadecpiatc!,  and  tlu!  far  superior  processes  in  use  to-day  may  yet 
be  made  more  |)erfeet.  IFoiisc'  disinfection  is  often  most  insidli('ir;nt, 
even  when  wliat  has  been  <lon(!  has  been  e;irrie(|  out  with  every  care 
and  under  most  favorable  conditions,  since  it  is  the  usual  practice  U) 
disinfect  only  the  particular  room  which  the  |)atient  ha.s  occupied  dur- 
ing- his  sickness,  without  rei>;ard  to  the  f"a(!t  that  all  the  connectinp^ 
rooms,  hallways,  and  distant  parts  of  the  house  may  hav<!  become 
infected. 

The  open  doorway  opposes  no  iniseeu  obst;icle  to  the  passage  of 
niinnte  dried  particles  of  false  membrane  or  c]>idcrmal  scales  floatin^^ 
in  the  air,  nor  are  these  attracted  to  and  retained  by  tlie  interj)r>se<l 
sheet  like  particles  of  iron  by  a  magnet.  Even  when  the  door  is  closed, 
there  are  air  currents,  now  one  way,  now  the  other,  under  it  and  al>ove 
the  threshold.  Infective  material  may  be  carried  in  one  way  and 
another  by  members  of  the  family,  visitors,  attendants,  and  even  by 
the  patient  himself,  to  various  parts  of  the  house,  and  the  room  in 
which  he  has  lain  ill  may,  by  reason  of  proper  attention,  lie  the  least  in- 
fected one  in  the  house,  but  yet  in  ordinary  practice  it  is  the  only  one 
treated.  Probably  oftener  than  not,  much  more  than  one  room,  and  io 
not  a  small  proportion  of  cases,  the  Avhole  house,  should  receive  atten- 
tion. 

The  existing  methods  of  room  disinfection  comprise  mechanical 
treatment,  direct  appliaition  of  disinfectant  solutions  as  spray  or 
washes,  liberation  of  gaseous  agents,  and  combinations  of  all  three. 
The  bread  process,  devised  by  Esmarch,^  consists  in  rubbing  the  walls 
with  pieces  of  bread,  to  which  bacteria  adhere  with  great  tenacity. 
This  is  not  applicable  to  rough  walls,  and  when  thoroughly  and  prop- 
erly done,  involves  such  an  amount  of  labor  and  material  as  to  be  ex- 
ceedingly expensive.  The  bread  pieces,  together  with  all  crumbs 
which  break  oif  and  fall  to  the  floor,  are  carefully  removed  and  de- 
stroyed by  lire.  For  the  rest  of  the  room  and  its  contents,  other  proc- 
esses are  necessary,  including  scrubbing  with  soft  soap  and  water, 
wiping  with  disinfectants,  and  transportation  of  certain  articles  of 
clothing,  furniture,  bedding,  etc.,  to  the  public  disinfecting  station  to 
be  treated  by  steam. 

The  method  of  tre;itinp-  walls,    floors,    furniture,   and  clothing  bv 

1  Zeitschrift  fiir  ITvffienc  and  Tnfectionskraukheiten,  XXIX.,  1S9S,  p.  276. 
''  Zeitschnlt  fur  Hygiene,  II.,  1SS7,  p.  491. 


614  DISINFECTANTS  AND  DISINFECTION. 

spraying  with  solutions  of  mercuric  chloride  and  other  agents  com- 
mends itself  in  some  quarters  and  not  in  others.  According  to  Rideal, 
35,000  houses  in  Paris  were  disinfected  by  means  of  sublimate  spray, 
1  :  1000,  in  1893,  and  a  still  larger  number  in  1894  with  satisfactory 
results  and  with  no  bad  effects  from  the  poison.  It  appears,  however, 
according  to  later  evidence,^  that  a  number  of  the  employes  of  the  dis- 
infecting scj[uad  have  shown  symptoms  of  mercurial  poisoning,  and 
liideal  mentions  cases  of  salivation  in  India  attributed  to  corrosive 
sublimate  wash  for  floors.  The  spraying  process,  whether  satisfactory 
or  not,  and  whether  dangerous  to  health  or  not,  is  not  quick,  and  requires 
other  ti'eatment  which  consumes  time  and  adds  to  the  expense. 

The  ideal  disinfectant  would  be  a  gas  with  no  destructive  or  harm- 
ful action  on  anything  but  micro-organisms,  capable  of  penetrat- 
ing materials  by  which  they  are  hidden,  and  acting  with  great  quick- 
ness. Such  an  agent,  it  is  safe  to  say,  will  never  be  discovered,  for, 
even  though  the  other  requirements  may  be  met,  it  is  improbable  that 
the  physical  law  governing  difiiision  will  ever  be  modified  by  any  gas 
as  yet  undiscovered.  Gaseous  disinfection  must  ever  be  superficial  or 
nearly  so,  and  should  be  assisted  by  other  methods  to  bring  about  the 
best  results.  Gaseous  disinfectants  which  exert  any  injurious  influence 
on  the  objects  treated  cannot  be  tolerated,  and  it  happens  that  this 
class,  which  includes  chlorine  and  sulphur  dioxide,  has  been  found 
wanting  in  efficiency. 

Formaldehyde  gas  approaches  more  nearly  the  requirements  of  the 
ideal  disinfectant  than  any  thus  far  tried,  and  has  supplanted  all  others. 
In  its  application,  no  matter  how  it  is  generated,  whether  from  for- 
malin or  paraform,  it  is  essential  that  every  obstacle  possible  shall 
be  interposed  against  its  escape  from  the  space  under  treatment,  and 
that  all  objects  within  that  space  shall  be  so  disposed  as  to  present  as 
much  of  their  surface  as  possible  to  its  action ;  and  even  then,  absolute 
perfection  of  results  cannot  be  attained.  Fliigge  ^  relates  that  twice  he 
prepared  a  small  room,  containing  but  little  furniture,  by  placing  patho- 
genic organisms  on  marked  locations,  and  had  the  local  disinfecting 
squad  perform  their  office  under  careful  supervision,  and  in  both  in- 
stances found  that  a  fair  percentage  of  the  bacteria  escaped  destruction. 
He  suggests,  with  good  reason,  that,  in  routine  practice,  the  results  must 
ordinarily  be  far  less  favorable. 

For  the  attainment  of  the  best  results,  the  various  articles  of  furni- 
ture should  be  moved  away  from  the  walls,  all  articles  of  clothing, 
blankets,  and  other  textiles  should  be  suspended  freely  on  lines  or 
clothes-horses,  the  pockets  of  clothing  turned  inside  out,  and  all  cracks 
and  other  outlets  carefully  stopped  with  wet  cotton,  putty,  adhesive 
paper,  or  other  suitable  material. 

Particular   attention   should  be  paid  to  the  complete  closure  of  all 

inlet  and   outlet  registers  j  those  in  the  walls  should   be  pasted  over 

with  stout  paper,  and  those  in  the  floor  should  be  so  treated  or  covered 

with  thick  cloth  wrung  out  in  sublimate  solution  or  diluted  formalin. 

1  Journal  of  State  Medicine,  IV.,  189G,  p.  146.  ^  Loc.  cit. 


PRA crrrM  l  disinfection.  0 1 5 

Loosdly  fii.tiii};'  wiiidow-sMslics  \\\:w  ln'  mi;i(Ic  ti^lit  !>)'  nic'iriH  u\'  \vot)fJcn 
W(!<lji;(!H,  ;mi(I  IIh!  ci'mcIvm  iiroiiinl  iIkmi  piopcrly  Hliifl'cd.  I C  there  Ih  a 
hIovc  ill  (:li(!  room,  ils  doors  ;iiid  o|)(iiiiijrH  lor  drafts  hlioiild  Ix;  H-cnn-Iy 
Healed.  Open  (ireplaccs  and  I'^ranklin  stovffH  re«jiiire  eoriiplet*;  elosiire 
of  iJieIr  (Iiie-oiil  lets.  The  doors  of  all  eloseis  and  eiij(lH»ards  and  the 
drawers  of  all  hiireaiis  and  eahinds  should  ho  left  open.  All  soi|f<| 
])lu(;es  on  IIki  walls,  floor,  and  Cnnill  iirc,  jioHHibly  diK-  to  infcelive 
inaierial,  should  he  welted  with  lornialiii  or  siihliinate  solution. 

When  the  room  has  been  |)roperly  prepared,  the  generation  of  the 
^as  may  he  l)e<2;iin.  if  paraform  lamps  or  lln'  Ureslaii  ajijjaratusj-s  an; 
onij)loye(l,  the  ojx'ialor  leaves  the  room  and  stops  the  e,raek  under  tlie 
door  with  wot  cotton  and  closes  llie  keyhole  with  a  ^nmniod  hihel  f»r 
with  putty.  If  an  autoclave  or  other  similar  apparatus  is  employed, 
the  stop|)inn>  of  the  keyhole  of  the  door  is  necessarily  (ieferrcd  until 
tlie  f>;eneration  of  the  gas  is  c()ni])leted.  The  room  is  then  loft  uiiopenefl 
over  night  or,  if  the  process  is  hegiin  in  the  morning,  through  the  day. 
On  the  expiration  of  the  required  time,  ammonia  in  the  nowissjiry 
amount  is  vaporized  tln'ough  th(>  keylK)le,  or  tlie  room  is  ontore<l  at 
once,  the  windows  lhi-own  open,  and  free  aeration  estahlisliod.  In  the 
latter  case,  the  operator's  eyes  should  be  protected  by  closely  fitting 
goggles,  and  he  should  hold  his  breath,  if  possible,  until  his  object  is 
a('(!omp1ished.  If  ammonia  is  employed  to  neutralize  the  gjis,  the 
room  will  be  sooner  inhabitable  than  otherwise,  especially  if  steam  has 
been  generated  simultaneously  with  the  gas,  as  advocated  by  Fliigge, 
for  aeration  may  require  many  hours,  and,  in  some  cases,  days,  to  rid 
the  room  of  the  odor.  This  is  a  matter  of  extreme  importance  with 
])eoi)le  of  small  means  living  in  limited  sjiaecs,  who  cannot  afford  even 
the  temporary  inconvenience  and  expense  of  finding  outside  accommo- 
dations. 

Mattresses  which  have  been  polluted  by  soakage  of  urine  and 
excreta,  thick  clothing,  and  other  articles  which  do  not  lend  themselves 
to  su])erticial  gaseous  disinfection,  require  treatment  by  steam  in  the 
special  a]iparatuses  described  on  a  preceding  ]iage.  Straw,  corn-husk, 
and  "excelsior"  mattresses  should  be  differently  treated.  Their  con- 
tents should  be  removed  and  burned,  and  the  ticking  soaked  in  disin- 
fectants and  boiled.  Stuffed  furniture  covered  with  woven  fabrics 
should  be  taken  out  of  doors  and  be  ^vell  beaten  and  left  exposed  to  the 
air  and  direct  sunlight.  If  upholstered  in  leather,  it  should  be  well 
wdped  in  all  the  crevices  with  cloths  Avrung  out  in  sublimate  solution  or 
diluted  formalin. 

Heavy  clothing  and  other  fabrics  sometimes  are  sent  to  be  treated  by 
the  benzene  process,  in  the  belief  that,  by  this  means,  not  only  are 
grease  spots  removed,  but  that  sterilization  is  effected.  Riipp,^  how- 
ever, has  pointed  out  that,  in  the  ordinary  benzene  process,  pus  cocci 
and  the  bacilli  of  typhoid  fever,  anthrax,  diphtheria,  and  tuberculosis 
are  not  destroyed. 

^  Correspondenzblatt  fiir  Schweizerische  Aerzte,  1S97,  Xo.  19. 


616  DISINFECTANTS  AND  DISINFECTION. 

Disinfection  of  Books. — Bot)ks  are  extremely  difficult  to  sterilize 
with  certainty,  on  account  of  the  protectiou  that  is  given  to  bacteria  by 
the  juxtaposed  pages.  Unbound  books  may  be  subjected  to  treatment 
by  steam,  but  this  process  is  not  suited  to  bound  volumes,  because  of 
its  eifect  on  the  glue.  For  bound  books,  the  only  available  disinfectant 
is  formaldehyde,  but  even  this  agent  is  not  efficient,  unless  the  leaves  are 
so  disposed  that  the  gas  can  have  access  to  every  page.  Books  of  value 
will  require  very  thorough  and  repeated  treatment ;  but  those  of  small 
value,  known  to  have  been  probably  or  possibly  infected,  are  best 
destroyed  by  fire.  If  formaldehyde  treatment  is  deemed  advisable, 
they  should  be  placed  on  edge,  with  the  leaves  opened  as  much  and  as 
freely  as  possible,  and  subjected  re]:)eatedly  to  the  action  of  the  gas  in 
a  tight  closet  or  box. 

Disinfection  of  Water-closets.  —  Water-closet  bowls  may  be 
treated  with  dilute  formalin  or  5  per  cent,  solution  of  the  cresol 
preparations.  The  wood-work  around  and  near  them  may  be  washed 
with  the  same  agents.  Sublimate  solution  should  not  be  used  in 
plumbing  fixtures,  on  account  of  its  action  on  lead. 


on  A  i'^im<:r   I  X. 
MHJTAiiV  in'(iii:.\K. 

SiN(.jK  lli(!  mosi,  iiii|M)r(;inl  (":i('t(»r  in  (he  clliclciif^y  of  un  army  is  its 
ii(!iil(li,  i(  lullows  llial  ('VciTlliiii<r  \vlii<-Ii  iiiiiy  iiiflncncc  lliis  in  any  way 
for  the  Ix'Mcr  <ir  worse  slmiilil  he  Idokcil  :i('tcr  with  the  utiriost  cnw.. 
The  men  who  conipo.se  an  army  ai'ech'awn  IVom  eivil  life,  in  whieh  eaeh 
in(livi(hi:i,l  has.  to  a  irroatcr  or  lesscir  (!Xt(^nt,  independent  ertntrol  of  his 
time,  <!li()ie(!  of  O(!cui)ation,  H(!l(!(;!i<in  of  food  and  dwellin^--|)lae<',  and 
general  sanitary  care.  After  enlistment,  soldiers  lose;  most  of  this  indr;- 
pcndence  ;  they  are  housed,  clothed,  fed,  and  exercised  under  regulatioua 
wlii(^h  it  is  beyond  theii-  powei-  to  amend  ;  they  are  moved  frr>m  one 
point  to  another,  dilferiiifjj  |)erhaps  very  widely  in  climatir-,  and  other 
conditions,  under  orders  which  they  may  not  ])resume  to  cjuestion  ;  their 
hours  for  sleep,  meals,  \vork,  and  recreation  are  fixed  for  them  without 
consultation  with  them,  and  without  regard  to  individual  or  communal 
preference. 

Since  the  s^overnmcnt  necessarily  deprives  the  soldier  of  his  indepen- 
dence of  action,  it  is  bound  by  every  principle  of  fairness  to  him  to  look 
after  bis  health  and  comfort,  to  promote  contentment,  and  to  waixl  off 
ennui  by  all  reasonable  and  proper  means.  Thus,  the  care  of  troops  is 
a  double  oblig-atiou  ;  the  men  have  every  right  to  expect  it,  and  the 
efficiiency  of  the  army  is  dependent  upon  it.  But  no  matter  how  care- 
ful the  sanitary  administration,  it  is  a  matter  of  common  knowledge 
that  in  all  wars,  excepting  the  Franco-Prussian,  and  in  that  only  with 
regard  to  the  Germans,  the  mortality  from  disease  has  been  far  in  ex- 
cess of  that  from  casualties,  and  in  all  armies,  more  discharges  are  due 
to  sickness  than  to  injui'ies. 

The  responsibility  for  the  care  of  troops  and  health  of  camps  is 
placed  upon  the  medical  officers,  who  have  no  power  to  com- 
mand and  are  hampered  by  being  subordinate  to  laymen  having 
often  no  adequate  appreciation  of  matters  purely  medical.  They 
have  only  advisory  functions,  and  must  be  most  careful  in  recom- 
mending changes  to  the  very  conservative  military  mind,  which  finds 
in  long  continuance  of  a  condition  the  strongest  argument  for  its 
longer  retention,  and  is  prone  to  look  upon  recommendations  for 
sweeping  changes  as  evidence  of  whimsical  disposition  and  deficient 
training  in  sanitary  science.  Nevertheless,  the  medical  officer  has 
a  very  heavy  responsibility  placed  upon  him,  and  must  advise  his 
lay  superiors  and  explain  the  im]iortance  of  the  princi]>les  underlying 
sanitary  practice.  He  must  make  ]iroper  recommendations  for  the 
protection  of  health  of  the  troops  in  war  and  in  peace,  in  camps  and  in 
garrison. 

617 


618  MILITARY  HYGIENE. 

Since  the  efficiency  of  a  military  body  is  so  largely  dependent 
upon  the  health  of  the  units  of  which  it  is  composed,  the  result 
of  a  campaign  may  be  largely  influenced  by  the  adoption  or 
rejection  by  the  commanding  officer  of  the  recommendations  of 
his  medical  adviser.  Unfortunately,  if,  by  reason  of  physical  un- 
fitness of  the  troops,  a  moyement  fails  or  an  epidemic  of  disease 
occurs,  the  public  c\t  once  places  the  blame  upon  the  medical  depart- 
ment, and  especially  upon  the  head  thereof,  the  Surgeon-General,  and 
demands  a  reorganization,  a  sifting  out  of  incompetent  material,  and 
especially,  a  change  in  the  head,  quite  regardless  of  the  possible  fact 
that  the  choice  of  an  unsanitary  camping  place  may  have  been  made 
against  the  judgment  and  advice  of  the  medical  branch,  that  the  com- 
missary department  may  have  been  largely  to  blame,  or  that  other 
influences  quite  beyond  the  control  of  the  medical  corps  may  have  been 
at  lault. 

The  medical  officer,  both  at  home  and  in  most  countries  abroad,  has 
much  ^vith  which  to  contend.  The  corps  is,  as  a  rule,  not  sufficiently 
large  for  the  body  for  which  it  is  to  care,  but  is  expected  to  perform 
an  amount  of  work  and  assume  a  responsibility  which  would  fairly  tax 
the  capacity  of  one  of  double  size.  In  an  emergency  requiring  large 
additional  levies  and  consequent  employment  of  civilian  physicians 
untrained  in  military  life,  the  responsibility  becomes  proportionately 
greater. 

The  recent  experiences  of  this  country  and  of  England,  when  the 
outbreak  of  war  necessitated  the  assembling  and  transportation  of 
large  armies,  serve  very  well  as  illustrations.  With  us,  on  the  break- 
ing out  of  war  with  Spain,  a  standing  army  of  25,000  was  suddenly 
increased  by  enlargement  of  the  regular  service  and  enrollment  of  vol- 
unteers to  ten  times  that  size,  but  the  small  body  of  trained  military 
surgeons,  too  small  before,  could  hardly  have  been  expected  to  be  equal 
to  the  demands  of  the  new  army,  even  with  the  assistance  of  the 
physicians  from  civil  life,  who,  although  doubtless  highly  efficient  in 
civil  practice,  were  for  the  most  part  inexperienced  in  camp  hygiene. 
The  difficulties  of  sanitary  administration  were  very  largely  increased 
by  the  recldessncss  and  ignorance  of  the  volunteers  in  personal  hygiene 
and  general  sanitation.  The  results  were  what  might  be  expected,  and 
are  too  well  known  to  need  further  mention.  The  blame  for  all  the 
disastrous  experience  was  placed  at  once  upon  the  medical  department, 
which  had  luit  little  to  say  in  the  choice  of  camps,  and  nothing  what- 
ever to  do  with  the  inadequate  means  of  transportation  and  other  factors 
in  the  production  of  a  large  mortality  from  disease.  The  experience 
of  the  English  in  the  war  in  South  Africa  was  essentially  the  same,  and 
was  due  to  the  same  causes. 

In  the  large  standing  armies  on  the  Continent,  a  diffisrent  order  of 
things  obtains.  The  officers  of  the  line  are  more  inclined  to  defer  to 
the  opinions  and  advice  of  the  medical  staff  in  matters  requiring  expert 
sanitary  knowledge,  and  the  authorities  demonstrate  a  much  higher 
appreciation  of  the  value   of  an   adequate   medical    service.      As  an 


77//';   lll'JUHJIT.  019 

illiistr.'itioii  of"  llic  (liU'crcnrc   in   ili(!  imh'v'\\\\£  of  Mirli    irinttirH  in  ('ti:r- 
nijuiy  iuid   rjnjj;l;in(l,  IIk;  following  is  cited  : 

'V\\(\  Jirilisli  (irsl,  inriiiilry  flivision  nnd  (irst  ciivalry  liri^iidc,  wifli 
two  batteries  of  (ield  nilillery,  ;i  eoni|);iny  (tC  rmj.dneepH,  tel(;gra|)li 
(!()rj)H,  railway  eoiii|»;niy,  niiiinniiilion  corps,  and  lio,~|)it;d  eorpH,  onJerod 
to  Sontli  ACriea  in  tlie  antinnn  of  I  .SIMJ,  and  llie  (ierniaii  exjx'ditionary 
(5or|)S,  eonsislinjr  of  two  brij^jules  of"  infantry,  three  .sfjuadrons  of  chiv- 
alry, l"onr  batteries  of  n<rbt  artillery,  a  batallion  of  j)ioneers,  with  a 
telegraph  corps,  railway  <!onipany,  sanitary  company,  anitnunition 
coi-ps,  and  hospital  corps,  organized  in  the  summer  of  1000  for  Hcrvia; 
in  (!hina,  were  abont  e((nal  in  nnniber  of"  men.  For  the  can;  of  thes<i 
troops,  the  l]ii<;lisii  aiitliorilies  detailed  -I!)  rej^nlar  medical  officers  and 
13  civilian  sni-n;eons,  a  total  of  02;  the  Germans  debiiled  91  re^rnlar 
army  sni"f2;eons,  or  nearly  50  per  cent.  more.  The;  Knjrli.sh  h(j.spital 
shij)  liad  .'}  surgeons  ;  the  German  had  10.  The  Enjjjlish  sent  4  (ield 
liosj)itals  with  10  snrneons  ;  (lu!  (Jermans  sent  an  equal  number  with 
24.  The  l^^nglish  general  hospital  bad  18  surg<,'ons,  of  whom  11  wore 
civilians;  the  German  had  19,  all  of  whom  were  regulars. 

The  superior  medical  equipment  of  the  Germans  is  not  dictated  by 
extravagance,  but  by  a  greater  a})])reciation  of  the  necessity  of  furnish- 
ing adequate  medical  service. 

In  a  standing  army  such  as  is  maintained  in  this  country,  it  would 
be  far  better  to  err  on  the  side  of  extravagance  than  of  undue  economy 
in  the  size  of  the  medical  corps.  There  should  be  systematic  instruc- 
tion in  general  hygiene,  which  should  not  be  limited  to  the  medical 
officers  alone,  for  the  line  officers  also  should  be  required  to  accpiaint 
themselves  Avith  the  principles  of  the  science,  and  especially  with  the 
sanitation  of  camjis.  Then,  when  the  medical  officers  point  out  meth- 
ods of  conserving  the  health  of  troojis,  those  in  actual  command  would 
be  in  a  better  position  to  ap})ly  their  authority  with  a  larger  apprecia- 
tion of  the  advice  given. 

Military  hygiene  has  to  deal  with  the  selection  and  examination  of 
men  offering  themselves  as  recruits,  their  habitations,  clothing,  exercise, 
food,  diseases,  and  medical  care ;  with  camp  sanitation,  including 
water  supply  and  sewerage,  disposal  of  waste,  and  general  police  ;  and, 
in  general,  with  all  matters  having  any  bearing  on  the  health  and, 
impliedly,  the  efficiency  of  troops. 

THE  RECRUIT. 

Not  every  adult  man  accustomed  to  hard  work  can  be  transformed 
into  a  good  soldier,  for  there  are  many  points  of  disqualification  for 
military  service,  and  an  unsound  man  can  never  be  depended  upon 
when  his  services  are  needed.  The  ideal  recruit  is  one  who.  in  the 
first  place,  is  M'ell  built  and  of  superior  muscular  force,  capable  of 
resisting  influences  tending  to  depress  the  nervous  and  physical  powers. 
According  to  the  great  Napoleon,  "  The  first  quality  of  a  soldier  is  the 
power  to  endure  fatigue  and  privation  ;  courage  is  only  second.''     This 


620  MILITARY  HYGIENE. 

primary  qualification  is  very  coinnionly  tlu)Ui;;ht  to  be  an  attribute 
more  of  the  ectuntry-bred  than  of  the  city-bred  hid. 

Dr.  AVoodhull/  Lt.-Colonel,  Med.  Dep't  U.  S.  A,,  however,  says  on 
this  point :  "  In  raising  new  troops,  when  it  is  possible  to  select,  for 
sharp  and  immediate  active  service  take  town-bred  men.  If  a  year  or 
two  can  be  ailded  in  which  to  train  them,  take  country-bred  men. 
Open-air  military  life  is  physical  promotion  to  city  men  accustomed  to 
irregular  hours,  unwholesome  meals,  and  poorly  ventilated  rooms.  To 
country  lads  the  irregular  and  sometimes  scanty  meals,  broken  rest, 
necessity  for  prompt  and  exact  action,  and  above  all  the  certainty  of 
acquiring  such  diseases  as  measles,  whooping-cough,  and  nnuiq)s,  which 
town  boys  always  have  in  childhood,  are  \'ery  exhausting.  After  a 
year's  training,  country  youths  are  more  valuable." 

"Applicants  for  first  enlistment  must  be  between  the  ages  of  eighteen 
and  thirty-live  years,  of  good  character  and  temperate  habits,  able-bod- 
ied, free  from  disease,  and  must  be  able  to  speak,  read,  and  write  the 
English  language. 

"  No  person  under  eighteen  years  of  age  will  be  enlisted,  reenlisted,  or 
accepted  with  a  view  to  enlistment,  and  minors  between  the  ages  of 
eighteen  and  twenty-one  years  must  not  be  enlisted,  or  accepted  with 
a  view  to  enlistment,  without  the  written  consent  of  the  father,  only 
surviving  parent,  or  legally  appointed  guardian,  to  the  minor's  en- 
listment. 

"  Original  enlistments  will  be  confined  to  persons  who  are  citizens  of 
the  United  States,  or  of  Porto  Rico,  or  who  have  made  legal  declaration 
of  their  intention  to  become  citizens  of  the  United  States.  Applicants 
for  original  enlistment  who  claim  to  have  been  naturalized  or  to  have 
declared  their  intention  to  become  citizens  of  the  United  States  will  not 
be  accepted  for  enlistment  or  enlisted  unless  they  exhibit  to  the  recruit- 
ing officer  documentary  evidence,  under  the  seal  of  a  court  of  competent 
jurisdiction,  of  their  naturalization  or  their  declaration  of  intention  to 
become  citizens.   .   .  . 

"  Married  men  will  be  enlisted  only  upon  the  approval  of  a  regimental 
commander,  or  other  proper  commanding  officer  if  for  other  than  a  reg- 
imental organization. 

''Applicants  wall  be  required  to  satisfy  the  recruiting  officer  regarding 
age  and  character,  and  should  be  prepared  to  furnish  the  necessary  evi- 
dence.^ 

"  For  infantry,  coast  artillery,  and  engineers  the  height  must  be  not 
less  than  five  feet  four  inches,  and  weight  not  more  than  one  hundred 
and  ninety  (190)  pounds. 

"For  cavalry  the  height  must  be  not  less  than  five  feet  four  inches,  and 
not  more  than  five  feet  ten  inches,  and  weight  not  to  exceed  one  hun- 
dred and  sixty-five  (165)  pounds. 

"  For  field  artillery  the  height  must  be  not  less  than  five  feet  four 
inches  and  not  more  than  six  feet,  and  weight  not  more  than  one  hun- 

*  Notes  on  Military  Hygiene  for  OfScers  of  the  Line,  New  York,  1898,  p.  18. 
^  Circular  No.  69,  War  Department,  Oct.  25,  1910. 


77/ a;  iii'.cnrir. 


621 


(Ircd  and  iiiiiciy  (ll>0)  |)(>iiii(ls.  Vnr  tlic  inoiiiil.iln  Iciflcric-  iIm-  li«'i;;lit 
rnusl,  he  nol,  less  lli:iii  live  (rd-  ('ijrlil  iiwlx-. 

"A  v;ifi;ii  ion  nutcxrccdiiiir  a  (V;ict  ion  olnn  inch  ulKtvc  llic  rnaxilniirn 
luii<;li(.  f^ivcn  (<»r  c'lNiiIrN'  ;iii<l  liild  ;iillll(  ly  i-  jxrniJHsiljIc  if  llic  ajipli- 
ciinl,  Ih  in  <:;<)()d  licnllli  ;ni(l  i:-  in  fitlicr  n-pf  ct^  dcsirahlo  as  a  V(f-n\\\. 

"'I'lui  niininnini  \v<ii;lil  Inrall  ai'ins  of  llic  stirvirc  is  <»nf!  [iundn'«l  aiicl 
tw('nliy-('ii!;li(.  (1-5'^)  poinids,  siihjccl  to  variafi«tns  hclow  tliaf,  standard  as 
ox|)lain('d  licicin  ;  l)ii(  in  no  <!aso  will  an  ai)|)liratit  wlios(!  weight  fall.s 
below  one'  hnn<li<(i  ;nid  twenty  (120)  pounds  Ik;  a('f!('j)t(!d  without  sftr-- 
ciid  antliority  IVoin  I  lie  Adjutant  (inncral  of  the  Army. 

Ty\Hi,i';  OK  I'livsicAi,  1 'iM n'ouTioNH  I'Oit  IlKKiU'r,  Wkk; nT,  A Ni» ( 'uKST  MeA8i;bkment. 


Height. 

Weight. 

Chest  measurement. 

Feet. 

Inches. 

Pounds. 

At  expiration : 
Inches. 

Mobility : 
Inches. 

r;  9 

51? 

6 

6A 

fit 
fi5 
60 
G7 
68 
69 
70 
71 
72 
73 

128 
130 
132 
134 
141 
148 
155 
1G2 
1()9 
170 

32 

32 

32^ 

33 

33} 

33J 

34 

34} 

34| 

35} 

2 

2 

2 

2 

2J 

2i 

2i 

2i 

3 

3 

"In  ealcnlatino;  the  proportional  weight  and  chest  measurements  of  an 
ap])lioant  for  enlistment  any  fractional  part  of  an  inch  in  height  equal 
to  or  greater  than  a  half  inch  will  be  counted  as  a  full  inch  ;  any  frac- 
tional })art  of  an  inch  in  height  less  than  a  half  inch  will  be  disregarded. 
It  is  not  necessary  that  the  applicant  should  conform  exactly  to  the 
figures  indicated  in  the  foregoing  table.  The  following  variations  below 
the  standtird  given  in  the  table  are  permissible  when  the  applicant  is 
active,  lias  firm  muscles,  and  is  evidently  vigorous  and  healthy. 


Height. 

Chest  at 
expiration. 

Weight. 

Inches. 

64  and  undor  OS 

OS  mid  umkn-  09 

69  and  undor  70 

70  and  upward  ....                .        ... 

Inches. 
2 
2 
2 
2 

Pounds. 

8 

12 

15 

20 

"  Marked  disproportion  of  weight  over  height  is  not  a  cause  for  rejec- 
tion unless  the  applicant  be  positively  obese." 

Enlisted  men  of  good  character  and  faithful  service,  who,  at  the 
expiration  of  their  terms,  are  undergoing  treatment  for  injuries  incurred 
or  disease  contracted  in  the  line  of  duty,  may  reenlist.  and  if  the  dis- 
ability prove  to  be  permanent,  they  will  be  subsequently  discharged. 


622  MILITARY  HYGIENE. 

An  enlisted  man,  not  under  treatment,  but  with  infirmities  eontracted 
in  the  line  of  duty  not  such  as  to  prevent  his  performing  the  duties  of 
a  soldier,  may  be  reenlisted  by  authority  of  the  War  Department,  on 
application  made  throusih  the  surgeon  and  proper  military  channel, 
since  it  is  recognized  that  Mhat  he  may  lack  in  some  minor  particulars 
in  soundness  may  be  counterbalanced  by  experience  and  habits  of  dis- 
cipline. 

Those  whose  enlistment  is  prohibited  include  former  soldiers  having 
bad  record,  deserters,  drunkards,  insane  persons,  minors  below  16 
years  of  age  (musicians),  persons  who  have  been  convicted  of  felony 
or  who  have  been  imprisoned  under  sentence  of  a  court ;  and  for  first 
enlistments  in  time  of  peace,  non-citizens,  except  those  who  have 
legally  declared  their  intentions  to  become  citizens,  those  who  cannot 
speak,  read,  and  write  English,  and  those  over  35  years  of  age. 

It  is  almost  the  universal  opinion  that  recruits  ought  not  to  be  ac- 
cepted below  20,  or,  better,  22.  At  18  years,  the  recruit  is  immature  ; 
the  bones  are  not  fully  formed,  nor  have  they  reached  their  final  hard- 
ness ;  the  epiphyses  have  not  become  incorporated  with  the  shafts  of 
the  long  bones ;  the  joints  are  not  fully  developed  ;  the  muscles  are 
soft  and  not  wholly  developed ;  the  chest  has  by  no  means  attained  its 
full  capacity ;  and  the  organs  of  the  body,  in  general,  are  immature. 
So  it  happens  that,  at  this  age,  it  is  useless  to  expect  them  to  be  in 
good  condition  after  long-continued  exertion  or  to  undergo  privations 
which  are  as  nothing  to  the  man  of  mature  years  and  strength.  At 
this  period  of  life,  he  is  still  in  the  growing  stage  and  needs  all  the 
energy  of  his  body  to  bring  the  organism  to  completion,  and  the  in- 
fluences which  mature  soldiers  contend  against  with  varying  degrees  of 
success,  namely,  vicissitudes  of  weather,  long  marches,  hard  work  in 
trenches,  possible  overcrowding  in  barracks  and  camps,  poor  ventila- 
tion, and  poor  and  insufficient  food,  send  him  very  quickly  to  the 
hospital.. 

It  is  beyond  reason  to  expect  the  same  work  and  endurance  of  a 
youth  of  18  to  20  as  of  a  fully  mature  man.  During  the  Civil  War, 
most  of  the  boys  who  enlisted  under  18,  and  many  of  those  above  that 
age  and  under  20,  had  to  be  discharged  within  the  first  few  months. 

It  has  been  demonstrated  repeatedly  that  the  least  efficient  armies 
are  those  containing  the  greatest  proportion  of  men  below  the  age  of 
22.  The  first  Napoleon  objected  to  boys,  saying  on  one  occasion,  "  I 
demand  a  levy  of  300,000  men.  But  I  must  have  grown  men  ;  boys 
serve  only  to  fill  the  hospitals  and  encumber  the  roadsides."  A  re- 
markable example  of  the  importance  of  maturity  in  soldiers  is  related 
by  Tardieu.^  In  the  campaign  of  1805,  in  which  the  army  marched 
400  leagues  to  reach  Austerlitz,  hardly  any  sick  or  stragglers  were  left 
on  the  way.  In  this  array  the  youngest  were  22  years  of  age  and  had 
had  two  years'  training.  In  the  campaign  of  1809,  on  the  other  hand, 
the  army,  which  had  but  a  short  distance  to  march  on  its  way  to 
Vienna,  filled  all  the  hospitals  on  the  way  with  its  sick.     More  than 

1  Pictionnaire  d'llygiene,  III.,  p.  2., 


Till':  nKcnuiT.  623 

half  Mic  Holdiors  of  iJiis  nriiiy  wen;  iirMlcr  20  years  of  u^o  and  inex- 
j)(!ri(!n(',c(l.  Ill  (1)(!  (•(■Icl)r;il('(l  /narcli  of  fionl  IJohf-rtH  from  Kafjiil  t^) 
Kaiidaiiar,  <,li(!  yoimti;  soldicPH  f^a,V('- <»ii(  (Voin  dny  today  and  fell  l)fliind, 
wliil(!  the  old  cMiiiiwiif^iicrs  ii|>|)(;ar<!(i  to  i^uin  in  vi^or  with  <-;i''li  <l;i\'- 
niai'cli. 

Not  only  an;  ymnji;  rccirnils  I(wh  al)l(!  tx)  iinderfrr)  the  usual  work  and 
tli(^  harclships  ihan  seasoned  men,  bnt  they  are  rnneh  more  HUHfMtplihh: 
to  disease.  Ai(-I<en  '  relat(!s  tliat,  (hirin;:;  th('  Crim(sin  W^ar,  wlien  the 
Commaii(h;r-in-(yhief',  Lord  Ilafj^lan,  was  informed  that  2,000  rf;eruit« 
were  ready  to  be  .sent  to  him,  h(!  r('j)Iied  :  ''Those  hist  sent  were  »o 
yonnuj  and  nnformed  that  they  fell  victims  to  disease  and  were  swept 
away  like  Hies."  He  preferred  to  wait  rather  than  iiave  sufili  young 
lads  sent  to  him  as  soldiers.  Other  eomtnandcr-  in  ihe  Crimea  testi- 
fied that  young  reeriiils  were  of  very  infei-ior  value. 

Tlio  greater  susceptibility  of  young  soldiers  to  typhoid  fever  wa.s 
demonstrated  by  Dr.  l^'arr,  the  l>ritish  Registrar-General,  and  by  I)r, 
JJalfour,  who  showed  that,  in  1S8.'>,  the  army  in  India  contained  41 
})er  cent,  of  soldiers  under  25  years  of  age,  and  that  among  this  con- 
tingent the  death-rate  from  this  disease  was  4.34  per  tliousand,  while 
that  of  the  men  of  25  to  29  years  was  but  1.50  per  thousand.  Jn 
newly-arrived  ivgiments,  nearly  half  of  the  total  death-rate  was  from 
this  disease.  Aitkcn  gives  a  number  of  instances  of  the  influence  of 
youth  and  short  residence  on  the  prevalence  of  this  fever.  At  one 
station,  for  example,  out  of  44  cases,  35  occurred  in  one;  regiment  com- 
posed principally  of  young  soldiers,  and  33  among  men  of  less  than 
one  year's  residence  in  India. 

In  1883,  in  India,  36.55  per  cent,  of  those  invalided  home  were 
under  25  years  of  age,  and  in  1884,  38.70,  the  principal  diseases  neces- 
sitating invaliding  being  anremia,  debility,  phthisis,  he])atitis,  and  dis- 
eases of  the  heart  and  arteries.  Throughout  the  Peninsular  AVar,  from 
1805  to  1814,  it  was  observed  that  the  "  corps  Avhich  arrived  for  service 
were  always  ineffective  and  sickly  in  proptirtion  as  they  were  made  up 
of  men  who  had  recently  joined  the  ranks,"  and  it  was  calculated  that 
300  men  having  five  years'  experience  were  worth  more  than  1,000 
newly-arrived,  including  the  usual  proportion  of  young  recruits. 

Surgeon-General  Sternberg,  of  the  U.  S.  Army,  in  his  annual  report 
for  1885,  shows  that  the  greater  proportion  of  sickness  occurred  among 
soldiers  under  31  years  of  age,  and  that  up  to  the  age  of  25,  the  rate 
was  so  much  above  the  average  foi"  the  whole  army,  that  he  questions 
whether  their  services  had  been  a  fiiir  return  for  the  cost  of  their  luain- 
tenanee.  In  1899,  the  British  ]\Iedical  Association  passed  a  resolution 
requesting  the  Council  to  communicate  to  the  AVar  Office  the  opinion 
of  the  Section  of  INIedieine,  that  no  soldier  ought  to  serve  in  the  tropics 
earlier  than  22  years  of  age. 

In  favor  of  the  young  recruit,  Woodhull  says  that  young  men  are 
more  easily  trained  and  moulded  than  older  men,  especially  for  the 
cavalry,  and  when  well  led,  fight  as  well,  as  flir  as  mere  courage  goes. 

1  On  the  Growth  of  the  Kecruit  ;uul  Young  Soldier,  2d  Edition,  London,  18S7,  p.  58. 


624  '     MILITARY  HYGIENE. 

But  as  we  cannot  keep  young  soldiers  several  years  in  training,  and  as 
large  bodies  of  troops  can  only  be  raised  for  sudden  war,  men  not 
absolutely  mature  must  be  rejected.  Ijord  AVolseley  prefers  young  men, 
and  says  :  ^  "  Give  me  young  men  :  they  do  what  they  are  bid,  and  they 
go  where  they  are  told  ;  they  become  more  amenable  to  discipline,  and 
though  when  you  catch  them  first  they  may  have  some  difficulty  in 
carrying  their  knapsacks,  once  they  get  beyond  that  they  are  in  a  fit 
condition  to  take  the  field." 

If  young  men  are  enlisted,  the  work  should  be  suited  to  their 
strength,  and  it  should  be  kept  in  mind  that  they  are  still  in  the  grow- 
ing and  developing  stage,  and  should  have  no  greater  amount  of 
physical  exercise  than  is  suited  to  their  condition.  In  other  words, 
their  work  should  be  proportioned  to  their  growth,  and  in  two  years 
they  will,  perhaps,  have  developed  into  valuable  soldiers.  Taken 
between  the  ages  of  18  and  20,  and  drilled  and  trained  with  due  regard 
to  his  immaturity  and  limit  of  endurance,  the  recruit  often  shows  great 
progress  in  general  development  within  the  first  half-year,  particularly 
if,  before  enlistment,  he  was  poorly  fed,  clothed,  and  housed,  and 
engaged  in  an  indoor  occupation.  His  work  should  be  moderate  in 
the  beginning  and  only  gradually  increased,  since  changes  for  the  better 
in  the  human  body  cannot  be  brought  about  suddenly  like  those  for  the 
worse,  induced  by  attempting  to  do  too  much  at  the  outset.  Since  his 
lungs,  heart,  and  blood-vessels  are  not  yet  fully  developed,  he  can 
neither  go  through  the  manual  nor  cover  ground  like  the  seasoned 
soldier.  The  heart  is  called  upon  by  the  new  and  unaccustomed 
exercise  to  contract  at  a  greater  rate  than  had  been  its  habit,  and  he 
soon  becomes  "winded."  When  this  stage  is  reached,  and  he  begins 
to  feel  or  show  distress,  he  should  be  allowed  and  encouraged  to  rest 
until  the  throbbing  of  the  heart  and  the  swelling  of  the  blood-vessels 
sul^side  and  permit  his  lungs  to  resume  easy  breathing ;  otherwise,  he 
is  more  than  likely  to  break  down  sooner  or  later.  AVith  properly 
regulated  exercise  and  good  food,  he  ought  soon  to  show  gain  and  not 
loss  in  weight.  Should  progressive  loss  be  observed,  it  is  a  question 
whether  he  is  likely  to  become  an  efficient  soldier,  and  he  should  forth- 
with be  referred  for  medical  examination.  Under  the  regulations  of 
the  British  army,  all  recruits  are  kept  under  medical  observation 
during  the  first  three  months  of  service,  during  which  time,  in  addition 
to  the  ordinary  drill,  they  have  an  hour  of  gymnastic  exercise  daily, 
under  the  supervision  of  a  medical  man  ;  and  if,  during  this  period,  a 
man  shows  unfavorable  indications,  he  is  examined  by  a  medical  board. 
Should  this  body  conclude  that  he  will  not  ultimately  develop  into  an 
efficient  soldier,  he  is  at  once  discharged  on  that  ground. 

^Military  organizations  composed  exclusively  of  very  tall  men  of 
imposing  appearance  are  intended  for  display,  and  not  for  the  usual 
work  of  the  soldier,  and,  indeed,  have  often  proved  to  be  lacking  in 
the  essentials  of  good  soldiers,  unless  they  are  unusually  well  propor- 
tioned. The  superiority  of  additional  height  is  commonly  found  to  lie 
*  Quoted  b^'  Aitken.     Loc.  cit. 


77/ a;  iiF.cnniT.  625 

in  tlic  1(!^  ;in(l  neck,  ;iii(l  wIkii  0  (cft  .'!  iii'ln-  is  exceeded,  the  iii- 
clividuul,  ;iH  !i,  rule,  is  not,  projtoilioiiMlely  descloixd  in  the  chc«t  and 
niii,seul;ir  syslcni.  Siieii  men  are  said  to  he  more  jtronc  io  di.seahCH  in 
^eiK'ral,  and  more  es|)e('ially  ('»  pnlmoiiajy  eomplaiiils,  (lian  rnen  of 
mcidiiim  li<'i^lil,  and  lliey  beeomc;  liiii^ned  iriorc  early  on  llu;  niareli  and 
nndei'  all  eirenmsianees  vvlicrc,  enduranee  is  of  the  first  new.-hhity. 
Tlieir  nHis('|('s  are  Ioniser,  poHHCSS  less  fa.sei^-nli,  and  work  lonfjor  levcrH 
than  those  ol"  tin-  short  men.  "^riiey  also  oiler  a  hefler  tar^'et  for  fhr- 
eiKMny.  On  the  other  hand,  very  short  rcn'U  an;  ((iiitc  as  ohjeetionahle 
as  their  over-tall  comrades.  I)nrin<^  the  (Jivil  War,  tlic  Hniallest  nx^n 
enlisted  broke  down,  as  a  I'nle,  after  hnt  a  few  weeks'  service  in  the 
field.  There  are,  of  (bourse,  exceptionally  short  men  who  are  unu.siially 
ninscidar,  hut,  as  a  class,  they  are  wanting;;  in  streiif^th. 

Examination  of  the  Recruit. — The  first  step  in  the  examination  of 
a  recruit  is  thorough  washing  with  soa|»  an<I  water.  "  Jt  is  not  believed 
to  be  (»;o()(l  ])olicy  to  enlist  men  who,  thon<:h  ahle-bodit^d  and  intelligent, 
ap|)eaf  at  recruiting;  stations  in  ragji^ed  or  fdthy  dress,  as  the  chances 
are  such  men  are  tramjis  and  vagabonds  and  will  not  make  ^ood 
soldiers.  Men  who,  though  attired  in  clean  and  respectable  clothing, 
are  found  to  be  filthy  in  their  persons,  should  be  promptly  rejected  for 
like  reason."^  He  is  then  presented  to  the  examining  officer  without 
clothing,  in  a  well-lighted  room  large  enough  for  exercise  in  walking, 
running,  and  jumping.  Here,  he  is  subjected  to  a  searching  physical 
examination,  and  each  deviation  from  the  normal  standard  is  notcfl. 
In  addition,  his  family  and  personal  history  are  obtained  of  the  appli- 
auit,  whose  replies  to  the  prescribed  questions  are  recorded  with  such 
other  information  as  bears  on  his  fitness  for  the  duties  of  a  soldier. 
This  inquiry  is  made  before  the  physical  examination  is  begun. 

The  examination  is  very  thorough,  and  includes  the  mental  condition, 
the  senses,  the  principal  organs  of  the  body,  the  general  formation,  the 
chest  capacity,  the  condition  of  the  teeth,  skin,  jciints,  and  feet,  and  the 
presence  or  absence  of  hernia,  varicocele,  and  other  disqualifieatirms. 

The  leading  characteristics  of  a  good  constitution,  as  enumerated  by 
Dr.  C.  S.  Tripler,  U.  S.  A.,  are  as  follows:  "  A  tolerably  just  propor- 
tion between  the  different  parts  of  the  trunk  and  members,  a  well- 
shaped  head,  thick  hair,  a  countenance  expressive  of  health,  with  a 
lively  eye,  skin  not  too  white,  lips  red,  teeth  white  and  in  go<xl  condi- 
tion, voice  strong,  skin  firm,  chest  well  formed,  belly  lank,  parts  of 
generation  well  developed,  limbs  muscular,  feet  arched  and  of  modemte 
length,  hands  large.  The  gait  should  be  sprightly  and  springy,  sj^eech 
prompt  and  clear,  and  manner  cheerful.  All  lank,  slight,  puny  men, 
"vvith  contracted  figures,  whose  development  is,  as  it  were,  arrested, 
should  be  set  aside.  The  reverse  of  the  characteristics  of  a  good  con- 
stitution will  indicate  infirm  health  or  a  weakly  habit  of  body  :  loose, 
flabby,  white  skin  ;  long,  cylindrical  neck ;  long,  flat  feet ;  very  fair 
complexion  ;  fine  hair  ;  wan,  sallow  countenance." 

On  being  accepted,  the  recruit  must  be  vaccinated  immediately,  unless 
^  Manual  for  the  Medical  Dej^artnient,  "Washington,  189S,  p.  65. 
40 


626  MILITARY  HYGIENE. 

there  is  unmistakable  evidence  of  successful  vaccination  within  a  rea- 
sonable jieriod. 

Chest  Capacity. — The  determination  of  chest  cajiacity  is  of  great 
value  and  importance,  since  it  furnishes  an  index  of  the  vigor  of  the 
candidate.  The  factors  employed  are  the  chest  measurements  and 
extent  of  mobility.  The  chest  girth  is  measured  by  means  of  a  tape- 
measure  passed  round  on  a  line  including  the  lower  portions  of  the 
scapulsD  and  on  a  level  with  or  just  below  the  nipples.  It  is  taken  at 
forced  inspiration  and  forced  expiration,  and  the  difference  in  the  two 
measurements  represents  the  chest  mobility,  which  is  one  of  the  best 
indications  of  cajiacity  for  endurance,  and  is  of  ranch  greater  value  than 
the  actual  maximum  and  miuimum  circumferences,  since  a  very  large 
chest  may  have  less  mobility  than  one  considerably  smaller.  For  men 
under  5  feet  7  inches,  the  mobility  should  be  not  less  than  2  inches ; 
between  that  height  and  6  feet,  not  less  than  2.5  inches ;  6  feet  and 
above,  not  less  than  3  inches. 

Chest  girth,  weight,  and  height  are  very  closely  correlated  in  the 
growth  and  develo])ment  of  a  healthy  man,  and  these  proportions 
should  be  carefully  observed.  (See  table  of  physical  proportions,  taken 
from  the  Manual  for  the  Medical  Department,  on  page  621.) 

Grounds  for  Rejection. — The  most  frequent  single  cause  for  rejection  is 
defective  development;  during  1898,  more  than  a  fourth  of  the  rejec- 
tions of  candidates  for  the  regular  army  were  made  on  this  ground. 
Second  in  order  was  defective  vision  ;  third,  diseases  of  the  circulation. 
Such  is  the  order  which  commonly  obtains  also  in  the  British  army. 
Other  causes,  in  order,  M^ere  diseases  of  the  genito-urinary  organs, 
diseases  of  the  digestive  apparatus,  bad  character,  general  unfitness, 
deafness,  and  illiteracy.  Men  of  defective  development,  if  admitted, 
are  noted  for  the  time  which  they  spend  in  the  hospital  and  in  the 
guard-house.  During  the  early  part  of  the  Civil  War,  thousands  of 
physically  inefficient  men  were  allowed  to  enter  the  army,  only  to  be 
discharged  after  a  few  weeks'  service,  most  of  which  was  passed  in  the 
hospitals.  Another  element  which  it  is  most  important  to  exclude  is 
the  habitually  intemperate.  As  Dr.  Tripler  has  said,  "  First  in  a 
mutiny  and  last  in  a  battle,  the  intemperate  soldier  is  at  once  an 
example  of  insubordination  and  a  nuisance  to  his  comrades," 

Inasmuch  as  the  ability  to  march  is  one  of  the  prime  qualifications 
of  a  soldier,  particular  attention  is  ]5aid  to  the  condition  of  the  kgs, 
ankles,  and  feet.  The  existence  of  enlarged  veins  of  the  ankle  or 
thigh  or  back  of  the  knee  is  sufficient  cause  for  rejection.  Large  or 
recent  bunions,  and  corns  on  the  sole,  flatfoot,  and  "  hammer-toe  "  are 
disqualifications.  Foetid  perspiration  of  the  feet  is  an  intolerable 
nuisance  to  others  in  close  association,  and  is  sufficient  ground  for 
exclusion. 

The  loss  of  many  teeth  or  a  condition  of  general  decay  indicates,  as 
a  rule,  a  lack  of  stamina.  Moreover,  the  soldier  in  the  field  needs  good 
teeth  to  chew  his  hard  biscuit  and  not  always  tender  meat.  An  insuffi- 
cient number  of  opposed  molars  to  insure  proper  mastication  is  suf- 


77//';   IIYdll'lNK   (>!•'  Till':  SOLDfFJl.  027 

flnicni  f^roimd  for  njccliori.  In  18f)H,  in  Imij^IuikJ,  (>f'  ()f>,o()]  n.*crnit,H 
lor  rcjriilnr  H(;i'vic.(',  I,7'I7,  *»r  tic-irly  1  in  .''X,  were  rcjfcl<'(|  dw  ar-fount, 
of  biul  l;(!((ili  nlonc  ;  \)\\\,  IImh  fi^nr(!  ^iv(!H  no  in(li(;ii  iuii  <i('tli.-  |)ro|)()r(io(i 
of  (!iin(li(lii,(('S  who  nii^lil,  li;ivc  hccn  r(!J('(!ic<l  on  llial,  ^ronn<l,  Hin<<;  many 
weni  Hiirninurily  rcjcclcd   on   (dlicr  jrroiindH  wit.lionf.  (!X!iniinaf  ion  f»*' tlio 

Defective  liear'inj^,  (lial  is,  inal)ility  lo  dislin^nisli  ordinary  r-onv^rwi- 
(ion  wiili  either  cur  ut  50  foot,  is  ji  (lisfjiiHlificatioii,  fsincie  ordorH  may  fx) 
either  not  heard  at  nil  or  niisnnderstood. 

THE  HYGIENE  OF  THE  SOLDIER. 

Personal  cleanliliess  is  of  <i;reat  imporlunee  in  the  rnainfenanef;  of 
health  and  eiliciency,  and  should  be  the  .subject  of  nuich  attention  on 
the  part  of  inspecting  officers.  General  bathing  can  hardly  be  expecUid 
in  a  large  camp  in  the  winter  months,  or  at  any  time  \vhf;n  water 
is  scarce;  but  whatever  the  season,  a  small  amount  of  water,  a  quart 
or  so,  applied  with  a  wash-rag  or  sj)onge,  and  with  soap,  should  be 
sufficient  for  a  decent  degree  of  cleanliness.  In  the  warmer  months, 
where  water  is  plenty,  full  baths  and  swimming  should  be  encouraged. 
During  prol(Miged  campaigns  with  limited  oj)})ortnnities  for  keeping  the 
person  and  clothing  clean,  many  men  are  disabled  by  chafing  and  ul- 
cerations, following  irritation  of  the  skin  by  perspiration,  dust  and  dirt, 
and  contact  with  unvvashed,  hardened  underclothes.  Body  lice  always 
make  their  appearance,  and  add  much  to  the  discomfort,  which  is  only 
temporarily  relieved,  but  eventually  augmented,  by  scratching  with  the 
nails.  Infested,  dirty  men  convey  the  evil  by  contiguity  to  their  cleaner 
associates,  who  then  satfer  not  only  in  body  but  in  mind,  filled  with 
disgust  and  loathing,  and  longing  to  return  to  civil  life. 

Contentment  and  cheerfulness  are  very  essential  to  the  well-being 
of  an  army  ;  discontent  and  ennui  undermine  health  and  discipline  and, 
consequently,  efficiency.  In  the  continental  armies,  ennui,  leading  to 
homesickness,  is  believed  to  be  a  prime  cause  of  the  large  number  of 
suicides  and  cases  of  insanity.  This  is  more  marked  with  the  infantry-, 
which  branch  requires  less  time  devoted  to  work.  In  all  armies,  it 
is  recognized  as  leading  to  excessive  use  of  tobacco  and  liquor,  and  to 
all  manner  of  bad  habits.  On  the  march  and  in  time  of  general  ac- 
tivity, the  mind  is  stimulated  and  needs  no  special  diversion  ;  but  after 
a  camp  has  been  permanently  established,  and  the  men  have  settled  do^sTi 
to  the  routine  of  camp  life,  they  begin  to  fret,  and  soon  seek  solace 
in  tobacco,  alcohol,  and  gambling,  and  not  infrequently  in  pei'\'ersions 
of  the  generative  function.  Gambling  is  not  only  an  unheidthy  excite- 
ment, but  engenders  serious  quarrels,  bitterness  and  disappointment, 
and  is  commonly  carried  on  in  crowded  quarters  and  foul  air. 

The  ability  to  keep  troops  in  camps  contented  is  regarded  as  one  of 
the  strongest  evidences  of  capacity  for  command  and  administration. 
To  keep  men  occupied  is  not  sufficient ;  the  occupation  should  not  be 
wholly  routine  drilling  and  marching,  but  interesting  and  pleasant  work 


628  MILITARY  HYGIENE. 

of  other  kinds,  and  entertainments  largely  of  an  amusing  nature.  Extra 
drills,  known  to  the  men  to  be  unnecessary,  and  carried  out  only  to  keep 
them  busy,  do  not  relieve  the  situation,  but  add  to  the  difficulty.  The 
establishment  of  reading-rooms  and  opportunities  for  following  mechan- 
ical trades  are  of  much  service.  All  men  of  exjiei'icuce  testify  to  the 
great  value  of  athletic  sports,  competitive  target  shooting,  gardening 
for  pleasure-  and  proiit,  vocal  and  instrumental  concerts,  vaudeville  and 
minstrel  shows,  theatricals,  and,  in  fact,  anything  which  will  offer  a 
change  from  the  hum-drum  of  life.  Very  little  things  suffice  to  break 
the  monotony  of  life  in  camps,  just  as  in  the  country  and  at  summer 
hotels,  where  the  arrival  of  the  train  or  stage,  or  the  passing  of  a 
strange  carriage,  is  an  event  calling  forth  the  deepest  interest,  and  a 
new  arrival  a  genuine  excitement. 

Clothing-  of  the  Soldier. 

Since  the  primary  object  of  clothing  is  the  conserving  of  body  heat 
in  cold  weather  and  protection  from  the  direct  heat  of  the  sun,  it  is 
essential  that  that  worn  in  any  one  kind  of  climate  should  be  adapted 
to  the  necessities  of  that  particular  climate.  It  is  obvious  that  the 
same  uniform  cannot  be  used  in  the  Northwest  and  in  the  West  Indies 
and  the  Philippine  Islands,  where  the  blue  uniform,  ordinarily  used  in 
our  army,  has  been  universally  condemned  on  account  of  its  weight. 
Therefore,  the  material  should  vary  according  to  the  nature  and  place 
of  service.  In  choosing  material  for  uniforms,  the  chief  points  to  be 
borne  in  mind  are  the  properties  of  heat  conduction  and  heat  absorp- 
tion, permeability,  and  durability. 

Wool  is  a  poor  conductor,  and  is  not  easily  penetrated  by  cold 
winds ;  therefore,  it  is  very  suitable  for  cold  climates,  but  is  likely 
to  be  oppressive  in  the  tropics.  It  absorbs  water  freely,  being  very 
hygroscopic,  and  thus  it  absorbs  the  persj)iration  and  prevents  it 
from  evaporating  directly  from  the  surface  of  the  skin  and  causing 
thereby  loss  of  heat.  The  chief  disadvantage  of  wool  is  the  diffi- 
culty with  which  it  is  properly  washed.  When  improperly  washed, 
the  fiber  shrinks  rapidly,  and  the  fabric  becomes  smaller  and  much  less 
soft  and  absorbent.  During  washing,  M'oollen  materials  should  never 
be  rubbed  or  wrung.  They  should  be  placed  in  water  containing  a 
proper  amount  of  soap  in  solution,  and  moved  about  freely,  well  rinsed 
in  water  containing  no  soap,  and  hung  up  to  dry  without  wringing. 
The  soap  used  should  be  of  good  quality,  as  free  as  possible  from 
excess  of  alkali,  which  injures  the  woollen  by  acting  upon  the  natural 
fat  of  the  wool,  which  is  largely  cholesterin. 

Cotton  and  Linen. — Both  these  articles  are  good  heat  conductors, 
but  are  non-absorbent  of  moisture.  Both  soak  up  moisture  from  the 
skin,  and  evaporation  of  this  requires  so  much  heat  as  sometimes  to 
cause  chilling  of  the  body.  Both  are  durable,  and  neither,  particularly 
cotton,  need  be  very  expensive.  For  underclothing,  both  are  much 
inferior  to  wool,  which,  being  a  poor  beat  conductor  and  a  good  absorb- 


CLOTiffNC/  Of''  nil':  snijxrji  629 

ent  of  moiHtiirc>,  ])r('VciilM  rnpid  cooWw^r,  "(*  the  hody  wlifii  it  is  in  ;i  cou- 
(lition  of  !i<'Xiv(!  ncifspiciilion  ;i('lcr  |ili\.-Ic;il  cxci'cisc.  Jl  \~  \\w  more 
]K;nn(!!il)l(!,  iilsi),  lo  ;iii',  wliidi  il  liold  in  I  lie  -|i:i<i-  Lcl  ween  iIk-  \\\>(TH, 
lUid  vvliicJi  ndds  io  i(s  properly  fd"  iion-coiidiict  ion. 

IiiL;li(;  vvocdicn  nndcrciol  liin^-,  llici-cCorc,  i-  |»rc('cr:d)lc  lo  <itli<r  fotton 
or  linen.  A  \vv\  !j(K)d  ninlerinl  is  wliiif  is  (commonly  KtHiwn  as  rncriiio, 
.'I  inixini'e  o(  woollen  ;ind  eodon,  in  wliieli  flu-  codon  fotisf ilnf^-s  nl»ont 
U  third.  This  ('oinhines,  in  .-i  w.'iy,  the  ;id\;int:ijr''S  of  holh  rnaff-rialH, 
and  is  :i  nin(;h  more  washable  l;d)rie  Ihan   pure  woollen. 

Shoddy  is  a  very  inCerioi-  inalerial,  made  of"  llie  (iher  of  old,  used 
woollen  ^oods,  mixed  with  f'rcsli  wool,  with  whieh  i(  i.s  wovfii.  The 
mannliu'turcrs  do  not  inli'odnee  any  more  fresh  wool  than  is  ahwdutcly 
ne(H!Ssary. 

Color. — '^riie  color  of  clothing  has  an  im])ortant  hearing'-,  hf)th  [)hy.s- 
io!ot;ie.ally  and  Crom  a,  military  |»oint  of  view.  Color  iiifln<'ne(;s  the 
absorption  of  lu-at  more  than  the  nature;  of  tlu;  material  itself".  \\  hite 
mat(!rials  absorb  least  and  bhu^k  the  most  heat.  The  difference  in  ab- 
sorptive power  of  different  colors  is  shown  in  a  marked  degree  by  the 
fact  that  white  cotton  (wer  a  black  surface  will  reduce  the  temj)erature 
in  the  sun  more  tlum  10  degrees  F.  Gray  stands  next  t<;  wliite,  and 
blue  next  to  black. 

From  a  military  point  of  view,  color  is  important,  since  different 
colors  vary  in  their  cf)nspicuousness,  and,  thei'cfore,  strategically,  the 
one  which  stands  forth  the  least  in  the  landsca])e  is  the  best.  The 
most  conspicuous  color  is  red,  next  white,  then  black  and  other  dark 
shades,  light  blue  and  light  brown  and  gray ;  but,  naturally,  much  de- 
pends on  the  background  :  thus,  green  would  be  inconspicuous  against 
grass  and  otlier  green  vegetation,  but  would  show  veiy  distinctly 
against  bare  soil,  whereas  the  light  brown  of  the  ordinaiy  khaki  is 
the  least  conspicuous  in  the  latter  position.  Color  also  influences  the 
absorption  of  odors  by  materials  in  practically  the  same  order  in  which 
it  influences  the  absorption  of  heat ;  that  is,  black  and  the  dark  shades 
are  most  absorbent,  and  white  the  least. 

Military  dress  coats  are  usually  closely  fitting,  warm  and  oppres- 
sive, and  interfere  with  proper  expansion  of  the  chest,  through  tight- 
ness. In  active  service  in  the  field,  they  are  not  worn.  Undress  coats 
are  usually  loose,  and  are  fir  more  comfortable  and  adapted  to  muscu- 
lar effort.  The  khaki  suits,  worn  by  our  troops  in  the  tropics,  are  stiff 
and  heavy  at  first,  but  become  softer  and  more  pliable  with  repeated 
washing.     They  are  sufficiently  loose  for  all  purposes  of  comfort. 

Trousers  are  made  sufficiently  roomy  in  the  seat,  and  reasonably 
tight  about  the  waist,  with  an  inner  belt,  as  no  suspenders  are  worn. 
The  bottoms  are  cut  narrow^  rather  than  with  a  "spring." 

Gaiters  and  leggings  are  used  for  protecting  the  ankles  and  legs 

from  dust  and  mud.    They  are  made  of  brown  cotton  duck  with  lacings, 

and  commonly  are  not  well-fitting.     When  lined,  as  they  sometimes 

.  are,  with  thiu  leather,  they  are  likely  to  be  uncomfortably  hot.     The 

puttee  is  made  of  a  soft  kind  of  cloth^  in  a  strip  4  inches  wide  and 


630  MILITARY  HYGIENE. 

6  or  7  feet  long.  To  one  end,  about  2  feet  of  strong  tape  are 
fastened.  In  applying  the  pnttee,  it  is  rolled  up  with  the  tape  in  the 
center  of  the  roll.  Two  turns  are  wound  over  the  top  part  of  the 
ankle-boot  and  it  is  then  wound  spirally  up  the  log  to  a  point  below 
the  knee,  and  the  tape  at  the  end  is  then  continued  spirally  over  the 
whole  and  fastened  at  the  end.  It  is  found  to  be  more  comfortable 
and  more  pliable  than  leggings,  and  does  not  blister  the  heels,  which 
leggings  sometimes  do. 

Head  Covering. — The  head  covering  is  a  very  important  article  in 
the  dress  of  a  soldier.  It  should  protect  against  cold,  heat,  rain,  and 
the  burning  sun.  It  should  be  light,  durable,  and  comfortable,  not  too 
closely  fitting  nor  pressing  unduly  anywhere.  Leather  helmets,  worn 
in  some  armies  abroad,  and  felt  helmets  formerly  used  in  ours,  are  hot, 
heavy,  and  oppressive.  The  ordinary  white  helmet  is  conspicuous,  but 
comfortable  in  the  sun.  The  ordinary  forage  cap  is  flexible  and  ser- 
viceable, but  is  not  sufficiently  ventilated  for  hot-weather  use.  The 
campaign  hat  of  drab  felt  with  broad  brim  and  high  crown  has  been 
found  to  fill  most  of  the  requirements  in  the  field.  In  Cuba  and  in 
our  new  possessions,  it  was  found  at  first  to  be  too  heavy,  but  experi- 
ence, especially  during  the  rainy  season,  has  shown  that  it  has  advan- 
tages not  possessed  by  any  other  form  of  head  covering. 

In  foreign  armies,  unnecessarily  heavy  helmets  and  other  head  cov- 
erings are  used  largely  for  purposes  of  display,  but  to  a  cei'tain  extent 
also  as  a  protection  against  mechanical  injury.  In  the  matter  of  dis- 
play, there  can  be  no  question  that  many  of  them  fulfil  their  object 
admirably ;  but  as  a  means  of  defence,  helmets  of  heavy  leather  and 
metal,  weighing  from  three  to  four  pounds  and  more,  would  hardly  seem 
to  secure  such  an  amount  of  protection  as  to  compensate  for  the  great 
discomfort  and  the  waste  of  energy  which  their  use  entails.  In  hot 
climates,  helmets  of  bamboo,  provided  with  puggeries,  are  very  largely 
used,  being  light  and  affording  good  protection  from  the  sun. 

Stockings. — Concerning  stockings,  a  great  divergence  of  opinion 
exists.  Woollen  stockings  frequently  cause  the  feet  to  perspire,  even 
in  cold  weather  ;  but  they  are  much  warmer,  and  hence  more  conducive 
to  comfort  than  cotton  at  that  time.  Cotton  is  naturally  more  com- 
fortable in  summer,  and,  to  many  people,  also  in  winter.  In  our  army, 
both  kinds  are  issued.  Many  regard  thick  woollen  stockings  as  the 
best  for  walking,  in  all  climates,  and  as  a  protection  against  foot-sore- 
ness ;  yet  it  is  probable  that  many  cases  of  sore  feet  are  brought  about 
by  the  excessive  perspiration  induced  by  them.  Perhaps  a  happy 
mean  is  a  thin  woollen  stocking  or  one  of  fine  merino.  It  is  impor- 
tant that  the  stocking  should  fit  the  foot  properly,  for  an  ill-fitting 
stocking,  particularly  one  too  long  in  the  foot  or  too  broad,  gives  rise 
to  folds  which  cause  excoriations  and  blisters. 

Boots. — The  value  of  well-fitting  comfortable  boots,  permitting 
unobstructed  action  of  the  muscles  and  joints  and  free  circulation 
of  blood  when  walking  for  pleasure  and  exercise,  is  too  well  known 
to  need  extensive  discussion.     To  the  soldier,  the  importance  of  good 


CLOTJIINfJ    OF  Till':  SOLDIER.  0^ 

boots  Ih  Htill  ^njatcr,  Hiiia;,  us  lius  h(!('H  wiid,  .'in  flTif.ifiif  ;iiiiiy  ih  otu: 
tliat  cull  inurc.li  well  ;  uiid  soldicrH  cannot  nianrli  vvidi  ciipidcfl  fV-ct. 
Moreover,  il.  lia,|)|)(  m.m  rrc()ii('nf,ly  in  liiiic  of  war  that  in  an  crncr^cnf-y 
wliicli  rnuI<(!S  Ji  niaii  <l('|)cn(|(  iit  n|»on  his  walking.';  power  for  his  own 
life  and  liberty  or  for  the  jiropcr  carrying  out  of  his  order,  a  j/o'kI 
boot  is   his  Ix^sl,   friend. 

The  sole  shonid  be  thick  and  ^cnei-onsly  broad,  so  as  to  |)rojeet  all 
round  bc^yond  the  n])|)(r,  bnl  should  not  Ix;  too  heavy.  The  Intel 
slionid  be  broad,  low,  and  Hat.  The  boot,  shonM  br;  srjuare  at  the  toe 
or  slif^htly  rounded  on  the  oiiier  side  in  accordaner;  with  the  natural 
outline  of  the  foot,  so  as  to  allow  the  toes  full  j)lay  in  walkiufr.  AVhen 
placed  sid(!  by  side,  the;  iniuu"  margins  of  each  should  nearly  tonch 
throughout  the  whole  len<:;th  from  the  end  of  tin?  t<»e  to  the  ball  of  the 
foot.  The  inside  should  nowhere  have  rouf^h  inner  scams  or  projec- 
tions, whicih  may  cause  chafing  and  blistering. 

AcH'ording  to  Reno,i  soldiers'  feet  are  ])adly  deformed,  :ind  this  de- 
formity restricts,  to  a  marked  d(!gree,  the  marehing  ra«lius.  In  521 
enlisted  men  rarely  a  normal  foot  was  seen  ;  "  73.9  i)er  cent,  were  wear- 
ing ill-fitting  shoes,  and  corns,  callosities,  fissures,  bunions,  ingrowing 
nails,  hammer  toes,  over-riding  toes,  crowded  toes,  jammed  toes,  and 
sha])eless  toes  were  present  in  great  profusion.  In  00  per  cent,  ftf  the 
men  a  very  serious  defect  was  observed,  that  is  to  say,  the  crowding  f»f 
the  first  toe  out  of  its  natural  aligmnent — i.  c,  hallux  valgus.  This 
latter  defect  reduces  the  marching  radius  in  direct  ])roportion  to  the 
deviation."  In  Reno's  opinion  army  shoes  resemble  too  much  those 
of  civilians.  They  must  be  made  to  conform  more  nearly  to  the  natural 
foot. 

If  treated  to  a  liberal  amount  of  oil  or  grease  at  frequent  intervals, 
the  leather  will  be  made  more  supple  and  at  the  same  time  more  imper- 
vious to  water.  A  preparation,  recommended  by  the  late  Professor 
Parkes,  consists  of  a  mixture  of  a  half  pound  of  shoemaker's  dul)l)ing 
in  a  half  pint  each  of  linseed  oil  and  of  a  solution  of  India-rubber. 
Solution  is  effected  by  gentle  heat,  which  should  not  be  applied  by 
naked  flame,  since  the  India-rubber  solution,  containing  naphtha  or 
ether,  is  exceedingly  inflammable.  This  preparation  is  well  rubbed  into 
the  leather  and  renew^ed  at  intervals  of  three  months.  This  is  said  to 
be  the  best  water-proofing  material  for  leather. 

Cavalry  boots  with  long  legs  are  not  suited  to  walking,  as  they  are 
likely  to  produce  chafing.  On  account  of  the  disadvantages  attending 
their  use  on  dismounted  duty  they  have,  since  1902,  been  given  up  in 
all  branches  of  the  United  States  army. 

Underclothing'. — Undershirts  should  be  of  woollen  or,  better,  of 
merino,  since  pure  woollen  is  unbearable  by  many  and  because  of 
the  rapid  deterioration  which  follows  improper  washing.  The  woollen 
undershirts  issued  at  first  to  the  troops  in  Cuba  and  the  Philippines 
were  complained  of  as  causing  much  irritation  of  the  skin  from  prickly 
heat.  In  the  tropics,  a  light-weight  woollen  undershirt  is  of  the  high- 
1  Military  Surgeon,  September,  1910. 


632  MILITARY  HYGIENE. 

est  importance  in  the  prevention  of  IxmIv  ehillinsj:  from  evaporation  of 
pers[)iration.  Half  cotton  and  half  woollen  or  two-thirds  cotton  and 
one-third  woollen  are  hitrhlv  recommended  as  advantageous  combina- 
tions. 

The  ordinary  shirt  <»f  the  soldier  is  made  of  flannel,  with  a  collar 
and  breast  pockets.  It  is  made  fairly  full  and  is  very  conafortable. 
AA'oodhull  recommends  the  carrying  of  au  extra  shirt  for  wearing  next 
the  body,  the  two  being  worn  alternately.  "  At  the  close  of  the  day's 
work  the  worn  shirt  should  be  taken  off,  dried,  stretched,  well-beaten, 
and  hung  in  the  wind  and  sun.  This  should  be  done  even  "when  there 
is  no  change."  Drawers,  stockings,  and  trousers  should  be  treated  in 
the  same  manner.  Drawers  are  necessary  for  cleanliness  and  warmth. 
They  are  made  of  the  same  material  as  undershirts.  In  many  of  the 
foreign  armies,  drawers  are  not  issued,  and  men  who  desire  them  are 
obliged  to  furnish  them  at  their  own  expense. 

Abdominal  Bands. — Abdominal  protectors,  either  in  the  form  of 
the  well-known  abdominal  band  or  of  small  flannel  aprons  to  be  worn 
next  the  skin  over  the  bowels,  are  regarded  as  very  essential  in  pre- 
venting bowel  troubles,  which  so  commonly  appear  after  abrupt  changes 
in  temjierature ;  protectors  are  especially  valuable  in  the  tropics,  where 
diarrheal  diseases  should  be  ])revented  as  much  as  possible,  on  account 
of  their  possible  serious  and  fatal  results.  The  abdominal  band,  com- 
monly called  also  "  cholera  belt,"  encircles  the  whole  of  the  lower  part 
of  the  body.  The  flannel  apron  protects  only  the  anterior  part,  and  is 
fastened  with  a  tape  around  the  waist. 

The  "  kummerbund  "  is  much  preferred  by  many.  This  is  a  com- 
mon article  of  dress  among  the  natives  of  hot  Eastern  countries.  It 
is  a  broad  fold  of  cloth,  wound  tightly  five  or  six  times  about  the 
waist,  for  the  protection  of  the  lower  part  of  the  spine  from  the  sun's 
rays,  and  to  act  as  a  support  to  the  back  and  loins.  It  is  made  of 
silk  or  cotton,  or  a  mixture  of  the  two,  in  lengths  of  ten  to  fifteen 
feet  and  about  twelve  to  eighteen  inches  in  width.  To  put  it  on, 
one  needs  the  assistance  of  a  companion.  It  is  folded  once  length- 
wise, so  that  its  bi'eadth  is  reduced  a  half  and  its  thickness  doubled, 
and  then,  while  stretched  taut,  one  end  is  placed  in  position  and  held 
there,  and  the  person  turns  the  body  round  rapidly  until  the  full 
length  is  wound  off,  when  the  end  is  carefully  fastened,  so  that  it  may 
not  work  loose. 

These  protectives  of  the  abdomen  prevent  the  evaporation  of  per- 
spiration and  chilling  of  the  abdomen ;  without  them,  diarrha?a  is 
likely  to  be  induced  by  slight  causes. 

Water-proof  blankets  of  rubber  or  other  material  are  very  im- 
portant as  a  protection  against  rain  or  soil  moisture.  When  obliged 
to  lie  on  damp  ground,  they  are  a  great  protection.  In  the  tropics, 
at  certain  seasons,  the  rainfall  is  exceedingly  heavy  and  makes  the 
use  of  some  form  of  water-proof  overcoat  necessary  ;  but  since  these 
are  very  hot,  it  is  important  to  obtain  them  of  as  light  a  material  as 
possible    without    sacrificing    lightness    to    durability.      India-rubber 


'77//';  s()ij>ii':irs  f.xkik'Isi:  and  woiik.  633 

itself  ciimiot  Ik;  worn  li;iltitii;illy  or  for  ;i  loiif^;  titru',  hocauw;  of  ite 
(rMiisiiiji;  ^iciil  (liscoinCoil  lliroii^h  rclciilioii  of  lirat  jiiid  )H'n-|»iralioii. 
li,  is  of  iiiiicli  more  \:iliic  in  tlic  form  of  a  Maiikcl  to  f-jinad  on  \\\(: 
^\'{)\\\\i\  (lian  as  ;iii  ;iil  idc  of  ch.lliin^.  ('lolli  niiiy  Ix-  niaric  water- 
proof l)y  allcnialc  (li|)|iiiiL'  inlo  solntion.-  of  .-ihniiinntn  hnljdiafe  and 
soap,  oi"  by  llioroiiali  soaking  in  I'aw  lin.-ccd  oil  nnd  cxixisinf^  to  tin; 
snii  iinlil  llioron<;lily  <lry. 

Other  articles  issued  <Inrinii  very  cold  weather  for  extra  warmth 
inehidc  hoods,  <;l()Ves,  ovei'shoes,  and  ovcrcouts.  'Jlie  ovcreo;i(-  an- 
unlined. 

The  Soldier's  Exercise  and  Work. 

Marching". — Since  Ihe  most  eirieieiil  airny  is  that  which  lias  the 
p;realest  eapacifv  (o  (luhire  hardship,  it  follows  that  Huoh  an  army  can 
do  the  loiio-est  and  Itest  marchiiit;'.  While  the  civilian  may  repird 
daily  walUs  of  ten,  lil'teen,  twenty,  and  more  miles  as  no  grejit  strain 
oil  the  system,  the  first-mentioned  figure  is  accounted  good  average 
travelling  for  soldi(>rs  on  a  long  march,  and  the  second  for  short 
movements  ;  hut  either  of  these  figures  may  represent  exceedingly 
good  work  by  the  best  of  men  in  some  climates  and  seasons  and  over 
some  roads,  or  by  raw  recruits  in  their  first  marches  over  the  best  of 
roads.  This  is  not  for  a  moment  to  be  looketl  upon  as  evidence  of 
the  civilian's  superiority  over  the  soldier  as  a  walker,  for  the  two  per- 
form the  exercise  under  very  different  conditions. 

The  civilian,  in  the  first  place,  walks  alone  or  with  a  companion 
or  two,  at  his  own  gait  and  according  to  his  ow^n  will.  He  may  vary 
his  step  and  may  rest  at  his  pleasure  ;  he  carries  no  greater  burden  than 
a  walking  stick,  and  may  suit  himself  in  the  matter  of  dress  and  in  the 
manner  of  wearing  it.  The  soldier,  on  the  contrary,  is  one  of  a  large 
body  proceeding  somewhat  stiffly  at  a  pace  set  by  one  in  command 
and  not  alterable  at  will.  He  carries  his  arms,  accoutrements,  and  all 
his  belongings,  aud,  perhaps,  his  rations  for  a  number  of  days,  and  is 
hampered  by  straj^s  and  clothing  which  interfere  with  free  circulation. 
He  rests  wlien  ordered,  may  be  halted,  without  resting,  with  annoying 
frequency,  and  may  "  march  at  eiise  "  only  when,  in  the  judgment  of 
the  commanding  ofhcers,  this  is  practicable.  At  one  time,  he  is  moving 
Avith  exasperating  slowaiess  on  account  of  obstacles  ahead,  and  again,  is 
hurrying  to  catch  up  with  those  gone  before.  iSIoreover,  his  marching 
ground  is  chosen  for  him,  aud  his  miles  are  either  throuijh  dust  or 
mud,  for  a  soil  so  damp  as  to  give  off  no  dust  is  spee<lily  converted  to 
mud  by  the  impress  of  many  feet.  Therefore  it  is,  that  the  soldier's  10 
miles  represents  much  more  physical  exertion  than  the  civilian's  20, 
and  his  15  miles  much  more,  all  things  considered,  than  50  per  cent, 
increase  over  his  10.  Forced  marches  of  25  miles  and  longer  are 
very  exhausting,  and  cannot  be  kept  up  for  more  thau  a  very  short 
time. 

One  of  the  most  niitable  instances  of  louo;  distance  marchius:  in  a  few 


634  MILITARY  HYGIENE. 

hours  in  recent  times  is  that  of  the  city  of  London  Imperial  Volun- 
teers M-ho,  in  South  Africa,  in  August,  1900,  covered  30  miles  in  10 
hours  hoping,  according  to  a  despatch  of  Lord  Roberts,  to  prevent 
General  DeWet  from  crossing  the  Krugersdorp-Potchefstroom  railway. 
The  celebrated  march  of  Lord  Roberts  from  Kabul  to  Kandahar,  in 
1880,  over  very  rough  country,  was  performed  in  23  days.  The  long- 
est day's  marches  were  20  and  21  miles,  and  the  average  distance  cov- 
ered was  nearly  17  miles. 

Among  the  best  known  long  marches  are  several  by  United  States 
troops,  who  hold  the  record  for  long  distance  continuous  marching. 
In  1859,  for  example,  a  regiment  of  infantry  marched  from  Fort 
Leavenworth,  Kansas,  to  a  point  in  California,  a  distance  of  1,800 
miles  in  190  days,  28  of  which  were  given  up  to  resting,  so  that  in 
162  days  of  actual  marching,  an  average  distance  of  a  little  more  than 
11  miles  was  traversed.  In  1860,  a  portion  of  another  regiment  went 
from  Camp  Floyd,  Utah,  to  Fort  Buchanan,  New  Mexico,  a  distance 
of  1,000  miles  in  140  days. 

In  the  Franco-Prussian  War  of  1870,  a  company  of  French  chas- 
seurs marched,  in  very  inclement  weather,  over  an  exceedingly  difficult 
road,  for  41  hours,  with  one  rest  of  an  hour,  another  of  two  and  a  half 
hours,  and  halts  of  8  minutes  in  each  of  the  marching  hours.  The 
exact  distance  marched  is  not  known,  but  the  instance  is  cited  as  one 
of  exceptional  endurance  and  hardship. 

In  our  army,  ordinary  and  quick  marching  call  respectively  for  90 
and  120  steps  of  30  inches  each  per  minute,  or  slightly  over  2.5  and 
3.4  miles  per  hour.  Double  time,  which  is  quickly  exhausting,  calls 
for  180  steps  of  35  inches  each  per  minute,  the  equivalent  of  nearly  6 
milas  per  hour ;  it  can  be  sustained  for  not  longer  than  2  miles  by 
more  than  average  good  troops.  With  the  weight  carried,  30  inches 
per  step  is  quite  sufficient.  In  the  French  army,  2.5  miles  per  hour 
are  considered  good  average  marching,  beginning  with  120  steps  per 
minute,  increasing  gradually  to  125  and  135,  and  returning  during 
the  second  half  hour  to  the  original  rate.  The  English  quick-step  is 
the  same  as  ours  ;  the  "  double  quick  "  is  less  than  ours  in  length  and 
frequency — 33  inches,  175  to  the  minute.  The  German  step  is  between 
31  and  32  inches,  and  114  to  the  minute;  the  Austrian  and  Italian, 
29  inches,  120  to  the  minute;  the  Russian,  28  inches,  120  to  the 
minute.  From  the  above,  it  will  be  observed  that  in  none  of  the 
great  armies  of  the  world  is  the  marching  rate  equal  to  that  of  the 
active  civilian  when  out  for  an  exercise  walk. 

Every  soldier  is  obliged  to  carry,  besides  his  arms  and  accoutre- 
ments, certain  necessary  articles,  the  aggregate  weight  of  which  is 
variable,  but  always  considerable.  In  the  carrying  of  this  weight, 
great  care  is  necessary  so  to  dispose  it  that  it  shall  not  be  over-burden- 
some or  detract  from  his  efficiency.  In  all  services,  the  reduction  to  a 
minimum  of  the  weight  to  be  carried  is  a  matter  of  great  importance, 
but  the  disposition  of  the  weight  is,  perhaps,  of  greater  importance,  for 


THE  SOLDI  Kirs   EXEltCISK   ANI>    WOHK.  fJ35 

conHi(l(;r;il)I(!  liurni  ni:iy  be  induced  by  intfrfcnjiicc  witli  reHpinitioii  and 
(■,ii'<rnl;i,(i(>n  hy  j)Icss(M'c  from  I  lie  ncfcssary  sJrapH  iUTosH  IIk-  dx^t  and 
nndcr  the  arni-pils.  (Iiidcr  (';i\(ii;ilil<'  ciiciiniHianfjdH,  IiIh  irnpcditiicnbi, 
wiili  tlic  ('X<!('|)tion  of  arms  and  eanLctii,  may  Ix;  transpf»rt<'d  for  liirn, 
ilic  result  bcin^  not  only  greater  covering  of"  ground  with  Ichh  t-train, 
but  ji;i'(^'it  (;onser\'aiIon  of"  viVw'wury .  In  adjusting  \vei|rbl,  «-are  hbonld 
b(!  taken  to  avoid  compression  of  (he  ebesl  as  mneh  as  jtossibic  an<J  to 
e(|naIi/(!  the  distribution  so  as  io  avoid  I'Mti^nin^  any  one  set  f>f  inun- 
cles  un(hdy. 

Th(!  (J(!nnan  irdiinliy  soiihcr  is  more  heavily  e(|nip|»c(|  tii;in  liir-  lirit- 
isli  (>!•  American,  the  total  load  exceeding'-  70  pounds,  of  which  hi.s 
(slothing,  e\(!hisiv(!  oi'  the  heavy  polished  leather  liemlet,  accounts  for 
n(!arly  24  pounds,  and  liis  arms  and  e(|iii|)meiits,  filled  water-bottle, 
and  cntrenchiufij  tools  nearly  4'i  pounds,  the  i-emainder  bein^  rations 
and  sundries.  His  kit  is  carried  in  a  leather  knaj)sa(;k,  around  whif;h 
his  rolled  overcoat  is  fastened,  and  to  the  l)ack  of  which  his  c;imp  ket- 
tle is  strapped.  Tlu;  Russian  soldier  also  carries  more  than  70  pounds  ; 
the  Italian,  about  the  same ;  the  French,  between  65  and  70^  and  the 
Austrian,  about  (50  pounds. 

The  blanket  bag,  which  was  substituted  for  the  knapsack  in  our  army 
in  1882  and  abandoned  after  twenty  years'  use,  is  more  oj)pressive 
than  the  blanket  roll ;  but  the  blanket  roll  is  also  oppressive,  since, 
being  carried  across  the  body  from  one  shoulder,  with  the  ends  tied 
together,  it  impedes  -the  raov^ements  of  the  chest.  Morever,  its  use 
involves  a  certain  degree  of  inconvenience,  since  when  the  blanket 
itself  is  in  use,  the  articles  contained  must  be  cared  for  in  some  other 
way.  Other  devices  to  take  the  place  of  blanket  rolls  and  knapsacks 
are  in  use,  and  meet  with  difi'erent  degrees  of  approval.  The  one  most 
highly  commended  neither  impedes  respiration  or  circulation,  nor  in- 
volves contact  with  the  back  and  consequent  shutting  out  access  of  air. 
The  weight  is  supported  chiefly  by  the  hips. 

With  new  levies,  the  first  marches  should  not  exceed  a  very  few 
miles,  the  distance  being  increased  gradually  day  by  day,  until  they 
become  w^ell  seasoned,  with  occasional  days,  not  including  Sundays,  set 
apart  for  rest  and  recreation.  When  thoroughly  seasoned,  there  is  less 
friction,  and  with  greater  experience,  comes  increased  efficiency.  It 
takes  but  a  short  time  for  new  soldiers  to  learn  not  to  attempt  to  ciirrv 
unnecessary  articles,  which,  at  first,  they  are  iuvariably  prone  to  look 
upon  as  essential  to  comfort  and  pleasure. 

Cavalry  and  infantry  should  march  separately  if  possible,  and  in  as 
open  order  as  practicable,  in  order  to  avoid  crowd-poisoning,  which  is 
a  consequence  not  alone  of  indoor  overcrowding,  but  also  of  close 
aggregation  of  men  in  the  open  air. 

If  possible,  marching  by  night  and  in  the  hottest  part  of  the  day 
should  be  avoided,  for  in  hot  weather  the  men  are  easily  exhausted  by 
exercise  in  the  blazing  sun,  and  since  they  can  get  no  sleep  during  the 
day,  they  need  the  night  hours  for  their  proper  rest.  The  early  morn- 
ing hours  are  the  best  for   marching,  as  for  other  forms  of  work,  the 


636  MILITARY  HYGIENE. 

men  being  then  at  their  best ;  but  unless  absolutely  necessary,  their 
sleep  should  not  be  broken  before  the  usual  time,  since  what  is  thereby 
gained  in  distance  is  more  than  lost  through  the  interruption  of  neces- 
sary sleep.  Before  starting,  a  light  breakfast,  including  hot  coifee, 
should  l)e  taken. 

During  the  first  hour,  the  pace  should  be  fairly  slow,  and  when 
two  miles  have  been  covered,  there  should  be  a  halt  of  at  least  a 
quarter  of  an  hour,  during  which  the  men  should  attend  to  calls  of 
nature  and  throw  oif  their  loads  and  rest  at  full  length.  When  the 
march  is  resumed,  the  distance  to  be  covered  may  be  lengthened  by  a 
half  mile,  and  when  this  distance  has  been  traversed,  there  should  be 
another  halt  of  about  the  same  length  as  the  first.  After  this,  the  rate 
may  be  increased  to  three  miles  per  hour  with  a  halt  of  ten  minutes  in 
each  hour,  and  this  rate  is  sufficiently  fast,  except  for  forced  marches. 
The  halt  in  the  middle  of  the  day  for  dinner  should  be  of  several  hours' 
duration,  so  that  the  men  may  have  a  good  rest,  avoid  heavy  work 
directly  after  a  hearty  meal,  and  look  after  the  condition  of  their 
feet.  As  it  is  unsafe  to  eat  heartily  or  drink  copiously  while  greatly 
fatigued  or  overheated,  a  reasonable  interval  should  be  allowed  before 
dinner. 

Halts  due  to  accidental  circumstances  are  very  trying  to  patience 
and  strength,  and  when  their  probable  duration  can  be  determined,  this 
should  be  communicated  down  the  column,  in  order  that,  if  the  inter- 
val is  to  be  of  sufficiently  long  duration,  the  men  may  have  the 
advantage  of  resting,  rather  than  stand  with  their  arras,  losing  patience 
and  temper.  Since,  also,  irregular  rate  of  movement  is  fatiguing  and 
annoying,  minor  obstacles,  such  as  mud  and  water,  should  not  be 
allowed  to  interfere  with  regular  progress.  Music  of  all  kinds  is  very 
invigorating  to  marching  men  ;  baud  music,  fife  and  drum,  the  drum 
alone,  and  singing.  In  the  continental  armies,  singing  is  much 
encouraged,  as  it  keeps  up  the  spirits  and  gives  a  rhythm  and  swing  to 
the  march. 

If  the  weather  is  hot,  men  should  be  allowed  to  promote  evapora- 
tion of  perspiration  by  opening  their  coats  or  blouses ;  otherwise,  water 
is  lost  from  the  body  without  performing  its  function  of  reducing  the 
body-heat.  To  avoid  excessive  thirst,  a  full  drink  of  water  should 
be  taken  before  starting.  The  canteens  should  be  filled  with  water 
or  cold  tea  for  use  during  the  day ;  but  free  drinking  on  the  march 
is  not  to  be  advised,  since  it  tends  to  beget  constant  thirst.  The 
mouth  should  be  kept  closed  as  much  as  possible  during  the  march, 
and  the  sensation  of  thirst  can  be  controlled  by  holding  a  smooth 
pebble  in  the  mouth  or  chewing  a  green  leaf.  Simple  occasional 
moistening  of  the  mouth  is  better  than  free  and  frequent  drinking. 

In  case  of  exhaustion  by  excessive  loss  of  fluid  by  perspiration,  drink- 
ing on  the  march  is  necessary  ;  but  under  the  usual  conditions,  the  can- 
teen should  be  used  only  at  meals  and  near  or  at  the  end  of  the  day's 
march.  Another  reason  for  abstaining  as  much  as  possible  from  drink- 
ing is  the  uncertainty  of  supply,  for  no  dependence  can  be  placed  on 


THE  SOU) flag's   EXI'inaiSE  AND    WORK.  637 

tliC!  prohahilily  of  rcCilliii^  (Jic  c.-uiU'cii  (lining  the  duy'.s  mur<:li.  Il'ii''-, 
ciicli  rniiii  should  conwirvc!  his  Hni)|)ly  uh  tlioii^h  he  wore  wrfaiti  that  no 
rnon;  is  to  Iw.  Ii;i(l  bcCorc  Ihc  day's  dcsliiiaiion  is  reached.  The  :mioiirit 
carri(!d  may  he  I<<'pl'  (iiirly  i-ool  l»y  \vr-a|)|)iii^  ihc  caiit^cii  in  a  \\<-l  floth, 
the  eva|)oration  I'loni  wliidi  cmscs  pcrecptihlc!  h)\\('i-in^  of  icrnpcratiin;. 
A  litth!  vinc<^ar  or  lime  jnicc,  if  ohtainahh',  added  to  the  wuU-r,  ^dvej* 
it  a  relish  and  helps  to  :dl;iy  thirst. 

"  In  many  jjarts  oC  <h((  West,  water  is  so  searee  lliat  jndifiouH 
mutiafi;ement  is  re(piired  to  forward  troops  ov(!r  tiie  ront<'.  Srtrnc; 
cam[)inf^-Htations  li;iviii<;  only  cnontili  (or  one  or  two  companies,  the 
eonnnand,  iriai'<;er,  innst  pass  in  d(!lachnienls.  Or  it  may  hapiK-u  that 
tli(!  distance  hetween  the  nearest  water-snpplied  sites  is  too  jireat  to  Ix* 
marehcnl  withont  rest,  in  which  ease  a  dry  eanip  nnisl  he  formed  at 
.some  intervening^  ])oint.  The  |)assa<r(!  of  the  (lila  J>end  J)esert,  .'>'>  or 
40  miles  from  water  to  water,  is  nsnally  effected  by  making;  a  ni^rht 
march  of  25  miles,  when  the  troops  o^o  into  camp  to  rest  for  a  few 
lion rs  before  resnmin<>;  their  jonrney,  and  to  have  coffee  issued  from  a 
\vater-snp|)ly  carried  in  the  wap;<)ns."  (Smart.')  On  arrivin?:  at  a 
camping-place,  the  water  supply  should  be  innnediately  {guarded  to 
prevent  ]K)llution  and  tramjilinp;  of  the  margin.  If  the  supply  is 
small,  the  _i>;uard  should  be  doubly  efficient.  If  the  sup])ly  presented 
is  a  small  and  shallow  stream,  it  may  be  well  to  make  small  reser- 
voirs by  means  of  temporary  dams,  one  for  drinking-water  fV»r  the 
men,  another  below  for  the  horses,  and  another  for  bathing  and  laundry 
purposes. 

Straggling  should  be  prevented  as  much  as  possible,  since  it  is  a 
very  serious  evil  to  the  morale  and  efficiency  of  the  body  as  a  whole. 
If  strafffflina:  becomes  considerable,  the  column  should  be  halted 
until  the  stragglers  can  overtidce  it,  else  they  will  get  no  rest,  since 
the  hourly  intervals  for  rest  must  be  utilized  by  them  in  coming  up, 
and  the  column  is,  ]icrhaps,  already  in  motion  again.  Those  claiming 
to  be  sick  or  unable  to  march  should  be  examined  by  the  medical 
officers,  who  will  separate  the  really  unfit  from  the  malingerers  ;  the 
former  are  given  careful  transportation  ;  the  latter,  disposed  of  accord- 
ing to  their  deserts. 

At  the  end  of  a  day's  marching,  the  men  should  lie  dismissed  as  soon 
as  possible,  and  they  should  be  careful  to  guard  against  becoming  chilled 
through  reckless  removal  of  clothing,  and  should  again  look  after  the 
condition  of  their  feet  and  persons. 

On  long  marches,  an  occasional  day  should  be  taken  for  complete  rest 
and  recuperation,  otherwise  an  inevitable  diminution  in  efficiency  will 
be  occasioned,  Woodhull  cites  an  interesting  instance  of  overmarching 
in  the  Franco-Prussian  War.  The  German  Grarde-Corps,  consisting  of 
30,000  infantry,  left  the  Rhine  on  August  3d,  lost  less  than  0,000  in 
action,  and  on  September  2d,  the  day  after  Sedan,  numberal  13,000  for 
duty.     On  September  19th,  they  reached  Paris  with  but   9,000  men, 

1  Buck's  Hygiene  and  Public  Health,  New  York,  1879,  Vol.  H.,  p.  119. 


638  MILITARY  HYGIENE. 

more  than  11,000  having  been  broken  down  by  exertion,  little  actual 
sickness  having  occurred. 

Care  of  the  Feet  on  the  March. — If  good  marchers  make  the  best 
soldiers,  it  follows  that  the  possession  of  the  best  soldiers  is  largely 
dependent  upon  the  condition  of  the  feet,  and,  therefore,  it  is  incumbent 
on  the  line  officers  and  medical  corps  to  see  that  the  individual  men 
are  properly,  instructed  in  their  care,  and  that  they  are  faithful  in  per- 
formance. The  footsore  man,  so  far  as  efficiency  is  concerned,  is  a  sick 
man  and  becomes  the  equivalent  of  baggage.  He  cannot  march,  and 
suffi?rs  pain  when  at  rest.  Nearly  all  new  men  not  accustomed  to 
marching  are  likely  to  suffer  from  excoriations  across  the  toes,  on  the 
insteps  and  malleoli,  and  on  the  back  and  sides  of  the  heels.  This  is 
due  to  friction,  and,  if  attended  to  at  once,  may  be  prevented  from 
becoming  serious. 

The  application  of  strips  of  adhesive  plaster  of  generous  size  to  the 
affected  parts  will  affbrd  the  same  protection  as  is  given  by  a  leather 
glove  to  the  hand  engaged  in  any  frictional  work.  Blisters  should  not 
be  opened,  except  by  a  minute  puncture  at  the  edge ;  after  the  fluid  has 
oozed  away,  the  spot  should  be  protected  with  adhesive  plaster.  The 
extensive  opening  of  a  blister  permits  access  of  air  to  the  sore  area 
beneath,  and  the  stimulation  therefrom  is  very  active  and  painful. 
Men  should  be  instructed  to  trim  their  toenails  square  across  and  not 
too  close. 

Before  marching  is  begun,  all  men  with  any  soreness  of  the  feet 
should  report  themselves  and  be  examined,  and  at  the  end  of  the  day, 
if  not  before,  they  should  be  regularly  inspected.  Men  unused  to 
marching  will  often  find  greasing  or  soaping  the  feet  and  stockings  an 
excellent  prophylactic  against  soreness.  A  neutral  grease  like  mutton- 
tallow  is  preferable  to  soap,  since  sometimes  it  happens  that  the  latter 
assists  the  perspiration  in  macerating  the  cuticle.  If  the  boots  are 
made  supple  with  grease,  they  tend  less  to  cause  soreness,  and,  in  addi- 
tion, are  rendered  waterproof.  An  excellent  plan  for  officers  and  others 
who  can  afford  them,  is  to  wear  silk  stockings  under  the  ordinary  socks, 
especially  when  the  feet  are  naturally  tender.  The  feet  may  be  tough- 
ened by  being  soaked  in  warm  strong  solutions  of  alum  or  common 
salt.  Zinc  ointment,  containing  5  per  cent,  of  tannin,  is  also  very 
useful.  Salicylated  talc  (talc  87,  starch  10,  salicylic  acid  3  parts  by 
weight)  is  used  in  the  German  army  both  on  the  march  and  in  garrison. 
It  is  sifted  from  a  dredging-box  into  the  shoes  and  over  the  feet. 

If  the  soreness  is  due  to  the  stockings  and  not  to  the  shoe,  it  is 
often  advantageous  to  change  them  from  one  foot  to  the  other,  or  to  put 
them  on  inside  out.  Some  of  the  continental  armies  use  bandages  in 
place  of  stockings,  and  some  use  neither,  substituting  therefor  a  liberal 
coating  of  grease.  Soreness  is  due  often  to  neglected  bunions,  corns, 
both  hard  and  soft,  and  infleshed  nails.  These  troubles  need  special 
treatment.  In  the  British  army,  the  authorities  have  caused  a  number 
of  the  non-commissioned  officers  to  be  instructed  in  chiropody,  and  the 


THE  SOIjDIICH'S   I'OOh;    "  RATfONS."  639 

HUoccHs  of"  the  (^xp(!rim(!rif,  Ikih  rn.'i(l<!  it  [)rol):il)I(!  llinl  ;i  j)(;riniuif;nt  corps 
of  tr;i,in(;(l  (chiropodists  will  ])('.  cstahliKlicd  for  the  infantry. 

During  th(;  loii^  hall  at  midday,  each  man  slioiild  rciiirtvc  his  hIio«;h 
and  Htoclvings,  and,  if  walcr  is  <x»  he  had  in  ahnndaiK-c,  he  hlioiild 
remove  the  acrid  p(!rH]>ir;ili<>ii  imd  dirt  frf)rn  hin  feet  by  llioroiigJi  waxh- 
'"K>  [)ayin^'  |)artienlar  atlcnlion  to  th(!  Hurfatces  between  tlir;  toe.s,  whr-re 
(excoriations  and  soft  <'orns  are  prour  to  appear.  I)iistinf^-[)owder  or 
zine  ointment  on  absorbent  (vitton  may  l)e  applied,  if  advisable,  between 
the  toes.  Th(\  feet  should  be  made  (piite  dry  before  the  stockings  are 
a^ain  drawn  on.  If  water  eann(»t.  be  obt^iined  in  snflieient  anirjiirit, 
wiping  with  a  dry  or  moist,  (-loth  will  be  found  to  add  rnat<'rially  U) 
comfort,  and  is  much  to  Ix;  preferred  to  lon^  soakin^r^  which,  by  Hoft- 
ening  the  cuticle,  assists  the  formation  of  blisters.  At  the  eiifj  of  the 
day,  the  feet  should  be  washed  and  the  stockings  changed  ;  thfjsc 
removed  should  be  washed  as  soon  as  practicable  and  dried  during  the 
night. 

Care  of  Other  Parts. — Not  uncommonly,  soldiers,  especially  raw 
recruits,  arc  much  inconvenienced  and  annoyed  by  chafing  at  various 
points,  particularly  on  the  inside  of  the  thighs  and  between  the  nates. 
This  is  promoted  by  pcrsj)iration  and  restrained  by  dusting-powder, 
zinc  ointment,  vaseline,  and  cleanliness.  Wo<»dhul]  advises  against 
washing  the  face  and  neck  in  thv.  morning  while  on  the  march,  because 
the  removal  of  the  natural  secretion  makes  the  skin  more  susceptible 
to  the  influence  of  heat  and  dust.  He  recommends  washing  the  eyes 
and  mouth,  and  merely  wi|)ing  the  face  and  neck  with  a  damp  clotTi, 
At  night,  the  face,  neck,  and  whole  body  should  be  washed,  if  possible  ; 
but,  foremost  of  all,  the  head,  armpits,  feet,  and  g(!nitids  and  adjacent 
parts. 

Care  should  be  taken  that  the  bowels  are  not  neglected  while  on  the 
march,  any  more  than  wdiile  in  garrison.  If  purgatives  are  required, 
those  given  should  be  mild  in  character,  and  not  such  as  may  require 
repeated  operations  at  short  intervals. 

The  Soldier's  Food;  "Rations." 

The  word  "  ration  "  is  understood  commonly  to  mean  the  amount  of 
food  issued  to  each  soldier  for  a  single  meal.  This,  however,  is  far 
from  being  the  truth.  Under  the  regulations,  "  a  ration  is  the  allow- 
ance for  sustenance  of  one  person  for  one  day,  and  consists  of  the  meat, 
the  bread,  the  vegetables,  the  coffee  and  sugar,  the  seasoning,  and  the 
soap  and  aindle  components."  Enlisted  men  and  hospital  matrons, 
and,  when  the  circumstances  of  their  service  make  it  necessary*,  civil- 
ians employed  by  the  army,  each  draw  one  ration  each  day.  The 
ration  is  not  necessarily  the  diet,  since  parts  of  it  may  be  exchanged 
for  other  things  or  for  the  cash  equivalent  with  which  to  buy  them. 
It  is  fixed  by  laAv,  and  can  be  changed  only  by  legislative  enactment. 

The  different  articles  composing  the  ration  for  troops  in  garrison  or 
in  permanent  camps,  excepting  in  Alaska,  and  their  amounts,  are  as 
follows  : 


640 


MILITARY  HYGIENE. 
Gakkison  Kation.^ 


Component  articles  and  quantities. 


Beef,  fresh 


Flour  

Baking  powder 
Beans     .... 


Potatoes  2 , 


Prunes ' 


Coflfee, roasted  and  ground 

Sugar 

Milk,evaporated,unsweet- 

eued 

Vinegar    

Salt 

Pepper,  black 

Cinnamon 

Lard 

Butter 

Syrup  

Flavoring  extract,  lemon 


20  ounces . 


18  ounces . 


.08  ounce 
2.4  ounces 


20  ounces . 


Substitutive  articles  and  quantities. 


1.28  ounces, 


1.12  ounces 

3.2  ounces  . 

.5  ounce  . 
.16  gill   .   . 

.64  ounce  . 
.04  ounce  . 

.014  ounce 

.64  ounce  . 
.5  ounce  . 
.32  gill  .  . 
.014  ounce 


f  Mutton,  fresh 

I  Bacon ' 

Canned  meat,  when  impracticable  to 
I'uriiish  fresh  meat 

Hash,  Corned  beef,  when  impracticable 
to  furnish  fresh  meat 

Fish,  dried 

Fish,  pickled 

Fish,  canned 

Chicken  or  turkey,  dressed,  on  national 

i     holidays  when  practicable 
Soft  bread 
Hard  bread,  to  be  ordered  issued  only 
when   impracticable  to  use  flour  or 
soft  bread     

[Corn  meal 


JRice 

( Hominy 

f  Potatoes,  canned 

I  Onions,  in  lieu  of  an  equal  quantity  of 
potatoes,  but   not    exceeding  20  per 

I      centum  of  total  issue 

I  Tomatoes,  canned,  in  lieu  of  an  equal 
quantity  of  potatoes,  but  not  exceed- 

!  ing  20  per  centum  of  total  issue. 
Other  fresh  vegetables  (not  canned) 
when  they  can  bo  obtained  in  the 
vicinity  or  transported  in  a  whole- 
some condition  from  a  distance,  in 
lieu  of  an  equal  quantity  of  potatoes, 
but  not  exceeding  30  per  centum  of 

[     total  issue. 

f  Apples,  dried  or  evaporated    .... 

I  Peaches,  dried  or  evaporated  .... 

■{  Jam,  in  lieu  of  an  equal  quantity  of 

1      prunes,    but    not    exceeding   50   per 

[     centum  of  total  issue. 

(Coffee,  roasted,  not  ground 

-|  Coflfee,  green 

(Tea,  black  or  green 


Pickles,  cucumber,  in  lieu  of  an  equal 
quantity  of  vinegar,  but  not  exceed- 
ing 50  per  centum  of  total  issue. 


(  Cloves 

J  Ginger    .   .   .   . 
(Nutmeg  .   .    .   . 

Oleomargarine 

Vanilla  .  .   .  . 


20  ounces. 
12  ounces. 

16  ounces. 

16  ounces. 

14  ounces. 

15  ounces. 

16  ounces. 


16  ounces. 
IS  ounces. 


16  ounces. 
20  ounces. 

1.6  ounces. 
1.6  ounces. 
15  ounces. 


1.28  ounces. 
128  ounces. 


1.12  ounces. 

1.4  ounces. 

.32  ounce. 


.014  ounce. 
.014  ounce. 
.014  ounce. 

.5  ounce. 

.014  ounce. 


'  In  Alaska  16  ounces  bacon  or,  when  desired,  16  ounces  salt  pork,  or  22  ounces  salt  beef 

2  In  Alaska  the  allowance  of  fresh  vegetables  will  be  24  ounces  instead  of  20  ounces,  or 
canned  potatoes,  18  ounces  instead  of  15  ounces. 

'  At  least  30  per  centum  of  the  issue  to  be  prunes  when  practicable. 

Note. — Food  for  troops  traveling  on  U.  S.  Army  transports  will  be  prepared  from  the  articles 
of  subsistence  stores  which  compose  the  ration  for  troops  in  garrison,  varied  by  the  substitution 
of  other  articles  of  authorized  subsistence  stores,  the  total  cost  of  the  food  consumed  not  to 
exceed  24  cents  per  man  per  day. 

The  ration  issued  to  troops  in  the  field  in  active  campaign  is  the 
same  in  amount,  but  is  somewhat  less  elastic.  Thus,  the  various  forms 
of  fish  are  eliminated,  as  also  are  peas  and  hominy,  and  when  potatoes 
are  not  procurable  locally  the  desiccated  form  is  served.  The  fruit 
component  consists  of  canned  jam  (1|-  ounces). 


i221. 


General  Orders  No,  47,*War  Department,  Washington,  April  3,  1908,  Paragraph 


THE  .SOLDI Kirs  FOOD;   "RATIONS." 

I'lKI.I)    ItATION. 
Cdiiiixini'iil,  arliclcH  U)i<l  i|iiiuilit.iiH. 


641 


Beef,  frcHh,  wh(!ii  jiro  I 
curable  l(ically  .   .   .   .  / 

Flour 

Iluklii^'  I)OW<lt:r,  wlu^ii 
()V(!liK  UTi:  iiol  iivailalilc, 

YeiiHt,  dried  or  <'oiti- 
pri'SHcil  when  ovens  are 
availahlc 

Beans 


Potatoes,      wluMi      i)ro- 
curable  locally  .   .   .    . 


Jam 

Cofl'eo,  rousted  and  ground 

Sugar 

Milk,cvaporated,unsweet- 

eued 

Vinegar    

Salt 

Pepper,  black 


20  ounces 

IK  ouneeH 
.(il  ounce 


.01  ounce 
2.4  ounces' 


l.'l  ounces  . 
1.1'.!  ounces 
'i.2  ounces  . 

.5  ounce   . 
.16  gill  .   . 


.61  ounce  . 
.04  ounce  . 


HubHtitutivc  urtldcH  and  riuantities. 


Mutton,  fresli,  when  i)rocurttblc  locully 

(.'uniicil  jiical , 

Iliicon 


I  llusb,  ('orned  lieef 

/Holt  bread 

(  Hani  bread  .... 


KIce 

Potatoes,  f^an tied 

Oidons,  wben  |>roeiirable  locally  ,1n  lieu 
of  an  ei)nul  i|iiiintity  of  |i<j|alf)CH.  but 
not  exc(;e<ling  20  per  centum  of  total 
issue. 

Toniutors,  canniKl,  in  Heu  of  an  equal 
(|uiititity  of  potatoes,  but  not  exceed- 
ing 'JO  per  centum  of  total  isHUc. 

Tea,  black  or  green 


Pickles,  cucumber,  in  Vww  of  an  equal 
i)uanlity  of  vinegar,  but  uf>t  exceed- 
ing f)0  per  centum  of  total  issue. 


20  oiin(u«. 
10  ounc<i( 
12ouneeH. 
If)  ouriccH. 
IHouuecH. 
1(1  ounccM. 


1.0  ounces. 
r.i«UMce«. 


.32  ounce. 


What  is  known  as  the  "  travel  ration "  is  issued  in  place  of  the 
ordinary  ration  "when  troops  travel  otherwise  than  by  marching,  or 
when  for  short  periods  they  arc  separated  from  cooking  facilities  and 
do  not  carry  cooked  rations."  It  consists  of  the  following  articles  and 
is  issued  in  the  amounts  stated,  jier  hundred  rations : 


Travel  Kation. 


Soft  bread 

Beef,  corned 

Beans,  baked 

Tomatoes,  canned    .... 

Jam 

Coftce, roasted  and  ground 

Sugar 

Milk,     evaporated,     un- 
sweetened    


18  ounces    . 
1'2  ounces    . 

4  ounces    . 

5  ounces  . 
1.4  ounces . 
1.12  ounces 
2.4  ounces . 


.5  ounce 


Hard  bread .... 
Hash,  corned  beef 


16  ounces. 
12  ounces. 


On  arrival  at  their  destination  the  ordinary  ration  is  resumed. 
The  haversack  ration  is  as  follows  : 


Haversack  Kation. 

Component  articles  and  quantities. 

Substitutive  articles  and  quantities. 

Bacon    

Hard  bread 

Coffee, roasted  and  ground 

l.l'J  ounces 

Sugar 

Salt 

Pepper,  black 

AVhen  travelling  unaccompanied  by  an  officer,   each  man   may  be 
allowed  a  cash  sum  per  day  for  the  purchase  of  liquid  coifee  in  place 
of  the  coffee  and  sugar  portion  of  the  travel  ration. 
4X 


642  MILITARY  HYGIENE. 

Aq  "  emergency  ration/'  now  being  tested  by  the  War  Department, 
but  not  yet  definitely  adopted,  owing  to  the  fact  that  a  sufficient  time 
has  not  elapsed  since  its  preparation  to  determine  its  keeping  qualities 
under  all  conditions  of  service,  is  composed  of  the  following  : 

45.45  per  cent,  chocolate  liquor, 


7.27       " 

nucleo-casein, 

7.27       " 

malted  milk, 

14.55       " 

egg-albiimen, 

21.82       " 

powdered  cane-sugar, 

3.64       " 

cocoa  butter. 

Percentage  of  moisture  not  to  exceed  3  per  cent. 

"  Each  ration  weighs  8  ounces  net  and  is  put  up  in  three  cakes  of 
equal  size,  each  cake  wrapped  in  tin-foil,  and  all  three  inclosed  in  a 
hermetically  sealed,  round-cornered  tin,  with  key-opening  attachment."  ^ 

Abroad,  the  well-known  pea  sausage,  consisting  of  pea  flour  and  fat 
pork,  is  much  used  in  the  emergency  ration.  This,  mixed  with  hot 
water,  makes  a  very  good  soup,  but  soon  proves  to  be  cloying.  Meat 
biscuits  and  dried  meats  also  are  much  used. 

It  will  be  observed  that  the  ordinary  ration  is  fairly  flexible  as  it 
stands,  but  it  may  be  made  more  so  by  exchanging  articles  not  wanted. 
It  is  established  by  law,  but  is  not  necessarily  the  daily  dietary.  Thus, 
the  various  articles  (excepting  the  fresh  vegetables,  bread,  and  baking- 
powder)  not  needed  for  consumption  may  be  purchased  by  the  com- 
missary as  savings  at  the  invoice  prices.  "  Savings  and  sales  of  fresh 
beef  (except  of  that  issued  for  the  sick  in  hospital,  the  detachment  of 
the  hospital  corps,  and  the  hospital  matron  serving  therein)  are  pro- 
hibited,"^ but  the  fresh  meat  allowance  may  be  reduced  in  amount  and 
its  money  value  drawn  in  other  things.  For  each  ration  of  flour 
turned  in,  the  company  is  entitled  to  one  ration  of  bread  or  the  price 
of  one  flour  ration. 

In  many  permanent  camps,  gardens  may  be  cultivated  and  a  supply 
of  fresh  vegetables  thus  obtained  both  for  immediate  and  future  use. 
Commutation  for  these  is  allowed  at  the  prices  of  potatoes  and  onions 
in  the  vicinity  or  in  the  market  from  which  supplies  are  derived,  in 
the  proportion  of  80  per  cent,  of  potatoes  and  20  per  cent,  of  onions. 
The  amounts  of  money  from  all  sources  form  the  company  fund,  which 
is  disbursed  by  the  company  commander  solely  for  the  benefit  of  his 
own  men. 

Fruits  and  vegetables  are  very  essential  in  the  dietary,  on  account 
of  their  antiscorbutic  properties.  The  most  valuable  of  the  anti- 
scorbutics is  held  commonly  to  be  lime  juice;  the  juice  from  the 
fresh  limes  is  superior  to  the  bottled  article.  Lemons  are  of  about 
the  same  value  as  limes.  Among  vegetables,  potatoes,  onions,  and 
cabbage  take  high  rank.  The  legumes  are  devoid  of  antiscorbutic 
properties.     According    to  Woodhull,   the    best    antiscorbutic    is    the 

1  Personal  communication  from  Henry  G.  Sharpe,  Commissary  General,  Jan.  10, 
1911. 

'  Army  Kegulations,  p.  180. 


Till':  ,S()LI)IF,i;'S   FOOD;    "RATIONS."  643 

agave.  "  To  pnijKirc  it,  cut  f)fT'  IIk;  K-.'ivch  close  to  tin;  r<H)i,  cfiok 
tiicm  W(!ll  ill  liol,  aslics,  (ixpniH.s  tlic  juice,  arid  driiiU,  raw  or  HWf-ct/- 
(UK!(1,  1—4  wiiu^jj^IaHsfuls  1,Iin;(!  <irn<!.s  a  day,  Tlic  wliif/;  interior  of  the 
]cav(!H  may  Ik;  (!at(!ii."  Tlic  dried  v(!^(;t^il)l('H  and  frnit  are  Ichh  valu- 
able than  the  fresii,  and  should  h(!  alIo\v(;d  t*)  HMfHTsedf!  the  lattfjr  only 
when  th(!S(!  cannol,  h(!  ohiaiiicd,  hnt  th(!y  arr;  far  snjM-rior  U)  com- 
pressed V(!}^(!tal)l('s,  which,  in  th(!  process  of  compression,  If)Sf!  much 
of  their  salts  and  a  ])ortion  of  their  proteids.  Dried  vegetables  should 
be  soaked  W(!ll  in  wat(!r  befon;  use,  (!ls(!  tln^y  may  (xiuse  digestive 
disturbance;  and  diarrhfea. 

Alcohol  in  the  Ration. — TIk;  (juestion  of  the  advisability  of  in- 
(diiding  a  si)irit  allowaiKic  in  tlu;  ration  has  be(!n  th(!  subject  of  much 
careful  consixleration  in  all  countries,  and  has  been  answered  with 
practical  unanimity  in  the  negative.  IJut  there  are  times  when  a  single 
issue  of  spirits,  or  repeated  issues  according  to  circum stances,  may  1)6 
useful  and  even  necessary.  Thus,  on  a  forced  march,  when  exhaustion 
is  great,  a  stimulant  may  be  of  very  great  necessity,  although  it  is  said 
that  hot  tea,  if  time  admits  of  its  preparation,  may  be  equally  or  still 
more  serviceable.  When  given  at  all,  sj)irits  should  be  taken  well 
diluted,  and  never  in  concentrated  form. 

During  the  Civil  War,  a  daily  issue  of  a  gill  of  whiskey  to  f^ach 
officer  and  man  of  the  Army  of  the  Potomac  was  ordered,  half  to  be 
given  out  in  the  morning  and  half  in  the  evening.  This  was  brought 
about  by  the  I'act  that  for  several  weeks  the  men  had  been  subjected  to 
unusual  hardships  and  extra  duty,  and  were  ])reaking  down  under  the 
strain.  The  issue,  wliich  was  to  continue  "  until  further  orders,"  was 
greeted  with  enthusiastic  appreciation  of  the  farsightedness  of  the 
authorities  responsible  for  it.  "  Until  further  orders  "  proved  to  be 
exactly  one  mouth,  and  hot  coffee  was  substituted  for  the  whiskey,  the 
issue  of  which  was  ordered  to  be  "  immediately  di.'icontinued."  During 
the  month,  the  general  condition  of  health  of  the  troo])S  was  not  only 
in  no  way  improved,  but  became  markedly  worse,  while  drunkenness, 
with  its  attendant  evils,  became  much  more  common. 

Concerning  the  use  of  beer  and  light  wines,  a  very  different  opinion 
is  held  by  many  of  those  best  qualified  to  judge  by  results  observed. 
In  several  of  the  great  armies  of  Europe,  an  allowance  of  light  wine 
is  customary,  and  it  seems  reasonable  to  suppose  that  where  the  im- 
portance of  a  large  standing  army  is  so  great,  alcohol  in  this  form 
would  not  be  issued,  were  it  not  upon  the  belief,  based  on  long  experi- 
ence, that,  directly  or  indirectly,  it  is  a  benefit,  and  not  an  evil.  A 
little  light  wine  at  the  close  of  a  day  of  hard  work,  but  not  before  or 
during  its  performance,  appears  to  be  recuperative  and  restful,  either  in 
the  usual  strength  or  diluted  with  water.  In  this  countiy,  the  S(i-called 
canteen  system  is  believed  to  have  been  productive  of  a  distinct  gain 
for  temperance  among  the  soldiers ;  and  by  temperance  is  not  meant 
total  abstinence. 

The  canteen  is  a  place  at  a  military  post  where  small  wares,  httle 


644  MILITARY  HYGIENE. 

luxuries,  tobacco,  and  the  li<;hter  alcoholic  driuks  may  be  ]uirchased 
under  close  supervision,  so  that  abuses  ciinnot  occur.  There  is  no 
inducement  held  out  for  the  men  to  buy  drink,  and  what  is  sold  must 
be  consumed  on  the  premises.  AVhat  small  profit  is  derived  goes  to 
the  post  exchange,  Avhich,  besides  the  canteen,  comprises  a  general 
store,  a  lunch  counter,  recreation  rooms  supplied  with  reading  matter, 
and  a  gymnasium. 

It  is  believed  that  the  canteen  system,  before  its  abolishment,  had 
worked  out  the  solution  of  much  of  the  problem  concerning  drunken- 
ness in  our  army.  The  soldier  accustomed  in  civil  life  to  the  use  of 
beer  -was  enabled  to  obtain  it  in  a  decent  way  and  only  to  a  reasonable 
extent,  and  hence  had  no  temptation  to  seek  alcohol  in,  perhaps, 
stronger  forms  elsewhere  and  not  under  supervision.  He  was  more 
likely  to  remain  habitually  sober,  instead  of  being  occasionally  help- 
lessly drunk  and  commonly  in  difficulties.  It  is  said  that  the  order  of 
things  that  obtained  on  pay  day  under  the  old  system  had  been  very 
largely  abolished.  Then,  pay  day  was  a  source  of  satisfaction  to  nobody 
but  the  saloon-keepers,  who  sold  bad  liquor  at  high  rates ;  men  were 
absent  days  at  a  time  without  leave ;  courts-martial  were  busy,  and 
there  was  much  guard-house  service.  Those  who  have  studied  the 
matter,  regard  the  canteen  as  the  friend  of  decency  and  discipline,  and 
the  enemy  of  every  saloon  near  a  garrison.  Naturally,  the  saloon- 
keepers and  that  class  of  reformers  who  believe  in  the  possibility  of 
bringing  about  radical  changes  in  human  nature  by  legislation,  became 
violently  opposed  to  the  continuance  of  the  system ;  and,  indeed,  the 
latter  were  so  successful  in  their  agitation  against  it  that,  in  spite  of 
the  practical  unanimity  of  the  officers  of  the  army  of  all  grades  in  its 
favor,  it  was  abolished  by  Act  of  Congress  in  January,  1901. 

Preparation  of  Food. — The  art  of  cooking  is  a  very  valuable  ac- 
complishment of  a  soldier,  especially  when  on  active  service.  In  camps, 
cooking  is  done  by  persons  enlisted  for  that  purpose,  one  cook  being 
allowed  by  law  for  each  company,  troop,  or  battery.  On  application, 
he  must  first  pass  the  regular  examination  of  a  recruit,  and  then  one 
in  which  he  must  demonstrate  his  knowledge  of  methods  and  skill  in 
caring  for,  preparing,  and  serving  food.  Kitchens  are  placed  under 
the  immediate  charge  of  non-commissioned  officers,  who  are  held  re- 
sponsible for  their  condition  and  for  the  proper  use  of  rations.  Only 
those  employed  or  those  on  duty  are  allowed  to  visit  or  remain  in  the 
kitchens.  The  general  supervision  of  the  cooking  and  messing  devolves 
upon  the  company  commanders,  who  are  charged  to  exercise  personal 
care  and  judgment  to  prevent  waste  and  nuisance,  and  to  see  "  that 
suitable  men  in  sufficient  numbers  are  fully  instructed  in  managing  and 
cooking  the  ration  of  the  field,"  since  when  the  conveniences  for  cook- 
ing on  a  large  scale  are  not  at  hand,  it  becomes  necessary  for  men  to 
divide  into  small  squads  and  prepare  their  own  meals. 

The  baking  of  bread  is  carried  on  in  post  bakeries,  under  the  charge 
of  enlisted  men  detailed  as  chief  and  assistant  bakers.  Baking  by 
companies  at  posts  is  expressly  prohibited,  but  is  the  rule  in  temporary 


77//';  SOI.IUKICS   FOOh;    "  HAT  I  OSS."  645 

oamps  and  with  inarrliin^  columns,  portnhlc  ovr-n.s  of  various  kirnlH 
aruJ  barrel  ov(!(is  Ixmhu;  cniplo^wid.  TIk;  barrel  oven  is  hcHt  rna«lf;  with 
a  barrel  witli  iron  hoops,  whi(;h  is  plaecd  oti  its  .-ide,  (;overed  eom- 
phitely  with  elay  or  stilT  mud,  exeejtt  at  i(s  open  end,  and  then  with  a 
thiek  lay(!r  o("  diy  (iarth,  leaving!;,  liow(!ver,  a  small  (.'{-ine,}!)  openirif^  at 
th(!  I<)|)  oC  (he  iuiKir  (Mid  lo  servo  as  a  flu('.  A  fire  is  made  in  tlie 
barnsl  and  l<(!|)t  up  until  all  the  wood  is  burncKl,  leavinj^  an  rtven  of 
clay,  for  whi(;h  the  lumps  aet  as  a  support. 

In  the  ti(!ld,  on  aeciount  of  transportation,  it  is  neeessary  that  (X)okinfj 
ap|)liane(!S  shoid<l  be  as  siinj)l(!  and  eeonomieal  of  space  jjus  possible. 
The  ijjnialc.r  tlu;  amount  of  bai:;<z;a<^(',  the  ^reat(T  the  numbf;r  of  wajrons 
neccsstiry  ;  the  ^-nNiter  the  nuuiber  of  wagons,  tlu;  greater  the  nuridjer 
of  animals  and  tlu;  greater  the  amount  of  necessary  forage. 

Com])arison  of  the  United  States  ration  with  that  of  European 
countries  demonstrates  that  ours  is,  in  most  resj)eots,  the  most  liberal 
ration  in  the  world.  In  only  on<»  instance  is  there  a  conspicuous  suj)e- 
rioritv  in  the  amount  of  an  important  constituent ;  namely,  the  very 
generous  aUowance  of  potatoes  in  the  German  ration.  Not  only  is  the 
U.  S.  ration  the  most  abundant,  but  it  admits  of  greater  variety  than 
any  other.  But  even  at  that,  it  is  held  by  many  to  Ije  insufficient  in 
amount  for  the  proper  performance  of  the  work  a  soldier  may  be  called 
upon  to  perform.  Experts  in  the  making  of  dietaries  have  proposed 
increasing  the  flour  and  soft  bread  allowance  by  about  a  fourth,  and 
adding  about  5  ounces  of  flour  to  the  alternative  allowance  of  hard 
bread  and  20  per  cent,  to  the  alternative  allowance  of  corn  meal,  with 
a  reduction  of  40  per  cent,  in  the  allowance  of  potatoes,  and  the  alter- 
native of  money  value  in  milk  or  cheese  in  place  of  the  allowance  of 
peas  or  beans. 

In  the  consideration  of  tile  question  of  quality  and  variety,  it  should 
be  borne  in  mind  that,  while  it  is  necessary  to  have  a  standard  of  food 
value  fixed  by  law',  it  is  uot  necessary  to  consume  precisely  the  articles 
named.  Nor  is  it  possible  to  fix  a  money  value  to  the  ration,  and  give 
out  the  cash  equivalent  iu  place  of  actual  food,  for  the  soldier  is  not 
always  near  a  market,  and,  moreover,  if  he  M'ere,  it  is  most  evident 
that  the  same  amount  of  mouey  iu  diiFereut  places  would  yield  ver^' 
diflereut  amounts  of  nutriment,  since  in  one,  the  food  supply  is  abun- 
dant and  cheap,  and,  in  another,  scanty  and  expensive.  What  the  soldier 
eats,  d(>pends  upon  circumstances,  and  largely  upon  the  discretion  of 
company  commanders  guided  by  the  advice  of  the  medical  officers,  but, 
as  said  before,  the  actual  food  value  is  fixed  by  Congress,  and  is  based 
on  the  experience  and  study  of  many  years. 

Is  the  United  States  Ration  Suited  to  the  Tropics  ? — The  ques- 
tiou  of  the  suitability  of  our  ration  to  the  tropics  is  one  which  has 
assumed  great  importance  since  the  necessity  arose  for  maintaining  large 
armies  iu  our  uew  possessions,  aud  its  discussion  has  been  mai'ked  by 
a  much  more  temperate  tone,  and  has,  therefore,  yielded  better  results. 
The  beginning  of  the  discussion  may  be  said  to  have  arisen  from  the 
fact  that  it  became  generally  understood  that  bacon  was  a  necessary 


646  MILITARY  HYGIENE. 

constituent  of  the  daily  food,  both  in  caniji  and  in  active  operations,  in- 
stead of  an  alternative,  as  may  be  gathered  from  the  wording  of  the 
statute — fresh  beef,  or  fresh  mutton,  etc.,  or  pork,  or  bacon,  or  salt 
beef,  or  dried  fish,  or  pickled  fish,  or  fresli  fish.  Bacon  lias  its  advan- 
tages at  certain  times,  but  is  not  eagerly  sought  after  by  those  not  in 
good  health,  nor  is  it  acceptable  in  very  hot  climates  as  a  regular  diet 
any  more  than  any  other  fatty  food.  Fats  are  much  needed  in  cold 
climates  for  the  production  of  heat ;  in  hot  climates,  the  necessity  for 
their  use  is  but  slight  in  comparison.  But  when  fresh  meat  cannot  be 
obtained  either  on  the  hoof  or  from  cold  storage,  and  when  the  appe- 
tite is  cloyed  by  canned  meats  (and  this  is  soon  brought  about),  bacon 
is  acceptable  as  an  occasional  substitute. 

To  those  at  a  distance  and  uniacquainted  with  local  conditions,  the 
ideal  supply  of  fresh  meat  is  cattle  on  the  hoof.  But  the  cattle  of  the 
tropics  are  not  the  same  as  those  which  we  know,  nor  are  they  always 
to  be  had  in  even  small  numbers.  Sending  live  cattle  from  home,  to 
be  driven  along  on  the  march  to  be  killed  as  needed,  is  not  always 
practicable,  for  even  if  landed  in  good  condition,  they  cannot  be  kept 
on  the  march,  and,  unless  the  country  traversed  is  good  grazing  land, 
they  lose  weight  and  die  off  rapidly.  Canned  meats  are  much  inferior 
to  fresh  meats,  and  cannot  long  be  eaten  with  relish.  The  canned  so- 
called  7'oast  beef  is  commonly  the  residue  of  meat  after  the  extractives 
have  been  boiled  out  of  it  for  the  manufacture  of  meat  extract,  and  it 
is,  therefore,  lacking  in  flavor,  although  not  materially  diminished  in 
nutritive  properties.  It  is  often  as  tasteless  and  almost  as  difficult  to 
chew  as  towelling,  and  is  far  from  inviting  in  appearance,  especially 
when  the  cans  are  opened  at  ordinary  hot  summer  temperature. 

According  to  many  experienced  minds,  the  consumption  of  meat  in 
any  form  should  be  much  limited  in  the  tropics.  Koquemaure  '  ad*^ises 
the  European  in  the  tropics  to  take  nothing  into  his  stomach,  except 
articles  easily  digested ;  mutton,  beef,  and  pork  only  in  moderation, 
and  not  too  thoroughly  cooked,  and  not  regularly  or  too  often  ;  birds, 
eggs,  and  fish  are  more  to  be  commended ;  especially  to  be  relied  upon 
are  rice,  dried  vegetables,  fresh  vegetables,  starchy  foods,  and  ripe  fruits 
in  good  condition.  Kohlbriigge  ^  places  above  all  other  influences  in 
the  deterioration  of  Europeans  in  the  tropics  the  too  extensive  use  of 
animal  fats,  which,  he  claims,  are  responsible  for  much  of  the  diarrhoeal 
troubles  of  the  tropics.  He  recommends  the  vegetable  oils  for  supply- 
ing what  fats  are  needed  by  the  body. 

The  observations  of  Dr.  L.  L.  Seaman,^  in  Porto  Rico,  lead,  in  part, 
to  the  same  conclusion.  He  relates  that,  within  a  week  after  landing 
in  the  summer  of  1898,  in  spite  of  the  strictest  sanitary  precautions 
and  personal  hygiene,  the  entire  force  with  which  he  was  connected 
suffered  from  some  form  of  intestinal  catarrh  from  one  cause  and 
another,  and  that  medication  was  of  no  avail,  since  the  diet  of  bacon, 

'  Hygiene  alimentaire  aux  pays  chands,  Bordeaux,  1895. 

"^  Die  Acclimatisation  der  Europiier  in  den  Tropen :  Deutsche  medicinische  Wochen- 
Bchrift,  1898,  Nos.  27  and  28. 

=*  New  York  Medical  Journal,  March  18  and  25,  1899. 


Tni<:  soLini'iiL's  food;  " nAT/oNS."  C47 

Hali.cd  ]H'i)C,  <:ii\\\U'(\  Ix'uiiK  and  pork,  .and  liurdia<;k-  f)rovf'd  U)  ))('.  a  fon- 
tinuid  ii-ritaril,,  hy  wliirJi  ilic  (loiiMcs  w<!rc  a^r^n-aval'd  and  (lu;  jxiwor 
of  rcHiHtaiKH'  niiidi  rcdnccil.  (iidir  sik-Ii  ••oiidilion.'-,  malaria  and 
typhoid  U'vcr  gained  ;i  (oollioM  in  (Jk;  HyhU-in  vvilli  nnifli  caw; ;  firHt 
oani<!  tlu!  nialai'ial  (('vci-s  oC  ilw  variouH  tyjx'H,  and,  in  tlic  fjirly  part  of 
S(;pi(^rnl)('r,  on  I  Ik;  introdn<"li(»n  of"  <li(;  ^crrtiH  from  Tampa  and  Cliicka- 
manf2;a-,  typhoid  fever  hrokc  out,  and,  spread  hy  flic.-,  eonfinned  wilJi 
varying;  severity  until  onibarkation  for  hon)(!  in  Novendier.  'I'lie  vahie 
of  a  milk-diet  was  einj)hati(!ally  demonstrated. 

K()(!rfer's  ^  re<!ommen<Ia(ion  to  Europeans,  to  hyive  (Ixir  pork  fat, 
nu^ats,  and  al(H)lioI  at  home  witii  their  healing  sloves  an<l  Ihrs,  when 
they  ^o  to  resi<le  in  the  tropics,  is  (jMote<l  in  (confirmation. 

While  the  use  of  green  vegetables  is  universally  rccommend(Hl  in 
the  tropics,  it  is  not  always  easy,  and,  in  fact,  it  is  often  extremely  diffi- 
cult or  impossible,  to  ol)tain  them,  sinc(;  the  natives  of  the  tropics  are 
commonly  content  to  live  on  rice,  <lried  beans,  and  fruit,  with  an  o(;ca- 
sioual  taste  of  fish  or  meat.  Canned  vegetables,  while  gratefid  to  the 
system,  are  not  wholly  to  be  recommended,  on  account  of  transporta- 
tion. A  can  of  string  beans,  for  exam])lc,  contains  a  maximum  of 
water  and  a  minimum  of  nutriment,  and  for  its  real  service  in  the 
dietary  may  be  said  to  be  hardly  worth  its  cost  of  carriage.  Dried 
vegctiiblcs  and  fruits  are  more  economical,  but  should  be  well  .-^oaked 
before  use. 

The  Court  of  Inquiry,  appointed  to  investigate  the  food  supply  of 
the  army  during  the  war  with  Spain,  reported  among  other  concliL'^ions 
the  following  :  "As  to  the  effects  of  the  food  supply,  htiving  regard  to 
sufficiency  and  quality,  it  seems  U)  be  clearly  established  that  tlie  aniiy 
ration  as  supplied,  without  modification,  to  the  troops  serving  in  the 
West  Indies  was  by  no  means  well  adapted  for  use  in  a  tropical  climate. 
If  this  be  true,  the  unfitness  of  the  ration  should  have  manifested 
itself  by  its  failure  to  keep  the  troops,  who  subsisted  upon  it,  in  the 
best  possible  condition  for  service  in  hot  climates.  This,  in  the  opinion 
of  the  court,  is  fully  established  in  evidence."  Seaman  advocates  a 
reduction  in  the  meat  components,  the  use  of  salted  meats  not  oftener 
than  twice  per  Aveek,  and  an  increase  in  the  allowance  of  vegetable  and 
farinaceous  foods  and  dried  fruits. 

Dr.  Edward  L.  Munson,  U.  S.  A.,^  has  studied  the  subject  of  trojv 
ical  diet  from  the  standpoints  of  physiological  science,  availability,  and 
practicability,  and  concludes  that  the  articles  of  the  ration  are  correct 
as  they  stand,  being  admirably  selected  and  of  good  variety,  but  need 
some  rearrangement  in  their  respective  amounts.  He  proposes  cei*tain 
modifications,  and  offers  four  dietaries,  the  average  of  which  is  not 
widely  variant  from  a  proposed  nutritive  standard  for  soldiers  in  the 
tropics,  as  follows  :  Protein,  100  grammes  ;  carbohydrates,  G50  ;  flits, 
65.      (Nitrogen,   16  ;  total  carbon,   392  ;  fuel  value,  3,491   calories.) 

^  Deutsche  medicinische  Wocheiischrift,  July,  1S98. 

-  The  Ideal  Ration  for  an  Army  in  the  Tropics.  (Prize  essay.)  Boston  Medical  and 
Surgical  Journal,  May  3,  10,  17,  and  24,  1900. 


648 


MILITARY  HYGIENE. 


Dietary  I.  contains  the  greatest  amount  of  food  material  which  may 
be  drawn  by  the  soldier  : 

TROPICAL  DIETARY  I. 


Articles. 


Quantity, 
ounces. 


Fats, 
grams. 


Carbohy- 
drates, 
grams. 


Protein, 
grams. 


Nitrogen, 
grams. 


Fuel 

value, 

calories. 


Fresh  beef 
Flour  .  . 
Beans  .  . 
Potatoes  . 
Dried  fruit 
Sugar     .    . 


10 
18 

2.4 
16 

3 

3.5 


44.75 
5.60 
1.22 
0^45 
1.53 


380.46 
40.18 
81.70 
33.80 
94.25 


41.68 

55.08 

15.16 

9.50 

1.77 


6.67 
7.90 

2.42 
1.52 
0.27 


590 
1,850 
240 
380 
220 
397 


Total 


52.9 


53.55 


630.39 


123.19 


18.78 


3,677 


Total  carbon,  395.14  grams ;  nitrogen  to  carbon,  1  :  19.6. 


Dietary  II.  is  especially  applicable  to  field  service ;  in  this,  the  fatty 
constituents  attain  their  maximum  and  the  potential  energy  is  high : 

TROPICAL  DIETARY  II. 


Articles. 

Quantity, 
ounces. 

Fats, 
grams. 

Carbohy- 
drates, 
grams. 

Protein, 
grams. 

Nitrogen, 
grams. 

Fuel 

value, 

calories. 

Bacon 

Hard  bread 

Beans     

Dried  fruit 

Sugar     

6 
18 
2.4 
3 
3.5 

105.06 
6.63 
1.22 
1.53 

371.81 
40.18 
50.70 
94.25 

15.64 

73.12 

15.16 

1.77 

2.49 

11.74 

2.42 

0.27 

1,042 

1,926 

240 

220 

397 

Total 

32.9 

114.44 

556.94 

105.69 

16.92 

3,825 

Total  carbon,  328.76  grams ;  nitrogen  to  carbon,  1 :  23. 


Dietary  III.  is  proposed  for  garrison  duty  : 


TROPICAL  DIETARY  IIL 


Articles. 

Quantity, 
ounces. 

Fats, 
grams. 

Carbohy- 
drates, 
grams. 

Protein, 
grams. 

Nitrogen, 
grams. 

Fuel 

value, 

calories. 

Fresh  beef 

Soft  bread 

Potatoes  and  onions     .    . 

Dried  fruit 

Sugar     

10 
20 
16 

3 

3.5 

44.75 
6.80 
0.72 
1.53 

299.20 
73.09 
50.70 
94.25 

41.68 

53.83 

8.60 

1.77 

6.67 
8.61 
1.40 
0.27 

590 
1,506 
340 
220 
397 

Total 

52.5 

53.80 

517.24 

105.88 

16.95 

3,053 

Total  carbon,  328.76  grams ;  nitrogen  to  carbon,  1 :  18. 


Dietary  IV.  is  a  combination  of  the  several  articles  of  the  ration  most 
closely  approaching  in  character  the  food  materials  used  by  the  natives 
of  the  tropics,  proportioned  according  to  the  proposed  standard  : 


I'OSTS  AND   CAMPS. 


649 


'll.'oi'K'Ai,   |)ii;'r,\i;.v    IV. 


Articles, 

Qiiiiiitlly, 

OUUCUH. 

I'-IltH, 

({riiiiiit. 

(^iirboliy- 
driitcM, 
grarnH. 

rrol«!lii. 

grUKIM. 

NltroKon, 
gram*. 

Fu«l 

vftlue, 

ciiloriM. 

FrcHli  HhIi  ((!oc1),  whnlo  . 

Soft,  l)rc'ji(l      

lixvM 

I'oImIoch  ;iii(1  totiuitooH     , 

Dried  IVuit 

Supiir 

14 

20 
4 

k; 

3.5 

0.79 

fi.8() 

o.'ir, 
0.61 

1.6:i 

2!i!i.20 
88.87 
06.80 
60.70 
94.25 

31.73 

6.",.8.", 
8.76 
8.17 
1.77 

607 

8.01 
1.10 
l..",0 
0.27 

120 
1,600 
407 
297 
220 
341 

Total!    ....... 

64.6 

10.11 

598.82 

104.25 

16.71 

2,947 

Total  carbon,  327.50  grams;  nitrogen  to  carbon,  1 :  19.6, 


TIi(>  Tollowino;  tivMo  slunvs  tlic   monn    nutrient   of)mpositiV)n   of  i]w. 
four  dietaries,  and  udniits  of  ready  coMi[)ari.son  of  one  witii  another  : 


Dietary. 


No.  I. 
No.  11. 
No.  III. 
No.  IV. 


Average 


(iiijuitit.y, 


52.9 
.32.9 
52.6 
64.6 

50.7 


I'atH, 


53.55 
114.44 

63.80 
10.11 
67.97 


Carliohy- 
d  rates, 
gruiuii. 


630.39 

666.94 
617.24 

69S.82 
575.85 


Protein, 
graiim. 


123.19 
106.69 
106.88 
104.26 
109.76 


Nitro(?ftn, 
graiuH. 


18.78 
16.92 
16.95 
10.71 
17.34 


Fuel 

value, 

[caloriefl. 

3,677 
3,825 
3,063 
2,947 
3,.375 


Total  carbon,  350  grams;  nitrogen  to  carbon,  1 :  20. 


The  so-called  "Filipino  Ration"  is  as  follows  :^ 

Filipino  Ration. 


Component  articles  and  quantities. 

Substitutive  articles  and  quantities. 

12  ounces    . 
8  ounces    . 

.32  ounce  . 
20  ounces     . 
8  ounces    . 

1  ounce .   . 

2  ounces    . 
.08  gill  .   . 
.fi4  ounce  . 
.02  ounce  . 

("Bacon 

8  ounces. 
8  ounces. 

Beef,  fresh 

Flour 

1  Fish,  canned 

L  Fish,  fresh 

Hard  bread 

12  ounces. 
12  ounces. 
8  ounces. 

Baking  powder,  when  in 
field  and  ovens  are  not 

Rice 

Potatoes 

Coftce,  roasted  and  ground 

Onions 

8  ounces. 

Salt 

Pepper,  black 

Posts  and  Camps. 

Posts  are  permanent  camps  or  those  of  position,  and  camps,  in  the 
usual  sense,  are  temporary  or  incidental.  At  posts,  the  troops  are 
housed  in  barracks,  while  at  temporary  camps  they  occupy  tent*  and 

!  It  will  be  noticed  that  the  first  and  sixth  columns  do  not  add  up  acconiing  to  (he 
totals  expressed.  The  latter,  however,  being  used  in  the  table  below,  are  retained 
unchanged. 

*  General  Ordei"s  No.  47,  War  Depai-tment,  Washington,  April  3,  1908. 


650 


MILITARY  HYGIENE. 


huts.  The  same  sanitary  considerations  apply  equally  well  to  both,  but 
choice  of  location  of  temporary  camps  in  time  of  war  is  determined 
commonly  by  immediate  and  strategical  considerations.  Both  should 
be  laid  out  in  such  a  manner  as  to  insure  proper  air  supply,  cleanliness, 


Fig.  103. 


K'-.''l  A 


Officer!  Bath  cul  Sink  Tent*. 


I*' 


Qffietn  KItdMi, 


Held  mi  Staff  Hc^ora 


■f         Non-Com  staff  Band 
o         and  Drum  CorpiTent*. 


})* 


Battalion  Offteert  Tents, 


€!•  •  •  •  « 

"f  Company  OfffoenTinta 

W  Wf\W  W"-  'H'  tt  W'  '9  '9'  '9'  in  ''S 
"""»  •  •  •  •  •  •  •  •  •. 


Company  Tenia. 


TJ  1  <  I  I  t  I  I  I  '  '  ' 

Company  KJtoAens. 


Ji    *       *■       ♦ 


Cempnny  Bath  and  Sink  Tentt. 
•       •       •        • 


*       *        •       * 


eoala64  t«tt  •!  tooh 


SV 


Explanation. 

•^    BTumlnff  Wat«r 


^^M  Cooorote  Fonndfttlon. 

Plan  of  camp  (reduced  so  that  scale  of  64  feet  to  the  inch  no  longer  applies). 


and  general  salubrity,  and  should  be  as  compact  as  is  consistent  with 
the  principles  of  hygiene,  for  a  compact  camp  is  more  easily  cared  for 
and  defended,  while  one  unnecessarily  extended  involves  increased  labor, 
slower  delivery  of  orders  and  supplies,  and  greater  difficulties  in  sani- 
tary policing.  With  the  tactical  and  strategical  requirements  and  gen- 
eral plan,  which  is  a  matter  of  regulation,  the  hygienist  has  nothing  to 
do,  and  his  interest  lies  only  in  the  distances  between  different  bodies 


rOSTS  AN/)   ('AMPS.  051 

of  men,  tho  sizo  of  oornjKuiy  Jirciis,  (Ik;  (tiihic;  Hp.'K;^  pfT  rnuii,  flif  proper 
locution  of, sinks,  l.'ili'iiics,  and  iiriiiiils,  llic  nicuHuniH  aiJoptcd  for  hurlatx; 
(lrainaji;<i,  (lis|)(>sal  (»("  scwaj^c,  p;arl>af^c  and  Htiiblc  rrijmurf,  the  watcr- 
HUj)])iy,  and  oilier  niaUcrs  having  a  hearin/j;  on  tlie  liealtli  of  tlie  trof»pH. 

']'li(!  ^cnei-id  plan  of  a  canip  is  shown  in  I*'i^.  lO.'i,  taken  from  flit* 
Jidiintry  J)i'ill  IJe^ulalion,  and  amended  in  (lie  maltcr  of  distaiiees  and 
intervals  hy  Dr.  I*.  (-.  Harris,  IT.  S.  A.,'  since  no  distances  and  inter- 
vals arc  f!;iven  in  the  rej^idation,  lor  they  rniiHt  vary  acc/»rdin^  lo  the 
nature  of  the  ^roinid  and  the  strene;th  of  tin;  (^onunand.  The  plan  i.s 
made  "on  a  basis  of  .'>  men  to  a  coriniion  tent  or  10  to  a  eonieal  wall 
tent;  the  maxinnuii  allowance;  of  tentaf^e  is  G  men  to  a  common  tent 
and  20  to  a  conical  wall." 

Sites. — One  of  the  most  important  matters  connected  with  military 
hygiene  is  the  selection  of  a  proper  site  for  cam|)s.  Kverythinj^  hear- 
ing on  the  health  of  those  who  are  to  occuj)y  the  camj)  should  he  con- 
sidered important,  and  every  eifort  should  Ik;  made;  to  insure,  so  far  a.s 
it  is  possible,  that  there  is  no  ])oint  of  least  resistance  in  the  barriers 
against  disease.  If  an  unhealthy  site  is  chosen,  no  amount  of  care  can 
ward  olf,  though  it  may  check  the  extent  of,  evil  conse(|uences.  In 
active  wai'fare,  choice  of  sites  is  not  always  a  wide  one,  and  convenience 
and  necessity  play  a  greater  part  than  sanitary  consideration.  A\'hen 
practicable,  they  should  be  placed  on  high,  well-drained  ground 

Proximity  to  water  is  always  necessary,  and  this  may  involve  ex- 
posure to  malarial  infection  ;  but,  other  things  being  equal,  the  driest 
site  should  be  selected.  Where  the  choice  is  restricted,  advantage 
should  be  taken,  in  cold  weather,  of  any  available  protection  from 
winds,  and,  in  hot  climates,  from  the  burning  sun.  The  general  slope 
of  the  ground  should  be  considered,  so  that  surface  drainage  may  be 
best  provided  for. 

The  soil  should  be  dry  and  porous ;  clay  and  other  soils  of  low 
permeability  to  air  and  moisture,  but  with  high  retentive  power  for  the 
latter,  should,  if  possible,  be  avoided.  If  the  ground-water  level  is  high, 
it  should  be  lowered  by  tile  draining  or  ditching,  in  case  the  camp  is  to 
be  one  of  permanence.  A  clay  soil  or  a  soil  underlaid  at  a  short  dis- 
tance by  a  clay  soil  is  regarded  commonly  as  the  worst  possible  site  for 
a  camp,  since  it  is  retentive  of  water  and  is  cold,  and  causes  the  atmos- 
phere immediately  above  to  be  damp.  Old  river  bottoms,  deep  allu- 
vium, and  marshy  ground  should  be  avoided.  Grass  land  may  com- 
monly be  accepted  as  good  camping  ground,  but  ground  covered  with 
rank  vegetation,  as  in  the  tropics,  is  not  acceptable,  because  such  is 
generally  rich  in  decaying  organic  matter,  and  the  presence  of  rank 
vegetation  is  in  itself  evidence  either  of  a  very  humid  atmosphere  or 
of  an  undesirable  degree  of  soil  moisture.  Lauds  subject  to  periodical 
flooding,  especially  by  salt  water,  should  be  avoided  as  unhealthy. 

Above  all,  it  should  be  a  rule  to  avoid  old  camp  grounds,  for  these 
usually  are  left  in  a  filthy  condition  by  the  previous  occupants,  and  the 
soil  is  always  contaminated  extensively  and,  perhaps,  infected.  If  an 
*  Camps  of  Instruction,  Reprint,  Buffalo,  Dec.  14,  189S. 


652  MILITARY  HYGIENE. 

old  camp  site  is  particularly  desirable  on  account  of  the  accessibility 
of  wood,  water,  and  g;rass  (the  three  essentials  demanded  by  the  line 
officer),  a  position  to  windward  and  as  near  as  is  consistent  with  hy- 
gienic considerations  may  be  selected. 

Dryness  of  the  site  and  vicinity  is  of  prime  importance  in  its  bear- 
ing on  the  health  of  troops,  but  too  great  dryness  with  much  dust  is 
hurtful  to  the  eyes.  A  position  on  the  side  of  a  hill  is  warmer  than 
one  at  the  top  and  drier  than  one  at  the  bottom,  and  is  favorably  situ- 
ated as  regards  that  most  essential  provision  in  camp  sanitation, 
drainage. 

Barracks. — Barracks  are  permanent  structures  for  the  lodgment  of 
soldiers,  and  are  built  commonly  of  one  or  two  stories,  but  not  more. 
Each  building  of  a  group  should  be  completely  independent  of  the 
others  and  placed  with  reference  to  prevailing  winds  and  exposure  to 
the  sun.  It  is  essential  that  the  site  be  dry  ;  the  foundation  walls 
solidly  laid ;  the  walls,  of  whatever  material  constructed,  dry  and  pro- 
tected against  capillary  moisture ;  the  floors,  of  hard  wood,  tightly  laid  ; 
and  the  ventilation  efficient.  Barrack  rooms,  which  are  the  soldiers' 
living  rooms  as  well  as  sleeping  quarters,  are  generally  made  long  and 
narrow,  and  each  occupant  has  floor  space  and  air  space  according  to 
the  regulations  obtaining  in  the  country  which  he  serves.  In  this 
country,  600  cubic  feet  of  air  space  per  man  are  reckoned  adequate, 
and  this,  in  a  room  12  feet  from  floor  to  ceiling,  gives  a  floor  space  of 
50  square  feet.  Cavalry  and  artillerymen  are  given  somewhat  more, 
on  accoimt  of  the  odors  which  cling  to  them  from  contact  with  horses. 
A  less  amount  is  allowed  when  troops  are  quartered  in  ordinary  dwell- 
ings. At  Southern  posts,  800  cubic  feet  of  air  space  and  70  square 
feet  of  floor  space  are  allowed.  In  England,  the  allowances  are  the 
same  as  with  us  for  infantrymen  in  the  North  ;  in  India,  they  are  from 
1500  cubic  feet  and  75  square  feet  to  double  those  limits.  In  France, 
the  cubic  space  allowed  is  420  cubic  feet  for  infantry  and  500  for 
cavalry.      In  Germany,  it  is  500  cubic  feet. 

The  wash-rooms,  urinals,  and  latrines  should  be  placed  with  due 
regard  to  convenience  and  to  general  hygienic  considerations. 

Ventilation  should  be  planned  with  a  view  to  the  greatest  possible 
reduction  of  the  natural  impurities  due  to  occupancy,  but  with  the  pres- 
ent cubic  space  allowance,  whatever  the  system  employed,  ideal  results 
cannot  be  attained.  Barrack  life  is  necessarily  one  of  overcrowding, 
but  the  conditions  which  now  obtain  are  far  superior  to  those  which 
formerly  prevailed.  Tlie  evils  of  overcrowding  of  soldiers  were  first 
brought  to  light  by  an  investigation  of  the  health  of  British  soldiers 
in  1858.  It  was  shown  that,  whereas  the  mortality  rate  of  the  popu- 
lation of  England  and  Wales  of  the  same  age  as  the  army  was  9.2  for 
town  and  country  and  7.7  for  country  alone,  and  12.4  for  the  most 
unhealthy  town  (Manchester),  that  of  the  different  arms  of  the  service 
ranged  from  11  for  the  household  cavalry  to  20.4  for  the  footguards. 
According  to  age  periods,  the  mortality  was  distributed  as  follows  : 


POSTS  AND   CAMI'S.  fi-O.'J 

A          >m  ,      iir     f  nviliariH HA 

I  iSi)l(|i('rn I/O 

.         or  ,     ..A    f  ( Iivili;iiiH '.i.'J, 

*                        I  SoIiIhth ]H..i 

A         .,,1  ,     .,r    (  (Iivili:inH 10.2 

"                         I  SoldiciH IH.'l 

1  .,r    ,       iu     I  ( 'ivilillllH II.fi 

A^liH  •'■'  lo  '10.  ^  i.    I  I-  II.  •> 

Since  tli(!  soldiers  wv.vv.  picked  men,  all  iipplicanls  vvltli  any  evidence 
of  weakness  or  tendency  to  diswise  bein^  nijeetcd,  tlie>i(!  datn  indicated 
a  serions  (condition  of  alVairs.  CoinpMiison  was  made  witli  tlic  rates 
obtainiiiji;  amoiio;  ili(«  cImss  (»!"  ao;ri(Mllnial  lahorer.-^,  tlicir  work,  lik(!  tliat 
of  the  soldiers,  bein^  mainly  <>iil  <>(  door.-^.  It  wonld  be  expect<;<l  tliat 
tlic  latter,  beinti;  well  clollied,  lionsed,  and  i'vA,  and  ^iven  free  medical 
care,  would  present,  the  better  sliowinj^,  but  sncli  j)roved  not  to  b(;  the 
case,  for  the  moi-tality  of  the  lai)orer  beint:  expressed  as  ],  that  oi'  the 
household  cavalry  was  l.(S,  dragoons  2.2,  infantry  of  tlu;  line  2.0,  and 
footguards  3.8.  Comparison  with  men  in  other  occupations  showed 
that  the  soldiers  presented  the  most  uniavorable  stiitistics. 

Tnciuiry  as  to  the  cause  n^vealed  that,  whereas  among  civilians  at  the 
soldiers'  ages  the  deaths  from  diseases  of  the  lungs  were  0.8  ])er  1000, 
they  Avere  7.8,  10.2,  and  18.8  resj)ectively  for  the  cavalry,  infantiy  of 
the  line,  and  guards ;  and,  furthermore,  that  of  the  entire  number  of 
deaths  from  all  causes  in  the  army,  the  j)roportif)n  due  to  lung  diswises 
amounted  to  58.1),  57.8),  and  07.7  per  cent,  respectively  in  the  arms 
above  mentioned.  Finally,  by  exclusion,  the  cause  of  tins  great  mor- 
tality was  attributed  to  overcrowding  and  lack  of  ventilation.  Com- 
parison of  the  mortality  of  the  army  at  home  with  that  of  the  troops 
quartered  before  Sebastojiol  in  1856  was  much  in  favor  of  the  latter. 
The  rates,  reckoned  per  annum,  were  as  follows  :  Jicfore  Seloastopol, 
including  death  by  violence  and  accident,  12.5;  at  home,  17.0  (infan- 
try), and  20.4  (guards). 

Increase  in  space  allowance  was  soon  followed  by  a  marked  decrease 
in  jihthisis  mortality. 

Tents. — In  the  United  States  Army,  four  kinds  of  tents  are  used : 
1.  The  conical,  or  modified  Sibley,  tent.  This  is  16  feet  5  inches  in 
diameter  at  the  base;  wall,  3  feet  high  ;  apex,  10  feet  from  the  floor; 
the  area  of  the  floor  equals  212  square  feet ;  the  air  space,  1450  cubic 
feet;  allowance,  20  infantry  or  17  cavalry.  The  original  Sibley  tent 
had  a  diameter  of  18  feet  at  the  base  and  was  18  feet  high.  The  apex 
was  cut  oif,  thus  giving  place  to  a  circular  aperture  which,  being  left 
open  in  fair  weather,  promoted  ventilation.  In  foul  weather,  it  was 
covered.  The  allowance  was  the  same.  2.  Common  tent,  "  I "  or 
modified  "  A."  Wall,  2  feet  high ;  base,  8  feet  4  inches  by  6  feet  10 
inches ;  ridge,  6  feet  10  inches  from  the  ground  ;  floor  space,  57  square 
feet ;  air  space,  250  cubic  feet ;  allowance,  4  mounted  or  6  infantry. 
3.  Wall  tent.  Wall,  3  feet  9  inches;  floor,  9  square  feet;  ridge,  8 
feet  6  inches  above  the  ground  ;  floor  space,  81  square  feet ;  air  space, 
500  cubic  feet ;  covei'e*.!  by  fly  or  false  roof.  4.  Shelter  tent.  These 
are  issued  to  troops  in  the  field,  and  are  not  regarded  as  tent  allowance. 


654  MILITARY  HYGIENE. 

but  are  provided  in  order  that  men  and  officers  in  bivouac  while  on 
active  campaign  or  on  the  march  with  deticient  means  of  transportation 
may  be  shelteral.  One  forms  a  shelter  for  2  men,  each  of  whom 
carries  his  half,  which  A\eig-hs  about  2|  pounds.  The  pieces  are 
joined  together  by  buttons  and  put  over  a  ridge  pole,  which  is  suj)- 
ported  by  uprights  about  4  feet  high.  The  corners  are  fastened  to 
pegs  driven  into  the  ground,  and  the  uprights  are  steadied  by  guy 
lines.  Hospital  tents  are  wall  tents  of  a  larger  size ;  they  may  be 
closed  or  open  at  the  ends,  and  several  may  be  joined  together  so  as  to 
make  a  continuous  whole.  They  are  14X15  with  a  4|-foot  wall; 
ridge,  12  feet  from  the  ground. 

The  English  army  uses  the  circular,  or  bell,  tent.  Diameter  at  base, 
12  feet  6  inches;  walls,  1  foot;  apex,  10  feet;  floor  space,  123  square 
feet;  air  space,  492  cubic  feet;  allowance,  12  to  16  men,  and  in  war 
18  to  20.  Formerly,  the  ventilation  was  practically  nil,  but  now  it 
has  been  somewhat  improved.  The  French  army  uses  a  similar  tent, 
ventilated  at  the  top.  The  air  space  is  1059  cubic  feet ;  allowance, 
16  men.  The  Germans  use  a  conical  tent  like  the  English  bell  tent. 
Diameter,  under  15  feet;  apex,  12  feet  from  the  ground;  floor  space, 
180  square  feet;  air  space,  1050  cubic"  feet;  allowance,  15  men. 
They  use  also  small  bivouac  tents  designed  to  shelter  2  or  more  men. 
The  different  parts  are  distributed  among  and  carried  by  the  men  who 
are  to  use  them. 

It  will  be  observed  that,  of  the  four  armies  mentioned,  ours  is  the 
most  liberal  in  point  of  air  space,  the  minimum  allowance  in  the  larger 
tents  being  72|  cubic  feet,  against  a  maximum  of  41  in  the  English 
service,  66  in  the  French,  and  70  in  the  German  service. 

The  material  of  which  tents  are  made  is  cotton  duck,  which  has 
proved  to  be  much  better  for  shedding  water  than  linen.  Compara- 
tively little  ventilation  occurs  through  this  material  under  the  best 
of  circumstances,  and  none  at  all  when  it  is  wet  by  rain,  for  then  it  is 
impervious  to  air.  Ventilation  of  tents  is  always  defective,  and  com- 
monly the  atmosphere  becomes  exceedingly  foul.  Since  there  is  so 
little  ventilation,  it  is  necessary  that  the  sides  should  be  kept  raised 
during  the  day,  in  order  that  thorough  airing,  and,  if  possible,  sunning, 
may  occur ;  and  at  night,  when  practicable,  the  sides  to  leeward  should 
be  open,  and  the  others,  too,  if  advisable. 

Dr.  Edward  L.  Munson,  U.  S.  A.,^  has  suggested  improvements  in 
the  regular  tentage,  and  especially  in  the  hospital  tents,  for  service  in 
our  tropical  possessions,  since  the  several  forms  in  use,  although 
well  adapted  to  our  climatic  conditions,  are  intensely  hot  and  close  in 
the  high  temperatures  and  humid  atmosphere  that  there  obtain.  He 
proposes  enlarging  the  tent  fly  of  the  hospital  tent  2  feet  in  length 
and  4  in  width,  and  that  it  be  raised  upon  a  light  false  ridge,  4 
feet  longer  than  the  true  ridge  and  projecting  2  feet  to  the  front  and 
rear.     Further,  he  proposes  that  the  canvas  forming  the  top  of  the 

*  Tentage  for  Tropical  Service,  Boston  Medical  and  Surgical  Journal,  Nov.  16,  1899, 
p.  487. 


rOSTS  AND   (JAM IS.  Gr>.'j 

tent  be  out  out  for  a  Hi)a(!(!  2  U'cX  wide;  on  cadi  Hide  of  tin;  rid^*;  an<] 
running;  i\\v,  c^iitin;  Icii^tli  of  the  ton!,  cxrcpl  1  fool,  front  and  rfjir, 
the  (!aiiviis  thus  reinovf^l  heiii/^  I'cplaecd  hy  heavy  ro|K!  netting'  with  a 
2-inch  mesh.  Jn  order  heller-  to  reflect  llie  heiit  niys,  the  fly  slionld 
be  made  of  white  canvas,  Ihe  (enl  ilself  beinjf  of  d;nl<  (janvaK,  with  a 
view  to  snlxhiiti^  the  li^ht  in  lh(!  inlerictr.  An  experinientid  tent, 
mad(!  nnd<\r  orders  of  the  Snr^eon-(jcneral,  was  j)il(h<(|  within  a  few 
feet  of  a  re<!;nl;ir  hospital  lent  and  a  rcfi;id!ir  conical  wall  lent,  for  f)iir- 
poscs  of  (iomparison.  'fhernutnietric!  observations  showed  an  average 
difForencc  of  7  decrees  in  favor  of  the  improved  tent,  which  was  never 
less  than  ^J)  det;'rees  cooler,  twice;  was  8.5  degrees,  and  onw;  10.5 
d(>grces  coolei-  than  i\\v.  rcgnlnr  hospital  tent,  ('onipared  with  the 
conical  wall  tent,  the  tcmperatnre  ranged  0.5  to  ]8.5  degrees  lower 
in  the  improved  tent,  which  dilference  "  means  in  the  tropi(;s  all  the 
difference  between  comfort  and  distress  for  the  well  and  snch  relief 
from  great  and  depressing  heat  as  wonld  do  miuih  to  bring  abont  recov- 
ery in  the  si(;k."  The  exjx'riniental  tent  demonstrates  that  no  tent 
should  be  issued  for  use  in  the  tropics  without  the  protection  afforded 
by  a  fly.  The  U.  kS.  A.  Board  of  Equipment  promptly  adopted  the 
imjirovcd  hosjiital  tent. 

Dr.  Myles  Standish,  M.  V.  M./  first  called  attention  to  the  intense 
white  glare  to  which  the  occupant  of  the  hospital  tent  is  subjected  from 
the  covering  above  his  head,  and  which  must  be  a  source  of  actual 
injury  to  eyes  already  in  a  pathological  condition.  Rea.soning  from 
general  laws,  he  recommends  a  jxile  blue  or  an  olive  green  as  the  safest 
color. 

In  India,  the  British  use  a  tent  with  a  double  fly,  having  an  air 
space  of  2373  cubic  feet  and  accommodating  16  healthy  or  8  sick  men, 
which  gives  a  far  greater  allowance  of  space  than  in  the  service  else- 
where. For  field  service,  tents  of  686  cubic  feet  capacity,  accommo- 
dating 16  British  or  20  native  soldiers,  and  smaller  ones  of  392 
cubic  feet  capacity,  accommodating  8  British  or  10  native  soldiers, 
are  in  use. 

Tents  are  arranged  best  in  short  single  lines,  the  individual  tents 
being  distant  from  each  other  at  least  once  and  a  half  the  tent's  diam- 
eter ;  the  intervals  are  not  fixed  by  regulation.  If  possible,  the  tent 
should  face  the  east,  so  that  when  the  day  is  advanced,  the  southern 
wall  may  be  lifted  so  as  to  admit  the  sun's  rays  to  the  whole  of  the 
interior.  Each  tent  should  be  ditched  as  soon  as  it  is  placed  in 
position. 

The  tent  ditch  should  be  6  inches  wide  and  4  deep,  and  should  con- 
nect with  the  company  ditches,  and  these  in  turn  with  each  other, 
forming  a  complete  system  of  surface  drainage.  All  surface  drainage 
from  higher  ground  should  be  prevented  by  being  intercepted  and 
turned  aside. 

The  floor  of  the  tent  should  never  be  lowered  by  excavating,  for 

1  Color  the  Canvas  of  Hospital  Tents.  Reprint,  Transactions  of  the  Association  of 
Military  Surgeons  of  the  United  States,  1896, 


656  MILITARY  HYGIENE. 

nieu  sboiild  sleep  above  the  level  of  the  ground,  and  never  below  it. 
If  the  soil  is  not  quite  clean  and  lirni,  it  should  be  dug  out  to  the 
depth  of  about  a  foot  and  replaced  bv  clean  gravel  or  sand,  if  such  is 
obtainable,  and  then  covered  with  boards.  Elevated  platforms  are 
eminently  desirable,  and  tents  not  so  provided  should  be  moved  eveiy 
week  to  the  open  spaces  between,  so  that  the  sun  may  exert  its  purify- 
ing influence  and,  together  with  fresh  air,  may  put  the  vacated  sites 
again  in  a  condition  for  occupancy.  The  floors  of  the  tents  should, 
when  possible,  be  covered  with  loose  boards,  if  these  are  obtainable ; 
and  occasionally  the  surface  of  the  soil  should  be  scrajied  and  replaced 
with  clean  gravel  or  sand.  In  malarial  and  yellow  fever  districts, 
nettings  to  exclude  mosquitoes,  especially  at  night,  and  individual 
netting  on  light  frame-work  for  the  protection  of  the  head,  the  other 
parts  of  the  body  being  protected  by  clothing,  will  be  found  to  have 
great  influence  in  checking  infection. 

Huts. — During  cold  "weather,  wooden  huts  are  much  better  adapted 
for  occupation  than  tents,  and  have  come  into  extensive  use  in  the 
German,  French,  and  English  armies,  both  in  war  and  in  time  of 
peace.  The  use  of  log  cabins  is  advocated  by  Colonel  Charles  Smart, 
M.D.,  U.  S.  A.,  to  house  4  men  apiece.  The  inside  dimensions  given 
are  13  X  7  feet;  walls,  6  feet;  ridge,  10  feet  from  the  floor;  the  door 
to  open  in  the  middle  of  one  side ;  the  chimney  opposite  the  door  out- 
side the  wall ;  the  roof  consists  of  canvas  14X12  feet,  with  a  larger 
fly.  This  is  regarded  as  the  best  size  and  allowance,  but  the  present 
tactics  require  squads  of  8,  for  whom,  according  to  Woi)dhull,  "  there 
should  be  two  huts  8X11  feet  end  to  end,  6  feet  apart,  with  one  con- 
tinuous roof  and  door  in  the  adjacent  ends,  but  not  midway.  The 
chimney  should  be  in  the  middle  of  one  long  end.  Two  platforms 
each  6J  X  4|  feet,  one  lengthwise  and  one  across  the  end,  would  ac- 
commodate 2  men,  sleeping  with  their  heads  adjacent.  The  covered 
porch  between  the  huts  would  be  6  X  9  feet  in  the  clear,  the  sleeping 
platform  be  open  beneath,  and  under  no  pretence  should  two-storied 
Ininks  be  allowed."  On  damp  sites,  the  walls  should  be  raised  a  foot 
from  the  surface ;  but  on  dry  soil,  they  may  be  built  directly  on  the 
ground  level,  the  soil  well  pounded  down,  covered  with  sand  and 
gravel,  and  concreted. 

The  floor  of  the  huts  raised  from  the  ground  is  made  best  of  split  or 
dressed  logs.  The  canvas  roof  and  fly  are  attached  in  such  a  way  that 
they  may  readily  be  removed  when  it  is  desired  to  admit  the  sun  to 
the  interior.  Portable  huts  may  be  furnished,  having  frames  of  wood 
or  iron.  The  German  huts  are  made  with  wooden  or  iron  frames 
covered  Avith  felt  and  lined  with  canvas.  They  are  easily  ventilated 
and  Avarmed.  The  French  huts  are  made  circular  in  shape ;  the  walls 
are  of  boards  wdth  glass  wdndows.  They  are  easily  ventilated  and 
heated.  The  huts  should  be  at  least  10  feet  apart  at  the  ends,  and 
the  interspaces  should  be  carefully  protected  from  pollution. 

Water  Supply. — It  goes  without  saying,  that  one  of  the  first  consid- 
erations in  the  establishment  of  a  permanent  camp  is  an  adequate  sup- 


J'OSTS  AND    CAMI'S.  fio? 

ply  of  |)otji])l(!  wntcr,  wliir.li  Hiibjcci  is  prcsr-nlrd  clscvvlK'n'.  It,  Ik  ciiih- 
toinnry  to  iillow  ;ii  IcmsI,  U  ^.'iIIoms  per  <:;i|»it;i  per  dictii  f'oi-  all  piirpoHOH, 
and  iiH  intKili  more  uh  is  j)riic-lic!il)l('.  Watciw^loscfs  and  li.itliH  r(;(jiiin', 
iiiiturully,  u  V(!ry  ^(^ncroiis  allowaiK^c.  Ilospifals  i((|iiirc  tmifli  nion; 
per  capita  tluin  barnicks.  I'oi-  hoi-st's^  (Voin  U  to  10  ji^idlons  j)fr  di<rri 
arc  r<!(pilr('d.  In  f»;(!n(!ral,  it  may  he  said  tlial  tlic  inorc  generous  tli*; 
Hii|)ply,  \\\v  ji^rcatc-r  tlic  general  clcanliiicss  and  cirK-iciicy. 

Ill  tctnjiorary  <!atiij)S,  tlic  supply,  Ixttli  :is  to  (|iiality  and  f|iiantity,  is 
determined  hy  natural  (loiiditions,  and  must  he  taken  as  it  is  found. 
If  ])uri(i(!ation  of  that  intended  for  (h'inkiiif^  appears  to  be  necx;«8ary, 
the  methods  mentioned  in  the  eonsidei'alioii  of  the  suhjcet  of  wat^jr 
snp))lies  niay  Ik^  a(lo|)tc(l  a(;eoi'din^  to  availahilily.  'i'lie  simjtle.st  arc 
boil iiifi;  and  the  apjilieation  of  ahim,  with  siibsecpjent  filtration,  if  f)r)ssi- 
ble,  through  sand  lieUl  in  suitable  rece])taele.s  sueli  as  half  barrels  witli 
perforations  through  their  bottoms.  The  so-mlled  "  meehaniail  fil- 
ters," so  much  used  in  the  ])urifi(;ation  of  jHiblie  wat<'r  supplies,  are 
more  efficient  and  convenient.  Kxperi(!n(!e  has  shown  that,  no  mat- 
ter how  urgent  the  necessity  for  care  in  the  avoidance  of  pollution  of 
water,  it  is  always  difficult  to  prevent  some  of  the  men  from  reckless- 
ness in  drinking.  The  operation  of  purification  should  be  in  the  im- 
mediate (sharge  of  a  non-commissioned  officer,  properly  instructed  and 
with  a  suitable  detail. 

Sewerage. — The  introduction  of  an  abundant  water  supply  in  a 
camp  is,  of  course,  followed  by  more  or  less  lavish  use  of  water  fV)r 
all  general  purposes,  and  this  necessitates  a  system  of  sewerage  for 
carrying  off  liquid  waste  and  human  excreta.  Camp  sewers  should 
be  constructed  in  a  proper  manner  of  bricks  or  drain-pipe,  and  never 
of  wood.  The  method  of  final  disposal  of  the  sewage  at  the  outfall 
will  depend  upon  individual  circumstances.  All  permanent  camps 
should  be  properly  sewered. 

In  case  of  outbreaks  of  typhoid  fever,  cholera,  or  other  diseases 
of  the  same  general  class,  the  excreta  should  be  disinfected  before 
being  otherwise  disposed  of.  In  army  practice,  chloride  of  lime 
4  per  cent.  And  carbolic  acid  5  per  cent,  are  commonly  used,  with 
weaker  solution  of  carbolic  acid  and  corrosive  sublimate  1  :  1000  for 
washing  floors  and  articles  of  furniture  or  for  soaking  soiled  clothes. 
Milk  of  lime  is  highly  to  be  recommended  for  excreta,  as  is  also  for- 
maldehyde solution,  if  it  can  be  obtained.  The  JNIanual  for  the  Med- 
ical De]>artment  says  on  this  point :  "  Sulphate  of  iron  and  other  cheap 
antiseptics  and  deodorants  may  be  used  when  necessary.  But  the 
necessity  for  their  use  is  a  reproach  upon  the  sanitary  police  of  a 
post,  and  should  only  be  required  under  exceptional  circumstances, 
The  alvine  discharges  of  healthy  persons  do  not  require  disinfection, 
and  when  properly  disposed  of,  do  not  require  treatment  with  any 
chemical  agent  whatever.  If  water-closets  or  earth-closets  are  offen- 
sive, this  is  due  to  faulty  construction,  to  insufficient  supply  of  water 
or  dry  earth,  or  to  neglect  of  ordinary  cleanliness.  The  attempt  to 
remedy  such  defects  by  the  systematic  use  of  antiseptics  is  expensive 
42 


658  MILITARY  HYGIENE. 

and  iinsatisfiictorv  in  its  results.  The  same  is  true  of  foul  drains,  bad 
smelling  urinals,  accumulations  of  garbage,  etc.  The  proper  remedy 
for  such  conditions  is  cleanliness  and  strict  sanitary  police." 

AVhen  there  is  reason  to  believe  that  infectious  diseases  are  present 
in  camps,  the  latrines  and  cesspools  should  be  disinfected  with  milk 
of  lime  to  the  extent  of  one-twentieth  of  their  contents,  to  which  should 
be  added  every  day  an  amount  equal  to  at  least  a  tenth  of  the  daily 
addition  of  excrement.  Hospital  sewage  is  dangerous  enough  to 
warrant  treatment  on  the  spot  with  disinfectants. 

In  the  absence  of  a  regular  system  of  sewerage,  Sternberg  recom- 
mended cylindrical  galvanized  iron  vessels  18  inches  in  depth  and 
diameter,  with  a  trough  around  the  upper  end  3  inches  deep,  filled 
with  disinfectant.  Into  this,  the  cover  fits,  and  thus  serves  as  a  valve 
and  prevents  the  escape  of  foul  odors  and  the  entrance  of  flies.  A 
second  cover  with  a  hole  serves  as  a  seat.  The  receptacle  is  to  be 
partly  filled  with  carbolic  solution  or  the  contents  are  to  be  treated 
with  caustic  lime,  or  ashes,  or  dry  earth.  These  vessels  should  be 
removed  at  regular  times,  and  clean  ones  should  be  substituted  while 
they  are  removed,  emptied,  and  cleaned. 

Sinks  and  Latrines. — A  sink,  in  military  parlance,  is  a  cesspool  or 
pri\y  vault  in  a  temporary  camp ;  usually,  a  trench  from  twelve  to 
fifteen  feet  in  length,  about  two  feet  in  width  and  eight  in  depth,  with 
the  earth,  which  has  been  thrown  up,  piled  along  one  side.  The  requi- 
site number  should  be  dug  before  a  camp  is  occupied  or  as  quickly 
thereafter  as  possible.  They  should  be  placed  to  leeward,  or  in  such 
position  that  the  prevailing  winds  shall  not  convey  the  odor  therefrom 
over  the  company  areas,  and  they  should  never  be  placed  near  existing 
wells.  They  should  not  be  placed  any  farther  away  from  the  men's 
quarters  than  is  absolutely  necessary.  For  convenience  of  use,  a  strong 
pole  is  laid  horizontally  on  upright  forks  at  the  proper  height  and  on 
the  side  opposite  the  excavated  earth.  The  latter,  kept  as  dry  as 
possible,  is  thrown  back  each  day  over  the  deposited  excreta,  often 
with  caustic  lime,  chlorinated  lime,  or  ashes. 

Behring '  recommends,  in  case  of  necessity,  from  5  to '7.5  liters  of 
milk  of  lime  for  each  250  men  ;  Pfuhl  ^  advises  400  cc.  per  man. 
The  addition  of  chlorinated  lime  possesses  a  double  advantage,  since  it 
not  only  acts  as  a  disinfectant,  but  also  serves  to  drive  way  flies,  which 
otherwise  collect  and  may  become  active  agents  in  the  spread  of  infec- 
tious disease. 

Small  sinks  for  each  company  are  regarded  as  much  better  on  several 
accounts  than  one  or  more  large  ones  for  each  regiment.  They  afford 
greater  privacy  when  enclosed  with  brushwood,  and  are  generally  better 
looked  after,  since  the  responsibility  for  their  care  is  more  definitely 
fixed.  When  filled  to  within  two  feet  of  the  surface,  the  remaining 
earth  should  be  thrown  in  and  rounded  over,  the  site  marked,  and,  at 
the  same  time,  new  trenches  prepared.  On  breaking  camp,  all  sinks, 
however  little  used,  should  be  filled  up  and  marked. 

X  Zeitschrift  fur  Hygiene,  IX.,  p.  395,  '  Ibid.,  IV.,  p.  97. 


POSTS'  AM)    CAM/'S.  659 

Wh(!ii  (li(!  |)f(il);il)l('  s(;iy  ih  \n  l»c  more  lli.in  of  a  [(;\v  duyh'  durution, 
the  li()ri/(»nl;il  |)<»l(:s  uvc  (•orimioiily  r(|»l:H'(Ml  l»v  hox  H(;alH,  <>\)t:t]  at  tho 
hiU'.k.  Ill  wiiilcr,  IIk;  Irciiclics  sIkhiM  he  ((Hiiplch-ly  coycrcA  by  box 
H(!ii.t>t  wil.li  cdvcrs  ;  liiii^iiij^  oC  lln'  to|)  oi-  i-f;ii' >)(lc  will  !)<•  iii;ceHHary  for 
tlio  |)r()|K!r  throw iiifj:;  in  of"  (lie  cxt^avMlcd  cMilii. 

TIh!  vv<»I(I  /(ilriiw  is  coiiiMioiily  UHcd  as  syiioiiyiiioiis  with  Mink.  It  \h 
properly  dcliiicd  a.s  "  ji  |)rivy  or  watcr-cloHct,  ('spcfinlly  in  froiifrh  form 
accommodating  several  at.  th(!  same  tiiiK;."*  A  further  deseriplion  of 
a,  lafcrino  is  clsevvliore  ^iven  (sec;  paf^e  301).  L;il  lines  are  more  eom- 
nionly  installed  in  barracks  or  permanent  camps.  'I  hey  n-«jnire  fre- 
quent (lushing',  if  comiected  with  a  system  of"  sewerage,  and  fn-qiient 
emptyinj*;  and  cleansiiiLT,  il"  iidt  so  connected.  TIk;  seats  and  floors 
should  be  kej)t  thoroughly  clean  by  periodical  washing;  twice  daily  Ih 
strongly  recommended. 

TIrinals  ajiart  from  sinks  and  latrines  arc  installed  in  both  perma- 
nent and  temj)orary  camps,  and  in  both  it  is  essential  that  they  be  of 
easy  access,  and  their  use  compelled  on  account  of  the  nuisance  arising 
from  indiscriminate  voiding  of  urine  on  the  ground  and  of  the  possi- 
bility of  the  dissemination  of  typhoid  fever  by  the  urine;  of  ambula- 
tory cases  of  that  disease  and  of  convalescents  therefrom.  In  inclement 
weather  and  at  night,  all  parts  of  a  camp,  and  especially  the  company 
areas,  are  liable  to  urinary  contamination,  which  should  be  prevented 
as  far  as  possible  by  stringent  rules  and  constant  vigilance. 

Inspections. — Under  the  Army  Regulations,  an  amuial  inspection  of 
the  buildings  at  every  post  is  made  by  the  commanding  oftieer  and 
quartermaster  on  the  first  day  of  March,  and  immediately  afterward 
a  report  is  submitted  giving  a  description  and  showing  the  condition 
and  capacity  of  each  building,  and  the  character  and  extent  of  any 
additions,  alterations,  and  re})airs.  Sanitary  inspections  are  more  fre- 
quent and  more  searching  in  character.  The  surgeon  is  required  to  ex- 
amine, at  least  once  a  month,  and  to  note,  in  the  medical  history  of  the 
post,  the  sanitary  condition  of  all  public  buildings,  the  drainage,  sew- 
erage, amount  and  quality  of  water  supply,  clothing  and  the  habits  of 
the  men,  and  character  and  cooking  of  the  food,  and  immediately  after 
such  examination  to  report  thereon  in  writing  to  the  commanding 
officer,  with  such  recommendations  as  he  may  deem  projier.  Su[)er- 
ficial  inspection  is  not  enough,  for  everything  may  look  clean  exter- 
nally and  yet  the  general  condition  may  be  bad. 

The  condition  of  the  air  is  of  much  more  importance  during  the 
sleeping  hours  than  during  the  day  ;  therefore,  ventilatiou  should  be 
investigated  at  night.  AValls  and  floors  should  be  ciirefully  examined, 
especially  if  they  are  made  of  porous  material.  Walls  found  to  be 
contaminated  with  organic  filth  should  be  scraped  and  then  thoroughly 
whitewashed.  The  floors,  whether  of  barracks,  tents,  or  huts,  should 
be  scrupulously  clean  and  dry  ;  the  bedding  should  be  free  from  damj>- 
ness ;  the  spare  clothing  and  the  men  them^relves  and  their  clothing  in 
use  should  be  clean.     The  site  and  inunediate  surroundings  of  every 

1  Standard  Pictionarv. 


660  MILITARY  HYGIENE- 

permanent  or  temporary  structure  should  be  examined  with  particular 
reference  to  the  drainage  and  general  condition  of  the  soil. 

Sanitary  Police. — Exceedingly  strict  sanitary  policing  is  necessary  to 
keep  a  camp  in  a  healthy  condition.  The  responsibility  for  condition 
rests  ^vith  the  commanding  officer,  but  is  shared  in  by  the  company 
officers,  who  must  look  after  their  quarters  and  men.  Under  the  title 
of  "  officer  of  the  day,"  company  commanders  serve  in  turn,  each  for  a 
day,  in  charge  of  general  sanitation,  and  each  is  responsible  to  his  com- 
manding officer  for  the  order  and  cleanliness  of  the  camp  on  the  day 
of  his  service. 

It  has  been  demonstrated  repeatedly  that  untrained  or  incx])erienced 
soldiers  cannot  be  depended  upon  for  thorough  cleaning  or  keeping 
things  clean,  for  they  do  not  know  how  to  take  care  of  themselves, 
because  at  home  they  are  looked  after  by  others  ;  and  unless  sanitary 
police  be  very  strict,  a  clean  and  everyway  good  natural  site  may 
quickly  be  contaminated  and  made  unhealthy.  Until  discipline  is  well 
established,  the  enforcement  of  proper  sanitary  regulations  is  extremely 
difficult,  for  while  they  may  be  most  carefully  formulated,  the  neces- 
sary orders  are  difficult  of  enforcement.  Even  with  the  utmost  care 
and  vigilance,  contamination  of  the  site  is  only  a  question  of  time,  but 
the  more  efficient  the  system,  the  longer  is  that  time  deferred.  A  camp 
in  which  no  attention  is  paid  to  cleanliness  of  the  company  streets  and 
to  habits  of  personal  clea»'iliness  is  sure  to  be  an  unhealthy  one,  and 
men  who  will  permit  such  conditions  to  obtain  are  commonly  bad 
soldiers  in  every  sense  of  the  word,  with  no  esprit  de  corps,  slovenly  in 
all  their  habits,  conspicuously  attentive  to  sick  call,  and  with  no  respect 
for  themselves  or  their  superiors. 

In  such  a  camp,  the  development  of  epidemics  of  infectious  diseases, 
particularly  typhoid  fever,  is  only  a  question  of  time,  since  it  needs 
only  the  introduction  of  the  specific  germ  and  favorable  opportunities 
for  its  dissemination.  Since  this  disease  is  endemic  in  all  parts  of  the 
country,  it  is  not  strange  that  among  large  numbers  of  men  brought  in 
from  diffisrent  quarters  there  should  be  one  or  more  carriers  of  the 
infection.  In  any  camp  of  whatever  degree  of  efficiency  in  sanitar}^' 
police,  unless  such  cases  are  recognized  at  once  and  their  excreta  com- 
pletely disinfected  or  otherwise  disposed  of,  so  that  no  danger  shall  be 
possible  therefrom,  the  site  is  likely  to  become  polluted  and  the  bacilli 
to  be  distributed  through  the  usual  agencies. 

One  of  the  first  essentials  of  maintaining  cleanliness  in  camp  is  good 
surface  drainage.  If  the  soil  is  damp,  the  site  soon  becomes  an  expanse 
of  mud,  owing  to  the  constant  impress  of  hundreds  of  feet.  Mud  assists 
in  the  conservation  of  refuse  and  filth  which  it  envelops  and  masks, 
and  hence  arises  the  necessity  for  efficient  and  thorough  ditching,  and 
for  filling  up  depressions  likely  to  retain  surface  water.  The  usual 
pathways  and  sidewalks  should  be  made  as  dry  as  possible  by  the  appli- 
cation of  gravel,  and  by  such  other  methods  as  are  applicable  to  each 
individual  case. 

All  refuse  of  whatsoever  kind  should  be  prevented  from  accumulating 


POSTS  AND   CAMf'S.  001 

wltliin  tlio  liiKis;  ovfTyiliiiip;  slioiiM  ]>(:  proriijjily  rfriiovod  aii<l  (li.sjtOH-d 
of",  if  |t(>ssil)l(',  \>y  hiiniinj^.  Kifclicd  icCiisc  should  f>c  (l())0)-it<<l  in 
covered  rec(!|)luel(!K,  wliieli  hIioiiI(1  Ix-  f.-iiricd  nwny  twi(!<!  daily.  On  no 
ae(!ount  .sliould  it  ]h'.  left  (ixposcd  on  llic  /^ir)und  or  elwiwherc,  hiiKu-  not 
only  do(«  it  K|)('('dily  d(',V(!lo|>  tlic  well-known  niiiiwoiiH  mlor  of  swill, 
and  tlins  hcconK^  a  nuisance,  hiif  if  is  an  aflracfion  for  flif"<,  wliifji,  jjy 
tlieir  invcsl  iuation  ofail  sorts  (»(  lillli,  Inclndinn-  flic  ficcal  discharges  in 
the  Kinks,  and  tiicn  of  IIm'  soldiers'  Cood  itotii  in  tin?  kit^then  and  at  iiichh, 
have  a<z;ain  and  a;j,ain  proved  (hcrnscivcs  to  i)e  iarffely  responsihlc  for 
the  spread  of  epidemic  diseases,  as  will  he  explained  more  in  d(;fail  on  a 
later  pa<2,'e. 

The  linal  disjiosition  oC  kit(;i)en  refuse  is  often  a  |iiol)lem  fiauj^ht 
with  serious  difficulties.  When  possible,  it  should  lie  liurncd  in  (tne  of 
the  num(>rous  forms  of  incinerators  devised  for  the  pur|)ose;  Ijut  on  no 
account  should  it  Ik;  sprea<l  out  in  th(!  vicinity  of  the  apparatus  to  dry. 
If  it  be  advisable  to  bury  any  part  (ti'  it,  at  whatever  distance; 
below  the  surface  it  is  deposited,  it  should  be  well  covered  with  clean 
earth.  The  deeper  it  is  buried,  the  longer  will  it  resist  a^mplete 
decom])osition. 

Stable  manure  should  be  removed  every  day  and  deposited  at  a  suffi- 
cient distance  and  in  such  a  location  as  to  insure  that  it  shall  not  be  a 
nuisance  or  a  source  of  danger  to  the  water  supj»ly.  Incombustible 
harndess  refuse  should  be  removed  out  of  sight,  and  not  ha  allowed  to 
accumulate,  for  anything  ]iromotiug  untidiness  of  appearance  invites 
additional  untidiness  by  its  example. 

Considering  the  many  details  of  camp  police  and  the  necessity  for 
cooperation  on  the  part  of  every  man,  it  is  not  strange  that,  in  our 
war  with  Spain,  the  hasty  gathering  together  of  large  bodies  of  un- 
disciplined troops  from  all  parts  of  the  country  into  large  improvise<l 
camps,  largely  under  the  control  of  inexperienced  officers  both  of  the 
line  and  medical  service,  was  followed  very  quickly  by  the  outbreak  of 
epidemic  diseases,  which  carried  off  large  numbers  of  men  who,  to  a 
certain  degree,  were  victims  of  their  own  carelessness.  It  is  related, 
for  example,  that  a  certain  regiment  of  volunteers,  encamping  nearly 
side  by  side  with  one  of  regulars,  was  invaded  to  an  extraordinary 
degree  by  typhoid  fever,  while  the  regulars  were  practically  free  from 
disease.  One  of  the  medical  officers  informed  the  author  that  most  of 
these  men  were  so  dirty,  lazy,  ignorant,  intemperate,  and  immoral,  that 
nothing  short  of  an  extensive  epidemic  among  tliem  could  have  been 
expected,  and  was  expected  from  the  start.  They  Siiw  some  active 
service,  and  were  conspicuous  for  general  inefficiency  and  lack  of  disci- 
pline. Their  ranks  were  reductxl  very  largely  by  disease,  and  the 
casualties  were  practically  nothing.  The  survivors  returned  to  civil 
life  and  were  welcomed  as  heroes  ;  those  who  perished  in  consequence 
of  their  own  and  their  comrades'  revolting  habits  of  life  are  enrolled 
with  those  who  sacrificed  their  lives  in  defence  of  their  coimtry's 
honor. 

The  necessity  of  constant  supervision  and  of  enforcement  of  disci- 


662  MILITARY  HYGIENE: 

pliue  lias  beeu  well  set  forth  by  Jolm  S.  Wise/  who  says :  "To  appre- 
ciate fully  the  truth  that  men  are  but  ehildreu  of  a  larger  growth,  one 
must  have  commanded  soldiers.  AVithout  constant  guidance  and 
government  and  ]mnislnnent,  they  become  careless  about  clothes,  food, 
amnumition,  cleanliness,  and  even  ])ersonal  safety.  They  will  at  once 
eat  or  throw  away  the  rations  furnished  for  several  days,  never  con- 
sidering the  morrow.  They  will  cast  aside  or  give  away  their  clothing 
because  today  is  warm,  never  calculating  that  tomorrow  they  may  be 
suffering  for  the  lack  of  it.  They  will  open  their  cartridge  boxes  and 
dump  their  cartridges  on  the  roadside  to  lighten  their  load,  although  a 
few  hours  later  their  lives  may  depend  upon  having  a  full  supply. 
When  they  draw  their  pay,  their  first  object  is  to  find  some  way  to  get 
rid  of  it  as  quickly  as  possible.  An  officer,  to  be  really  efficient,  must 
add  to  the  qualities  of  courage  and  firmness,  those  of  nurse,  monitor, 
and  purveyor  for  grown-up  children,  in  whom  the  bumps  of  imjjrovi- 
dence  and  destructiveness  are  abnormally  developed." 

A  striking  and  interesting  object-lesson  in  camp  sanitation  is  given 
by  Colonel  Charles  R.  Greenleaf,  M.  D.,  Medical  Inspector,  U.  S.  A." 
Two  camps  located  very  near  together,  nearly  equal  in  the  number  of 
men  contained  (about  12,000),  and  with  the  same  conditions  of  climate, 
soil,  water  supply,  and  food,  showed  very  different  records  of  morbid- 
ity and  mortality.  In  one,  "  the  men  were  scourged  with  sickness  and 
death,  and  large  numbers  of  them  were  permanently  invalided  ;  local 
epidemics  became  general,  and  soon  the  entire  camp  was  so  thoroughly 
infected  that  it  was  of  necessity  abandoned."  In  the  other,  "  but  little 
sickness  (the  percentage  never  exceeding  five  and  a  half  of  the  aggre- 
gate strength),  few  deaths,  and  a  few  cases  permanently  invalided ; 
local  epidemics  of  contagious  disease,  due  to  importation,"  were  quickly 
controlled,  and  never  extended  beyond  the  respective  commands  which 
brought  them,  nor  did  a  single  case  of  infectious  disease  originate  in  the 
camp. 

The  difference  in  the  health  conditions  of  the  two  camps  was  due  to 
the  fact  that  in  one,  "  the  advice  of  sanitarians  was  seldom  asked,  and 
when  asked  was  not  followed,  and  nearly  every  law  of  health  was 
either  ignored  or  violated,"  while  in  the  other,  "the  advice  of  sani- 
tarians was  freely  sought,  accepted,  and  carried  out,  no  pains  being 
spared  to  secure,  as  far  as  possible,  compliance  with  the  laws  of  health." 
The  benefits  of  sanitation  were  recognized  by  both  officers  and  men, 
and  the  advice  of  its  teachers  was  carried  out  by  all  to  the  fullest 
extent. 

The  following  sanitary  regulations,  published  for  the  governing  of 

certain  model  camps  established  in  the  Presidio  Reservation,  one  for 

five  regiments  of  volunteers    returning  from  the  Philippine  Islands, 

one  for  four  regiments  of  out-going  volunteers,  or  about  5200  men, 

and  one  for  about  2000  recruits  for  the  regular  regiments  already  in 

'  The  End  of  an  Era,  Boston,  1900,  p.  347. 

^  An  Object  Lesson  in  Military  Sanitation,  Boston  Medical  and  Surgical  Joumal, 
Nov.  16^.1899,  p.  485. 


POSTS  AND   CAMPS.  003 

ilu!  IMiili|>|>iii('M,  :\Y('  (;oiiiriiuiii(!iit<'(l  hy  I>r-  (Jnciilciif.  C"  In  plaiiiiiuf^ 
tiKiSc  ciunps  llic  priiiiiiiy  ohjccis  wci'c  In  icinov  tlif  l>  ilclMii-  ji.s  iiir  an 
])(),ssil)l(',  IVoiii  Ihc  Inlriiics,  \u  |)r(»vi<l('  a  safe  inclliod  \'<<v  tlu;  <liH|M)HaI 
of  oxcrcta,  ^ai'ha^c,  clc,  (o  secure  iiicaiis  for  tlic  |k  ihoiial  cleanliiK-HH 
of  the  men,  to  licat  tlicir  (|iiaricr.s,  and  to  siijiply  llicrii  wifli  an  ahnn- 
dancc  of  good  food  and  vvat<!r.") 

"The  coniinandinjj^  olTiccr  of"  fh<'  troops  oreupyinfr  the  camp.-  will 
detail  from  liis  coniniand  (wo  .sanitaiy  inspecfors;  on<!  from  the  line, 
preferably  a  major  o("  the  rej^imenf,  and  the  other  a  re^iinfintal  medieal 
oflicer,  whose  daily  duty  it  shall  he  to  jointly  insj)eet  the  regiment,  in- 
quiring into  the  general  jioliee  of  the  company  (piarters  and  HtrectH,  the 
kit(^h(>iis,  the  food,  its  pre|)aration,  (|iiality  and  method  of  serving,  tlie 
latrines,  urinals  and  sewers,  and  malving  to  the  regimental  (lommander 
a  brief  report  of  any  unsanitary  (conditions  they  may  discover,  this 
report  to  be  forwarded  the  same  day  to  the  medical  insjjeetor  of  the 
army  at  department  headquarters. 

"One  medical  officer  and  one  hosj)ital  steward  from  each  regiment 
will  be  recjuired  to  be  present  for  duty  with  the  regiment  at  all  times 
of  the  day  and  night. 

"A  daily  siek  call  will  be  held,  and  slight  eases  of  illness  treated  in 
quarters  or  in  the  regimental  hosjiitalrs  provided  for  that  purpose,  but 
all  men  who  are  likely  to  remain  siek  more  than  three  days  will  be 
promptly  sent  to  the  General  Hospital  at  the  Presidio  of  San  Fran- 
cisco. 

"  If  any  case  of  infectious  disease  occurs,  the  fact  ^vill  l)e  promjitly 
reported  to  the  camp  surgeon,  who  is  authorized  to  make  proper  dispo- 
sition for  its  isolation  and  care. 

"An  ambulance  fully  equipped  with  a  team  will  be  assigned  to  the 
camp  by  the  commanding  officer  of  the  Presidio.  This  ambulance  will 
report  daily  to  the  camp  surgeon  at  sick  call,  remaining  in  the  camp 
during  the  day,  subject  to  his  orders.  Under  no  circumstances  will 
this  ambulance  be  used  for  any  other  ]nu'posc  than  the  transportation 
of  the  sick,  or  medical  supplies.  The  commanding  oliicer  of  the 
Presidio  wnll  also  cause  another  ambulance  to  be  sent  to  the  camp  for 
service  at  night  time.  This  ambulance  mOI  remain  on  duty  from  re- 
treat to  reveille  foj*  uight  emergency  service.  AVbeu  the  night  ambu- 
lance reports  for  duty,  the  day  ambulance  will  be  relieved  and  returned 
to  the  post." 

"  Company  commanders  will  caution  their  mcu  against  exposure  to 
the  fogs  and  high  winds  that  prevail  here,  especially  in  the  early 
morning  and  evening,  at  which  time  overcoats  avlII  be  worn.  Riding 
on  the  '  dummy '  of  the  street  cars,  especially  at  night,  is  particularly 
hazardous  to  men  recently  returned  from  service  in  the  tropics.  GuaixJ 
duty  and  other  military  functions  required  at  these  hours  will  be  held 
in  overcoats,  and  at  breakfast  and  supper  the  stoves  in  the  dining-rooms 
will  be  providai  with  tires.  The  s;\le.  by  civilians,  of  food  or  di'iuk 
within  the  limits  of  the  camp  will  be  forbidden. 

"  At  retreat,  urine  tubs,  two  to  each  company,  will  be  placed  in  each 


664  MILITARY  HYGIENE. 

company  street,  and  men  desiring  to  urinate  at  any  time  during  the 
night  will  be  required  to  use  them.  The  tubs  will  be  removed  from 
the  company  street  at  reveille  to  a  place  convenient  for  tlie  scavengers, 
who  will  remove,  clean  and  place  lime  in  them  for  use  the  next 
night. 

"  The  quartermaster's  department  will  be  required  to  provide  an 
ample  force  of  scavengers  to  clean  the  latrines  and  urinal  troughs  at 
least  once  daily,  and  to  refill  the  troughs  with  milk  of  lime ;  they  will 
also  remove  all  kitchen  garbage,  and  either  cremate  it  or  dispose  of  it 
in  such  ]>lace  as  the  quartermaster  shall  direct.  Particular  care  will  be 
enjoined  on  company  cooks  to  keep  grease  traps  clean,  and  to  deposit 
all  solid  garbage  in  cans  prepared  for  that  purpose  in  time  for  its  re- 
moval by  the  scavengers. 

"  The  quartermaster's  department  will  furnish  to  each  regiment  an 
ample  supply  of  necessary  policing  implements,  to  enable  the  men  to 
thoroughly  and  effectively  police  the  camp  daily." 

These  regulations,  Dr.  Greenleaf  reports,  were  promptly  carried  out 
by  officers  and  men,  and,  in  spite  of  the  fact  that  nearly  every  body  of 
men  brought  some  form  of  infectious  disease,  including  typhoid  fever, 
tropical  dysentery,  diphtheria,  smallpox,  measles,  and  mumps,  not  a 
single  case  of  any  infectious  disease  originated  in  the  camps,  all  of  the 
imported  cases  being  promptly  segregated  from  the  command,  all  in- 
fected material  disinfected  or  destroyed,  and  all  men  who  had  been 
exposed  isolated  and  quarantined. 

In  all  these  camps,  the  latrines  and  bath-houses  were  placed  on  the 
flanks  and  rear ;  the  kitchens  and  mess  halls,  in  the  central  lines.  In 
the  rear  of  each  mess  hall,  a  zinc-lined  wash  trough,  supplied  with  a 
dozen  bib  cocks,  was  placed  to  be  used  as  a  lavatory ;  near  the  door  of 
each  kitchen  was  a  grease  trap  connected  with  the  sewer,  and  galva- 
nized cans  for  garbage  and  ashes  were  placed  on  the  porch.  Large 
caldrons  for  heating  water  for  laundry  and  other  purposes  were  set  up 
in  convenient  places.  Two  galvanized  wash-tubs  were  furnished  to 
each  company,  and  "  night  soil  tubs  were  placed  in  every  company 
street  at  '  tattoo '  for  the  use  of  the  men  during  the  night,  a  sentinel 
being  posted  in  the  street  to  see  that  the  orders  regarding  their  use 
were  carried  out."  The  construction  of  latrines  and  disposal  of  excreta 
were  carried  out  according  to  the  recommendations  of  a  board  of 
medical  officers,  consisting  of  Major  Reed,  U.  S.  A.,  and  Majors  Vaughan 
and  Shakespeare,  U.  S.  V.,  as  follows  : 

"  A  trough  made  of  No.  22  galvanized  iron,  fourteen  feet  long, 
twenty-two  inches  wide  at  the  top,  parabolic  in  cross  section,  and  with 
a  maximum  depth  of  eighteen  inches,  if  set  in  a  light  wooden  frame- 
work, which  serves  as  a  protective  crate  in  transportation,  gives  sup- 
port to  the  ti^ough  while  in  position,  and  serves  for  the  attachment  of 
a  lid  in  two  sections,  furnished  with  seven  seat  holes.  These  holes  are 
shaped  so  as  to  render  soiling  of  the  seat  difficult,  and  a  slanting  board 
one  foot  wide,  permanently  fixed  at  a  proper  angle  above  the  seat,  pre- 
vents the  men  from  getting  up  on  it  with  their  feet.     When  in  position. 


77//';  Df.'^h'Asns  Of''  Tiff':  s(>f,f>jRn.  666 

one  end  of  the  troiifrh  is  nii.scrl  four  indnjH  lii^li<;r  ilian  llu;  otiicr. 
The  troiifi;!!  is  plnccd  in  ,-in  ordinary  {'v;\\\u\  pr-ivv  lion-c.  Al  tlic  njtjKT 
(ind  of  ilu;  iioufrli  llicic  is  plar.cd  a  ^alviini/.id  iron  ^uttcrr  of  |)i(t|KT 
Ii((if;-Iit  and  inc^lination  Icadinj^  inio  llic  tron;|li  lo  sfrvc  as  a  urinal. 

''  TIk!  rear-  side  (»('  llic  ^iificr  or  tli;it  attaclicd  fo  tlu-  wall  of  tin-  hnild- 
in^  is  hif^her  than  llic  (ronl,  side,  Id  jircxcnl  i-oilin^r  ih,.  jinildin^'-.  'I  lie 
iron<.';li  is  prepared  for  llic  rcccplion  oC  (!ic;il  nmtlcr  liy  (illiii^  i(  with 
water  niilil  a  ccrlain  level,  indiealed  liy  a  line  on  flic  inside;  of  the 
trough,  is  reac,lie<l.  A  incasnre  ("or  the  purpose,  and  lioldiiifr  one-sixfh 
of  a  barrel,  is  now  (illed  with  <jniel<linie  and  einptied  into  lli<;  water; 
som(>  dry  lime  shonld  also  be  placed  in  (he  nrinal.  The  jinie  in  the 
trono'h  is  thoron<i;hly  stirred  with  a  wooden  paddle.  Thi-  stirring  is 
rep<;aie(l  three  times  every  day.  The  wooden  ])addle  when  not  in  use 
stands  in  a.  ])ail  tilled  with  milk  of  lime.  'J'oilet  paper  is  jirovided  for 
the  men's  nse  in  the  latrines,  beeanse  large  pieces  of  newsjiaiier  will 
float  on  the  water  holding  masses  of  faecal  matter  above  the  surface, 
thnsexj>()sing  it  to  the  flies  and  other  insects. 

"Once  a  day  the  contents  of  these  tronghs  :ire  pnmped  out  into  an 
odorless  excavator,  carted  away  and  jiroperly  (lis))ose(l  of  The  milk 
of  lime  destroys  the  typhoid  bacillus,  and  the  contents  of  the  trough, 
if  properly  cared  for,  will  be  quite  innocuous.  Not  only  is  the  milk 
of  lime  and  faical  matter  innocuous,  but  its  value  as  a  fertilizer  is  con- 
siderable." 

It  may  be  stated,  however,  that  these  excellent  results  in  sanitary 
police  w^ere  not  brought  about  without  outside  assistance,  for  it  was 
found  advisable  to  employ  a  corps  of  civilian  scavengers  consisting  of 
2  overseers,  22  night  scavengers,  54  day  scavengers,  and  17  teamsters, 
with  5  odorless  excavating  carts,  6  sanitary  cars,  and  12  dust  carts. 
By  means  of  this  outside  force,  the  camp  was  kept  thoroughly  clean, 
and  the  excreta  were  promptly  removed  and  disposed  of.  The  latrine 
troughs  were  emptied  twice  in  twenty-four  hours,  and  garbage  and  all 
manner  of  waste  material  were  removed  twice  daily.  The  tent  floors, 
kitchens,  mess  halls,  and  comj^any  streets  were  swept  daily  by  the 
soldiers  themselves,  and  one  man  from  each  company  did  duty  each 
day  in  the  company  latrine  to  keep  it  clean  and  stir  the  lime  solutit)n 
frequently. 

During  the  past  few  years  great  im]irovements  have  been  made  in 
methods  of  disposing  of  garbage  and  human  excrement  tlu'ough  the  use 
of  portable  incinerators  of  different  types,  two  of  which  have  been 
tried  out,  with  a  large  measure  of  success,  by  the  United  States  War 
Department. 

The  Diseases  of  the  Soldier. 

While  there  are  no  diseases  peculiar  to  the  soldier,  there  are  many 
to  which  the  circumstances  and  conditions  incident  to  camp  life  render 
him  conspicuously  susceptible.  These  are  mainly  of  the  preventable 
class,  and  may  be  largely  checked  by  ]>roper  regard  to  the  principles  of 
camp  sanitation,  by  avoidance  of  polluted  water,    improper  cooking, 


Q6Q  MILITARY  HYGIENE. 

overcrowding,  and  overwork,  and,  in  some  degree,  by  the  incnlcation 
of  the  principles  of  moral  living. 

It  is  difficult  or  imj)0ssible  to  determine  how  soldiers  compare  with 
civilians  in  the  amount  of  sickness  which  they  suffer,  since  we  have  no 
statistics  of  general  morbidity,  especially  of  corresponding  age  periods, 
of  the  civil  population ;  and  even  were  such  available,  it  would  be 
necessary  to  bear  in  mind  that  the  soldier  is  often  on  the  sick  list  with 
ailments  which,  in  civil  life,  wt)uld  neither  deter  him  from  attending  to 
his  daily  work  nor  cause  him  to  go  to  the  added  expense  of  medical 
advice.  The  soldier  has  absolutely  free  medical  attendance  and  care, 
and  of  this  he  freely  avails  himself,  excepting,  with  many,  in  case  of 
venereal  troubles. 

Concerning  the  constitution  of  the  medical  corps,  the  hospital  accom- 
modations, aild  general  administration,  all  of  which  are  fixed  by  law 
and  regulation,  no  descri]-)tion  or  discussion  is  necessary ;  and  a  brief 
consideration  of  the  prevalence  and  predisposing  causes  of  the  chief 
diseases  of  armies  is  all  that  lies  within  the  scope  of  this  work. 

It  is  a  well-known  fact  that  in  both  war  and  peace  the  greatest  mor- 
tality among  soldiers  is  from  disease,  and  not  from  violence,  the  single 
exception  which  history  records  being  afforded  by  the  German  army  in 
the  war  of  1870  with  France.  In  our  war  with  Mexico,  according  to 
Woodhull,  935  of  the  regular  force  were  killed  or  died  of  wounds,  and 
4714  died  of  disease  in  the  field.  .In  the  Civil  War,  99,183  whites 
and  3417  negroes  were  killed  or  died  of  wounds,  and  171,806 
whites  and  29,963  negroes  died  of  disease.  In  our  war  with  Spain 
and  troubles  in  the  Philippines,  during  the  year  from  May  1,  1898,  to 
April  30,  1899,  according  to  the  report  of  the  Surgeon-General,  968 
men  were  killed  or  died  of  wounds,  injuries,  and  accidents,  and  5438 
died  of  disease.  Typhoid  fever  was  responsible  for  more  than  half  the 
deaths  from  disease ;  next  in  order  came  malaria,  followed  by  pneu- 
monia, yellow  fever,  and  smallpox. 

Tuberculosis. — In  the  large  standing  armies  of  the  world,  tubercu- 
losis has  long  played  a  leading  part,  due  largely,  as  has  been  pointed 
out,  to  overcrowding  and  deficient  ventilation,  and  to  the  enlistment  of 
men  in  whom  the  disease  is  latent  before  entrance  and  developed  by 
changes  in  habits  of  life,  climate,  etc.  Yet,  according  to  Colin,^  In- 
spector-General of  Hygiene  in  the  French  Army,  many  persons  with 
latent  tuberculosis  not  only  withstand  the  hardships  of  military  service 
well,  but  even  become  stronger  and  generally  healthier.  According  to 
a  statement  by  Surgeon-General  Schjerning  at  the  Tuberculosis  Con- 
gress in  Berlin  (1899),  a  decided  decrease  in  tuberculosis  has  been 
observed  in  the  German  army,  while  in  other  armies  an  increase  from 
year  to  year  in  loss  of  men  from  this  cause  may  be  looked  for  as 
a  certainty,  especially  when  large  increases  in  enlistment  necessitate 
the  inclusion  of  many  not  fit  for  service.  Colin's  statistics  of  losses 
to  the  French  array  are  corroborative  of  Schjerning's  statement^  espe- 
cially those  for  the  year  1895,  when  a  large  increase  of  the  army, 

*  Journal  d'llygiene,  March  1, 1900. 


TTiT':  nis'i<:AS/':s'  of  'rin<:  sf)TJ)Ti-:n. 


(u;i 


noccHHitidinfT  ;i  rcdiKifion  in  ilic  (|ii!ili(y  (IciiiuiHlcd,  wa.s  fdllowi d   li\'  a 
nioi'c  iiiiu'kcd  iiicrcuHc  in  yearly  Iohh.     'I'Ik;  li^iiics  follow  : 


Year. 

IilH('lmi-K('H  per  1000 

Ii(!itMiH  |j(!r  1000  uniiy 

Tot4il  IrMN  per  IWIO  armj 

iirtiiy  HlniiiKlli. 

'i.;5() 

HtriMiKtti. 

ilrciigth. 

1888 

1.18 

6.48 

1889 

■\.'M 

l.or, 

6.99 

IHDO 

5.70 

1.08 

6.78 

l,Si)l 

(i.IO 

1. :',.'{ 

7.4.'i 

]S<)2 

(•,j,r, 

1. 01 

7.59 

18!).", 

(> '.')'.') 

0.91 

7.'J7 

1 8!)1 

ii'riry 

1.01 

7.50 

1895 

8.34 

1.14 

9.48 

1896 

7.34 

0.94 

8.'28 

III  \hc  Knnlish  scrNicc,  plilliisis  is  the  cliicC  ciiiix'  oC  iiior(alit\'  and 
invaliding,  the  annual  lo.ss  avera<rin^  .sonicwliat  below  5  per  1000 
iinny  strcnirth.  In  the  French  service,  the  di.seu.se  .stands  .second  to 
typhoid  fever. 

In  armies,  as  in  ocueral  life,  iiilx'rcnlosis  finds  the  greater  nnriiber 
of  its  victims  ainon<;'  tho.sc  who  are  most  confined,  and  is  more  frecjuent 
in  the  garrisons  of  large  towns  than  among  troops  in  the  less  thickly 
settled  j)arts.  The  most  carefnl  prophylaxis  is  demanded  to  jirevcnt 
its  spread,  and  the  ideal  measures  would  include  the  discharge  of  all 
per.sons  capable  of  acting  as  foci  of  the  disease. 

Typhoid  Fever. — Typhoid  fever  is  very  prominent  as  a  scourge, 
especially  in  time  of  war,  when  large  bodies  of  raw  and  undisciplined 
troops  are  brought  together  in  camps  of  instruction.  Among  large 
bodies  of  men  drawn  from  different  ])arts  of  a  country  in  which  the 
disease  is  very  generally  distributed,  it  is  almost  inevitable  that 
there  will  be  some  who  will  introduce  the  specific  germ.  The  indi- 
vidual soldier,  owing  to  age  and  the  abrupt  changes  in  the  nature  of 
his  surroundings  and  general  habits  of  life,  is  very  susceptible  to 
infections  in  general.  Statistics  demonstrate  that  the  seasoned  regular 
suffers  much  less  from  disease,  in  proportion  to  numbers,  than  the  un- 
disciplined volunteer  and  raw  recruit.  This  is  due  to  the  fact  that  he 
has  become  accustomed  to  the  mode  of  life,  and,  through  training,  has 
learned  better  how  to  take  care  of  himself  in  all  departments  of 
personal  hygiene.  Great  care  is  necessary  to  isolate  cases  as  soon  as 
recognized,  and  to  treat  excreta  so  that  their  final  disposal  shall  not  be 
a  menace  to  the  safety  of  others. 

Of  the  highest  importiince  is  the  prevention  of  access  of  flies  to  the 
discharges,  for,  as  has  been  stated  elsewhere,  these  pests  have  been 
responsible  for  the  spread  of  this  and  other  diseases  by  contaminating 
the  food  supply  after  visiting  the  sinks.  Also  of  the  highest  impor- 
tance is  the  avoidance  of  a  polluted  water  supply  ;  boiling  of  water 
concerning  which  nothing  is  known  should  always  be  done  as  a  matter 
of  routine  precaution,  and  the  attention  of  the  men  should  be  drawn 
to  the  danger  which    thev  incur  in    the   indiscriminate  di'inkius:  of 


66S  MILITARY  HYGIENE. 

water  which  has  not  been  thus  treated  or  shown  by  competent 
authority  not  to  require  it.  In  general,  it  may  be  stated  that,  without 
efficient  sanitary  police,  typhoid  fever  among  troops  is  always  to  be 
expected. 

The  origin  and  spread  of  ty])hoid  fever  in  our  army  during  the 
Spanish  War  (1898)  were  investig-ated  by  a  board  consisting  of  Dr. 
Walter  Reed,  U.  S.  A.,  and  Drs.  Y.  C.  Vaughan  and  E.  O.  Shake- 
speiire,  U.  S.  V.,  who  reported  that  more  than  1)0  per  cent,  of  the  vol- 
unteer regiments  developed  the  disease  Avithin  eight  weeks  of  going 
into  camp.  In  certain  regiments  of  regulars,  the  disease  developed 
M'ithin  three  to  five  weeks.  Among  the  whole  body  of  troops  there 
were  no  less  than  20,000  cases  between  May  and  September.  The 
causes  included  polluted  water  and  dissemination  of  fiocal  matter  by 
flies.  In  some  cases,  camps  were  set  up  despite  the  protests  of  the 
medical  officers  against  the  unfitness  of  the  sites  selected. 

Preventive  inoculation  against  this  disease,  although  in  its  infancy, 
has  given  sufficiently  encouraging  results  to  warrant  trial  on  a  large 
scale.      (See  section  on  "  Immunity.") 

Dysentery. — In  the  South  and  in  our  new  tropical  possessions, 
dysentery  is  one  of  the  most  important  camp  diseases ;  in  fact,  it  is 
said  that,  within  the  tropics,  dysentery  annually  claims  far  more  vic- 
tims than  Asiatic  cholera.  Once  introduced,  like  typhoid  fever,  it  is 
likely  to  become  epidemic. 

Shiga,^  in  an  effort  to  secure  protection  against  the  disease,  inocu- 
lated 10,000  people  in  Japan  with  a  mixture  of  dead  bacilli  and 
specific  serum.  The  incidence  of  the  disease  was  not  much  affected, 
but  the  mortality  was  reduced  from  20  to  30  per  cent,  to  practically 
nothing.     (See  also  section  on  "  Immunity.") 

Malaria. — The  various  forms  of  malarial  diseases  are  always  a  curse 
to  armies,  especially  those  operating  in  hot  climates.  Though  the 
death-roll  from  malaria  may  not  be  great,  sickness  and  consequent 
invaliding  are  commonly  enormous  in  amount,  and  an  army  stricken 
with  malaria  is  an  army  unfit  for  field  operations.  The  infection 
weakens  the  natural  power  of  resistance  to  other  infections,  and  is  said 
to  predispose  the  victim  especially  to  infection  by  typhoid  fever,  and  to 
exert  a  particularly  pernicious  influence  on  those  who  have  already 
acquired  or  subsequently  acquire  venereal  diseases. 

The  great  value  of  measures  directed  against  the  presence  of  mosqui- 
toes is  well  shown  in  a  report  by  Dunbar.^  A  naval  board,  appointed 
to  consider  anti-malarial  prophylactic  measures  at  the  naval  station, 
Olongapo,  Philip))ine  Islands,  recommended,  first,  filling  in  the 
swampy  land  on  the  range  and  further  clearing  of  the  ground,  so  that 
there  should  be  no  shelter  for  the  mosquito  within  at  least  200  yards 
from  the  range ;  and,  second,  the  erection  of  thoroughly  screened  quar- 
ters for  officers  and  men.  The  result  of  these  measures  was  very 
striking ;  for  whereas  during  the  first  quarter  of  last  year  there  were 
105  admissions  to  the  hospital  ship,  giving  2214  sick  days,  during  the 

1  Osier's  Modem  Medicine.  ^  Pliilippine  Journal  of  Science,  Aug.,  1910. 


TUK   DTSEASEN   O/-'   THE  SOI.Dir.l! .  W.) 

('l;ij)H(!(l  |>;ii't,  over  (inc  li;il("  <i("  (lie  (irsl  (|ii;ii't(i'  oC  tlii-  y<:ir,  tlicrc  li;i'l 
l)('(!n  l)til,  JS  ;i(liiiissi(iiis  to  llic  lio:-j)il;il  sliip  for  in:il;iii:i,  \n\\\\[r  120  .sick 
(liiys. 

Siii(!(!  tlio  ciOTifinriiitioii  "C  the  discovciy  «("  lli''  iinportaiit  [)art 
j)l:iV(!(l  by  iii(»s<|iiil,(K'S  ill  lln'  (lissciniiijilioii  oC  flic  iii;il;iri;il  poinoii, 
tlic  IK!C(^sHi(y  oC  the  use  oC  netting  ugain.st  thcHC  pcstH  liuH  been  vor)* 
(^Iciirly  (huiKiiisI rated.  The  prcvciitivt^  nicasiircs  a^ain.st  malaria  cjonMni 
ill  the  avoidaiuH',  if  |»(i.ssil>l<',  <»!'  sites  near  wliicli  tlic  coiiditionn  are 
favorable  to  llic  piiddlc-hrccdin!;-  iiios«jiiilocs,  (lie  avoidance  of  nnncccs- 
surv  ^oinji;  about  diiriiiL!,'  tlie  lioiii's  when  nioscjuitoes  arc  most  active, 
prevention  of  access  of  iiios(|iiiloes  lo  tin;  sicejjinj^  (juarters,  ancl  the 
sy.stcmiatic  us(!  ol"  ))ro|)liyla(!(ic  doses  of  •|iiiiiiiie  morning  and  ni^lit. 
Whiskey  is  not  lujcch'd  as  an  adjiixaiit,  ;iiid  is  more  likely  to  be 
an  injury  liian  an  aid.  Hot  lea  and  eollce  nre  nioi'c  hij/hly  re- 
garded. 

Measles. — In  all  new  levies  of  troops,  measles  is  a  seri(»ns  imp<'di- 
ment  to  ciiieiency,  for,  once  introduced,  the  disease  s])reads  rapidly 
througli  the  camp,  es])eeially  if  the  troops  are  hirgely  from  the  c/)untiy, 
where  they  have  esca])ed  the  diseases  of  childhood  which  ravage  the 
population  of  cities  and  large  towns.  The  importance  of  the  disease 
appears,  according  to  recent  evidence,  to  be  likely  to  be  underrated  by 
commanding  olficers. 

Diarrhoeal  Diseases  in  General. — Because  of  the  lesser  resistiince 
to  specific  infections,  which  appears  to  accompany  even  mild  cf)nditions 
of  diarrhwa,  it  is  essential  to  take  such  measures  and  precautions  as  are 
])ossible  to  prevent  them.  Among  the  prominent  causes  may  be  men- 
tioned the  use  of  im]n-o])erly  cooked,  indigestible  food,  and  chilling 
of  the  body,  particularly  at  night  while  sleeping  on  the  ground,  even 
although  separated  from  immediate  contact  therewith  by  rubber  blan- 
kets. The  prevention  of  the  first  cause  needs  hardly  to  be  pointed 
out;  for  the  prevention  of  the  second,  the  habitual  use  of  light  flannel 
p-armcnts  or  abdominal  bands  is  recommended. 

Sunstroke. — This  consequence  of  extreme  heat  or  over-cxertiou  m 
high  temperatures  is  very  likely  to  be  induced  by  imprudence  in  the 
matter  of  water  supply,  and  by  continuous  work  without  periods  for 
rest  and  recreation.  According  to  Dr.  Smart,  U.  S.  A.,^  "  If  the 
allowance  of  water  is  scanty,  it  must,  nevertheless,  be  used  at  regular 
intervals,  but  economically,  lest  it  give  out.  There  is  manifestly  less 
danger  of  a  fulminant  stroke  with  a  stinted  but  steady  supply  than 
with  full  alloAvance  for  a  given  time  followed  by  a  period  of  enforced 
abstinence.  On  the  other  hand,  if  the  supply  is  liberal,  it  may  he  in- 
dulged in  freely  and  with  advantage  when  the  skin  is  acting  well." 
He  relates  that,  during  a  service  of  four  years  in  the  hot  climate  of 
Arizona,  Avith  commands  of  varying  size,  making  long  marches,  often 
on  scant  allowance  of  water,  he  saw  sunstroke  on  but  one  occasion,  and 
in  this  instance,  the  rule  to  use  the  canteen  in  the  early  part  of  the 
march  with  caution,  as  if  no  more  could  be  had  until  arrival  in  camp, 

1  Philadelphia  Medical  Journal,  January  19,  1901,  p.  158. 


670  MILITARY  HYGIENE. 

was  not  followed.  It  was  the  rule,  when  a  supply  presented  itself  on 
the  line  of  march,  to  use  it  freely,  and  then,  on  proceeding,  to  use  the 
refilled  canteens  with  the  same  caution  as  before.  A  canteen  of  tea, 
not  necessarily  strong,  containing  a  little  lemon  juice,  lime  juice,  or 
vinegar,  is  more  desirable  when  obtainable  than  plain  water. 

Venereal  Diseases. — These  are  responsible  for  a  very  large  amount 
of  sickness  in  all  armies,  and  their  prevention  has  been  the  subject  of 
much  consideration  by  military  authorities  everywhei'e  ;  but  the  reme- 
dies against  the  prevailing  high  figures  of  morbidity,  namely,  scientific 
and  practical  control  of  prostitution,  find  ahvays  and  everywhere  active 
ojjposition  on  the  part  of  the  public. 


(MIA  l"IM<:il     X. 
NAVAI.    AND    MARIN!-:    IIVCIKNR 

TiiK  ('(tndilioiis  of  lil'c  at  .sc^a  in  i-rhition  lo  liciiltli  an;  very  difrcrcnt 
ill  many  rcspctits  IVoni  those  \vlii<'li  <»l)(ain  asli(»r<'.  Tin-  K-Jifarin^ 
man,  wIutc^ncm'  lie  g<»<!H,  travels  in  his  liahitation,  in  wliieh,  ricf/'s.sarily, 
his  share  of  (Uihie  spaxic  is  iiir  less  in  anioinit  than  that  which  the  jirin- 
ciples  of  g;eneral  hyfi:;iene  stijnilatc;  as  a  ixrmissihle  minimum  for  thowi 
ashore.  His  air-siij)ply  whiU;  at  work  on  and  above  the  deck  is  of  the 
greatest  known  j)nrity,  and  while  hclow  in  his  sl^'cpin^''  fjuarters  it  is 
likely  to  be  at  times  unutterably  foul,  and  under  usual  conditions,  even 
with  the  best  of  care  and  appliances,  is  usually  not  in  conformity  with 
the  generally  ac^cepted  standard.  His  work  exposes  him  to  the  hard- 
ships of  the  most  inclement  W(!athcr,  to  extremes  f)f  heat  in  the  stoke- 
holds of  vessels  proju'lled  by  steam,  to  long-sustainc-d  muscular  effort 
at  critical  periods  ;  and  involves  short  hours  for  sleep,  and  these  not  in 
one  consecutive  whole,  but  divided  by  intervening  periods  of  duty.  His 
food  su]iply  for  the  entire  period  from  port  to  ])ort  nuist  be  transported 
with  him,  uuist  necessarily  possess  keeping  (pialitics,  and  hence  con- 
sists largely  of  preserved  instead  of  fresh  jueats,  and  dried  and  canned 
vegetables  instead  of  those  fresh  from  the  fields. 

In  the  matter  of  kitchens,  cooking  appliances,  and  fuel,  he  is  circum- 
stanced more  fortunately  than  the  soldier,  since  wherever  he  goes  they 
accomj)auy  him,  and  he  is  independent  of  the  frequently  troublesome 
question  of  transportation  of  supplies  and  appliances  in  time  of  need. 
Thus  it  was  that,  during  the  battle  of  JNIanila  Bay,  all  hands  could  be 
piped  to  breakfast,  whereas  at  the  fierce  onslaught  by  the  land  forces 
at  San  Juan,  no  such  comfortable  relief  could  be  afforde^l. 

His  water-supply  must  be  carried  in  proper  storage  or  be  obtained 
by  distillation  from  the  salt  water  in  his  path.  But  he  has  not  to  cope 
with  the  difficulties  which  beset  the  soldier  in  the  matter  of  camp  sani- 
tation, for  his  sewer  is  the  boundless  ocean,  and  the  question  of  disposal 
of  garbage  requires  no  thought. 

NAVAL   RECRUITS. 

The  United  States  Regulation  forbids  the  enlistment  as  a  landsman 
of  any  man  over  25  years  of  age  unless  he  has  learned  some  mechan- 
ical trade,  and  in  this  instance  he  may  not  be  enlisted,  without  special 
authority,  if  over  35  years  of  age.  A  landsman  is  one  who  never  be- 
fore has  gone  to  sea,  or,  having  been  already  at  sea,  does  not  posses  the 
skill  required  of  an  ordinary  seaman.  An  ordinary  seaman  must  already 
have  had  two  years'  experience.  An  able  seaman  is  one  who  has  had 
at  least  four  yeai's'  experience  and  understands  the  navigation  of  ships. 

671 


672  NAVAL  AND  MARINE  HYGIENE. 

Apprentice  seamen  are  enlisted  from  17  to  25  years  of  age,  are  sent 
to  training  stations  and  given  snob  instrnctions  as  tends  to  make  them 
eligible  for  promotion  to  the  higher  ratings  in  the  seaman  branch  of  the 
service. 

"  The  mininmm  weight  for  acceptance  of  a  man  21  years  old  is  128 
pounds.  A  variation  of  10  pounds,  not  to  fall  below  128  pounds  in 
weight,  or  2  inches  in  chest  measurement  below  the  standard  given  in 
the  table  for  adults,  is  admissible  when  the  applicant  for  enlistment  is 
active,  has  firm  muscles,  and  is  evidently  vigorous  and  healthy,  except 
for  enlistment  in  the  rate  of  coal  passer,  for  which  rate  full  standard 
measurements  will  be  required. 

"Chest  expansion  of  less  than  2  inches  in  a  minor  or  of  less  than  2| 
inches  in  an  adult  is  a  sufficient  cause  for  rejection  of  an  applicant. 
Marked  disproportion  of  weight  over  height  is  not  a  cause  for  rejection 
unless  the  applicant  is  positively  obese. 

"  Any  one  of  the  following  conditions  will  be  sufficient  to  cause  the 
rejection  of  the  apj^licant : 

"  1.  Feeble  constitution,  general  poor  physique,  or  impaired  general 
health. 

"  2.  Any  disease  or  deformity,  either  congenital  or  acquired,  that 
would  impair  efficiency,  such  as  :  Weak  or  deranged  intellect,  cutaneous 
disease  not  of  a  mild  type,  parasites  of  the  skin  or  its  appendages,  de- 
formity of  the  skull,  abnormal  curvature  of  the  spine,  torticollis,  in- 
equality of  upper  or  lower  extremities,  inefficiency  of  joints  or  limbs, 
deformity  of  joints  or  bones  either  congenital  or  the  result  of  disease  or 
injury,  flat  feet,  evidence  of  epilepsy  or  other  convulsions,  defective 
vision  (minimum  }j-^-  S.  in  either  eye),  disease  of  the  eye,  color-blind- 
ness, impaired  hearing  or  disease  of  the  ear,  chronic  nasal  catarrh, 
ozsena,  polypi,  great  enlargement  of  tonsils,  impediment  of  speech,  dis- 
ease of  heart  or  lungs  or  predisposition  to  such  disease,  enlarged 
abdominal  organs  or  evidence  of  cirrhosis,  tumors,  hernia,  undescended 
testicle,  large  varicocele,  sarcocele,  hydrocele,  stricture,  fistula,  hemor- 
rhoids, large  varicose  veins,  disease  of  the  genito-urinary  organs,  chronic 
ulcers,  ingrowing  nails,  bad  corns,  large  bunions,  deformity  of  toes,  loss 
of  many  teeth  or  teeth  generally  unsound  (teeth  properly  filled  not  to 
be  considered  unsound).  Every  recruit  must  have  at  least  twenty  sound 
teeth,  and  of  these  not  less  than  four  opposed  incisors  and  four  opposed 
molars. 

"  3.  Any  acute  disease."  ^ 

THE  NAVAL  RATION.^ 

The  naval  ration  is  always  different  from  that  of  the  soldier  for  rea- 
sons already  given.  The  rations  for  the  United  States  navy,  as  pre- 
scribed in  1907,  consists  of  the  following  daily  allowance  of  provisions 
to  each  person  :  Furthermore,  it  will  be  noted  that  '^any  article  com- 

1  Circular  relating  to  the  Enlistment  of  Men  for  The  U.  S.  Navy. 
^  General  Order  No.  44,  Navy  Departraeut,  April  16,  1907. 


77//';   NA  VA  L    HA  TION. 


073 


prisod  in  tlic  navy  nilioii  ni.iy  Im'  i-siicd  in  exec--  of  flu;  iuitliori/.c'(l 
({nantity  provich.'d  i\\i\n\  he.  an  under-i.s.snc.  of  tlic;  hain<;  \aliU'  in  wmie 
other  article  or  artick's." 


'j'aiii,!';  of  lUrioN  (Jomtonenth, 


.0053 


Articles. 


liiiKAii : 

niuil  :    Hiscuit,  Sddii,  uikI  oyHtiT  (TiickiTS  .    . 

Soil:  (iriiliaiii  iiiiil  wheat  Wrciid  iiii<l  mils  .    . 

Flour  us   bread:   liiiekwlieat,  coninK'ttl,  iind 

wheat  Hour 

Mkats: 

Fresh:  Fresh  beef,  beef  liver,  beef  hearts, 
fish,  hamburger  steak,  mutton,  j)ork 
loins,  pork  sausage  (not  smoked),  and 
veal 

Chieken  and  turkey 


Chicken  luid  turkey,  on  other  than  holidays, 
(dams,  oysters, and  any  not  named  iiliove 
Preserved  :  Tinned  bacon,  beef  eoriied,  beef 
roast,  Vieef  chipped  (in  tins),  ham,  sal- 
mon, fish  (shredded  and  salt),  ham 
(compressed),  head-cheese,  and  pigs'  feet 

(comi)ressed) 

(!rab  meat,  sardines,  and  any  not  named 

above    

Salt:  Fresh  corned  beef,  salt  beef,  and  salt 

pork 

Smoked :    Sugar  or  salt-cured  bacon,  ham 
and  shoulders, beef  (diipped  (not  tinned), 

and  smoked  sausages 

Tongues  (lieef ),  and  any  not  named  above 

Eggs:    Fresh  eggs 

Evaporated    eggs,  dried    preparations   of 

eggs 

Vegetables: 

Canned :  All  tinned  vegetables  (including 

tomatoes) 

Potato  chips 

Desiccated  :  All  kinds 

Dried:  Beans  (white), beans  (lima), and  pease 
Fresh  :  Beets,  cabbage,  carrots,  onions,  pota- 
toes (Irish  and  sweet),  pumpkins,  and 

turnips  

Asparagus,  beans  (lima),  beans  (string), 
cauliflower,  celery,  corn  on  ear,  cucum- 
bers, kale,  lettuceipeasc  (green), spinach, 
squash,  tomatoes,  and  any  not  named 

above    

Cereals  and  starch  food:  Barley,  cornstarch, 
hominy,  oats  (rolled),  rice,  tapioca,  or 

sago 

Any  flours  not  issued  as  bread 

Fruits  : 

Canned :     Tinned    apricots,    peaches,    and 
pears;  fruit  butters,  jams,  and  jellies  .   . 

Any  not  named  above 

Dried  :    Apples,  currants,  peaches,  prunes, 

and  raisins     

Nuts    (on    holidays  only),  and    any   not 

named  above    ." 

Fresh  :  Apples,  bananas,  and  oranges  .... 
Berries  (all  kinds),  cantaloupes^  cherries, 
cranberries, grapes,  peaches,  pears,  water- 
melons, andany  not  named  above    .   .   . 
Beverages: 

Cocoa    

Coftee    

Tea 

Milk  : 

Cream  (evaporated),  and  milk  (condensed)  . 
Fresh  milk 


now  iHSUI-d. 


As  ration  ef|uivalent. 


As  miscellaneous. 

As  ration  equivalent. 
As  miscellaneous. 
As  ration  equivalent. 


As  miscellaneous. 
As  ration  equivalent. 


As  miscellaneous. 
As  ration  equivalent. 


Allowance. 


As  miscellaneous. 
.■Vs  ration  equivalent. 


As  miscellaneous. 

As  ration  equivalent. 

As  miscellaneous. 
As  ration  equivalent. 

As  miscellaneous. 
As  ration  equivalent. 


1  lb. 
li  IN. 

IJilbs. 


lbs. 

Ulbs.  (onholi- 
ayHonlv.Art. 
180,  N.  V..). 

By  value. 


I  lb. 

By  value. 

II  lbs. 


H  lbs. 
By  value. 


Jib. 


lib. 

By  value, 
ilb. 
3  gills. 


111b:, 


By  value. 


ilb. 
ilb. 


fib. 

By  value. 

Alb. 

Bv  value. 
iVlb. 


By  value. 

lib. 
Jib. 
Alb. 

tWlb. 

Aqt. 


43 


674 


NAVAL  AND  MARINE  HYGIENE. 
Table  of  Ration  Components — Continued. 


ggo 


^  U    -.    X 


.0117 


.0275 


.0333 
.0383 


.0081 


.0145 

.005 

.006 

.0025 

.01 

.0032 

.0123 

.0186 


Articles. 


Pickle^: 

Cucumber  pickles  (pay  department),  sauer 

kraut 

Chow-cho\v,olives, cucumber  pickles  (sweet), 

and  any  pickles  not  named  above     .  .   . 
Vinegar  and  sauce: 

Yinegrar  and  oil 

Catsup,  tabasco,  and  Worcestershire,  and  any 

sauces  or  salad    dressings    not  named 

above    

Other  ration  components  : 

Baking  powder 

Baking  soda 

Butter 

Cheese  .  .      

Extracts,  flavoring 

Hops 

Lard 

Macaroni 

Mustard 

Pepper 

Salt 

Syrup    

Spices 

Sugar    

Tomatoes  (canned) 

Yeast 

"Combined-ration"  Articles 


How  issued. 


As  ration  equivalent. 

As  miscellaneous. 
As  ration  equivalent. 

As  miscellaneous. 
As  ration  equivalent. 


As  miscellaneous. 


Allowance. 


i  lb.  (weekly). 

By  value. 

^  l)t.  (weekly). 

By  value. 

As  needed. 

Jib. 

i  lb.  (weekly). 

As  needed. 

7  lbs.  to  every 
100  lbs.  Hour 
as  bread. 

i  lb.  (weekly). 

^  lb.  (weekly). 

«W  lb.  (weekly). 

i  lb.  (weekly). 

i  pt.  (weekly). 

■j+Rlb.  (weekly). 

i'lb. 

i  lb.  (weekly). 

As  needed. 

By  value. 


Preserved  meats,  in  the  meaning  of  the  law,  comprise  canned  beef, 
mutton,  corned  beef,  bacon,  ham,  sausages,  salted  fish,  and  any  other 
smoked  or  salted  meats.  Flour  comprises  wheat,  rye,  oatmeal,  corn- 
meal,  and  hominy.  Dried  fruits  include  apples,  peaches,  prunes,  raisins, 
dates,  figs,  and  others  susceptible  of  preservation  by  drying. 

From  the  above,  it  will  be  noted  that  our  naval  ration  is  very 
elastic  and  generous,  and,  indeed,  is  said  to  be  superior  in  amount  and 
variety  to  that  of  any  foreign  navy,  just  as  our  army  ration  surpasses 
in  these  respects  those  of  other  armies. 

In  spite  of  the  elasticity  and  abundance  of  the  ration,  considerable 
improvement  and  much  greater  satisfaction  appear  to  be  attained  by 
the  system  of  the  consolidated  mess,  instituted  originally,  in  1889,  by 
Lieutenant  Delehanty,  of  the  U.  S.  S.  Independence.  Not  the  least  of 
its  advantages  is  the  improvement  in  the  preparation  and  serving  of 
the  food.  In  the  ordinary  method  of  messing,  the  ship's  company  is 
divided  into  a  number  of  messes  of  about  twenty  men,  and  each  has  its 
own  cook  and  mess  attendants.  The  preparation  of  the  food  for  all 
is  in  charge  of  the  chief  cook  and  a  number  of  assistants,  and  the 
serving  out  and  the  care  of  the  mess  gear  are  attended  to  by  the  mess 
attendants  or  berth-deck  cooks.  Accordinp;  to  Lieutenant  B.  C.  Decker,^ 
of  the  U.  S.  S,  Indiana,  "  the  present  system  of  messes  with  incom- 
petent and  often  broken-down  landsmen  as  cooks,  .  .  .  and  with 
general  waste  and  mismanagement,  is  a  failure." 

1  The  Consolidated  Mess  of  the  Crew  of  the  U.  S.  S.  Indiana,  Proceedings  of  the 
U.  S.  Naval  Institute,  XXIIL,  1897,  p.  463. 


WATh'i:  Sflff'LV.  075 

fn  ihv.  (!()riH(»II(l;i(((|  mess  of"  the  I nd'tdini,  :is  <\(-(:v'\\\it\  \,\-  \)ic\:<\' 
tlio  c.nnv  (>('  .'mSO  mcii  li:i\c  ;i  ciiiiiiikmi  iiilcr'csl,,  and  ;iif  ;il  Iciiilcl  lo  l>y 
SGV(M1    ('(Mtks,   (ilic  of   I  he    (irsi    clilSH,   I  Wo   oC  tllC   HOCOIld,   ;iii<l    (i»iir   nf  tlic 

tliird  (ilas.s,  a  coiiiniissai'y  ycomaii,  and  a,  Htorcroom  kccjicr,  I''iiiidH 
ioi"  proviHioniii/j^  (Ik^  mess  arc  derived  (Voiii  flie  eoiiiiiiii(e(|  rafidiis  arifl 
tJiC!  canlceii.  (Ilere  may  l»e  staled  llial,  in  llic  di.srMlHHion  of  (lie  paner 
noted,  tli(!  (lanlcen  system,  as  il,e.\ist('d  in  tli(!  iNavy,  was  (lie  snlijer-t  of 
severe  eritusism  by  ()fili(H'rs  oCliie  Iin(^      It  i.s  now  aholislied.j 

TIk!  system  saves  mneli  troiihie,  )'e(jiiires  fiiwer  eooks,  and  liv  mak- 
inji;  possible  tlie  j)ur(!liase  oC  a  still  wider  variety  of  food  inatorial.«,  in- 
sures ^renter  satisfa(!t  ion  (liroiinjioiit  a(  a  diminislied  cost. 

The  ])rincipal  defects  of  all  dietaries  for  scafiirin^  men  comprine 
monotony,  detiiaency  in  \'en(.(;il)le  components,  and  excess  of  prcwrved 
meats.  In  order  to  ^nard  ai^ainst  the  rcsidtsof  an  insMllicicnt  snjiplv  of 
antiscorbutic  veo'ctahles,  the  Kevised  (Statutes  recpiire  that  all  vessels  of 
more  than  75  tons  bonnd  across  the  Atlantic,  oi-  Pacific  or  around  Cape 
Horn  or  Cape  of  (Jood  Ilojie,  or  cnji^ii^ed  in  whaling  or  sealing,  shall 
cany  a  sufficient  su]ij)ly  of  lemon  juice  or  lime  juice,  and  vincfrar, 
which  shall  be  served  out  within  ten  days  after  salt  provisions  have 
been  served  out,  the  lemon  juice  or  lime  juice  at  the  rate  of  f)ne-half 
ounce  daily,  and  the  vinegar  at  the  rate  of  one-half  pint  weekly,  per 
man. 

WATER   SUPPLY. 

The  satisfactory  storage  of  water  aboard  ships  is  a  matter  of  some 
difficulty.  Small  vessels,  as  ordinary  merchant  ships  and  similar 
craft,  not  provided  with  distilling  a])paratus,  must  necessarily  carry 
a  sulliciency  of  water  for  the  passage  between  ports,  reckoned  at  three 
quarts  daily  per  man  plus  an  amount  sufficient  for  cooking.  Water  Ls 
stored  in  wooden  casks  and  metallic  tanks.  Storage  in  casks  is  far 
from  satisfactory,  on  account  of  the  deterioration  which  occurs  in  the 
quality  of  the  water.  This  is  due  to  the  action  of  the  water  in  extract- 
ing matters  from  the  wood,  and  to  decomposition  of  these  matters  in- 
duced and  carried  on  by  the  usual  agencies.  Casks  should  not  be  made 
of  soft  Wood,  and  the  interior  should  be  very  thoroughly  charred, 
in  order  to  diminish  as  nmch  as  possible  the  extraction  of  soluble  con- 
stituents and  to  guard  against  decay.  Tanks  are  commonly  made  of 
galvanized  iron,  lined  sometimes  with  cement.  They  should  be  placed 
in  easily  accessible  locations  which  admit  of  ready  inspection  and 
clcjmsing. 

No  water  should  be  taken  on  board  unless  its  source  is  known  and 
its  quality  is  such  as  to  preclude  the  danger  of  introducing  water- 
borne  diseases.  Large  vessels  and  steamships  provided  with  distilling 
apparatus  do  not,  of  course,  need  to  provide  for  the  storage  of  large 
volumes  of  water.  The  water  yielded  by  a  distilling  ajiparatus  is,  on 
the  Avhole,  far  superior  in  quality  to  that  which,  however  good  origi- 
nally, has  been  stored  for  any  considerable  time.  For  full  considera- 
tion of  the  subject  of  water  and  its  storage,  the  reader  is  referred  to 
the  chapter  devoted  to  that  subject. 


676  NAVAL  AXD  ^^ARTNE  HYGIENE. 

THE    SAILOR'S    SLEEPING  QUARTERS. 

The  sailor  is  berthed  coniinonly  either  in  deck  houses,  forecastles, 
or  between  Jeeks.  Deck  houses  are  by  far  to  be  preferred,  since  they 
are  well  lighted  and  can  be  well  aired.  They  are  })laced  about  mid- 
ships, and  are  most  accessible  and  convenient.  There  are  two  kinds 
of  forecastles  ;  one,  known  as  the  top-gallant  forecastle,  has  side  lights 
and  is  entered  through  a  doorway  ;  the  other,  commonly  found  on 
merchant  vessels  and  small  craft  in  general,  is  entered  from  above 
through  a  hatchway,  and  is  not  lighted.  This  is  the  least  desirable 
lodging  place,  and  is  exceedingly  difficult  to  keep  in  a  cleanly  condition. 
In  fact,  on  merchant  vessels,  it  is  commonly  infested  with  bedbugs  and 
other  vermin,  and  is  the  storehouse  for  wet,  dirty  clothes  and  all  man- 
ner of  rubbish.  Forecastles  are  likely  to  be  damper  than  other  parts, 
on  account  of  the  greater  amount  of  water  shipped  over  the  forepart 
of  the  vessel  when  under  way. 

Cubic  space  per  capita  depends  upon  the  facilities  for  the  convenient 
hanging  of  hammocks  ;  it  can  never  be  generous  :  it  is  always  far  less 
in  amount  than  is  regarded  ashore  as  essential  for  the  maintenance  of 
a  fair  degree  of  health.  In  fact,  sailors  are  almost  always  over- 
crowded :  they  have  nothing  like  the  allowance  which  obtains  in  bar- 
racks, but  rather  that  of  the  tent  in  the  field.  The  fact  that  the 
sailor's  rest  is  broken  in  upon,  so  that  at  no  time  does  he  get  more 
than  four  hours  of  consecutive  sleep,  may  perhaps  be  a  benefit  to  him 
in  that,  in  the  intervals,  he  breathes  the  pure  outside  air,  and  may  thus, 
in  some  measure,  counteract  the  evil  results  of  breathing  the  neces- 
sarily impure  air  below.  The  English  statute  requires  that  a  seaman 
in  the  merchant  marine  shall  have  not  less  than  72  cubic  feet  of  air 
space  and  12  square  feet  of  floor  space,  exclusive  of  that  occupied  by 
the  necessary  articles  of  furniture  and  dunnage. 

In  the  matter  of  cubic  space,  the  crews  of  merchant  vessels  are,  as  a 
rule,  better  oif  than  those  of  men-of-war,  since,  on  vessels  of  the  latter 
class,  the  complement  of  men  required  for  all  the  various  duties  is  so 
large  that  overcrowding  is  to  be  looked  upon  as  a  matter  of  course. 
The  sleeping  quarters  of  most  of  the  crew  are  located  below  the  water 
line  on  the  berth  deck.  Some  are  quartered  on  the  gun  deck,  which 
is  above  the  water  line,  and  consequently  is  circumstanced  better  as  to 
light  and  air. 

The  sailor  sleeps  in  either  a  hammock  or  a  bunk.  The  hammock  is 
a  hanging  bed,  made  of  heavy  canvas,  about  six  feet  long  and  half  as 
wide.  At  each  end,  brass  or  copper  eyelets  are  Avorked  in,  through 
which  the  nettles  of  the  clews  pass  and  are  fastened.  The  clews  end 
in  an  iron  ring,  to  which  the  lashing  for  each  end  is  attached.  In  the 
hammock  are  placed  a  mattress  and  the  necessary  coverings,  and  on 
this  he  gets  his  modicum  of  rest  in  a  constrained,  unnatural  position, 
bent  into  a  curve,  no  matter  how  he  may  dispose  himself.  Bunks  are 
far  more  rational  and  comfortable,  since  they  permit  of  a  horizontal 
attitude.  They  are  made  of  iron  framework,  wound  with  canvas  or 
other  non-conducting  material,  or  of  wood.     They  possess  the  addi- 


VF.Nrn.ATTON  OF    VFf^l^ELS.  077 

tioTijil  :i(lvantap;os  of  occiipNin^  lesH  Rpace  uii<l  of  liciut.''  rnon-  euHily  kept 
ill  clean  ('.ondilion.  ( Iddiiiioiily,  ilicy  arc  j)l;i('((l  in  two  tiers  and  '-nfli- 
oi(!ntly  far  iip;irl  lo  |»ci'iiii(,  of  easy  p!isHiijr(!  «»n  cillicr  side  'J'lio  lower 
tier  ,sli(»nl(l  be  not  less  (li;in  iiin(!  inelies  (Voin  the  deek. 

(inai'ters  (or  oHicers  nnd  [Kissenji-crs  ar<',  as  niav  n;itiii:ill\'  l»c  siip- 
poHcd,  more  lavorably  localccl  and  more  coiiiinodioii-  tliaii  those  a.s- 
si};n(«l   to   tli(!   v.vv.w. 

THE    DISEASES    OF    SAILORS. 

The  (^liieC  diseases  l(»  which  persons  on  shiphoiud  ai'c  subject  iiifiude 
diseas(>s  of  the  respiraiory  organs  (pail  ietdarly  tnherenlosis),  rlienrna- 
tisni,  diseases  ol"  the  di<i;estive  a])j)aia(ns,  venereal  diseases,  and  s(5i- 
siekness.  Of  nervous  lr<)ul)les,  nostalgia,  nieknudiolia,  and  hvj)Of;hon- 
driasis  are  conunon.  Skin  diseases  of  various  kinds  are  also  wtninion. 
Cholera  and  yellow  fever  and  other  ini])ortant  infectious  diseases  apjK-ar 
to  be  closely  (connected  with  shij)s,  by  which,  as  elsf!where  noted,  tlie 
contagion  is  I'recpiently  carried  from  one  eountiy  to  another.  F"or- 
mcrly,  scurvy  was  associated  especially  with  lif(!  on  shi})board,  but 
since  the  discovery  and  introduction  of  the  pro])er  jn'ophylactic  remedv, 
the  disease  has  been  practically  eliminated  from  the  list.  In  addition, 
troubles  of  minor  ini])ortance,  arising  from  sjx'cial  duties,  arc  of  eoni- 
nion  occurrence,  but  not  lasting  in  character  ;  such,  for  instance,  as  eye- 
strain and  other  disturbances  of  vision,  disturbances  of  hearing,  and 
trauma. 

In  s])ite  of  improved  hygiene,  diseases  of  the  lungs,  particularly 
tuberculosis,  appear  generally  to  be  on  the  increase  among  seafaring 
men,  instead  of  on  the  decline.  It  is  said  that  in  the  British  Navy, 
between  1883  and  1890,  diseases  of  the  lungs  increased  60  per  cent. 
It  had  been  supposed  that  the  doing  away  with  masts,  sails,  and  rig- 
ging, with  the  consequent  lessened  exposure  of  the  men  to  cold  and 
wet,  would  have  a  c(Miti-ary  eifect ;  but  its  influence,  if  any  it  had,  has 
been  more  than  counterbalanced,  by  the  change  in  conditions  below,  the 
men  living  now  in  a  very  crowxled  condition  in  hot  steel  ships. 

Firemen  and  stokers  are  very  prone  to  phthisis,  and  not  infi-equently 
the  exhausting  nature  of  their  work  causes  them  to  become  dcl)ilitatecl, 
morbid,  and  inclined  to  suicide.  Among  this  class,  vertigo,  stupor, 
and  convulsions  are  common. 

Hospitals  for  the  treatment  of  the  sick  at  sea  should  not  be  located, 
as  they  usually  are,  on  the  berth  deck  tbrward,  but  sh(iuld  be  about 
amidships,  where  they  may  receive  a  suliicient  amount  of  light  and  air. 
The  furniture  should  be  of  iron,  thus  permitting  easy  cleansing. 

VENTILATION    OF    VESSELS. 

The  air  of  a  ship  below  the  deck  is  commonly  far  from  meeting  the 
requirements  generally  accepted,  and  is  often  extremely  foul,  and  hence 
wholly  untit  for  respiration.  The  contributing  causes  of  this  condi- 
tion are  au  excess  of  aqueous  vapor  from  respiration  and  from  water 


678  NAVAL  AXD  MARINE  HYGIENE. 

used  in  swabbing  decks  or  ship])ed  over  the  sides  wliile  under  way; 
an  excess  of  carbon  dioxide  from  respiration,  conibnstion  of  illu- 
niinants,  and  decomposition  of  organic  matters ;  eitiuvia  from  the 
bilge-water,  from  oil,  tar,  paint,  and  other  necessary  snpplies,  from 
the  components  of  the  cargo,  and  from  other  sources.  The  crew's 
sleepiiig  quarters,  even  though  protected  by  all  practicable  means 
from  containinated  air  from  the  hold,  bilges,  and  fore-peak,  are  com- 
monly reached  through  some  channel  by  the  effluvia,  which,  mingling 
with  those  natural  to  the  place,  serve  to  make  a  very  bad  condition 
much  "SAorse. 

The  problem  of  efficient  ventilation  of  vessels  is  exceedingly  com- 
plex, and  is  quite  different  from  that  of  ventilating  dwellings  and 
other  buildings,  since  the  fundamental  conditions  are  so  little  in  agree- 
nient ;  and  it  becomes  more  complicated  with  increase  in  the  size  of 
the  ship.  The  principles  are  the  same  as  in  house  ventilation,  but  the 
application  of  methods  is  surrounded  by  greater  difficulties,  due  to 
peculiarities  of  construction  and  to  external  conditions.  Natural 
ventilation  may  be  effected  under  favoring  conditions  through  the 
medium  of  hatchways,  port  holes,  and  other  openings ;  canvas  tubes 
or  funnels  with  a  side  opening  at  the  top,  stayed  to  face  the  wind  or 
the  ship's  course,  known  as  windsails  ;  fixed  ventilating  tubes  acting 
in  the  same  manner,  hollow  masts,  and  other  appliances. 

Hatchways  are  commonly  the  only  openings  for  ventilating  the 
lower  forecastles,  and  in  foul  weather  they  are  kept  closed.  Some- 
times an  outlet,  capped  by  a  cowl,  is  provided,  but  it  is  usually  kept 
closed,  on  account  of  the  discomfort  of  drafts.  Deckhouses  and  top- 
gallant forecastles  are  much  more  efficiently  ventilated  through  the 
side  openings  and  because  of  their  greater  exposure  to  the  external 
air.  Holds  and  spaces  between  decks  are  ventilated  through  hatch- 
ways, fixed  tubes,  and  windsails,  hollow  masts  which  act  as  ventilating 
flues,  funnel  casings  which  act  like  jacketed  stoves,  and  other  means. 

Vessels  of  large  size  cannot  depend  upon  any  system  of  natural  ven- 
tilation, but  must  have  recourse  to  mechanical  methods  of  propulsion 
and  extraction,  and  even  then  only  an  imperfect  result  can  be  hoped 
for.  As  in  the  mechanical  ventilation  of  buildings,  propulsion  is 
likely  to  prove  far  more  effective  than  extraction,  and  its  efficiency  is 
very  greatly  dependent  upon  the  intelligent  planning  of  the  system  of 
the  channelways  and  valves.  Valves  are  required  not  only  for  the 
purpose  of  shutting  off  the  air  current  where  it  is  not  at  the  moment 
required,  but  also,  on  men-of-war  and  other  large  vessels,  for  the  pro- 
tection of  water-tight  bulkheads  in  case  of  accident,  and  of  different 
compartments  in  case  of  fire. 

The  ventilation  of  vessels  engaged  in  carrying  passengers  is  pro- 
vided for  in  part  by  legislation.  The  U.  S.  Revised  Statutes  require 
that  vessels  carrying  a  hundred  or  more  passengers  shall  have  for  each 
apartment  two  ventilators,  one  forward  and  one  aft,  of  a  capacity  pro- 
portionate to  the  size  of  the  apartments,  a  tube  12  inches  in  diameter 
being  regarded  as  the  proper  size  for  an  apartment  for  200  persons. 
If  other  means  of  attaining  the  same  measure  of  ventilation  are  pro- 


OENEIiAL   II  Yd  I  EN  H   OF  SI  HI'S.  07I> 

vidcd,  tlxy  rriiiy  he  used  in  j)litc.<!  ofllio.sc  .slijiiihitcd.  Ilridf-r  tlir  Kng- 
li.sh  law,  llu!  provisions  (or  lij^lilinj;  ;ind  vnlihilin^'-  niUHt  r<:(;<'iv('  flu; 
approvul  ol"  I  Ik;  lOmij^rnlion  Oflicc^r  ;il  iIk'  porl  of  ch^iraiUM!,  ;md  if 
ther(!  an;  as  niiuiy  ;is  a  Imiidrcd  piisscnjicis  on  board,  tlic  vcshcI  iniiHt 
1)0  |)r()vid(!<l  with  "an  ;id('(jM;if('  iind  pro|)('r  vent ihitin^'  apparatiiH  tf> 
\)v  jipprovcd    hy   such  olli(!(!r  and    lilted    lo  his   Katislliction." 

VVlicn  ai'tilicial  heating  is  rwjuircd,  use  is  made  of"ht»jv<'s  and  nU^ixn 
heating'.  ]ii  Uu;  lorwiaHtlc  of  Kuiling  vcssoIh,  Hmall  s(|uar(!  stovefl  of 
cast  iron  wilh  a  ni(»\ahl('  cover  an-  cin|)loycd.  'V\n'y  an;  dirty,  incori- 
veuicnt,  and  generally  nnsatisliictory. 

GENERAL   HYGIENE    OF    SHIPS. 

Of  the  very  lirst  ini|)orl;ince  in  IJie  hygiene  of  ^liip-  is  {rciieral 
cleanliness  of  ship  and  pcisonncl.  (Heanliness  of  the  >lii|>  retjuires 
constant  watchfulness  and  nnieniillinjj^  iittention,  ;iiid  daily  insj)eetion 
is  necessary  to  insure  that  cleanliness  is  not  wholly  sujx-rlicial,  since  it 
often  happens  that,  whereas  tlu!  decks  and  all  visible  portions  are  dean, 
parts  which  are  out  of  si<^ht  are  not  in  a  wholesome  condition.  Naval 
vessels  of  all  countries  are,  as  a  class,  much  more  carefully  looked  after 
in  this  respect  than  those  of  the  merchant  marine. 

In  securino;  cleanliness,  it  is  a  mistake  to  use  wat(;r  too  frecjuently  and 
in  too  great  abundance,  and  great  care  should  be  taken  that  all  sn|>er- 
fluous  water  is  renioved  as  (juickly  as  possible  from  all  parts  below 
decks,  since  one  of  the  cardinal  directions  is  to  keep  dry,  for  damp 
ships  are  notoriously  unhealthy.  Tlie  damjmess  that  condenses  from 
the  moist  air  u])on  the  surface  of  metal  plates  and  overhead  beams  is 
a  source  of  great  annoyance  from  its  constant  dripping,  and  keej)s  up 
a  continual  dampness.  This  can  be  remedied  only  by  sheathing  or 
coverings  of  non-conducting  material,  such  as  granulated  cork  or  as- 
bestos fiber. 

The  most  difficult  ]iarts  to  keep  in  even  fairly  sweet  condition  are 
the  bilges,  in  which  collects  that  most  disagreeable  and  offensive  liquid 
known  as  bifge-trafer,  the  internal  drainage  of  the  ship,  much  of  which, 
in  wooden  ships,  leaks  from  without  inward,  through  the  seams.  The 
disgusting  odor  of  bilge-water  is  due  to  the  decomposition  of  the 
organic  matters  present,  and  to  the  reduction  of  sulphates  of  the  salt 
water  to  sulphides.  The  bilges  require  periodical  pumping,  and 
are  connected  for  this  reason  with  pumps,  known  as  bilge-pumps. 
The  bilge-water  removed  is  discharged  into  the  sea,  and  after  removal, 
the  bilges  are  flushed  ■with  clean  sea-water  and  again  pumped  out ; 
sometimes  they  are  regularly  deodorized  and  disinfected. 

Next  in  importance,  on  account  of  their  commonly  unwhole- 
some condition  and  the  difficulty  with  Avhich  they  are  made  clean 
and  kept  so,  are  the  peaks.  In  small  vessels,  the  fore-peak  very 
commonly  causes  fouling  of  the  air  of  the  crew's  quarters  in  the  fore- 
castle. 

From  a  hygienic  standpoint,  the  stoke  holds  of  steamers  are  of  great 
importance,  for  here,  in  a  very  restricted  space,  exposed  to   excessive 


680  NAVAL  AND  MARINE  HYGIENE. 

heat  from  the  furnaces,  the  stokers  perform  their  exhausting  office. 
The  air  of  the  stoke  hohls  is  eonimonly  not  only  excessively  hot,  but 
exceedingly  foul,  and  these  conditions  can  be  abated  only  by  proper 
ventilation,  which  may  be  secured  either  by  means  of  mechanical  appli- 
ances or  windsails. 

Water-closets  and  latrines  should  be  of  as  simple  a  type  as 
possible  and  capable  of  effective  flushing.  The  soil-pipes  may  dis- 
charge above  or  below  the  water  line.  Where  closets  mnst  be  located 
below  the  water  line,  s])ecial  pum])ing  arrangements  are  provided  for 
their  emptying  and  flushing.  Their  placing  differs  according  to  the 
size  and  character  of  the  ships.  Latrines  for  the  crew  are  placed  for- 
ward and  completely  disconnected  from  the  forecastle.  They  are 
supplied  at  the  rate  of  not  less  than  three  for  every  hundred  men. 
Urinals  are  commonly  a  source  of  great  nuisance,  and  hence  require 
extra  care. 

On  passenger  ships,  three  closets  should  be  provided  for  every  hun- 
dred persons  carried,  and  they  should  be  so  located  with  reference  to 
sleeping  quarters  that  they  may  not  give  rise  to  nuisance. 

Whenever  weather  and  other  circumstances  permit,  all  bedding 
should  be  thoroughly  aired,  each  article  being  brought  up  from  below 
and  exposed  separately,  fastened  to  the  rigging  or  upon  the  girt  lines. 
Hammocks  should  be  thoroughly  cleaned  and  dried  about  once  in  every 
fortnight.  Blankets  should  be  washed  with  soap  at  least  every  six 
months;  hammocks  and  all  articles  of  bedding  should  be,  when  prac- 
ticable, exposed  for  part  of  each  day  to  the  direct  action  of  the  sunlight. 

For  methods  of  disinfection  and  general  cleansing,  the  reader  is 
referred  to  the  chapter  on  Quarantine. 

Personal  cleanliness  of  the  men  is  of  even  greater  importance  than 
cleanliness  of  their  surroundings,  and,  indeed,  the  two  go  hand  in  hand, 
for  men  of  cleanly  habits  will  not  permit  their  surroundings  to  be  other- 
wise than  wholesome,  and  those  who  are  not  naturally  so  inclined 
should  be  required  to  keep  themselves  clean.  Each  man  should  be 
allowed  a  sufficient  supply  of  fresh  water  daily,  and  the  necessary 
appliances  for  washing  should  be  provided.  In  navies,  the  \yashing 
of  the  person  is  commonly  made  a  part  of  the  routine.  Special  provi- 
sion for  the  care  of  the  person  is  required  for  those  who  have  the  dirt- 
iest work  to  perform,  namely,  the  firemen  and  stokers,  since  their 
occupation  precludes  the  use  of  much  wearing  apparel,  and  the  air  of 
the  place  where  the  work  is  laden  with  coal  dust  and  so  hot  that  their 
bodies  are  constantly  bathed  in  perspiration.  Short  bath-tubs  of  gal- 
vanized iron,  a  sufficient  number  of  wash-basins,  and  a  reasonable  allow- 
ance of  water  and  soap,  should  be  provided.  Given  the  conveniences 
and  encouragement  to  make  use  of  them,  the  chances  are  that  they  will 
be  appreciated  and  freely  used. 

As  in  the  case  with  soldiers,  it  is  of  very  great  importance  that  sailors 
should  be  kept  busy  and,  at  the  same  time,  should  have  sufficient  time 
for  relaxation,  which  they  should  be  encouraged  to  spend  in  such  pur- 
suits as  will  conduce  best  to  the  promotion  of  cheerfulness  and  the  pre- 
vention of  ennui. 


nil  A  PTK/Il    XT. 

1^|{()I'I('AL    lIVCIIvXK. 

THE   SOLDIER  AND  THE  CIVILIAN  IN  THE  TROPICS. 

'^riMO  Inllowiiiu;  |);ii;'<'S,  (Icnliiii:;  with  liy^ricnc  in  tlic  trdjtif.-,  Iiavo 
grcMlcr  o'onci'iil  ;i|>|)lic:il)ili(y  lo  the  life  nf  i'i\  ili.iiis,  who  have  ;i  wide.' 
choice  ill  their  mode  of  life  and  di.-t  ril»iil  ion  of  their  time,  hut  the;  Jiiaiii 
principles  are  c(]ually  ap|)Iical)l('  to  the  life  of  the  .<oh!ier,  even  although 
his  liberty  of  action  in  the  follow  in^-  of  his  own  inclinations  is  very 
greatly  restricted. 

It  is  a  very  coninion  mistake;  ainon<;  {)ersoiis  reared  in  temperate  cli- 
mates to  suppose  that  the  chati<^e  to  a  tropical  climate  means  chiefly  a 
sudden  access  of  heat,  and  that  it  is  sim])ly  this  increa.sed  heat  which  one 
has  to  consider  ;  hut  it  is  not,  as  a  rule,  the  actual  temperature  which 
affects  the  Individual,  for  in  the  North  we  may  have  for  days  at  a  time 
a,  hio;her  temperature  than  obtains  customarily  in  some  parts  of  the 
tropics,  wdthout  sufferin<^  in  the  same  Avay.  The  principal  clilference  lies 
in  the  excessive  tropical  humidity,  but  tropical  climates  are  not  equally 
humid,  some  being  exceedingly  moist,  and  some  excejitionally  dry. 

In  some  [)arts  of  Australia,  for  example,  tlie  climate  is  exceedingly 
dry  and  the  teiiTperature  is  very  high,  and  yet  there  is  much  less 
liability  to  sunstroke  and  heat  apoplexy  than  in  some  parts  of  India, 
where  the  temperature  is  less  high,  but  the  atrao.sphere  exceedingly 
humid.  Since  all  hot  climates  are  not  alike,  the  mode  of  life  also 
varies ;  and  in  any  case  it  is  necessary  to  take  into  consideration  the 
special  local  characteristics  of  climate  and  the  methods  of  life  followed 
by  the  natives,  and  if  one  takes  care  to  adapt  his  clothing,  his  diet, 
and  personal  habits  to  the  conditions  which  surround  him,  life  in  the 
tropics  may  be  bearable,  even  if  not  thoroughly  enjoyable.  On  this 
point.  Dr.  S.  O.  L.  Potter,  U.  S.  Y.,'  writing  on  the  spot,  says  :  "If 
people  can  take  reasonable  care  of  themselves,  and  do  not  give  way  to 
excesses  in  any  form,  drink,  eating,  or  working,  they  will  live  as 
healthily  in  Manila  as  in  New  Orleans  or  St.  Louis  or  New  York." 
But  they  cannot  withstand  the  oifeets  of  any  tropical  climate  for  long 
w'ithout  an  occasional  visit  to  the  temperate  zone,  for  prolongeii  resi- 
dence brings  about  an  undoubted  deterioration  of  the  system  in  spite 
of  all  possible  care. 

According  to  Freeman,-  Europeans,  after  some  years'  continuous 
residence  in  a  hot  country,  degenerate,  losing  energy,  initiative,  and 
memory,  which,  from  a  military  point  of  view,  is  not  compeusatetl  for 

1  Notes  on  the  Philippines,  Philadelphia  Medical  Journal,  April  7,  1900  p.  803- 
^  The  Sanitation  of  British  Troops  in  India,  Loudon,  1899. 

681 


682  TROPICAL  HYGIENE. 

by  diminished  liability  to  disease.  Hence  the  necessity  of  furloughs 
at  stated  intervals.  Potter  says,  "  jNIany  of  our  older  officers  liave 
undergone  a  process  of  rapid  aging  here  without  any  definite  aihneut 
to  account  for  their  condition.  Tliey  simply  grow  thinner  aud  thinner 
day  by  day,  running  down  gradually  in  physical  strength  as  emaciation 
goes  on,  until  finally  the  General  takes  pity  and  sends  them  home." 

According  to  a  numl)er  of  observers,  the  body  temperature  of  new 
arrivals  in  hot  climates  is  appreciably  elevated  (0.4— (X9  degree  F.) 
above  the  normal,  and  under  some  conditions  of  high  temperature, 
since  the  body  cannot  radiate  heat  to  hotter  surrounding  air,  the  body 
temperature  may  run  as  high  as  102°  in  health.  The  body  is  then 
dependent  chiefly  upon  evaporation  from  the  surface  for  the  keeping 
down  of  the  temperature  as  nearly  as  possible  to  normal.  But  when 
high  temperature  is  conjoined  with  high  humidity,  the  difficulty  and 
discomfort  are  much  increased.  Continued  moist  heat,  through  its  in- 
fluence ou  metabolism  and  the  various  functions  of  the  body,  causes 
great  nervous  exhaustion  and  general  deterioration.  The  respiration  is 
depressed,  the  force  and  rate  of  the  pulse  lowered,  the  mind  becomes 
dulled  ;  the  sweat  is  doubled  in  amount,  and  thirst  increased  in  pro- 
portion ;  the  digestive  function  is  weakened,  and  appetite  for  even  the 
lessened  necessity  for  food  is  diminished  and  requires  constant  stimula- 
tion.    The  body  loses  in  weight,  and  both  body  and  mind  in  energy. 

Dr.  Federico  Montaldo,  of  the  Spanish  Navy,  in  a  practical  hand- 
book ^  written  for  the  use  of  Europeans  intending  to  visit  the  Spanish 
colonies,  published  just  prior  to  the  outbreak  of  our  war  with  Spain, 
urges  upon  those  who  are  not  sure  of  the  soundness  of  their  health 
the  necessity  of  submitting  themselves  for  thorough  physical  examina- 
tion, since  a  trivial  ailment,  easily  corrected  at  home,  may  develop  in 
the  tropics  into  a  trouble  not  easily  managed.  Potter,-  also,  on  this 
latter  point,  remarks  :  "  It  is  all  very  nice  as  long  as  one  is  well,  but 
those  who  get  sick  don't  easily  recover  here.  Convalescence  is  very 
slow  and  very  difficult."  And  again,  ''  the  general  climate  of  these 
islands  is  not  pernicious  for  those  who  are  able  to  avoid  exposure,  but 
when  broken  down  by  hardship  or  incidental  disease,  complete  recovery 
is  doubtful  and  convalescence  is  very  slowly  established."  Burot  and 
Legfand,^  also,  lay  stress  on  the  necessity  of  selection  of  healthy  indi- 
viduals for  service  in  the  tropics,  saying  that  if  the  soldier  is  too 
young  or  if  his  constitution  is  not  strong,  he  will  be  an  easy  prey  to 
disease,  while  if,  021  the  contrary,  he  has  been  carefully  selected  in  the 
light  of  the  peculiar  conditions  and  the  demands  upon  his  strength, 
he  will  be  better  able  to  resist  morbid  influences. 

Dr.  Lucca,*  speaking  from  an  experience  of  a  number  of  years  as  a 
military  surgeon  in  Borneo,  urges  the  exercise  of  great  care  to  insure 
the  health  of  troops   on  transports,   so   that  they  may  not  be  landed 

'  Guia  Practica  Higi^nica  y  Medica  del  Europeo  en  los  Pafses  Torridos  (Filipinas, 
Cuba,  Puerto  Rico,  Fernando  Poo,  etc.),  Madrid,  1898,  p.  19. 
'  Loco  citato. 

'  Hygiene  du  Soldat  sous  les  Tropiques,  Paris,  1898. 
*  Einige  Bemerkungen  iiber  Acclimatisation  und  Leben  in  den  Tropen,  Munich,  1898. 


Tir/'J  HOI. 1)1  Hit    AND    Till':  (HVII.IAN   IN   Till':   TILOI'ICS.        083 

already  sick  ;mi<I  wc;i1<  :in<l  iv-idy  (or  :--lii|iiii<iil  Im.mm'.  RaHcli  '  adviwjH 
all  wlio  ari!  jifoiic;  lo  lu'ivoiis  <li-oi(|(r,  ilii).-,c  already  Hiiflrrin^,  and, 
above  all,  (!|)il(^|)li(!.s,  to  kec^p  awiiy  \'\i>\\\  (lie  tropics;  and  Marjeod  ^  (jilerH 
th(!  same  advi(',(!  to  niiyoiic  whose  lienil  ;iiid  l>Iood-veHHel8  an;  not  wliolly 
normal. 

It  i.s  also  well  to  cIkio^c,  if  po,--il)le,  the  bcHt  tim(!  of  year  for  land- 
ing. Tlier(!  ar(;,  it  is  true,  only  two  sejisons  in  the  tropieH,  th(!  <lry  and 
the  rainy  ;  hnt  there  are,  nev(!rthel(!ss,  transition  jMsriods  of  greater  or 
Iess(^r  (hirniioii. 

Residence. — If  one  has  a  (choice  in  the  matter  of  i-esidence,  it  is 
well  to  be  cautious  in  its  exercise,  and  to  l»ee;iii  on  hij^rh  land  and  away 
from  the  coast.  'V\\v,  lOnglish  have  long  recognized  tlu;  nec<:ssity  of 
sending  their  soldiers  inland  and  to  th(!  hills,  when  nnlitury  reqnire- 
nients  are  not  oj)posed.  After  getting  somewhat  accustomed  to  new 
conditions,  the  lower  parts  and  the  coast  may  gradually  be  ventured 
upon. 

In  some  ])arts  of  the  tro])ics,  it  is  customary  to  leave  sleeping  aj)art- 
mcnts  open  during  the  day  and  closed  at  night;  but  in  otJKirs,  the  con- 
trary is  the  ndc,  the  doors  and  windows  being  closed  by  day.  The 
best  form  of  bed  is  that  made  of  uot  too  heavy  iron,  with  a  frame  or 
other  device  to  support  a  mosquito  bar.  The  bed  should  be  placed 
away  from  the  walls  and  out  of  draughts.  The  legs  should  stiuid  in 
small  vessels  filled  with  water,  in  order  to  keep  away  small  crawling 
insects.  If  in  the  country  and  neither  bed  nor  hammock  is  to  be  had, 
and  one  is  obliged  to  sleep  on  the  floor  or  ground,  a  rubber  or  other 
waterproof  sheet  or  a  dressed  hide  should  be  spread,  and  the  body 
should  be  well  protected  against  condensing  moisture  and  troublesome 
insects. 

Habits  of  Life. — All  authorities  agree  in  at  least  one  particular,  and 
that  is,  in  urging  moderation  in  all  things — diet,  drink,  work,  exercise, 
dress.  The  diet  should  be  chosen  with  care,  and  ical  drinks  taken  in 
great  moderation,  if  at  all.  The  clothing  should  be  chosen  with  judg- 
ment, both  as  to  protection  from  the  heat  of  the  sun  and  against  chill- 
ing of  the  body. 

Work  should  not  be  excessive,  nor  should  it  be  jierformed  in  the  sun 
during  the  hottest  part  of  the  day.  iSIontaldo  ^  advises  one  to  rise 
with  the  sun  and  take  a  quick  cool  bath,  and  then,  after  a  light 
breakfast  of  coffee,  tea,  or  chocolate,  with  a  little  bread,  to  attend  to 
whatever  duties  one  has  to  perform,  until  about  10.30  A.  m.,  when 
luncheon  may  be  had.  This  should  not  be  heavy  as  to  food  or  drink. 
The  latter  may  consist  of  a  little  water  Mith  claret  or  lemon  juice,  or 
tea  or  coffee.  If  one's  Avork  is  out  of  doors,  it  should  not  be  resumed 
before  3  in  the  afternoon,  and  in  the  meantime  one  should  rest  indoors. 
After  6.30,  a  substantial,  but  not  too  hearty,  dinner  should  be  taken, 
observing  the  same  moderation  in  the  matter  of  drinking.  One  should 
never  go  out  with  an  empty  stomach  nor  do  work  immediately  after  a 

*  Allgemeine  Zeitschrift  fiir  Psychiatrie,  1897,  p.  745. 

*  Journal  of  Tropical  Medicine,  "S'ol.  I.,  Xo.  1.  *  Loco  citato. 


684  TROPICAL  HYGIENE. 

meal.  After  dinner,  a  walk  or  some  form  of  recreation  until  10.30  or 
thereabouts,  winch  is  tlie  proper  time  for   retiring. 

One  is  advised  strongly  not  to  expose  one's  self  to  the  cool  external 
night  air  ;  to  avoid  cold  bathing  and  cold  drinks  while  perspiring ;  and 
espeeially  to  avoid  standing  for  a  long  time  in  the  shade  in  garments 
wet  with  perspiration.  If  one  is  compelled  to  be  exposed  to  the  sun  for 
long,  the  ])rotection  aiibrdt'd  by  umbrellas  and  colored  spectacles  against 
heat  and  glare  should  be  sought.  The  consequences  of  exposure  may 
be  exceedingly  severe  or  even  fatal.  There  are  various  forms  of 
what  are  commonly  known  as  sunstroke  and  heat  apoplexy.  A  very 
common  form  is  one  of  syncope,  brought  on  by  overexertion  in  the 
direct  sunlight  or  even  within  doors  by  one  already  in  a  depressed  con- 
dition. The  skin  is  moist  and  clammy,  the  pulse  very  feeble  and 
almost  imperceptible,  the  muscular  power  almost  completely  lost.  Death 
may  occur  by  cardiac  failure,  but  recovery  under  appropriate  treatment 
is  the  general  rule.  Another  form,  due  to  direct  action  of  the  sun's 
rays  on  the  brain  and  cord,  is  in  the  nature  of  a  very  sudden  severe 
shock  afTeetingthe  respiratory  and  cardiac  centers,  and  commonly  quickly 
fatal.  Complete  recovery  is  rare.  A  third  form,  commonly  known  as 
heat  apoplexy,  is  due  to  exposure  to  constantly  high  temperature  not 
necessarily  involving  direct  exposure  to  the  sun,  and,  in  fact,  may 
occur  in  cloudy  weather  and  at  night.  The  whole  body  becomes  over- 
heated and  the  temperature  may  exceed  110°  F,  The  skin  is  generally 
dry,  although  sometimes  moist ;  the  pulse  full  and  regular  or  small 
and  irregular ;  respiration  labored.  There  is  intense  restlessness, 
and  epileptiform  convulsions  may  supervene.  These  cases  are  fre- 
quently fatal,  and  if  recovery  occurs,  it  is  not  complete.  In  India, 
according  to  Freeman,^  heat  apoplexy  and  sunstroke  occur  usually 
toward  the  end  of  hot  weather,  although  the  midday  sun  is  strong 
enough  in  most  places  to  cause  severe  headache,  if  not  sunstroke,  the 
year  round. 

For  the  avoidance  of  sunstroke,  in  addition  to  having  proper  head 
covering  and  umbrella,  the  neck  and  spine  should  be  properly  protected 
from  the  sun's  rays.  The  double  pleat  in  the  back  of  the  Norfolk 
jacket  is  intended  as  a  protection  to  the  spine.  A  few  green  leaves  in 
the  hat  are  sometimes  conducive  to  comfort. 

The  commonly  given  advice  to  follow  the  customs  and  habits  of  the 
natives  in  respect  to  diet  and  physical  exercise  can  be  accepted  only  in 
part,  for  the  native  of  the  tropics  is,  as  a  rule,  a  lazy  individual  who 
merely  exists  ;  the  wear  and  tear  of  his  system  require  but  little  in  the 
way  of  repair,  and  his  food  is  of  the  simplest  kind  ;  he  has  no  ambi- 
tion and  no  desire  to  hoard  up  a  fortune  w'hich  he  cannot  use ;  but 
between  his  indolence  and  our  high-pressure  life,  there  is  a  happy  mean, 
especially  in  the  tropics. 

Diet. — The  question  of  diet  in  the  tropics  is  a  very  serious  one,  for 
errors  may  l)e  followed  by  disastrous  results.  Since  prolonged  heat 
exerts  an  unfavorable  influence  on  digestion,  this  function  should  not 
^  Journal  of  Tropical  Medicine,  Vol.  I.,  No.  1. 


THE  SOLDI  Kit   AND   Tllh:  dlVIIJAN   IS   Till':   Tno/'K'S.       085 

l)(!  iruidc  lo  Ix'iir  l<»'»  lic;i\'v  :i  luiiilcii,  ;iiiil  i(  l)(;(!ottH'H  iK'CCHHJiry  to  H;- 
.stri<;t  ilic  diet  in  s('vci;il  |»;ii(  iciil.ii-.  No  more  food  hIioiiM  he  bikcfii 
than  o;u)  cDinCdrlahly  Ix;  (li^c^st^-d,  (or  lioili  dyHontcjry  and  dlarrlirx'ii  arc 
fiivorcd  by  llic  Ii-fif;ilIoii  ciiiiscd  in  the.  int<'HtiMCH  by  food  jKitiially 
di<f(!s(('<l  or  nnd('ri;oin<^  rcrnicntiif i\(!  prociisscs.  But  the;  (:h;in;^«-  (Voin 
the  aciciislonicd  diil  slioiild  iiol  be  ni;id(!  with  too  gnjat  abnijjtiic.sH. 

Tlio  iintivcs  d(|)(  11(1  fliiclly  n|)on  a  V(';i;cl:il)lc  diet,  in  whifb  r\c('  and 
bciiUiH  and  (Vuils  of  ,ill  kinds  play  [H-oinincnt  |)arts.  Meat,  i("  >:i\c\\  at 
all,  i.s  tal<(Mi  nsnali}'  in  xci'v  .small  (|iianlilics,  Asa  rnlc,  in  hot  rliinaU-H, 
it  is  not  t('n<l('r,  ("or  it  cannol  be  Immil';  days  and  \v(;cks,  a.s  with  u,h,  to 
ripen,  bnt  nnist  be  cooked  and  ealen  uitliin  a  very  few  hours  after 
slan<;lilcrin<;-.  i*'isli  slionki  not  be  iisi-A  nnless  very  fresh,  and  sliell-fi.sh 
of  all  kinds  slioidd  be  avoided.  Fresh  milk  is  ordinarily  not  to  ^>e 
had  or,  at  least,  is  didicnit  to  obtain.  It  speedily  sours  and  beeornes 
unlit  to  drink.  Condensed  milk  of  irood  quality  is  more  to  be  de- 
pended upon.  Vef^ctables  slionld  be  thoroughly  ettoked,  or  they  will 
.seriously  tax  the  digestive  organs.  Fruits  shoidd  be  perfeetly  ripe  and 
sound;  over-rij)eness  is  (juite  as  objee(ionabl(!  as  greenness.  (Jver- 
indulgeuec^  in  fruit,  (!veu  of  the  best  quality,  and  especially  in  the  sour 
fruits,  is  particularly  to  be  avoided. 

Tea,  coffee,  and  chocolate  are  advised  in  moderation.  Lime  juice 
with  water  or  cold  tea  makes  a  most  refreshing  driidv.  Tamarinds  in 
water  are  also  most  grateful. 

If  alcohol  in  any  form  is  desired,  the  light  wines  diluted  with  ■water 
are  recommended  niore  highly  than  beer.  Spirits  are  generally  con- 
demned, but  there  appears  to  be  no  valid  reason  why,  when  very  largely 
diluted  with  water  or  soda  water,  they  should  exert  a  more  pernicious 
intiueuce  than  wine  only  moderately  extended.  In  any  event,  alcohol 
should  be  taken  only  with  food. 

The  Use  of  Alcohol  in  the  Tropics. — Writers  on  tropical  hygiene 
are  almost  unanimous  in  the  opinion  that,  Avhatever  may  l)e  said  for 
and  against  the  use  of  alcoholic  drinks  in  other  climates,  their  use  in 
the  tropics  constitutes  a  distinct  danger,  and  that  much  of  disease 
commonly  attributed  to  climate  is  due  actually  to  alcohol.  Especially 
is  this  true  of  the  various  renal  and  hepatic  troubles.  According  to 
Treille,'  the  abuse  of  alcohol  is  the  chief  cause  of  the  frequency  of  dis- 
eases of  the  liver,  not  alone  among  visiting  Europeans,  but  among 
natives  as  Avell. 

Dr.  Chr.  Rasch,-  speaking  of  the  futility  of  talk  about  Euro]>eans 
getting  accustomed  to  continued  high  temperature  with  liigh  humidity, 
and  describing  the  various  steps  in  physical  and  meutal  deterioration, 
to  counteract  which,  one  turns  to  alcohol  and  other  stimulants,  says 
that  these,  together  with  insomnia  and  enforced  lack  of  exercise,  bring 
about  a  general  atonic  condition,  or,  in  other  moixIs,  a  lowered  physio- 
logical resistance  to  diseases  in  general.      Dr.  Breitenstern,^  who  for 

^  Principes  d'Hygione  coloniale.  Paris,  1899.  p.  272. 

*  Allgemeine  Zeitsehrift  fiir  Psvohiatrie,  1897,  p.  7-15. 

•*  Hygiene  in  deij  Tropen,  MiULTtiNSchrift  fiir  Gesnndheitspflege,  189S,  2^^os.  7  and  8. 


686  ,  TROPICAL  HYGIENE. 

twenty  years  serveil  as  an  army  surgeon  in  the  Malay  Archipelago, 
gives  it  as  his  o])inion,  based  on  long  observation,  that  total  absti- 
nence from  alcohol  is  far  preferable  to  even  the  most  moderate  indul- 
gence. 

A  writer  in  Manila  has  pointedly  remarked  couceruing  the  health 
of  the  American  troops,  "It  is  not  so  much  the  climate  as  the  glass 
bottle  Avhioh  injures  people  out  here/'  which  statement  is  corroborated 
by  another  who  had  seen  actual  service  as  a  member  of  a  company, 
many  of  whose  members  were  total  abstainers  and  the  rest  made  up 
of  moderate  drinkers  and  those  prone  to  excesses,  the  latter  constitut- 
ing 20  to  25  per  cent,  of  the  whole.  Of  the  latter  class,  only  two 
returned  home  in  approximately  the  same  condition  of  health  which 
they  enjoyed  at  the  time  of  enlistment.  Of  the  moderate  drinkers 
who  coulined  themselves  to  malt  liquors,  a  large  majority  suffered 
more  or  less  impairment  of  general  health.  But  the  total  abstainers 
returned  almost  to  a  man  in  excellent  health,  having  endured  the 
same  hardships  of  an  active  campaign.  The  same  correspondent, 
speaking  of  the  far  greater  harm  induced  by  the  stronger  alcoholic 
drinks,  relates  that  he  had  repeatedly  seen  American  soldiers,  after 
spending  several  hours  under  shelter,  drinking  round  after  round 
without  perceptible  harm,  fall  over  with  all  the  symptoms  of  sun- 
stroke as  soon  as  they  stepped  into  the  glaring  rays  of  the  hot  sun. 

On  the  other  hand,  in  opposition  to  the  general  opinion  adverse  to 
even  the  moderate  use  of  alcohol  in  the  tropics.  Dr.  C.  E.  Woodruff,^ 
U.  S.  A.,  after  a  careful  survey  of  the  conditions  obtaining  in  the  Phil- 
ippines, declares  that  he  would  change  the  statement  in  the  general 
order  from  headquarters  of  the  army,  July  2,  1898,  "The  history  of 
other  armies  has  demonstrated  that  in  a  hot  climate  abstinence  from 
the  use  of  intoxicating  drink  is  essential  to  continued  health  and  effi- 
ciency," to  "  Experience  has  demonstrated  that  in  a  hot  climate  the 
moderate  use  of  intoxicating;  drink  is  essential  to  continued  health  and 
efficiency."  He  asserts  that  the  almost  universal  drinking  must  mean 
a  natural  defensive  craving  occasioned  by  the  terrible  nervous  exhaus- 
tion, a  true  neurasthenia,  due  to  long-continued  exposure  to  great  heat 
and  atmospheric  humidity,  indicating  that  waste  is  greater  than  repair. 
He  asserts  that  men  who  want  no  alcohol  at  home  have  this  defen- 
sive craving  for  it  in  the  Philippines,  and  cites  Spanish  authority  that 
a  daily  ration  of  wane  has  been  found  necessary.  Whiskey,  when 
sufficiently  diluted,  is  the  equivalent  of  wine,  and  the  Scotch  variety 
is  regarded  by  him  as  superior  for  the  purpose  to  American,  which 
soon  occasions  nausea.  Beer,  by  reason  of  being  conducive  to  colic, 
diarrhoea,  headache,  loss  of  appetite,  and  general  distress,  he  regards 
as  distinctly  harmful.  While  advocating  the  moderate  use  of  alcohol, 
he  believes  that  the  results  of  abuse  are  far  more  serious  than  at 
home. 

Concerning  beer  in  the  tropics,  there  is  much  divergence  of  opinion, 
some  regarding  it  as  a  valuable  safeguard  against  abuse  of  stronger 
'  Philadelphia  Medical  Journal,  April  7,  1900,  p.  768, 


77//';  SOLDI  Kit   AND    Till':  < 'I  VI  LI  AS    IN   Till-:   Titni'ics.        'IH? 

alcolioIic.H,  ()ili(!r,s  a^nioiti^  with  VVorKlrii(f  (li:it,  it  is  hiiniil'iil.  It  Ih  Haid 
that  the  driiikln^  ofinucli  hccr  followed  hy  Inuivy  Hlc('|»iii^^  |)rc(lisj»oHr!H 
to  Hunntrokc:  and  licat  a|)o|»l('xy. 

Clothing. — OiK!  is  advised  to  tal<<!  |»leii(y  of  li^lit  ('otfon,  linen,  and 
merino  iniderwear,  a  generous  assortment  of  trousers  and  coats  of 
white.  dn(^i<  or  (lannel,  :ind  liHhl,  merino  stockings.  Ili^'h  hoots,  w<'ll 
oihid  and  with  hoh-nails,  laeed  h«»ots,  lej^j^ings  of  (rioth  and  leathtfP, 
and  iio-ht,  footwear  for  in(h»orand  city  use  should  Ix;  iru^hided.  [J^ht 
wa,ter|)roor  outer  <i;a,iMnents  with  (!!i|)(!  and  hood  are  recommended,  and 
for  |)rotcction  aa;ainst  the;  sun,  while  umhrell.is  lined  with  hluc  f>r  green 
material,  and  s|)e(^lacles  with  <i;reeii  or  l>lne  (•(ijored  glasses. 

The  head-covering  shouhl  he  selected  with  (he  douhle  consideration 
of  (^)mfort  and  protection  for  tlu!  head  and  neck.  The  material  of 
which  it  is  made  shouhl  he  chosen  with  regard  to  hieal  climatic  con- 
ditions. In  a  partictdarly  (hy  hot  climate,  ior  instance,  j)ith  is  the 
most  suitahlo  material,  being  lighter  than  cither  cork  or  felt;  but  a 
hat  made  of  this  material  is  absolutely  worthless  in  a  wet  climat<',  since 
on  being  exposed  to  rain  it  absorbs  water,  becomes  e.\eee(h"ngly  h(javy 
therefrom,  and  is  rechiced  to  a  worthless,  shapeless  pulp.  Hats  should 
bo  properly  ventilated  in  the  crown,  and  there  should  be  a  generou.s 
space  for  the  free  passage  of  air  between  the  head-band  and  the 
inner  side  of  the  hat;  that  is  to  say,  the  head-band  should  be  fastened 
to  the  crown  of  the  hat  at  only  a  limited  nmnber  of  points  and  with 
intervening  small  pieces  of  wood  or  other  material,  so  that  the  band 
shall  keep  its  proper  shape.  All  head-covering  of  whatever  form 
should  alibrd  pro[)cr  protection  for  the  sides  of  the  head  and  the  ears, 
as  well  as  for  the  front  and  back.  A  pnggery  affords  additional  pro- 
tection. 

The  brim  of  the  head-covering  .should  be  lined  with  some  material 
of  a  bluish  or  green  color,  as  a  relief  to  the  eyes.  The  outside  should 
be  light  in  color.  The  head-band  is  made  of  leather,  and  is  easily 
saturated  with  perspiration,  and  then  hardens  on  drying;  while  it  is 
yvQi,  it  is  exceedingly  uncomfortable.  If  covered  with  fine  flannel,  it 
will  be  found  to  be  much  more  comfortable. 

Jackets  and  other  outer  garments  should  afford  perfect  freedom  of 
action  in  both  ridiug  and  walking.  The  Norfolk  jacket  is  a  favorite 
form,  and  may  be  made  of  duck,  khaki,  or  similar  niaterial.  It  is 
well  to  leave  a  few  inches  of  the  arm-scyes  unstitched  for  the  sake  of 
ventilation.  For  shirts,  a  mixture  of  silk  and  wool,  known  as  ka.shmir, 
is  regarded  as  the  best  material,  being  very  light  in  texture  and  j>er- 
fectly  absorbent.  Gauze  undershirts  with  short  sleeves,  or  with  no 
sleeves  at  all,  shoidd  be  worn  beneath  the  .shirt.  Elastic  cotton  and 
jean  are  the  best  materials,  so  far  as  comfort  and  durability  are  con- 
cerned, for  drawers. 

If  one  is  to  do  much  ridiug,  it  is  advised  that  as  much  care  be  ex- 
pended in  the  selection  of  a  saddle  as  in  selecting  boots,  since  comfort 
in  horseback  riding  in  the  tropics  is  very  largely  dependent  upon  the 
fit  of  the  saddle. 


688  TROPICAL  HYGIENE. 

Care  of  the  Person. — The  irritating  effect  of  hot  winds,  which  fre- 
quently carry  tine  particles  of  sand  and  dust,  and  the  iilare  of  the  snu, 
Avhicli  ettuduces  to  troubles  with  the  eyes,  should  be  guarded  against. 
Not  infrequently  the  ears,  too,  are  affected  injuriously  by  hot  Avinds, 
but  they  are  easily  protected  by  external  coverings  or  by  cotton-wool 
plugs.  The  nose  and  lips  are  subject  to  cracking  and  uncomfortable 
dryness,  which  may  be  helped  by  cold  cream  or  some  similar  a])])lica- 
tion.  The  nails  should  be  kept  closely  pared,  since  they  become  bi'ittle 
and  crack  off. 

The  skin,  having  a  very  important  function  to  fulfil,  should  be  kept 
thoroughly  clean,  if  on  no  other  account ;  but  bathing  in  too  cold  water 
or  for  too  long  a  time  should  be  avoided.  Parasites  abound  in  tro})ical 
climates,  and  should  be  looked  for  on  the  jjersou  and  removed  with  all 
care.  Among  these  may  be  mentioned  the  chigoe,  or  jigger,  an  exceed- 
ingly troublesome  small  flea  (^Sarcopsylla  poietrans)  which  burrows 
beneath  the  skin,  particularly  of  the  feet,  and  beneath  the  nails.  At 
first,  it  causes  only  itching,  but  if  not  then  removed,  sharp  pain  and 
inflammation  ensue.  A  half  teaspoouful  of  flowers  of  sulphur  inside 
the  shoe  is  said  to  be  an  efficient  preventive.  Another  parasite  of  far 
greater  im])ortance,  especially  to  the  troops  in  the  Philippines,  is  that 
Avhicli  occasions  the  dhobie  itch,  which  can  be  avoided  only  by  very 
great  attention  to  personal  cleanliness  and  frequent  changing  of  under- 
clothes. It  first  attacks  the  perineum  and  axillae,  and  when  the  acute 
stage  passes  by  and  the  inflammation  somewhat  subsides,  the  scales 
become  rubbed  off  and  reach  the  feet,  where  the  trouble  spreads  rap- 
idly, causing  intense  itching  with  consequent  scratching  and  the  evil 
consequences  thereof. 

Diarrhoea  and  constipation  are  alike  to  be  avoided.  The  former  should 
be  checked  at  once,  and  should  on  no  account  be  allowed  to  continue 
without  treatment.  It  is  easily  brought  on  by  imjiroper  or  ill-cooked 
foods,  impure  water,  green  and  over-ripe  fruit,  sudden  changes  in  the 
weather,  and  intemperance.  Constipation  should  be  avoided  by  the 
acquirement  of  a  regular  habit.  Sometimes,  a  cup  of  tea  or  coffee  on 
rising  will  act  beneficially,  and  oatmeal  and  coarse  bread,  figs  and 
prunes  may  be  found  to  assist,  but  purgatives  and  enemata  should  be 
avoided,  if  possible  to  get  along  ^^dthout  them. 

Tropical  Diseases. — It  is  beyond  the  scope  of  this  work  to  enter 
upon  the  field  of  tropical  medicine,  but  it  may  be  said,  in  general,  that 
the  diseases  of  hot  climates  are  exceedingly  varied.  Some  of  them  are 
peculiar  to  certain  districts  ;  some  are  exaggerated  forms  of  what  we  in 
the  temperate  zone  regard  as  simple  maladies.  In  general,  it  may  be 
said  that  in  the  tropics  one  meets  nearly  all  the  diseases  of  the  tem- 
perate zone  plus  a  great  variety  of  others,  but  some  of  our  most  com- 
mon diseases  may  be  very  rare  in  certain  places.  Thus,  scarlet  fever 
and  diphtheria  are  rare  in  the  tropics  as  a  whole,  tuberculosis  is  rare 
in  parts  of  India  and  common  and  quickly  fatal  in  other  parts  of 
the  tropics.  Pabies  is  more  common  in  India  than  in  England,  and 
the  victims   are  almost  always  Europeans.      Eeprosy,  beri-beri,  and 


77//';  ,s()ij)f/':n  ani>  Tifh'  (HViuan  /.v  tiii-:  thoi'ich.      HMI) 

el(!|)li:inti;iHiM    un;    (U)iiiiii()ii    -aiwdu^    IIk;    ii;ili\cs,    hut    xcry  nin-   ainoii^ 
JOiir()|)(^juis. 

'J'lir<)ii;:,li()iil,  llic  l-r()|)i('s,  dyscnlcry  kills  iii:iiiy  iddic  |»c()|»jr;  ;Miiiii;illy 
than  cli()l(M';i,  ;iii(l  works  jr|-c;ilcr  liuvot;  in  armies  lliaii  flic  coiit^rifiiii^ 
forocH.  Typlioid  i(!V(!r  always  apjicars  sooner  or  later  in  camps  of 
soldiers  from  temperate  climates,  aii<l  tlic  new  airi\al.s  arc  cfimiiionlv 
ohs(>rved  to  be  tlu;  most  SMS(H'p(il)le.  This  disease  and  eliolera,  ac<'ord- 
inj^  to  Freeman,  ranjly  oeenr  in  India  diirinj^  tlu-  liotlcst  mf)ntlis,  when 
tlu!  hurninc-  rays  of  tlu;  snn  art  as  a  ^ermi(;ide  ;  \)\\\  when  tli(;  niin.s 
conu!  and  swec;])  the  accumulated  surfaiu-  dirt  into  the  water  courses, 
they  (jui(!kly  appear. 

For  a  most  intcrestinf;;  deserij)tion  of  the  diseasc^s  ol)serv'(!<l  in   tlie 
tro[)ics,  the  reader  is  referred  to  Castellani  and  Clialmcrs'  Manual  of 
Tropical  Medicine,  1910. 
44 


CHAPTER    XII. 
THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 

Although  a  supposed  relationship  between  insects  and  the  spread 
of  diseases  has  been  considered  in  greater  or  lesser  detail  by  writers  of 
all  times,  it  is  only  within  the  most  recent  years  that  the  possible  con- 
nection has  been  regarded  as  entitled  to  most  serious  consideration.  It 
is  not  strange  that  the  bare  statements  of  ancient  writers  concerning 
the  influence  of  flies  and  other  insects  as  disseminators  of  plague  and 
other  diseases  were  not  received  with  any  degree  of  credence,  for  until 
recent  advances  in  the  fields  of  bacteriology  and  zoology  made  demon- 
stration of  the  connection  possible,  there  was  no  more  reason  for  accept- 
ing them  than  for  accepting  similar  unsupported  assertions  concerning 
the  action  of  clouds  and  things  supernatural.  But  as  our  knowledge 
of  the  exciting  causes  of  diseases  grew  with  bacteriological  and  zoologi- 
cal research,  so,  also,  came  an  appreciation  of  the  fact  that  these  same 
causes  might  be  disseminated  by  insects  and  other  lower  forms  of  ani- 
mal life. 

Disregarding  the  not  infrequent  reports  of  sickness  and  death 
attributed  to  insect-bites,  Avhich,  so  far  as  one  may  know,  may  have 
become  secondarily  infected,  it  may  be  said  that  serious  attention  was 
not  drawn  to  insects  as  bearers  of  infection  until  the  early  90's.  And 
although  Nott,  in  1848,  had  suggested  the  mosquito  as  a  cause  of 
malaria  and  yellow  fever,  and  Finlay,  in  1881,  had  asserted  that  the 
latter  disease  was  transmitted  from  infected  to  non-infected  man  by 
these  insects,  it  was  not  until  the  closing  years  of  the  century  that 
these  theories  were  demonstrated  as  correct. 

The  insects  which  have  been  most  extensively  studied  are,  naturally, 
those  which  have  the  greatest  opportunity  for  contact  with  human 
beings,  namely,  flies,  fleas,  bedbugs,  and  mosquitoes ;  but  others  have 
been  the  subject  of  more  or  less  extensive  investigation  which  has 
demonstrated  their  capacity  for  conveying,  externally  or  within  their 
bodies,  virulent  bacteria  of  many  kinds.  That  insects,  coming  in  con- 
tact with  material  containing  pathogenic  bacteria,  may  convey  the  same 
directly  to  wounds  or  food-stuffs  upon  which  they  may  alight,  needs 
hardly  to  be  demonstrated,  whether  the  organisms  are  adherent  to  the 
body,  limbs,  or  proboscis  ;  but  how  long  the  bacteria  may  retain  their 
virulence  during  carriage,  and  whether,  if  taken  into  the  insect's  ali- 
mentary canal,  they  can  survive  the  process  of  digestion  and  be  dis- 
charged in  the  faeces,  can  be  determined  only  by  direct  experiment ; 
and  it  was  with  such  problems  that  the  first  researches  on  the  agency 
of  insects  in  the  transmission  of  disease  were  engaged.  It  has  been 
690 


FLIES.  (V.)\ 

found  that  (!(!rtain  Hpcicicis  of  |)!ic.l('ii;i  ate  (IIl-^i  :-l<(l  \iy  vA'.riiim  inwvjtH ; 
but  it  rniiHt  Ix;  hor'iic  in  tiiitid  in  |ir;i(ticc  ili.it  ihis  hIumiM  ii»»t  Ikj 
ac(;('|)t(!<l  as  tii(!  iiK^vilaMc  or  cscn  ii,-ii;il  n-uhj  fi.i-  altlioii^li  fli<-s,  Cor 
oxainphi,  will  <li^(!st  <^cr(;iin  l);i(;lcria,  llicy  ciiiiiiot,  ;il\v;iy,s  he  (l<'|)<-iMlr'(l 
uj)on  to  do  so,  and  may  cxcrcic  tlictn  willi  «t(li(:i'  nii<li^«'slfd  \'i)(A. 

.B(!,sid(!s  transniidiii};  spdoific.  Iciricri.i,  I  he  iiiHcct  world  is  n^HiKjriHJMo 
for  tli(!  sprcnd  ol"  jKiiMsitio  orji;aiiisMis  Lclon^injr  to  the  aniriial  kin^dofii, 
now  i-('(!oi;n !/,('(!  as  tin;  causes  of  malaria,  lilariasis,  and  yellow  fever,  a« 
will  be  shown. 

FLIES. 

Alth()U<i;h  the  possibility  oC  tlu;  spread  of  siieli  diseases  a.s  cholera, 
dysentery,  and  tyj)hoid  fever  was  demonstrated  as  early  as  1892, 
th(^  Jiuitter  did  not  receive  j)articular  atl<'ntion  until  the  umisual 
prevah^ice  of  ty|)hoid  fever  in  the  great  military  camps  in  (In;  South 
in  1898  was  made  the  subject  of  a  careful  in(|uiry,  which  led  to  the 
conclusion  that  the  jjjreat  swarms  of  Hies  which  infested  the  cani|)S 
were  largely  res])onsible.  A  scries  of  interesting  experiments  on  the 
subject  of  infection  through  the  agency  of  flies  was  conducted  by  Sawt- 
chenko  '  with  [)ure  cultures  of  cholera  bacilli.  The  bacilli,  iad  to  two 
kinds  of  Hies,  were  found  in  the  excreta  and  bowels  as  late  as  four  days 
after  ingestion  ;  removed  on  the  third  day  and  inoculated  into  guinea- 
])igs,  they  were  found  to  be  as  active  as  the  pure  cultures  themselves. 
Similar  results  were  obtained  when,  instead  of  ]nirc  cultures,  the  dis- 
charges of  cholera  patients  were  employed  as  feeding  material.  Some 
of  the  experiments  indicated  that  the  bacilli  jn-obably  multiply  within 
the  fly,  which  thus  acts  as  a  breeder  and  distributing  agent  at  the  same 
time.  A  fly,  caught  in  the  autopsy  room  at  Hamburg  during  the  great 
cholera  e])idenTic  of  1892,  was  examined  by  Siramonds,"  and  yielded 
numerous  bacilli.  This  suggested  an  inquiry  into  the  length  of  time 
the  poison  could  retain  its  activity  when  adherent  to  flying  insects, 
and  experiment  showed  that  it  remained  virulent  for  at  least  an  hour 
antl  a  half  after  drying.  Surgeon-General  Sir  William  IMoore^  drew 
attention,  in  1893,  to  the  fact  that,  in  India,  flics  abound  most  exten- 
sively during  the  time  and  season  of  greatest  prevalence  of  cholem  ; 
he  suggested  that  they  might  act  as  carriers  of  typhoid  fever,  phthisis, 
and  ophthalmia.  He  instanced  an  epidemic  of  anthrax  spread  by  flies 
whicli  had  covered  the  carcass  of  a  dog  thrown  into  a  ditch.  It  ap- 
pears that  the  specific  bacteria  of  this  disease  resist  the  digestive  proc- 
ess, and  may,  therefore,  be  deposited  from  the  external  surface  or  in  the 
faeces.  According  to  Nuttall,*  who  was  the  first  to  present  from  the 
exceedingly  scattered  literature  a  general  view  of  the  part  played  by 
insects  and  other  low  forms  in  the  transmission  of  human  and  oxhor 
diseases,  flies  do  not  convey  anthrax  by  biting,  but  may  become  crushed 
upon  the  skin,  and  thus  convey  the  organism  to  the  wound.     From  a 

^  Centralblatt  fiir  Bakteriologie  irnd  Parasitenkunde,  XII.,  p.  983. 

^  Deutsche  niedieinisohe  Woclicnschrift,  1S92,  Jso.  41. 

^  Medical  Matrazine,  Julv,  1803. 

*  Johns  Hopkins  Hospital  Reports,  VIII.  (1899),  Xos.  1  and  2,  p.  1. 


692 


THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 


study  of  the  cases  cited,  it  appears  likely  that  in  many  instances  the 
specific  organism  may  have  been  present  on  the  skin  prior  to  the 
advent  of  the  lly  or  other  insect. 

An  instance  of  strong  presumptive  evidence  of  an  outbreak  of  cholera 
through  the  agency  of  flies  is  furnished  by  Buchanan/  -who  relates  that 
in  June,  181)(i,  D  cases  of  the  disease  occurred  in  Burdwan  jail,  where, 
prior  to  and  after  the  attack,  there  was  exceptional  freedom  from  bowel 
complaints.  The  water  supply  was  above  suspicion  and  was  the  same 
for  all  the  inmates,  who  numbered  190,  and  were  divided  into  two 
groups,  the  ordinary  prisoners  and  the  "  infirm  gang."  The  latter 
worked,  slept,  and  associated  generally  with  the  former,  but  their  food 
was  cooked  specially,  and  they  were  fed  in  a  separate  place  in  the  hos- 
pital compound.    The  ordinary  prisoners — and  it  was  among  these  that 

Fig.   104. 


FEEDING 
PLACES 


COOK 
HOUSE 


s.w.  B 

GANG  AT  A  WERE.  ATTACK  ED. 
GANG  AT  B   ESCAPED. 

Plan  of  grounds  of  Burdwan  jail,  where  cholera  is  supposed  to  have  been  carried  by  flies. 

all  the  cases  occurred — had  their  food  prepared  and  were  fed  at  the 
extreme  opposite  comer,  diagonally  from  the  hospital.  Over  the  wall 
at  their  corner  were  a  deserted  compound,  and  a  row  of  dirty  huts 
where  cholera  had  existed  during  the  preceding  year.  At  the  time,  the 
city  was  more  than  usually  infested  with  swarms  of  flies,  and  just  before 
the  outbreak,  a  storm  had  occurred,  during  which  a  strong  E.N.E. 
wind  blew  across  the  jail  yard  from  the  locality  mentioned.  All 
who  were  seized  were  among  those  who  were  known  to  have  had  their 
evening  meal  in  the  corner  during  the  storm,  and  it  was  believed  that 
swarms  of  flies  were  blown  from  the  huts,  and  on  reaching  the  trees 
and  corner  of  the  high  jail  wall,  obtained  shelter  from  the  storm  and 
settled  upon  the  food  exposed  in  the  plates  before  the  gang.  The 
accompanying  figure  shows  the  relative  positions  of  the  two  gangs  at 
^  Indian  Medical  Gazette,  March,  1897. 


tlioir  rruiiil,  ;ui<l  oC  fiic  coiiipoiiinl  .'iiid  ImiH  from  vvliidi  i\u:  flicH  were 
Hii|)|)<)S(!(l  U)  have  conic.  'I'lic  evidence  hen;  is  juirely  eir<Mjinh.taiif iai, 
but  iL  is  io  he  noted  thai,  all  oCllH'sick  l.elon;,M<|  (o  I  h(!  HJUiic /^iilig  ;  that 
all  liud  been  more  than  a  inonlh  in  jail,  e\ce|tlin^  2,  who  had  heen 
there  H(!V(!n  and  Iwelve  days  respect  ivcly  ;  that  there  had  heen  no 
|)r(^val(!ne(!  oC  diari-hu'a  hcCorc,  dnrino^,  or  alter  the  oiithie;d<  ;  that  tlir; 
water  and  milk  sii]>|>iy  wen;  the  same  lor  all,  and  thai  the  onthnak 
was  very  limited  in  <!xtent. 

The  ability  of  llics  to  inl'ccit  food  was  wcW  d(!monstrat<-d  in  IH'.fl  by 
UlT'elmann,'  who  allowed  a  elioh^ra-inlected  fly  to  driid<  from  a  ^lass 
of  sterile  milk,  and  IIkmi  shook  the  latter  and  ke|)t  it  at  70''  F,  for 
sixteen  hours,  at  the  end  of  which  time  each  drop  contjiined  about  a 
hundred  organisms. 

The  prevalence;  of  typhoid  fever  among  TOuropeans  in  India  has  l)oen 
attributed  by  Surgeon-Major  15a  iters  by  "  to  the  agen(;y  of  Mies,  sina;, 
year  by  year,  outbr(>aks  occur  which  are  most  diilicult  or  impossible  U) 
trace  to  a  water-borne  cause,  the  water  supply  being  in  nuiny  iust;ince.s 
above  suspicion,  and  even  of  exceptional  purity.  During  our  war 
with  Spain,  investigation  of  tlie  great  prevalence  of  ty))hoid  fever  in 
the  large  (nimps  in  the  South  showed  the  abundant  oj)])ortunity  which 
exists  for  infection  by  flies,  and  demonstrated  the  necessity  of  thorough 
camp  sanitation,  and  of  excluding  them  from  contact  with  both  excreta 
and  foods.  Visiting  the  "  sinks  "  at  one  time  and  the  mess-tables  at 
another,  they  have  the  widest  opj>ortunity  for  spreading  infection. 

The  presence  of  plague  bacilli  in  the  intestines  of  flies  lias  been 
demonstrated  repeatedly  within  recent  years,  first  by  Yersin  in  1894, 
wlio,  noting  the  large  number  of  dead  flies  where  the  victims  were 
being  autopsied,  crushed  one  fly  and  inoculated  it  into  a  guinea-pig, 
which  died  of  the  disease  in  forty-eight  hours.  Further  investigiition 
showed  the  bacilli  present  in  the  intestines  of  the  living  fly,  and  led 
to  the  conclusion  that  they  actually  multiply  therein.  Nuttall  ^  proved 
that  flies  may  carry  the  disease,  and  that  they  themselves  die  of  it. 
It  is  interesting  to  note  that  the  statements  of  early  writers  to  this 
eifect  were,  therefore,  correct.  Most  of  these  were  vague,  and  gave  no 
intimation  of  how  the  contagion  was  carried ;  but  a  Venetian,  Mer- 
curialis,  in  1577,  wrote  (De  Pestilentia)  that  flies  go  to  infected  houses, 
alight  upon  the  sick,  and  then  convey  the  contagion  to  other  houses 
and  deposit  it  on  bread  and  other  foods. 

That  flies  may  play  a  part  in  the  s]>read  of  tuberculosis,  too,  seems 
probable,  for  the  specific  bacilli  have  repeatedly  been  found  in  virulent 
condition  both  in  their  intestines  and  in  their  excrements. 

Dr.  Frederick  T.  Lord  *  came  to  the  following  conclusions  : 

"1.  Flies  may  ingest  tubercular  sputum  and  excrete  tubercle  bacilli, 
the  virulence  of  which  may  last  for  at  least  fifteen  days. 

1  Berliner  klinisclie  Wochenschrift.  1892,  p.  1213. 
^  British  IMedical  Journal.  Ansiust  10,  1895. 

3  Centralblatt  fiir  Bakterioloa;ie,  etc.,  XXII.   (1897),  Xo.  4,  and  XXIII.  (1898), 
No.  15. 

^  Boston  Medical  and  Surgical  Journal,  Dec.  15,  1904. 


694         THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 

"  2.  The  clanger  of  human  infection  from  tubercalar  fly-specks  is  by 
the  ingestion  of  the  specks  on  food.  Spontaneous  liberation  of  tubercle 
bacilli  from  fly-specks  is  unlikely.  If  mechanically  disturbed,  infec- 
tion of  the  surrounding  air  may  occur. 

"  As  a  corollary  to  these  conclusions,  it  is  suggested  that — 

"  3.  Tubercular  material  (sputum,  pus  from  discharging  sinuses, 
fecal  matter  from  patients  with  intestinal  tuberculosis,  etc.)  should  be 
carefully  protected  from  flies,  lest  they  act  as  disseminators  of  the 
tubercle  bacilli. 

"  4.  During  the  fly  season  greater  attention  should  be  paid  to  the 
screening  of  rooms  and  hospital  wards  containing  patients  with  tubercu- 
losis and  laboratories  where  tubercular  material  is  examined. 

"  5.  As  these  precautions  would  not  eliminate  fly  infection  by  patients 
at  large,  foodstuffs  should  be  protected  from  flies  which  may  already 
have  ingested  tubercular  material."  They  are  believed,  also,  to  carry 
leprosy  and  various  conjunctival  diseases. 

According  to  Castellani  and  Chalmers  ^  flies  are  capable  of  carrying 
the  bacilli  of  dysentery  and  are,  therefore,  probably  a  prolific  source  of 
infection  in  tropical  countries. 

The  larvae  of  the  common  house-fly  are  sometimes  found  in  the  ali- 
mentary tract.  Thus,  Cohen  ^  reports  finding  them  in  the  dejections 
of  a  nursing  infant,  the  ova  having  probably  been  deposited  in  its 
mouth ;  and  Bachmann  ^  found  them  in  the  vomitus  of  a  hard  drinker, 
and  later,  after  the  administration  of  an  infusion  of  pyrethrum,  in 
large  numbers  in  his  fseces. 

Flies  may  also  transport  the  eggs  of  Tcenia  solium,  Trichuris  trichiura, 
Ascaris  lumhricoides,  and  other  parasites,  and  deposit  them  on  foods. 

Other  flies  mentioned  by  Castellani  and  Chalmers  are  Stomoxys  cal- 
citrans,  the  common  stable  fly  found  in  houses,  stables,  and  in  the  open 
near  cattle.  It  bites  all  classes  of  mammals  and  is  suspected  of  spread- 
ing trypanosomes,  especially  T.  evansl. 

Glossina  palpaUs  (tse-tse-fly).  The  bite  of  this  fly  has  long  been 
known  to  be  dangerous  to  animals,  but  Bruce  first  showed  that  it  was 
responsible  for  the  spread  of  Trypanosoma  brucei  and  the  cause  of  the 
disease  nagana  in  horses.  Furthermore,  Bruce  and  Narbarro  showed, 
in  1903,  that  Glossina  p)alpalis  is  the  means  of  transferring  T.  gamhi- 
ense,  the  cause  of  sleeping  sickness.  That  T.  gamhiense  undergoes  a 
cycle  of  development  in  Glossina  palpalis  has  been  shown  through  ex- 
periments recently  by  Kleine. 

FLEAS. 

In  1898,  Siraonds^  advanced  the  idea  that  fleas  from  rats  sick  with 
plague  might  spread  the  disease  to  other  rats,  and  even  to  man.  He 
found  the  specific  bacilli  in  such  fleas,  as  did  also  Ogata.^ 

1  Manual  of  Tropical  Medicine,  1910,  p.  992. 

2  Deutsche  medicinische  Wochenschrift,  March  24,  1898.  ^  Ibid. 
*  Annales  de  I'lnstitut  Pasteur,  XII.,  p.  625. 

^  Centralblatt  fiir  Bakteriologie,  etc.,  XXI.,  p.  769. 


liKDIiUaS.  CDfj 

The  rjiKistion  wan  iJioron^lily  invcsli^Mtcd  hy  (lu;  Iixliiui  I'I.-i^ik; 
Coiriiriis.sioii  in  WH)^),  and  jiic  riri(liii;^s  (ifiliis  ( 'orrwiiis.sioti  :irc  siuii/iiar- 
izcd  by  Jiliu; '  as  Col  lows  :  "That  Ih'as  (and  Wiif^sj  Uikcn  (Vom  pla^uc- 
sick  ruts  (iontain  Jl.  pcdlH,  and  tliat  Honu!  of  tiicini  n;rnain  alivt;  in  the 
bodies  of  tho  in.s<K!tK  from  five  to  Hix(x!(;n  ihiyi^',  that  pluf^iic,  \h  (jonvcywl 
by  (li(!  l>il(>s  of  (leas  vvlii(^li  liavc  previously  fed  on  tli(;  blood  of  animals 
Hullorinj^  vvil.li  llic  disease;;  thai  rat  lleas  bile  man  ;  lliat  nndc-r  cxjtcri- 
montal  conditions  tin;  infection  i.s  not  traiisfcirrod  from  rat  to  rat  in  tlio 
absence  of  fleas,"  TIk;  iKias  most  commonly  res[)onsibl(!  for  this  trans- 
fer are  (JeratophylhM /(w-Mdua,  the  common  rat  flea  of  Knrojx!  and  the 
Unitcid  States,  and  Lirniojtsy/fa  c/icojh'x,  tli(!  eomnum  rat  fl<a  in  fropieal 
and  sub-tropical  countries.  'J'lie  natural  inference  -would  be  that  the 
infection  is  transfeired  at  tlie  time  of  bitinjr ;  but  this  seemn  not  to  be 
the  case.  According  to  Fox,^  "  repeated  exann'nations,  both  })y  dis- 
secting out  the  salivary  glands  and  by  serial  sections  of  thf?  entint  fh-a, 
plague  bacilli  jiavc  never  been  demonstrated  in  these;  glands  or  any- 
where outside  of  the  alimentary  tract.  .  .  .  The  most  j)lausible  ex- 
planation that  has  been  advanced  has  been  based  on  an  observation 
that  blood-sucking  insects  at  the  time  of  biting  frequently  eject  a  drop 
of  blood  from  the  rectum.  We  know  that  the  rectum  may  contain 
numerous  plague  bacilli,  and  it  is  supposed  that  this  blood  ejected  in 
the  vicinity  of  the  bite  is  either  brought  in  contact  with  the  slight 
wound  by  the  feet  or  mandibles  of  the  flea  itself  or  is  rubbed  in  as  a 
result  of  scratching." 

Nuttall"''  speaks  of  the  possibility  of  transmission  of  Tccnia  cucu- 
merina  through  fleas.  The  adult  worm  is  found  in  dogs,  occasionally 
in  cats,  and  rarely  in  man.  The  larval  stage  is  found  in  dog  fleas  and 
lice,  and  even  in  the  flea  that  infests  man  (P,  irntans) ;  but  the  dog 
flea  is  the  usual  host,  and  may  carry  as  many  as  50  larvse.  Dogs 
infest  themselves  by  devouring  their  fleas  and  lice,  and  children  may 
become  infested  by  playing  with  and  kissing  dogs,  the  vermin  being 
unconsciously  swallowed.  The  larvfe  are  liberated  in  the  intestine 
through  digestion  of  the  body  of  the  insect,  and  they  then  exvaginate 
and  take  on  their  definite  form  as  tapeworms. 

According  to  Castellaui  and  Chalmers,^  fleas  may  also  carry  blood 
parasites,  as,  for  example,  Trypanosoma  lewisi. 

BEDBUGS. 

But  few  cases  of  transmission  of  disease  by  bedbugs  are  known. 
Nuttall  quotes  Dewevre's^  report  of  a  case  of  transmission  of  tuber- 
culosis after  disinfection  of  a  room  in  which  a  young  man  had  died  of 
the  disease.  After  the  process  was  completed,  the  room  and  bed  were 
occupied  by  a  brother  of  the  deceased,  and  he,  too,  died.  Investig-ation 
showed  his  body  to  be  much  bitten  by  bedbugs,  and  the  bed  to  be 
swarming  with  the  vermin.     At  this  time  the  floor  was  soiled  with 

1  The  Rat  and  Its  Eelation  to  the  Public  Health,  1910,  p.  146.         »  Ibid.,  p.  132. 
3  .Johns  Hopkins  Hospital  Keports,  VIII.,  Nos.  1  and  2. 
*  Manual  of  Tropical  ^Medicine,  p.  577. 
5  Revue  de  M^decine,  XII.,  1892,  p.  291. 


690         THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 

sputum,  and  had  not  been  cleaned  for  many  weeks.  The  contents  of 
30  bugs  were  inoculated  into  3  guinea-pigs  with  positive  results  :  all 
died  of  tuberculosis.  Virulent  bacilli  were  obtained  from  60  per  cent, 
of  the  bugs  examined.  , 

According  to  Castellani  and  Chalmers/  the  Spiroehceta  recurrentis, 
the  orgiinism  of  relapsing  fever,  can  live  in  the  bedbug,  Clmex  Icdu- 
larius,  for  some  days,  and  Nuttall  succeeded  in  transmitting  it  from 
mouse  to  mouse  by  the  bites  of  the  same  bug.  Goodhue,  furthermore, 
is  said  to  have  demonstrated  the  bacilli  of  leprosy  in  the  bedbug. 

ARACHNIDS. 

Ticks. — Although  for  some  years  it  has  been  known  that  ticks  were 
concerned  in  the  spread  of  certain  diseases  in  animals,  it  is  only  recently 
that  they  have  been  found  to  play  any  role  in  the  etiology  of  disease 
in  man. 

Especially  through  the  work  of  Ricketts,  it  has  been  demonstrated 
that  spotted  fever,  or  Rocky  Mountain  fever,  is  transferred  by  the  tick 
Dermacentor  occidentalis.  The  question  as  to  the  cause  of  this  disease 
is  still  in  dispute ;  but,  according  to  Castellani  and  Chalmers^,  the 
virus  can  be  acquired  and  transmitted  by  the  larva,  the  nymph,  and 
the  male  and  female  adults  of  D.  occidentalis,  and  in  a  few  instances 
can  pass  through  the  eggs  into  a  second  generation  of  ticks. 

Body  Louse. — The  epidemiological  facts  of  tabardillo,  or  Mexican 
typhus,  in  the  opinion  of  Anderson,^  point  unmistakably  to  an  insect  inter- 
mediary, and  he  believes  that  observations  made  by  him  and  Goldberger 
point  strongly  to  the  body  louse  {Pediculus  vestimenti)  as  this  insect. 

MOSQUITOES. 

Certain  genera  of  mosquitoes  have  been  definitely  proved  to  be  the 
intermediate  cause  of  several  of  the  most  disastrous  human  scourges, 
and  their  connection  with  others  has  been  suggested,  and  may  at  any 
time  become  demonstrated.  The  diseases  which  have  been  definitely 
connected  with  these  pests  are  malaria,  yellow  fever,  and  filariasis. 

Mosquitoes  appear  to  be  ubiquitous  ;  they  are  found  not  alone  in  the 
torrid  and  temperate  zones,  but  in  the  arctic  regions,  where,  according 
to  good  authority,  they  are,  in  their  season,  even  more  of  a  pest  than 
in  warmer  latitudes.  In  Siberia,  they  hibernate  under  the  moss ; 
and  in  all  inhabited  places  they  hibernate  in  cellars,  outhouses,  and 
other  retreats.  The  larvae,  also,  may  hibernate,  being  frozen  in 
the  ice  on  the  approach  of  winter,  and  able,  when  thawed  out,  to  re- 
sume growth.  Gorman  *  found  living  larvae  in  water  beneath  ice  at 
Providence,  R.  I.,  in  December;  and  Wright^  found  Anopheles  larvae 
beneath  ice  in  Aberdeenshire.  Nuttall  has  known  larvae  to  live  from 
seven  to  eight  months.     The  adult  mosquito  may  be  found  in  the  open, 

1  Manual  of  Tropical  Medicine,  p.  305.  *  Ibid.,  p.  714. 

3  Public  Health  Reports,  Vol.  XXV.,  No.  8,  p.  185. 

*  Journal  of  the  Boston  Society  of  the  Medical  Sciences,  V.,  p.  330. 

6  British  Medical  Journal,  April  13,  1901,  p.  882. 


MOSQIJITOr.S. 


007 


ovon  when  ilin  WfatluT  is  wliilry.  TliiiH,  Slcrlinjr'  nnw  mo.'<f|iiitor's  at 
M;ic,l<iiiaw  in  Murcli,  ISM,  wlifii  sdow  covcn-d  the  yr^rowiA  to  a  depth 
of  two  to  four  f(!o(,.  Ijiit  it  is  only  in  w.irin  wf-athcr  that  moHqiiitfM»H 
aj)poar  to  have  any  part  in  tlif  (ransinission  of  (jisoaso,  for  tornpfratnro 
lias  very  great  \\\\\\u\\\ci\  on  the  lifr;  and  (lr'Vclo|)rn(!nt  of  tin-  jiara^ites 
wliicli  tliey  sjtrcad,  and  npoii  tlicir  own  arfivify  and  in<-lina(ion  fo  hitt;. 
'^rii(t  parasilc  of  (lie  lro|)ic;d  .'I'stivo-antuninai  tyjx;  of  malaria,  for 
examj)lo,  will  (iiil  l<>  llnixc  in  ;i  tcnipcratnrc  not  too  low  for  tliat  of  the 
tertian;  and  tlic  lallcr  will  nol  live  at  05°  F.,  which  t<'(nperature  is 
not  too  low  lor  llial  of  I  lie  (|nartan  type.  Malaria  rarely  <lfv<'lo 
Ix'low  59°  F.,  and  is  coniplcldy  clicckcd  at  o2°,  a(  wliidi  ffinjtcratiin 
mosquitoes  are  very  sliijifrisli  and  d<»  not  hile. 

We  have  in  this  country,  aceordinj^  to  Dr.  L.  ().  Howard,^  0  genera 
of  mos(]uitoes,  re|)resented  by  ahout  2  4  sjH'cies,  tlie  larger  niimher  of 
which  belong  to  the  genus  C'n/r.r,  and  are  (piite  harndess.  We  have  3 
of  the  <S  or  more  species  of  malaria-bearing  Annj)hr/r.'<,  and  Sfrr/omyifi 
calojyus  (formerly  known  as  Culcx /a.Hci(Uus),  the  carrier  of  yellow  fever. 

Mosquitoes  and  Malaria. — The  indigenous  malarial  species  are  as 
follows  : 

1.  Anopheles  maculipennis  (yl.  (juadnmaculatus,  A.  daviger)  (Figs. 


|).S 


Fio.  105. 


Fig.  106. 


Anopheles  maculipennis.    Male. 


Anopheles  maculipainis.    Female. 


1 05  and  106)  has  the  "  dappled  wings  "  described  by  Ross.     The  palpi 
are  black. 

2.  Anopheles  punetipenuis  has  a  yellowish- white  spot  extending 
about  three-fourths  of  the  length  of  the  front  margin  of  the  wing. 
(Figs.  107  and  108.) 

3.  Anopheles  crucians. — The  scales  of  the  last  wing-vein  are  white, 
1  Insect  Life,  ITI.,  p.  403.  *  Mosquitoes,  New  York,  1901,  p.  230. 


698 


THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 


marked  with  three  black  spots.     The  palpi  are  marked  with  white  at 
the  bases  of  the  last  four  joiuts.      (Figs.  109  and  110.) 

A.  maeulipennis  and  A.  puncUpennis  are  distributed  very  widely, 
beiug  found  in  greater  or  lesser  abundance  thi'oughout  the  country.  The 
former  is  the  most  common  Anopheles  in  the  malarial  (.listricts  of 
Africa,  and  Southern  Europe,  and  is  found  in  Great  Britain,  Germany, 
France,  and  elsewhere. 

Fig.  107. 


Anopheles  punctipennis.    Male.    (After  Howard.) 


A.  crucians  is  a  Southern  form,  believed  to  be  the  carrier  of  the  per- 
nicious, tropical,  sestivo-autumnal  fever,  but  not  the  only  one,  for  in 
St.  Lucia,  for  example,  Avhere  the  great  majority  of  cases  of  malaria 
are  of  the  pernicious  type,  the  common  mosquito  is  A.  albipes. 


Fig.  108. 


Anopheles  punctipennis.    Female.    (After  Howard.) 


Unlike  Culices  and  Stegomyia,  the  Anopheles  do  not  breed  in  rain- 
water barrels,   troughs,  cisterns,   tin  cans,   pitcher  plants,   and  other 


MosQirrmi'K 


OfiO 


smuU  r('C(;j)l:icl(!M,  \m\  in  jkioIs,  puddles,  (ViiclwH,  can.-ilH,  aixl  oilier 
bodies  of  Htiigiiiuit  or  hiii  very  hIowIv  moving  wulor.  'J'iie  Jarvfc  thrive; 
in  clean  or  ioul  water,  hiil,  nol  in  lliat  wliioli  in  ho  foul  an  U)  .stink  ;  tlioy 
cannot  live;  in  wait-  oi'  v<iy  l»raeki.ili  water,  nor  where  (here  in  ia)»i<I 
movement. 

Imo.  100. 


Anopheles  crucians.    Male. 


It  is  only  the  female  imago  that  sucks  human  blood,  and  she  is 
active  only  at  night.     She  enters  dwellings  about  sundown  or  later, 


Fig.  110. 


Anopheles  crucians.    Female. 


and,  unless  leaving  before  morning,   seeks  out  the  darkest  corner  in 
which  to  pass  the  day. 


700         TEE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 

According  to  Nuttall/  Anopheles  are  attracted  variously  by  diiferent 
colors,  navy  blue  being  the  most  attractive,  followed  by  dark  red,  red- 
dish brown,  scarlet,  black,  and  slate  gray.  Yellow,  orange,  white,  and 
ochre  jiroved  to  attract  tlie  least.  Joly  is  quoted  as  stating  that  mos- 
quitoes in  Madagascar  are  attracted  more  to  brown  than  to  red  soil  or 
white  sand ;  that  wearers  of  black  shoes  and  stockings  are  bitten  more 
than  those  Avho  wear  white  ;  that  blacks  are  bitten  more  than  whiter, 
and  black  dogs  than  yellow.  Nuttall  noted  in  his  experiments  that, 
while  the  imagines  frequently  Hew  up  and  settled  on  persons  entering 
the  room  clad  in  dark  clothes,  they  never  did  when  the  dress  was  white. 
He  suggests  the  employment  of  boxes  colored  dark  inside,  in  which 
the  pests  may  be  cauglit  and  destroyed.  The  influence  of  color  is 
noted  also  by  Osborne  Browu,^  who  holds  that  walls,  furniture,  etc., 
should  be  of  light  color,  and  advises,  among  other  measures,  the  put- 
ting away  of  all  dark  clothes.  Anopheles  appear  to  be  attracted  also  by 
odors,  according  to  the  testimony  of  Stephens  and  Christophers,^  who 
found  that  when  native  Africans  slept  in  a  tent  previously  occupied  by 
Europeans,  the  insects  congregated  there  more  numerously.  During 
European  occupancy,  2  Anopheles  were  usually  found  in  the  morning  ; 
but  after  the  first  night  of  African  occupancy,  19  were  caught,  and 
after  the  second  night,  no  less  than  62  were  found. 

The  Malarial  Parasite. — The  malarial  parasite  was  discovered  in  1880, 
by  Laveraa,  a  French  military  surgeon  stationed  in  Algeria,  but  until 
some  years  later  its  method  of  development  was  not  demonstrated,  and 
only  recently  has  anything  been  known  definitely  as  to  the  manner  of 
its  entrance  into  the  human  body.  Before  proceeding  to  an  account  of 
the  researches  by  which  this  was  determined,  it  may  be  well  to  describe 
the  development  of  the  parasite  within  the  human  subject  and  within 
the  mosquito. 

The  several  malarial  parasites  belong  to  the  lowest  order  of  the  ani- 
mal kingdom,  the  protozoa,  suborder  Hceinosporidia.  The  different 
forms  corresponding  to  the  clinical  varieties  of  the  disease  were  differ- 
entiated in  1886  by  Golgi,  one  of  the  most  prominent  of  the  Italian 
biologists,  who,  between  1885  and  1890,  were  the  first  to  pay  especial 
attention  to  Laveran's  discovery,  and  study  the  life  cycle  of  the  para- 
site in  the  red  blood-corpuscle.  In  this  it  appears  as  an  amoebula, 
which  grows,  digesting  the  red  coloring  matter,  until  it  occupies  neai'ly 
the  whole  volume  of  the  corpuscle  and  shows  spots  of  pigment  in  its 
interior.  Then  the  nucleus  divides  and  forms  spores,  which,  when  the 
cell  wall  bursts,  are  liberated  into  the  blood  plasma.  This  point  marks 
the  beginning  of  the  malarial  chill.  The  spores  enter  into  other  cor- 
puscles, develop  into  mature  organisms,  segment,  and  produce  new 
spores,  which  on  being  liberated  proceed  to  infect  other  corpuscles,  and 
so  the  process  continues.  In  the  tertian  form  of  fever,  this  process  of 
sporulation  occurs  at  intervals  of  forty-eight  hours  ;  in  the  quartan 
form,  which  is  comparatively  rare,  the  intervals  are  seventy-two  hours ; 

1  British  Medical  Journal,  September  14,  1901,  p.  668. 

2  Joumal  of  Tropica]  Medicine,  October  1,  1901. 

3  Quoted  by  Nuttall,  Journal  of  Hygiene,  January,  1901,  p.  7, 


MOSQUITOES.  701 

in  the  pcrnioIoiiH  ,x\stiv<)-;iiiliimii;il  form,  tlio  intcrvalH  an;  very  irn-j^u- 
lar,  and  tlu;  Hiicc(!HHivc  proccsHcs  of"  .sponiliition  may  ocxjur  ho  rapidly 
that  the  fever  beeorneH  continiiotiH. 

A('l(;r  a,  miiiih(!r  of  ^ciieriitionH  of"  these  asexual  forniH,  male  and 
f"(!mal(!  pai'asifcs  appeal',  wliieh  are  inea|)al)h;  of  fiirllif-r  rej)rodiietion 
within  tlu!  hnnian  snhjecf,  hiil.  i('(|uire  external  e.onditionH  whieli  they 
find  within  tiie  body  of  jIiio/j/ic/ck  nio.s(jnito(!H.  'J'h(!  fernah;  paraHit(;H 
are  known  an  macrofjctmctcw,  liomolo<i;oiis  with  ova;  the  male  or^mihmH 
ixvv  known  as  inimxjaiiKiocylc.s.  'IIk'V  ^iv(!  off  fla<.';ella  or  inirrof/dfiicJ/'Mf 
homolojjjons  with  sjxirniatozoa.  In  (Ik;  next  (ryele,  discovered  l»y  I\ohh, 
these  adult  sexual  forms,  wluiii  sucked  up  in  the  bhmd  by  th(!  niosfpiito, 
coalesce  in  its  stomach.  The  fertilized  organisms  attach  themselvr's  U) 
the  walls  and  jKMuitrate  to  the  oiiler  nuisenlar  wall,  where  they  incniise 
in  size  and  become  mature  zyji;oles  (.sy>o/-oc//.s/.v),  U})on  the  surfitcc  of 
which,  clear  spaces,  ccntrovicrc.s,  begin  to  apju-ar.  Jn  a  short  time, 
these  become  surrounded  by  minute  spindle-shaped  exjlls,  fsporohlaMs, 
which  divide  into  minute  rods,  sporozoitrfi,  which  soon  fill  the  whole 
cyst,  which  bursts  and  liberates  them  through  the  outer  wall  into  the 
abdominal  cavity.  They  then  rapidly  jxnetrate  the  tissues  to  the 
salivary  duct,  and  thence  into  the  j)roboscis,  from  which  they  are  di.s- 
charged  with  the  salivary  secretion  into  the  blood  of  the  next  person 
bitten.  From  the  time  of  entrance  of  the  sexual  forms  into  the 
mosquito  to  the  completion  of  the  ]irocess,  about  ten  days  elapse,  and 
since  the  period  of  incubation  in  man  is  the  same,  it  follows  that,  under 
favoring  conditions  of  temperature  (for  in  cool  weather  the  process 
within  the  mosquito  is  slower),  about  twenty  days  must  elapse  between 
the  appearance  of  a  first  case  and  that  of  another  connected  therewith. 
The  inoculated  sporozoites  give  rise  to  the  successive  asexual  genera- 
tions above  described. 

The  tertian  parasite  invades  the  whole  corpuscle;  the  quartan, 
nearly  the  whole  ;  the  £estivo-autumnal,  from  a  fifth  to  a  fourth  of  its 
volume.  The  pigment  granules  in  the  tertian  Ibrm  are  fine ;  in  the 
quartan,  coarse  ;  in  the  wstivo-antumnal,  very  fine. 

Not  alone  man,  bnt  many  of  the  lower  animals,  as  cattle,  sheep, 
monkeys,  dogs,  various  species  of  birds,  frogs,  snakes,  turtles,  lizards, 
etc.,  are  subject  to  malaria ;  but  the  parasites  are  peculiar  to  each 
species,  and  are  not  transferable  from  one  to  another. 

Some  yeare  after  Golgi  and  others  of  the  Italian  school  had  dif- 
ferentiated the  several  malarial  parasites  and  traced  their  life  cycle 
within  the  human  subject,  JSIanson,  who  had  done  much  Avork  in  the 
investigation  of  mosquitoes  as  a  causative  agent  of  filariasis,  announced, 
in  1894,  his  belief  that  malaria  was  caused  by  drinking  water  infected 
by  mosquitoes  or  dust  from  the  dried  mud  left  on  evaporation  of  the 
water  in  which  they  had  bred.  He  believed  that  the  female,  ali-eady 
infested  with  the  protozoon,  laid  her  eggs  and  then  died  in  the  water, 
and  was  later  devoured  by  the  larvw.  Bignami  opposed  this,  and 
asserted  that  the  infecticMi  was  conveyed  directly  by  inoculation  in  the 
process  of  sucking  blood. 

In  1895,  Ross  discovered  the  malarial  crescents  in  the  stomachs  of 


702         THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 

mosquitoes  that  had  bitten  a  malarial  subject,  and  followed  them  in 
their  development  into  spheres  and  flagellated  bodies,  but  was  unable 
to  find  them  in  the  body  cavity  or  observe  any  metamorphosis  there. 
For  two  years,  Koss  ^  endeavored  to  cultivate  the  parasite  in  mosquitoes, 
but  without  success,  and  he  then  ceased  experimenting  with  the 
"brown  and  gray"  species  (Culex),  and  began  anew  with  a  few  speci- 
mens of  a  larger  kind  having  four  black  spots  on  the  wings  (^Anophelcny 
After  these  had  fed  on  malarial  blood,  he  observed,  on  examination  of  one 
of  them,  certain  pigmented  cells,  "the  pigment  absolutely  identiciil  in 
appearance  with  the  well-known  characteristic  pigment  of  the  malarial 
parasite."  In  a  second  mosquito,  killed  a  day  later,  the  cells  were 
observed  to  be  larger.  The  supply  of  Anopheles  having  become  ex- 
hausted, he  worked  with  other  kinds,  but  with  no  results  ;  but  later  ^ 
he  announced  that  he  had  found  the  pigmented  cells  in  a  third  "  dapple- 
winged"  mosquito  fed  on  crescent-containing  blood.  In  the  mean- 
time, MacCallum,  of  Johns  Hopkins,^  announced  his  discovery  that 
with  halteridum,  a  parasite  of  birds  strictly  analogous  to  the  malarial 
parasite  of  man,  the  function  of  the  flagellum  is  that  of  true  sperma- 
tozoa. Ross  then  took  up  the  study  of  bird  parasites  (Halteridium  and 
Proteosoma),  especially  of  the  proteosoma  of  sparrows,  larks,  and  crows, 
and  was  successful  in  growing  the  parasites  in  mosquitoes  that  had 
bitten  sick  sparrows,  and  in  reproducing  the  disease  in  other  bu-ds 
bitten  by  them.  He  observed  the  liberation  of  the  sporozoites  from 
the  zygotes,  their  passage  into  the  body  cavity  of  the  insects,  and  their 
presence  in  the  salivary  glands.  His  belief  that  Anopheles  acts  as  a 
carrier  of  the  malarial  parasites  was  proved  by  Grassi,  Bastianelli,  and 
Bignami,  who  allowed  different  kinds  of  mosquitoes,  including  A.  macu- 
lipennis,  to  bite  persons  afflicted  with  the  sestivo-autumnal  type  of 
fever,  and  found  only  in  the  species  mentioned  the  developmental 
changes  described  by  him.  Later,  Bignami  *  reported  that  he,  Grassi, 
and  Bastianelli  had  cauglit  a  number  of  specimens  of  this  mosquito 
in  a  malarious  district  twenty-two  miles  from  Rome,  and  had  re- 
leased them  at  the  Santo  Spirito  Hospital  in  a  room  occupied  for 
some  years  by  a  man  who  had  been  under  constant  observation  and  had 
had  no  kind  of  fever  whatever.  The  experiment  yielded  positive  re- 
sults, for  the  volunteer  subject  acquired  the  fever  and  yielded  para- 
sites in  his  blood.  The  demonstration  of  the  agency  of  these  pests 
was  thus  complete,  and  the  connection  has  been  proved  repeatedly 
on  a  much  larger  scale.  Thus,  Ross^  reports  that  of  21  persons  in  a 
camp  near  Calcutta,  17  who  slept  without  the  protection  of  mosquito- 
netting  were  seized  with  malaria,  while  the  others  who  slept  under 
nets  escaped.  Grassi's  experience  is  equally  convincing,  although  with- 
out a  control.  For  eight  consecutive  days,  accompanied  by  a  family  of 
seven,  he  left  Rome  each  day  at  5.30  in  the  afternoon  and  went  to  a 

1  British  Medical  Journal,  December  18,  1897,  p.  1786. 

^  Ibidem,  February  26,  1898,  p.  550. 

"  Journal  of  Experimental  Medicine,  January  7,  1898. 

*  BuUetino  della  E.  Accad.  Med.  di  Roma,  XXV.,  1898-1899. 

*  British  Medical  Journal,  July  22,  1899. 


MOSQUITOES.  TO.'i 

cottajijo  in  a  notoriously  inaI:ir-ioiiH  disfricl,  hfiwc*'!!  IJonif  ;im<1  <^'ivil;i- 
vcccliiii,  \vlicr<;  (licy  pjisscd  tlic  iii^lit.s  in  u  (;ott;i;.n',  flic  \viii(ioWH  ^^' 
which,  ,sci'<:('iH'(l  willi  |)(!rroi;ilc(l  y'ww,,  WVWi  \v\\  open  all  tin:  time.  Not 
OIK!  of  tli(!  |>iii-ty  was  in  the  least  an'rctcd. 

Tlic  loii}i;<T  (!X{)(;riiii('nt  of  Siiiiihoii  and  Low  in  an  ('jiialiv  nialaiioiiH 
district  is  even  moH!  convincinfr.  They  H|)(;iit  wtvcral  nionthn,  inclnd- 
ing  tli<!  sununcr  of  I'JOO,  with  malaria  raffing  all  abont  them,  hut 
were  thcnisclvcs  not  aflcct(!d.  Tiify  took  no  drup;s  hy  way  of  pro- 
phylaxis, and  went  ahout  frccdy  hy  day,  l)nt  l<c|)t  indorjrs  hotwecn  sun- 
sot  and  sniu'isc!,  proliH'tcd  hy  ncttini^s  and  screens. 

In  I !)()!,  an  intcrcstiiifi:;  experiment  was  tritid  hy  tlu;  Japanese  fj^ov- 
ermnent  with  two  battalions  of  soldiers  stationed  together  in  Fonnosa. 
One  battalion  was  complettdy  ])roteet(Kl  from  moscjuitocts  for  Kil  days 
dnring  the  malarial  season,  and  not  a  man  had  the  disease.  In  the 
other  battalion,  wliic^h  was  not  ])rote('ted,  259  eases  were  observed. 

Another  interesting  experiment  was  that  conducted  by  Fermi  and 
Cano-I3ruseo/  wlio  took  l(j  persons,  ranging  from  eighteen  to  thirty 
years  of  age,  wiio  liad  had  no  malaria  within  a  year,  to  a  malarious 
phiee  in  Sanhnia,  and  kept  them  there  eight  days.  Half  Mere  j)ro- 
tected  from  mosqnitoes  at  night,  and  the  others  not.  Of  the  non- 
protected, 5  were  seized ;  of  the  8  protected,  not  one. 

The  most  convincing  proof  of  tlic  agency  of  mosquitoes  may  be 
said  to  be  the  occurrence  of  the  disease  in  a  non-malarious  country 
through  inoculation  by  mosquitoes  imported  from  another  where  ma- 
laria abounds.  Such  an  instance  is  reported  by  Mauson,^  whose  sou 
was  bitten  in  Loudon  on  three  different  days  by  infected  mosquitoes 
brought  from  Italy.  Within  a  few  days  of  the  third  inoculation, 
the  characteristic  symptoms  of  tertian  malarial  fever  appeared  and 
the  parasites  were  found  in  the  blood. 

For  the  spread  of  malaria,  two  factors  are  thus  evidently  essential : 
the  parasite  in  humau  blood  and  the  Anopheles  mosquito.  Either 
alone  is  impotent.  There  are  many  jilaces  where  Anopheles  are  com- 
mon and  malaria  unknown.  Indeed,  if  the  Anopheles  aloue  could 
cause  the  disease,  no  place  would  be  safe,  for  although  they  are  not 
strong  fliers,  they  may  be  transported  through  hundreds  and  even 
thousands  of  miles  by  the  vehicles  of  ordinary  travel.  Thus  Grassi 
relates  that,  during  a  drive  lasting  two  hours,  he  caught  200  speci- 
mens inside  the  coach ;  and  others  have  noted  their  presence  in  rail- 
road cars  and  passenger  ships.  Whether  they  Mould  be  able  to  breed 
aboard  ship  is  doubtful,  although  instances  of  breeding  of  other  mos- 
quitoes in  this  manner  are  knoAvn.  Thus,  Dr.  Cumming,  of  the 
Marine-Hospital  Service,  reported  on  August  2,  1901,  to  the  Super- 
vising Surgeon-General,  the  case  of  the  Spanish  barque  Maria  Blan- 
quer,  Avhich  \vas  free  from  mosquitoes  until  the  twenty-second  day  out 
from  Rio  de  Janeiro,  M'hen  some  were  noticed  in  the  Avater  tank  when 
it  was  opened,  after  -which  the  crew  were  attacked  so  persistently  by 

1  Centralblatt  fiir  Bakteriolo^ie,  etc.,  XXIX.,  p.  985. 
^  British  Medical  Journal,  September  29,  1900. 


704         THE  EEL  AT/ON  OF  INSECTS  TO  HUMAN  DISEASES. 

them  that  they  were  obliged  to  cover  themselves  to  get  any  sleep. 
After  fumig-ation  of  the  forecastle,  the  daid  mosquitoes  could  be 
scooped  up  iu  the  hand.  Howard  relates  that  mosquitoes  were  intro- 
duced into  the  Hawaiian  Islands  by  sailing  vessels  from  the  United 
States,  aud  deems  it  ])robal)le  that  they  bred  more  or  less  continuously 
in  the  water  barrels  during  the  voyage. 

Mosquitoes  may  be  blo^vn  along  by  the  wind  through  long  distances, 
but  ordinarily  they  take  shelter  on  the  leeward  side  of  any  object  as 
soon  as  the  wind  beg-ins  to  be  strono;.  Howard  cites  an  instance  of 
mosquitoes  crossing  a  strip  of  water  a  mile  wide,  aided  by  gentle  and 
continuous  wmd,  and  another  in  which  a  migratory  cloud  of  the  insects, 
extending  three  miles  in  width,  traversed  60  miles ;  and  Dr.  Kallock, 
of  the  Gulf  Quarantine  Station,  reports  (/August  2,  1901)  that  the  cap- 
tain of  the  ship  America  stated  that  mosquitoes  came  aboard  the  vessel 
when  she  was  at  least  10  miles  from  laud.  But  Anopheles  are  not 
likely  to  fly  far  from  their  birthplaces.  They  are  not  such  strong  fliers 
as  CiiUces.  Stephens  and  Christophers^  believe  that  Anopheles  in  Sierra 
Leone  may  fly  a  quarter  of  a  mile  or  farther,  but  in  Freetown  they  found 
them  scarce  at  a  distance  of  200  yards  from  their  breeding-places. 

As  stated  above,  there  are  many  places  in  this  country  and  elsewhere 
where  Anopheles  are  common  and  malaria  unknown,  although  formerly 
the  disease  may  have  raged  most  extensively.  In  England,  for  ex- 
ample, where  malaria  was  once  one  of  the  great  national  scourges  aud 
is  now  seen  only  rarely,  NuttalP  and  his  associates  found,  in  1900, 
specimens  either  of  the  imago  or  of  the  larvae  in  no  less  than  173  dif- 
ferent places.  In  some  of  these  places,  malaria,  so  far  as  known,  has 
never  existed  ;  in  others,  it  once  had  raged  extensively.  In  France,  Ser- 
gent^  has  found  A.  maculipennis  and  A.  bifurcatus  in  great  abundance 
where  malaria  was  formerly  common,  but  now  is,  and  for  twenty  years 
has  been,  unknown  ;  and  in  Germany,  Pfeiffer*  has  found  them  in  great 
numbers  in  formerly  malarious  districts,  but  none  of  them  showed  the 
presence  of  the  parasite.  In  Italy,  too,  where  Grassi  has  held  that  the 
geographical  distribution  of  Anopheles  is  identical  with  that  of  malaria, 
Celli^  has  found  the  insects  in  situations  where  malaria  has  never  been 
known. 

To  what  the  disappearance  of  malaria  in  England,  Scotland,  parts  of 
the  United  States,  France,  Germany,  and  other  countries,  is  due,  is  not 
easily  explained.  To  a  very  large  extent,  it  is  doubtless  due  to  drain- 
age of  the  land  and  general  sanitary  improvement,  the  drying  of  the 
soil  diminishing  the  opportunity  for  puddle-breeding  mosquitoes  to 
multiply.  But  this  explanation  will  not  apply  generally,  for  in  many 
places  now  free  from  malaria  the  same  conditions  of  soil,  wetness,  and 
mosquitoes  are  found  to-day  as  existed  when  the  disease  was  endemic. 
It  is  interesting  to  note  that,  in  England,  the  Anopheles,  although  fairly 

^  Loco  citato. 

^Journal  of  Hygiene,  January,  1901,  p.  4. 

'  Annales  de  I'lnstitiit  Pasteur,  XV.,  Oct.  25,  1901. 

* CorrespondenzVjlatt  des  allgemeinen  iirztliclien  Vcr-eins  von  Thiiringen,  1901,  No.  7. 

^Centi-alblatt  fiir  Bakteriologie,  etc.,  XXVllI.,  p.  534, 


conimoii,  (l()(!,s  not  bile;  ;il.  Ic:is(-  NiiHiill  h(;i.I<',s  fli.if  inltliir  li<-  nor  any 
of  Ills  JiHK()(;iii(x!H  WHS  l)ill<Mi  while  collcttdii^';^  and  lli.il  M  i. 'I'licohaUl,  of 
ilic,  r»iiii,sli  MnHciiMi,  vvrolc  llial^  lie  lia<l  never  known  llieni  lo  hite  in 
Kn<i;lun<l.  (I  I.  is  (o  We  renienihered  tliat  /nos(|niloes  are  natni'allv 
vo^e-tariiUiK.) 

Nnttali  sn^'ii;esls  as  a  second  reason  lor  llie  disappearanr'c  oC  malaria 
i'roni  l^jii^land  IIk!  i'e(Iii(^li(»n  of  (Ik;  j)oj»nlation  of  llie  infected  disirictH 
by  emigration  at  about  (lie  time  of  (lie  disa))|Karanr-e.  'I  Ins  would, 
ol"  course,  rediic(!  the  mnnber  oC  inl'ectted  individn;ds  and  IcsKcn  tlie 
(chance  of  Ihe  yhyoy>Ar/r.s  becfimini;  inl'ecled.  Koch  and  many  others  are 
.str()n(:;ly  ol"  the  o|)inion  that  the  ns(!  of  (juininc  has  had  nif»rf;  t^)  do 
with  the  disappearance  of  malaria  than  anythinj^  else,  but  it  is  proiiablc 
tlmt  there  is  some  other  as  yet  nm-ecooni/cd  cause,  and  that  all  the  influ- 
ences luentioucd  have  contributed  in  (lillcrent  degrees.  'I'hat  there  is 
some  such  undiscovered  local  condition,  nm-t  be  very  evident  when  we 
consider  the  following'  facts  published  by  ( 'elli  and  CjIaspciHni  :'  Certain 
localities  in  Tuscany,  which  less  than  thirty  years  ajj^o  were  very  mala- 
rious, are  to-day,  so  iar  as  can  be  ascertained,  in  precisely  the  same 
geileral  condition  as  obtained  before  malaria  disajipeared  tlierefnjm. 
The  stagnant  marsh-water  swarms  with  Anopheles  larvae,  and  the  air 
above  with  myriads  of  the  imagines.  There  is  no  lack  of  the  malarial 
parasite  for  iniection  of  the  mosquitoes,  for  the  people  go  to  other 
districts  and  retiu-n  with  malaria ;  and  yet,  in  spite  of  the  presence  of 
the  essential  factors  for  an  extensive  epidenn'c,  no  outbreak  occurs.  The 
children  are  robust  and  healthy,  the  adult  population  shows  no  effects 
of  malaria,  and  many  who  have  lived  there  all  their  lives  have  never 
had  the  slightest  attack  of  the  fever.  This  freedom  is  not  due  to 
acquired  immunity,  for  the  inhabitants  take  the  disease  when  they  go  to 
malarious  districts  for  work.  The  mosquitoes  are  not  insusceptible  to 
infection,  for  specimens  captured  there  are  readily  infected  by  malarial 
blood  in  Rome.  Quinine  cannot  be  credited  with  being  the  cause  of 
the  exemption,  for  it  is  not  used  more  extensively  than  elsewhere.  In 
India,  too,  there  are  districts  Avhich  were  formerly  malarious,  but  are 
now  com]iaratively  healthy  in  spite  of  apparently  unchanged  conditions. 

But  although  Anopheles  may  exist  where  malaria  is  unknoMn,  the 
converse  is  not  true,  for  where  malaria  is,  there,  also,  are  mosquitoes. 
The  assertion  that  in  Java  there  are  places  where  malaria  abounds 
without  mosquitoes,  has  been  investigated  by  Koch,  Avho  found  that 
mosquitoes  were  everywhere  ]iresent  where  malaria  prevailed.  He  found 
also  a  place  in  East  Africa  with  all  the  conditions  favorable  to  malaria 
excepting  mosquitoes,  but  with  no  evidence  of  the  disease.  In  many 
of  the  islands  of  Polynesia,  where  marshes  are  very  extensive  and  all 
malarial  conditions  are  present  at  their  maximum,  with  the  exception  of 
mosquitoes,  no  malaria  is  known. 

It  seems  reasonable  to  assume  that,  given  the  necessary  species  of 
mosquitoes,  the  introduction  of  infected  persons  into  a  district  would 
probably  be  followed  by  the  appearance  of  other  eases  ;  but  there  are, 

»  Centralblatt  fiir  Bakteriologie,  etc.,  Oct.  23,  1901,  p.  523. 
45 


706         THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 

fortunately,  a  number  of  conditions  which  must  be  fulfiHotl  in  order  to 
bring  this  about.  First,  the  Anojjhch'i^  must  be  blood-drinkers  ;  sec- 
ond, they  must  bite  the  infected  individuals ;  third,  they  must  then 
develop  the  pai-asite  within  themselves  ;  and,  fourth,  they  must  live  to 
bite  another  person  when  the  sporozoites  are  still  present  in  the  salivary 
duct.  In  addition,  certain  favoring  conditions  of  temj^erature  are 
required,  both  for  the  activity  of  the  mosquito  and  for  the  development 
of  the  parasite.  Should  cold  weather  come  on  shortly  after  the  malarial 
subject  is  bitten,  no  liarm  might  follow,  for  about  ten  days  are  required 
before  the  mos([uito  becomes  fully  infective,  and  in  a  cold  atmosphere 
she  is  sluggish  and  will  not  bite. 

Preventive  Measures. — In  order  to  prevent  multiplication  of  Anoph- 
des,  measures  should  be  taken  to  diminish  the  number  of  breeding- 
places  by  drainage  and  other  means,  and  the  larv?e  should  be  destroyed 
where  it  is  not  possible  to  accomplish  removal  of  the  water.  The 
natural  enemies  of  the  larvae  may  be  introduced  at  very  slight  expense 
and  with  a  minimum  of  trouble.  Among  these,  Howard  mentions  as 
most  efficacious,  sunfish,  sticklebacks,  and  top-minnows.  Where  fish 
cannot  be  introduced,  the  application  of  the  chea])est  kerosene  at  regu- 
lar intervals  will  not  only  kill  all  larvse,  but  will  prevent  the  impreg- 
nated female  from  laying  her  eggs.  Kerosene  spreads  easily  and  does  not 
evaporate  too  quickly,  and  a  barrel  will  suffice  for  an  area  larger  than 
two  acres.  A  single  application  by  means  of  mops  or  watering-pots — 
about  an  ounce  to  fifteen  square  feet,  enough  to  give  a  very  thin 
film — will  remain  for  at  least  a  week,  and  generally  a  fortnight ;  and 
since  a  week  must  elapse  for  eggs  to  develop  into  pupae,  a  second  appli- 
cation need  not  be  made  until  about  seventeen  days  have  elapsed. 

The  sick  should  be  protected  by  mosquito-netting,  and  the  same 
means  should  be  employed  to  prevent  access  to  the  houses  of  the  well, 
and  for  the  protection  of  those  who  may  be  obliged  to  sleep  in  the  open. 
Local  applications  to  the  skin  (oil  of  pennyroyal,  oil  of  eucalyptus,  etc.) 
are  not  of  much  value. 

Fermi  and  Tonsini  ^  have  reported  a  noteworthy  instance  of  diminu- 
tion in  the  amount  of  malaria  after  systematic  destruction  of  the  larvae 
of  mosquitoes.  The  Island  of  Asinara,  inhabited  solely  by  convicts 
and  their  guards,  has  often  been  ravaged  by  malaria.  The  larvae  of 
different  species  of  mosquitoes  were  found  in  many  wells  and  horse- 
ponds,  and  were  treated  with  kerosene  a  number  of  times.  Screens 
were  placed  in  the  windows  and  doors  of  the  dormitories.  The  results 
were  most  satisfactory,  only  9  cases  of  malaria  occurring  during  the  year, 
against  99  in  the  year  preceding. 

If  Anopheles  gain  access  to  houses,  they  may  be  destroyed  by  fumi- 
gation with  sulphur  dioxide,  employing  1  pound  of  sulphur  for  each 
1000  cubic  feet  of  air  space. 

For  prophylaxis  by  means  of  quinine  sulphate,  the  daily  ingestion  of 
2.5  to  5  grains  is  advised.  However  efficacious  this  may  be,  it  will 
have  to  be  admitted  that  it  is  an  expensive  measure,  for  the  mini- 
1  Zeitschrift  fiir  Hygiene  und  Infectionskrankheiten,  XXX.,  p.  534, 


MosQiJiroKS.  707 

muni  <I()S(\  ;i(lvis('fl  would  |-c(|iii|-c  the  ;iiiiii|;il  use  of  no  Irv--  fli.'iii  V,')  tons 
per  million  popnialion. 

Mosquitoes  and  Yellow  Fever. — Sincf  |(;!k",,  wlu-n  y«llo\v  \'(\<r 
mude  ils  lirst,  a[)|)(;ii,rniic(,'  in  tliis  country,  flicic  iiiivc  ix-cri  no  \v)-h  iIijui 
05  ('iiidcniicis  oC  ^rciilcr  (»r  h-sscr  mjij^nitndc  witliin  tlic  l'nit<;d  Sfat<'s. 
Accordiu}^  to  l\,(U'd  juid  (yiirroll,'  sinc'c  171).'}  llic  di.sr-asc  Juih  Yh-c.w  i\\v. 
cuusc!  of"  no  ]c!s.s  tiijin  ]()0,()()f)  dcaflis,  llj.'MH  of  wliidi  liavj-  r)rcurn<i 
in  New  Orleans,  1(),().''>.S  in  l'liilad(l|)l)ia,  and  77o;i  in  McmpliiH 
riS^f),  '7.'},  '7.S,  '70).  liclAvccn  I  Mr,  I  jind  I  H,S;5,  it  cau-ed  2;{,;iP>« 
deaths  at  Kio  dc  Jancii-o,  where,  aeeordiiifr  ti)  (lonvea,^  previons  t/»  lH4f) 
it  was  unknown,  heinn-  introihieed  in  that  year  by  the  Jirazil  from  New 
Orleans  and  Havana,  and  by  the  Navarre  from  Bahia.  From  Rio  it 
spread  to  all  the  towns  in  the  bay.  Between  1853  and  HK)(),  it  ean.'^ed 
35,952  deaths  at  Havana,  where  it  had  flonrislied  eontinnou.'-lv  for 
more  than  a  eentury,  and  wliere,  after  a  practical  a])])lication  rtf  the 
knowledo;e  concerning  the  method  of  its  dissemination — the  outcome 
of  brilliant  work  on  the  part  of  Keed  and  his  associates,  of  the  United 
States  Army — it  was  demonstrated  that  it  could  be  completely  eradicated, 
and  that  even  thouo;h  outbreaks  shf)uld  occur  on  shij)s  arriving  from  in- 
fected jiorts,  removal  of  the  victims  to  the  fever  hos})itaI  need  give  rise 
to  no  new  cases. 

Inability  to  control  the  spread  of  the  disease  has  hitherto  been  due 
to  the  fact  that  the  manner  of  its  dissemination  was  not  known,  and 
that  all  efforts  to  control  it  were  exerted  in  tJie  wrong  directifm,  in 
the  belief,  now  shown  to  have  been  unfounded,  that  fomites,  filth,  and 
soil  conditions  were  the  distributing  agencies. 

It  was  in  1848  that  Dr.  Josiab  Nott,  of  Mobile,  suggested  that 
mosquitoes  might  be  responsible  for  or  connected  Avith  the  spread  of 
yellow  fever,  but  the  idea  appears  to  have  been  received  with  indiffer- 
ence. In  1881,  Dr.  Finlay,  of  Havana,  announced  his  theory-  of  mos- 
quito transference,  and  began  his  experiments,  but  it  remained  for 
Reed  and  his  associates  to  demonstrate  conclusively  that  mosquitoes 
are  the  principal,  if  not  the  sole,  carriers  of  the  exciting  cause,  and  that 
fomites  and  filth  have  absolutely  no  influence  whatever. 

The  experiments  proving  both  statements  are  exceedingly  interest- 
ing. In  October,  1900,  Reed'  reported  positive  results  of  exj^eri- 
ments  conducted  by  himself  and  Drs.  Carroll,  Agramonte,  and  Lazear 
M'ith  mosquitoes,  Stcgomy'm.  calopus,  furnished  by  Dr.  Finlav.  Carrol) 
was  bitten  by  one  that  had  bitten  four  yellow  fever  patients,  alternately 
severe  and  mild  cases,  respectively,  twelve,  six,  four,  and  two  days 
previously.  Four  days  afterward  he  took  to  h."s  bed,  and  on  the  fifth 
day  his  disease  was  diagnosed  as  yellow  fever.  Another  subject  was 
bitten  by  the  same  mosquito,  and  by  three  others  that  had  previously 
bitten  patients  with  the  disease,  and  in  seven  days  he  also  had  the 
fever.     Dr.  Lazear  was  bitten  without  result  by  an  infected  mosquito 

1  Medical  Eeoord.  October  26,  IWl,  p.  641. 
■■^  Bulletin  medical,  Octoher  12,  1901,  p.  861. 
'  Philadelphia  Medical  Journal,  Octoher  27,  1900. 


708         THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 

on  August  IGth,  and  bv  anothei',  an  accidental  stranger,  on  September 
13th.  In  five  days,  he  had  a  chill ;  on  the  day  following,  the  diagnosis 
of  yellow  fever  was  made,  and  in  a  week,  the  case  terminated  fatally. 
Between  August  17th  aud  October  13th  (fifty-seven  days),  these  three 
were  the  only  cases  which  occurred  among  1400  non-immune  Ameri- 
cans at  Quemados. 

On  November  20,  1900,  an  experiment  station.  Camp  Lazear,  was 
established  at  Columbia  Barracks,  Cuba,  under  tlie  direction  of  Reed, 
who,  with  his  former  associates,  continued  the  work  with  gratifying 
results.  A  very  strict  quarantine  Mas  established,  and  no  non-immune 
was  subjected  to  mosquito  inoculation  (with  one  exception)  who  had 
not  passed  the  full  period  of  incubation  of  yellow  fever  under  close 
observation,  nor  was  any  non-immune  who  left  the  camp  permitted 
to  return  under  any  circumstances.  Twenty-one  subjects  presented 
themselves,  mostly  immigrant  Spaniards  seeking  imnmnity,  and  the 
result  in  each  case  was   positive. 

Experiments  with  fomites  ^  were  equally  convincing  in  results. 
Three  large  boxes  of  sheets,  pillow-slips,  blankets,  etc.,  contaminated 
with  the  discharges  of  yellow  fever  patients,  many  of  them  purposely 
soiled  with  black  vomit,  urine,  and  faces,  were  placed  in  a  building 
of  2800  cubic  feet  capacity,  tightly  ceiled  and  battened,  with  small 
windows  to  prevent  thorough  circulation  of  air  and  wooden  shutters  to 
prevent  the  disinfectant  action  of  sunlight.  The  windows  were 
screened  with  wire  gauze,  and  the  entrance  with  a  screen  door.  The 
articles  were  unpacked  by  Dr.  Cooke  and  two  privates,  and  they  Avere 
shaken  so  that  the  specific  agent  might  be  disseminated  throughout  the 
room,  if  it  were  present.  They  were  then  used  on  the  three  beds  ])ro- 
vided,  and  some  were  hung  about  the  room  and  near  the  beds.  For 
twenty  consecutive  nights,  the  three  slept  in  the  uninviting  beds,  and 
every  morning  they  packed  the  filthy  articles  back  into  the  boxes, 
and  every  evening  unpacked  and  distributed  tliem  again.  They  passed 
their  days  in  tents  in  quarantine.  During  their  tour  of  service,  other 
bedding,  soiled  with  the  bloody  stools  of  a  fatal  case,  was  received  in  a 
most  offensive  stinking  condition,  and  used  with  the  rest.  Then  other 
non-immunes  repeated  the  experiment  for  twenty-one  nights,  sleeping 
in  the  very  garments  which  had  be:'n  used  by  patients.  Then  these 
subjects  were  followed  l)y  others,  who,  for  fourteen  nights  out  of  twenty, 
slept  with  pillows  covered  with  towels  that  had  been  thoroughly  soiled 
with  blood  drawn  from  a  case  of  well-marked  yellow  fever  on  the  first 
day  of  the  disease.  The  result  of  the  exposure  of  these  non- 
immunes in  relays  for  nine  weeks  was  wholly  negative,  for  not  one  had 
the  first  symptom  of  yellow  fever.  Not  so,  however,  in  the  case  of 
a  man  who  was  exposed  in  a  building  of  similar  size,  thoroughly 
ventilated,  and  containing  only  disinfected  articles  plus  infected  mos- 
quitoes. On  December  15,  1900,  15  of  the  insects  were  set  free,  and 
he  Avas  soon  bitten  several  times.  Later,  he  was  bitten  again,  and  also 
on  the  following  day.     He  contracted  the  disease  ;  but  2   men  who 

^  Kepoited  in  Medical  Kecord,  October  26,  1901,  and  in  other  American  journals, 


M()H(/(!i'r<)i':s.  700 

wlopt  for  ci^lilccii  iiiL";!!!.^  in  ;i  li;il(' 'if  l  he  i-ooni  w  liidi  wa.s  wirfMi''!  IVoni 
the  olJuii' . '111(1  (Voni  llic  rii()S(|iiil,oc.s  hy  iicltiiij/,  had  no  !<viii[»l<iiii.~. 

Wlialcvcr  (he  iialiirc  (tC  the  para.sifc,  i(s  life  vyr\i'  \\i\\\\t\  ap|H:ir  not 
to  wv.vA  Ihc  passa^'c  o("  the  |);iraMlf  ihrminh  [\\f  iiilcrriicdialc  hoKt,  for 
.R(!C<1  '  aixl  his  a.,sso(Ma(cs  .succeeded  in  piodiii'iiiK  ihcdisfasc  l)V  injec- 
tion of  bh)od  (h'iivvn  from  ili(!  ^cneinl  eiieidal  ion.  Allhon^'-h  ihc  j-pccific 
raiiKa  worhi  has  iioi-  yet  been  discovered,  il  :ipp(;ir>  lo  lie  deflniir'ly 
seliled  that:  it  is  not-  Sanarelli's  I',.  U'lcroiilcH. 

The  conchisions  ari"i\-ed  ;il  1)\-  iw'ed,  ^ ';nr()ll,  ;ind  .\i_M-atnonle,  and 
re|)orLed  to  tlie  A  nieriean  Medical  Associal  ion,  are,  in  hricf,  as  foHous  : 
'^rh(;  interrn(>(liat(^  iiost  is  the  Sl('(/()mi/i(t.  ca.lo/»iis^  which  is  eajtahh;  of 
transmit  lino;  Ihc  disease  alter  an  iiitci'va!  of  about  twelve  davs  or 
h)n<:;ei"  alter  becomiiit;'  eonfaminaled  by  biting  a  ]»erson  ab'ea«lv  sick. 
'I'he  disease  can  be  caused  by  subetilaneous  injection  of  blood  from  the 
o'cneral  circulation  during'  the  lirst  or  second  day  of  si(;l<ness.  Im- 
munity is  not  conferred  by  the  bile  of  a  mosfpiito  at  an  earlier  perir»d 
alti'r  cpntaniination  ;  but  when  the  disease  is  produced  throu^rli  the 
aji'ency  of  a  mos((nito,  the  subject  is  innninie  a<rainst  i?ifection  by  sub- 
(^utancous  injection  of  blood.  I'lie  period  of  incnbalion  in  cases  of 
induced  fever  varied  from  forty-one  hours  to  five  days  and  seventeen 
hours.  The  disease  is  not  conveyed  by  fomites,  an<l  hence  disinfection 
of  a  house,  except  as  to  mosquitoes,  is  unnecessary.  The  s])read  of 
the  disease  can  be  controlled  most  efFectually  by  measures  directed  to 
the  destruction  of  mosquitoes  and  to  protection  of  the  sick  ag'ain.st  them. 

That  not  less  than  twelve  days  are  required  for  the  W)ntaminatw3 
mosquito  to  acquire  the  power  to  transmit  the  disease,  is  borne  out  by 
the  observations  of  Dr.  H.  R.  Carter,^  who  found  that,  in  sixteen  houses 
in  which  95  secondary  eases  of  yellow"  fever  occurred,  the  interval  be- 
tween the  first  and  second  cases  ranged  between  twelve  and  twenty- 
three  days. 

The  Yellow  Fever  Mosquito,  Stcr/omi/ia  calopus  (Figs.  Ill  and  112), 
formerly  knowm  as  Culc.r  fasciatus,  is,  in  this  country,  confined  princi- 
pallv  to  the  tropical  and  subtropical  regions  along  the  Atlantic  Ocean 
and  Gulf  of  INIexico,  but  may  be  transferred  from  one  region  to  another 
bv  the  usual  vehicles  of  travel.  It  is  found  in  all  the  principal  cities 
and  some  of  the  smaller  towns  of  Cuba  ;  in  Jamaica,  Isle  of  Pines, 
and  Nicaragua  ;  in  Louisiana,  especially  in  New^  Orleans  ;  in  Eastern 
Texas  ;  in  various  places  in  other  Southern  States  ;  in  a  number  of 
towns  and  cities  in  Brazil,  and  in  certain  other  hot  countries.  It  is  not 
essentially  an  American  species,  for  ]Mr.  Theobald,  of  the  British  Mu- 
seum, states  that  he  has  received  specimens  from  Italy,  Greece,  Spain, 
Portugal,  and  ISIalta.  Its  presence  in  Spain  may  explain  the  occurrence, 
in  1800,  of  a  very  extensive  epidemic  of  yellow  fever  in  the  province 
of  Andalusia,  and,  in  1821,  of  another  at  Barcelona.  "Wherever  it  is 
found,  it  appears  to  prefer  the  larger,  populous  centres,  and  to  be  but 
little  common  in  rural  districts. 

»  Philadelphia  IMedical  .Jonrnnl.  .Tulv  (i,  1901. 
■•*  Medical  Kecord,  June  15,  1901,  p.  933. 


710 


THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 


The  Stcc/omi/ia  breeds,  like  Cidiccs,  in  small  collections  of  Avater. 
Reed  and  Carroll  found  the  larvoe  in  rain-water  barrels,  sagging  gut- 
ters containing  rain-water,  cesspools,  tin  cans  used  for  removing  ex- 
creta, tin  cans  ]>laced  about  table  legs  to  prevent  inroads  of  red  ants, 
horse-troughs,  leaves  of  the  Agave  Americana,  and  generally  in  any 
collection  of  still  water.  The  New  Orleans  IMosquito  Commission' 
found  the  larvoe  in  128  of  210  cisterns  examined  by  them.  According 
to  this  authority,  the  life  cycle  of  Stegomyia  is  somewhat  different  from 
that  of  other  genera,  and  these  diiferences  may  necessitate  more 
stringent  measures  than  will  suffice  for  the  suppression  of  Culices  and 
Anopheles,  for  the  eggs  hatch  earlier  (ten  to  twenty-four  hours),  and 
the  larval  (six  and  one-half  to  eight  days)  and  pupal  stages  (two  days) 
are  much  shorter,  so  that  full  development  requires  from  two  to  four 
days  less  than  for  Cidex  pungens,  and  two  weeks  less  than  for  any 
species  of  Anopheles.     According  to  Reed  and  Carroll,  the  eggs  begin 


Fig.  in. 


Fig.  112. 


Stegomyia  fasciata.    Male.     (After  Howard. 


Stegomyia  fasciata.    Female.    (After  Howard.) 


to  hatch,  as  a  rule,  on  the  third  day,  and  the  process  may  last  about 
a  week  ;  the  larval  stage  lasts  seven  or  eight  days  and  the  pupal  stage 
two  days ;  the  shortest  time  for  complete  development  observed  by 
them  was  nine  and  one-half  days.  At  an  average  temperature  of 
75°  F.  or  higher,  the  species  multiplies  abundantly,  but  exposure  to  a 
lower  temperature  for  even  a  short  time  daily  causes  much  retardation, 
and  eggs  kept  at  68°  F.  do  not  hatch.  They  found  that  newly 
hatched  larvae  kept  at  68°  F.  develop  slowly,  and  require  twenty  days 
to  reach  the  pupal  stage  ;  kept  at  50°  F.,  they  fail  to  reach  the  pupal 
stage. 

Although  low  temperatures  are  destructive  of  the  larvse,  it  is  other- 
wise with  the  eggs,  which  Reed  and  Carroll  found  to  be  very  resistant 
to  the  influence  of  dryness  and  cold.      They  observed  that  eggs  which 
had  been  dried  on  filter-paper  and  kept  ninety  days  hatched  promptly 
^  New  Orleans  Medical  and  Surgical  Journal,  January,  1902. 


M<)S(/iiiT()i<:s.  71 J 

on  bciiifj^  j)I;u!('(l  In  walci'.  hricd  c^j^h,  hr<>n/r|it.  from  Ilavnna  to 
Wiifsliin^lon  in  l^'chniaiy,  were  easily  liah-licd  in  iVIav,  aixl  f'nrnihlir;(l 
about  ()()  \)vv  (Thl.  of  llic  usual  iiiinihcr' of  larva;  liat<'lu'<l  from  f'rchh 
egf^H.  Kji.K''^  Irozcn  lor  an  lionr,  tliawcd  on!  at,  room  lcm|i«-ra)nr(',  and 
j)hic(!d  in  iin  incubator  al  \)U"  I'.,  hc^jan  to  luitcli  on  the  ^ixtli  <lay,  ;;nd 
furnislit'd  active  lai'\a'  on  llic  ciLjIilli  ;  wliili  ollicrs,  fro/on  for  a  half 
hour  on  two  successive  days,  l)e;:an  to  lialcli  uniU-r  th(r  Hau)(!  conditiouH 
on  tlie  third  day.  Thus  it  would  apix-ar  that  egf^H  may  Hurvivc  the 
ITiivanii  wintcM",  and  that  the  presence  of"  hibcrnalitif;  females  is  not 
necessary. 

The  female  ima^-o,  when  imprei^nated,  is  generally  ready  to  bit<!  on 
the  second  or  third  day.  Jn  JS'cw  (Jrleans,  accordinj;  to  the  Mosf|nito 
Commission,  the  moscpiitoes  are  active  durinjr  the  day,  and  partic^nlarly 
in  the  afternoon.  In  C^nba,  Iveed  and  Cairo]]  found  tliem  to  be  especially 
active  from  4  p.  M.  until  midnight,  allliouj^h  in  captivity  the  hungry 
impregnated  female  will  bite  at  any  hour.  When  freed  in  a  room,  she 
does  not  a])p(^ar  to  bite  a  second  time  within  five  to  seven  days. 

Having  bitten  a  yellow  fever  patient,  it  a])pears  that  the  niosfjuito  is 
incapable  of  inducing  the  disease  before  twelve  days  have  ])assed. 
Those  which  failed  to  infect  on  the  eleventh  day  were  successful  on  the 
seventeenth.  How  long  the  ability  to  infect  continues,  was  not  deter- 
mined, but  successful  inoculation  was  brought  al)out  as  late  as  fifty- 
seven  days  after  contamination. 

How  long  the  infected  moscpiito  will  live,  is  not  known.  The  speci- 
men which  conveyed  the  disease  on  the  fifty -seventh  day  lived  seventy- 
one  days,  others  have  been  known  to  live  five  months,  but  the  majority 
die  in  captivity  within  five  weeks.  In  a  state  of  freedom  their  length 
of  life  depends  largely  upon  access  to  water. 

At  temperatures  below  62°  F.,  Stegomyia  will  not  bite,  and  thus 
Reed  accounts  for  the  decline  in  epidemics  of  yelhnv  fever  at  Xew 
Orleans  in  November,  when  the  mean  temperature  is  61.8°  F.,  and 
their  cessation  in  December,  when  it  falls  to  55.3°. 

Preventive  Measures. — To  avoid  epidemics  of  yellow  fever,  Reed 
advocates  the  prevention  of  importation  of  cases  of  the  disease  from 
infected  localities,  and,  when  cases  do  appear,  the  application  of  meas- 
ures to  protect  the  sick  from  attacks  of  mosquitoes.  Screens  should 
be  used  for  this  pmpose,  and  even  the  dead  should  be  thus  protected, 
for  Stegomyia  will  bite  even  these.  All  mosquitoes  in  a  house  where 
a  case  occurs  should  be  caught,  and  search  should  be  made  for  them  in 
all  the  houses  in  the  immediate  vicinity.  They  may  be  destroyed  by 
fumigation  with  sulphur  dioxide  (1  pound  of  sulphur  for  each  1000 
cubic  feet  of  air-space),  which  Rosenau  ^  finds  far  su]terior  for  this  pur- 
pose to  formaldehyde,  for  very  small  amounts  of  the  dry  g-as  will  kill 
them,  even  when  they  are  protected  by  four  layers  of  towelling,  while 
formaldehyde  acts  feebly  and  Mith  uncertainty.  Pyrethrum  (Dalmatian) 
powder  may  be  burned  in  the  same  proportion,  and  Avill  either  kill  or 
stupefy  them,  so  that  in  three  hours  they  may  be  swept  up  and  burned. 
^  Bulletin  No.  6,  Hygiene  Laboratory  of  the  U.  S.  M.-H.  S.,  September,  1901. 


712         THE  RELATION  OF  INSECTS  TO  HUMAN  DISEASES. 

Nou-ininumes  entering  infected  houses  are  advised  to  nib  all  exposed 
surfaces,  iucludiug  the  ankles,  with  spirits  of  camphor,  oil  of  penny- 
royal, or  5  per  cent,  nicnthul  ointment ;  but  these  agents  exert  only  a 
temporary  protective  intiueuce  against  being  bitten. 

Of  very  great  importance  is  the  destruction  of  larvie  and  of  breed- 
ing-places. The  results  of  systematic  work  in  this  direction  and  of 
other  preventive  measures  are  manifest  in  the  innuense  imj)rovemeut  in 
the  sanitarv  condition  of  Havana.  Under  the  direction  of  Dr.  ^y.  C. 
Gorgas,  U.  S.  A,,'  tiic  "Stegomyia  Brigade"  began  its  work  of  in- 
spection in  March,  1901,  when,  in  16,000  houses  examined,  larvae  were 
found  "at  the  rate  of  100  per  cent.  This  does  not  mean  that  every 
house  examined  had  larvre ;  many  houses  were  found  that  had  several 
receptacles  which  contained  larvie."  During  December,  1901,  10,121 
houses  were  inspected,  and  in  but  1.5  per  cent,  were  the  larvae  found. 
From  May  7  to  July  1  (fifty-four  days),  no  case  of  the  disease  oc- 
cured  ;  then  it  was  introduced  from  Santiago  de  las  Vegas,  and  later  from 
other  places,  and  yet,  during  July,  there  were  but  4  cases,  and  in 
August,  but  8.  During  the  whole  year  (1901),  there  were  but  18  deadis 
from  yellow  fever,  and  12  of  these  occurred  in  January  and  February, 
before  the  work  of  prevention  was  begun.  During  the  preceding 
forty-five  years,  the  average  number  of  deaths  therefrom  was  751.44, 
the  minimum,  51,  occurring  in  1866. 

Mosquitoes  and  Filarial  Disease. — In  1872,  Dr.  Timothy  Lewis, 
of  Calcutta,  discovered  that  human  blood  is  the  normal  habitat  of  the 
embryo  nematode  discovered,  in  1863,  by  Demarquay,  in  the  milky 
fluid  from  chylous  dropsy  of  the  tunica  vaginalis,  and  named  it  Filaria 
sanguinis  hominis.  Later,  Manson,  in  consequence  of  the  discovery  of 
other  filariae  in  the  blood,  renamed  this  parasite  Filaria  nocturna,  and 
named  the  others  F.  diurna,  F.  perstans,  F.  demarquaii,  and  F.  ozzardi. 
The  most  important  of  these  is  F.  nocturna,  which  is  the  embryo  of 
F.  bancrofti,  discovered  in  1876  by  Bancroft,  of  Australia,  in  patients 
with  lymph-scrotum,  and  named  in  his  honor  by  Cobbold.  The  par- 
ental form  is  a  hair-like  nematode,  from  3  to  4  inches  long,  which 
infests  small  cyst-like  dilatations  of  the  distal  lymphatics,  lymphatic 
varices,  the  larger  lymphatic  trunks  between  the  glands,  the  lymphatic 
glands,  and  the  thoracic  duct.  The  embryos,  which  are  about  an 
eightieth  of  an  inch  in  length,  and  about  as  broad  as  the  diameter  of 
a  red  blood-corpuscle,  are  found  in  the  blood  of  persons  afflicted  with 
filariasis  from  just  before  the  approach  of  night  until  about  8,  or  9,  or 
10  o'clock  in  the  morning.  They  enter  the  general  circulation  as  night 
approaches,  and  increase  gradually  in  number  until  about  midnight, 
after  which  they  gradually  decrease  until  the  time  above  mentioned, 
when  they  disappear  from  the  peripheral  circulation.  According  to 
Manson,  it  is  not  unusual  to  find  at  midnight  as  many  as  300  to  600 
in  a  single  drop  of  blood,  from  which  he  concludes  that,  at  that  hour, 
as  many  as  40  or  50  millions  of  them  may  be  circulating  simultaneously 
1  Public  Health  Eeports,  February  14,  1902,  p.  363. 


MOSQUITOES.  713 

in  th(!  })l()()(]-V(!.sH('ls.  Diii'in^-  llic  tliiy,  tlic\-  iii;iy  he  CoiiikI  in  tlic  hirgcr 
artoricH  mikI  in  tlic  Innjis. 

Tlu!  piinisilc  is  round  in<liucii(ins  in  ;ilino.-(  ;ill  I  ii.|ii(;il  ;iri(l  .-iil>- 
tr(»|)i(;:il  (',(»iiMtri(!S,  and  in  tliis  (country  as  l;ir  noitli  a.-^  (  liarlc.slon,  S.  (,'. 
Jn  many  |»lac-(ss,  a  liall",  and  even  niofc,  (»!'  the  ]M»j)nlati(»n  arc  found  fo 
bo  infcstcid. 

Accord in<i;  to  Manson,  the  lollowin};-  (liscascs  arc  known  to  l»c  pro- 
duced by  this  |»arasil(' :  abscjcss ;  lyniplian^-iti.s ;  vari('os(;  j^roin  and 
axillary  <j;lands  ;  lyiujiii-scrofnni  ;  <;ntaiicons  and  dccj)  lyinpliatic  varix  ■, 
orcliitis;  cliylnria  ;  <'lc|)lianliasis  of"  tiic  Ic^,  scrotum,  vulva,  arm, 
mamma:!,  and  elsewhere;  cliylous  dropsy  of  the  tunica  vaginalis;  (;hy- 
h)us  ascites;  chylous  diarrhoa  ;  and  pi-obably  otiici-  diseases  (hie  U) 
obstruction  or  varicosity  of  IIk'  lyniphalics  or  to  the  deiith  of  the 
parent  worm. 

In  1.S7M,  Manson,  lia\inn-  conceixcd  the  idea  that  mostjuitocs 
might  be  instrumental  in  spreadinj^  the  disease  by  acting  as  an  inter- 
mediate iiost,  observed  the  develo])ment  of  filarijc  in  a  species  of 
Cidex  (C.  vUUirix,  vd  pipicn.s),  which  Avas  allowed  to  bite  an  infected 
person.  Within  a  few  liours,  the  bh)od  jilasma  in  the  mos(piito's 
stomach  becomes  thickened,  but  not  coagulated,  and  some  of  the 
embryos  manage  to  escape  from  their  sheaths  and  tlien  move  freely 
in  the  blood,  and  finally  esea])e  from  the  stomach  and  enter  the  tho- 
racic muscles,  where  they  remain  a  number  of  days  and  undergo  a 
process  of  metamorjihosis,  Mhich  results  in  the  formation  of  a  mouth, 
an  alimentary  canal,  a  peculiar  trilobed  tail,  and  great  increase  in 
size. 

It  wns  Manson's  idea  that  the  infested  mosquito  repaired  to  some 
body  of  water,  laid  her  eggs,  and  died  ;  and  that  the  parasites  freed 
themselves  from  the  dead  body,  lived  in  the  water,  and,  being  received 
into  the  stomach  of  man  through  drinking,  bored  their  way  through 
the  tissues  and  entered  the  lymphatic  trunks,  where,  attaining  sexual 
maturity,  fecuudatiou  occurred,  resulting  in  due  course  of  time  in 
new  generations  of  embryos  to  be  poured  into  the  lymph,  then 
through  the  glands  or  by  the  lymphatics  into  the  general  circulation. 
Bancroft,  however,  suggested  that  the  parasite  is  transmitted  back  to 
man  not  through  drinking-water,  but  by  the  bite  of  the  mosquito  : 
and  in  1900,  G.  C.  Low  discovered  that  the  metamorjihosed  worm 
makes  its  way  to  the  insect's  head,  and  finally  into  the  root  of  the 
proboscis,  in  which  it  lies  until  the  mosquito  bites  another  person,  when, 
stimulated  into  activity  by  the  warmth  of  the  encompassing  tissues, 
it  moves  from  its  position  in  the  proboscis  and  enters  the  wound. 
The  worms  thus  introduced  undergo  farther  development  in  their 
new  position  in  the  skin  and  become  adults,  and  proceed  to  breed 
embryos,  which  enter  the  lymph  spaces  or  vessels. 

According  to  ISIanson,  in  most  cases  of  infection  the  ]iarasite  exer- 
cises no  manifest  injurious  infiueuce  whatever,  and  in  those  cases  in 
which  injury  is  caused,  the  trouble  is  due  in  the  main  to  obstruction 
of  the  lymphatics  by  the  parent  worms. 


714         THE  RELATION   OF  INSECTS  TO  HUMAN  DISEASES. 

At  first  it  was  believed  that  the  intermediate  host  was  Culex  ciliaris 
(vel  pijjit'iis)  alone,  but  a  number  of  other  mosquitoes  are  now  known 
to  act,  including  species  of  Culex  and  Anopheles.  These  include, 
according-  to  James,  ^1.  Bo.ssii,  C.  albopuncfatus,  and  C  microannu- 
lattts;  and,  according  to  Low,^  C  J\(tigans  ;  and  to  Vincent,^  A.  ulbi- 
riianus.  Low  reports  that,  in  Barbadoes,  neither  malaria  nor  any  spe- 
cies of  Anopheles  is  knoM'n,  but  that  there  are  much  filarial  disease  and 
an  extraordinary  abundance  of  C.  fatigans.  In  600  blood  examina- 
tions of  persons  taken  at  random,  12.G6  per  cent,  yielded  Filar ia 
nocturna.  In  Trinidad,  Vincent  found  in  500  cases  taken  at  random, 
5  per  cent,  infested  with  filarise  and  6.6  per  cent,  with  elephantoid 
disease.  In  Culex  fatigans,  it  was  observed  that  the  final  stage  of 
metamorphosis  was  reached  between  the  sixteenth  and  nineteenth  days, 
but  with  A.  albimanus,  since  none  of  the  specimens  lived  in  captivity 
beyond  the  twelfth  day,  it  was  not  possible  to  determine  definitely 
when  the  final  stage  is  reached.  In  the  case  of  C.  ciliaris,  Bancroft 
prolonged  the  life  of  the  insect  and  followed  the  development  of  the 
parasite  to  the  last  stage  of  its  metamorphosis,  which  occurred,  under 
favorable  conditions  of  temperature,  at  about  the  sixteenth  or  seven- 
teenth day  after  feeding. 

Filaria  diurna  is  a  form  which  is  detected  in  the  blood  only  by 
day,  and  it  has  been  supposed  to  be  a  distinct  species,  although  nothing 
is  known  about  its  life  history  or  pathological  significance.  Accord- 
ing to  the  findings  of  the  Nigeria  Malaria  Expedition,^  however,  there 
are  so  many  points  of  resemblance  between  the  t\vo  forms  that  it  is 
possible  that  they  may  be  identical.  It  is  pointed  out  that  the  geo- 
graphical distribution  of  the  two  forms  is  in  close  agreement,  although 
in  many  places  where  F.  nocturna  is  known  to  exist,  F.  diurna  has 
not  been  noted ;  but  the  latter  is  not  known  to  exist  where  the  former 
is  absent.  Furthermore,  in  some  of  the  Pacific  islands  where  ele- 
phantiasis is  exceedingly  common  and  F.  nocturna  is  found,  there  is 
none  of  the  characteristic  nocturnal  periodicity.  Where  both  were 
found,  the  members  of  the  expedition  were  unable  to  distinguish  in 
any  way  the  one  form  from  the  other.  In  some  cases,  embryos  Avere 
found  during  both  day  and  night.  It  is  known  that  when  persons 
infested  with  F.  nocturna  change  ther  habits,  so  that  they  sleep  by 
day  and  keep  about  by  night,  the  filarise  are  found  in  the  peripheral 
circulation  only  during  the  day. 

Filaria  demarquaii  resembles  F.  diurna  and  F.  nocturna  in  shape, 
but  not  in  size,  being  about  half  as  large.  It  is  present  in  the  blood 
both  by  day  and  l^y  night  in  the  peripheral  circulation.  Low*  has 
attempted,  without  success,  to  determine  the  intermediate  host  neces- 
sary for  the  development  of  the  embryos  to  the  point  where  they  are 
capable  of  farther  growth  in  man,  but  is  of  the  opinion  that  the  inter- 
mediate host  is  a  blood-suckinar  insect. 

Mosquitoes  and  Dengue. — Concerning  the  etiology  of  this  disease 

'  British  Medical  Journal,  September  14, 1901,  p.  687.         ^  Ibidem,  January  25,  1902. 
^  Memoir,  IV.,  p.  89.  *  British  Medical  Journal,  January  25,  1902. 


MOSQUITOES.  715 

of  ^l■()|»i(^'^l  (•JiiriiiicM,  iiofliliif;  liiiH  v.wv  hccii  known,  iiltli'»ii^r||  riiany  liy- 
j)()l,li(!S('S,  dilTcrin^'  \vi<l('ly,  li;iv(!  Ween  ;wlviinr!c<l.  Iv«'<'cntly,  liowcvcr,  an 
inv(!sti^iiti()n  condnclcd  hy  Dr.  Iliirri.s  (iraliani,'  in  llic  vicinity  of  Ijcy- 
roiilli,  in  Syria,  ini|)Iicat('.s  (lie  in«»s«|nif<)  u.s  :in  inipfjrtant  I'aclor  in  its 
sj)rca(l.  At,  lli(!  |)la(;('  nicntiDncd,  tlif  dlHcaHu  Ih  very  pntvalciil,  and 
ni<)S(|ni(()('S  of"  (Jic  ^cnns  ('ii/c.r  arc  a  serious  pest,  (iraliani  «>l»s«'rvc<l 
that  tlic  discas(!  o(rc.ni-i'cd  in  persons  under  observation  only  wlu-n  tliey 
were  bittcni  by  infected  inos(|uitoes,  and  llial,  when  lliey  won;  biftrn, 
the  disease  invariably  followed.  I'^)r  example  :  he  ap|tli(!d  nios(piitoeH 
to  a  l)erson  suHerin^  (Voin  i(,  and,  ;d'l(  r  tluy  had  bitten,  carried  them 
in  a,  ])apei'  box  to  a  villa|;;e,  lii^h  up  on  a  mountain,  where  there  wa,s 
no  (iasc  ol' the  disease.  There  they  were  allowed  to  bit<r  two  apparently 
healthy  persons,  in  whom,  in  four  and  six  days,  rcsjicctively,  tyj)ical 
attacks  occurred.  In  a  large  number  of  cases,  he  made  exaininationH 
of  the  blood,  and  in  every  instance  he  found  in  the  red  corpuscles  an 
amo'boid  pai'asite  which  bore  considerable  resemblance  to  the  malarial 
organism,  but  iTcpiired  a  much  longer  time  for  its  cyclic  d(;velopment 
and  show^ed  no  ])igment  at  any  stage.  The  organisms  were  found  at 
times  also  in  the  blood  j>lasma.  Flagellated  forms  were  observed  also 
in  some  cases  when  the  blood  had  stood  for  some  time. 

Further  observation  and  study  are  obviously  desirable  and  necessary. 
1  Medical  Record,  February  8,  1902. 


CHAPTEK   XIII. 
HYGIENE  OF  OCCUPATION. 

The  influence  of  occupation  on  health  and  length  of  life  has  been 
the  subject  of  much  investigation  since  attention  was  first  called  to  its 
importance  by  Professor  Bernardino  Kamazzini,  of  Padua,  in  1700,  but 
more  particularly  during  the  last  half  century.  Although  his  work 
was  translated  anonymously  into  English  as  early  as  1705,  the  subject 
appears  to  have  been  one  that  did  not  appeal  with  any  special  force  to 
English  social  scientists  and  medical  men,  for  the  first  English  work 
of  any  importance  was  that  by  Mr.  C.  Turner  Thackrah,  a  pnictitioner 
of  Leeds,  ou  The  Effects  of  the  PrinGvpal  Arbi,  Trades  and  Professions, 
and  of  Civ'iG  States  and  Habits  of  Living,  on  Health  and  Longevity, 
published  in  1831.  A  French  translation  of  the  work  of  Ramazzini 
appeared  in  1777,  and  formed  the  groundwork  of  P.  Patissier's  Traite 
des  3Ialad'ies  des  Artisans  et  de  celles  qui  Resultent  des  Liverses  Pro- 
fessions, d'apr^s  Pamazzini,  which  was  published  at  Paris  in  1822. 
It  was  translated  early  also  into  German ;  but  the  first  work  of  any 
importance  on  the  subject  by  a  German  writer  was  that  of  Halfort, 
Entstehung,  Verlauf,  und  Behandlung  der  Krankheiten  der  Kunstler  und 
Gewerbetreibenden,  published  at  Berlin  in  1845. 

Since  the  awakening  of  interest  in  the  subject  in  England,  France, 
Germany,  and  other  European  countries,  and  the  United  States,  it  has 
been  extensively  and  minutely  studied  in  all  its  aspects,  and  to-day 
its  bibliogra]>hy  includes  thousands  of  titles,  mostly,  however,  as  would 
naturally  be  supposed,  of  monographs  and  memoranda  pertaining  to 
individual  callings.  From  this  vast  amount  of  material  from  all 
sources,  numerous  tables  have  been  constructed,  showing,  it  is  generally 
supposed,  liow  the  various  occupations  stand  relatively  in  the  amount 
of  influence  which  they  exert  on  the  longevity  of  those  engaged  in 
them.  From  these  tables  it  appears,  for  example,  that  those  who 
follow  some  particular  calling  are  more  prone  to  contract  certain  dis- 
eases than  those  engaged  in  another ;  that  in  each  hundred  individuals 
of  some  one  class,  a  greater  number  of  deaths  will  occur  in  a  year  than 
in  each  hundred  of  another ;  that  the  average  age  at  death  of  those 
engaged  in  one  employment  is  lower  or  higher  than  that  of  those  in 
another,  and  so  on. 

As  in  all  findings  based  upon  groups  of  units  with,  perha[)S,  but  one 

common  bond,  each  unit  being  subject  to  a  variety  of  outside  influences, 

the  conclusions  drawn  from  this  vast  mass  of  material  are  influenced 

largely  by  fallacy,  and   include  wheat   and  chaff,  fact  and  fancy.     In 

716 


IIYdlKNK   OF  OCaiirATION.  717 

mnny  cihcs,  ^cihm'mI  Hlnfcincrils  iin;  hnncd  upon  hii(;li  ;i  sli^lil,  foiinda- 
tioii  MM  l(»  iii(lii:i(c  (hill,  (iicir  jiiitliorH  an;  po.s.scM.scd  of  tlial,  dcj^rfc  of 
p;(!iiiii,s  wliicli  lias  hccn  defined  as  tlic  ability  to  ^reneralize  Irotn  a 
Hingl(!  inslance.  In  many  others,  th<y  nre  hased  npon  lael^  and  eon- 
ditiions  which  no  lonj^er  exist,  the  ni<lhod-  (olluwed  in  the  niaind'aetnn; 
of  iJi(!  |)a,rti<'nlai'  article  (Mtneerned  liavinj^-  nndei'j^one  a  eoni|tl<  te  <-hanjrc. 
For  example,  a  process,  I'oiiiieilv  carried  on  hy  men  in  small  otahlish- 
ijients  rnn  hy  water-power  in  the  conntry,  mav  have  heen  cfiticen- 
trutcd  in  hirj^c  mills  rnn  hy  steam  and  sitnated  In  crowded  cities;  the 
mtiohincry  is  dilferent,  and  more  peife<'l,  and  r((jiiires  nothinf;  more 
than  fecidinji,',  and  this  may  he  done;  hy  a  hoy  or  ^drl,  instead  of  ati 
adult  nuui.  Here,  tlu;  ohhsr  facts  may  no  hmj^cr  !ip))ly  in  any  way, 
and  for  j)rcscnt  pnr|)oses  shonid  he  ahandoned  as  helonjrin^-  to  an  ex- 
tinct occuj)ation. 

Jt  is  often  difficult  or  impossihie  in  the  sindy  of  the  effects  of  occn- 
pation  to  eliminate  outside  inflnences  which  may  affect  the  health  of 
the  worker  as  much  us  or  more  than  the  circumstances  oi'  his  trade. 
A  hundred  men,  for  cxani])le,  from  different  strata  of  .society — some 
married,  others  single  ;  some  living  in  comfortal)le  houses,  others  in 
cheerless,  unsanitary  tenements;  some  spending  their  evenings  in  whole- 
some recreation  amid  wholesome  surroundings,  others  doing  evening 
work  in  places  of  public  entertainment  and  elsewhere,  or  spending 
their  time  and  wages  in  the  ])aths  of  vice ;  some  naturally  robust,  anfl 
others  inclined  to  disease — engage  in  the  same  occupation  at  the  same 
time.  During  the  year,  there  is  considerable  sickness  among  them,  and 
some  of  them  die  ;  ]ierhaps  these  include  mainly  young  men.  Shall 
it  be  said  without  a,  careful  analysis  of  all  the  circumstances  of  their 
lives  and  of  the  immediate  causes  of  their  deaths,  that  their  calling 
is  necessarily  inimical  to  health  and  longevity?  This  one  died  of 
smallpox  ;  this  one  of  consumption  ;  this  one  of  a  blow  on  the  head 
while  drunk  ;  this  one  was  drowned  ;  two  were  victims  of  typhoid 
fever  and  two  of  pneumonia  ;  eight  in  all — truly  a  large  percentage, 
but  shall  the  trade  be  blamed? 

It  must,  of  course,  be  self-evident  that  certain  occupations  are 
intrinsically  dangerous  to  health,  because  of  the  nature  of  the  sub- 
stances Avith  which  the  workers  are  brought  in  contact ;  and  these  are 
properly  classed  as  dangerous  trades.  INIany  others  are  so  classed,  not 
because  of  any  intrinsic  danger,  but  on  account  of  the  peculiar  con- 
ditions under  which  they  are  ordinarily  carried  on,  these  tending  to 
reduce  the  physiological  resistance  to  disease.  Still  others  arc  classed 
as  dangerous  to  health  which  are  merely  dangerous  to  life,  the  individ- 
ual being  subject  to  mechanical  violence  while  in  the  enjoyment  of 
perfect  health.  These  also  are  properly  to  be  included  among  the 
dangerous  trades.  But  the  great  majority  of  callings  are  neither  intrin- 
sically dangerous  nor  carried  on  under  peculiar  C(^uditions  favoring  a 
low  state  of  health,  yet  many  of  these  figure  in  statistical  tables  in  such 
a  way  as  to  lead  to  the  conclusion  that  those  engaged  in  them  may 
have  little  hope  of  green  old  age,  while  others  in  occupations  of  practi- 


718  HYGIENE   OF  OCCUPATION. 

cally  the  same  character,  but  under  different  names,  give  promise  of  a 
full  period  of  usefulness. 

Statistical  tables  of  longevity  of  groups  of  individuals  engaged  in 
the  various  callings  should  be  used  with  much  circumspection  and  with 
a  due  regard  to  the  various  circumstances  which  determine  the  choice 
of  trade,  the  age  of  the  individual  at  the  time  of  engaging  u]>on  it,  the 
length  of  time  which  one  may  serve  before  engaging  in  another,  the 
peculiar  conditions  under  which  the  calling  is  pursued,  and  the  prob- 
able character  of  the  influences  which  aifect  the  well-being  of  the  in- 
dividual while  he  is  not  immediately  engaged ;  that  is  to  say,  his  home 
surroundings,  his  personal  habits,  the  nature  of  his  relaxations,  the 
quality  of  his  food,  and  other  factors.  Tables  based  on  foreign  statis- 
tics should,  furthermore,  be  not  too  freely  accepted  as  applicable  to  home 
conditions,  owing  to  differences  in  racial  peculiarities  and  of  conditions 
under  which  those  engaged  work  and  live,  for  one  can  hardly  suppose 
that  any  one  class  works  and  lives  under  the  same  conditions  in  all 
countries. 

The  conditions  which  govern  the  choice  of  an  occupation  are  of  very 
great  importance.  Many  callings  demand  men  of  robust  build  and 
good  health,  and  manifestly  are  unsuited  to  the  weakling,  who  natu- 
rally is  attracted  to  other  occupations  of  a  lighter  character.  On  this 
score  alone,  statistics  may  be  grossly  fallacious.  For  example,  in  cer- 
tain tables  it  will  be  observed  that  the  class  designated  as  clerks  have 
a  low  average  age  at  death,  and  from  this  it  may  be  inferred  that  the 
calling  is  one  which  is  intrinsically  incompatible  with  long  life.  But 
is  it  fraught  with  danger?  Is  it  conducted  under  peculiar  conditions 
which  tend  to  bring  its  unfortunate  followers  to  an  early  grave?  Or 
is  it  not  rather  the  fact  that  it  is  the  refuge  of  a  great  number  of  those 
whose  physical  powers  are  such  that  they  are  unsuited  to  employments 
which  call  for  greater  robustness,  and  who,  inevitably  marked  for  an 
early  death,  regardless  of  their  calling,  reduce  the  average  age  at  death 
of  the  entire  class. 

On  the  other  hand,  certain  occupations  involving  m^ch  severe  mus- 
cular effort  appear  to  be  conducive  to  long  life,  in  spite  of  the  condi- 
tions under  which  they  are  pursued.  Here  must  be  borne  in  mind 
that  in  these,  the  weaker  individuals  and  those  whose  powers  begin  to 
fail  are  forced  into  other  occupations,  and  that  those  who  remain 
until  the  end  show  an  average  age  at  death  which  is  eloquent  of  the 
benign  influence  of  the  calling.  It  is  undoubtedly  true  that  muscular 
efifbrt,  carried  to  excess,  will  undermine  the  health  ;  but  not  forced 
beyond  reasonable  limits,  and  particularly  if  carried  on  under  good 
hygienic  surroundings,  instead  of  being  in  itself  prejudicial  to  health, 
is  promotive  of  it.  Those  who  are  forced  into  lighter  occupations  may 
find  the  change  advantageous  ;  or,  on  the  other  hand,  entering  upon 
them  already  broken  in  health,  may  help  to  reduce  the  average  age  at 
death  of  all  those  engaged  therein. 

Another  influence  having  a  bearing  on  the  choice  of  occupation  is 
the  high  wage  offered  to  attract  workmen  to  trades  which  are  properly 


IIYdlKNE   OF   OCrjdl'ATfON.  7  Hi 

conceded  to  Ix;  dMii^crons  lo  li<;illli.  Tlics*' mh'  ii:i(iir;dly  iiiirittractive 
to  men  of  soniid  body  :iii<l  mind,  lo  wliom  lii;dlli  ;iiid  life  ;ire  Hwcct, 
mid  lienee  tliey  liiid  tlicir  i-ccriiits  jiinoiijr  the  hrnk*  ii-dou  n  and  vieiouH, 
to  wlioiii  (Ik!  riil,(!  of  |)!iy  oHcrs,  in  (lie  one  e.'isc,  itnMHdi:i(<-  iiHir-li-tifcded 
and  o(,lierwi.s(^  nn:iltMiii:d»l<'  linanciMl  rclicC,  juid,  in  the  otlici,  opprirlnnity 
for  a  sliort  jxiriod  o("  nnrestrained  li<;en.se. 

Statistics  (^Miccniin^  occupations  entered  upon  ;il  an  early  a^e  and 
folIovve(l  Cor  hut  a  lirnit^-d  nnnd)er  of  years  as  a  prelindnary  training' 
for  oilier  <'alliii<i;s,  and  those  wliieli  from  tiieir  very  natiu'c  demand 
men  of  wide  expfa-ic^nce,  lien(!e  well  matured,  can  \u'  of  litflf!  or  no 
value  unless  the  occuj)ations  are  in  some  w;iy  of  intrinsic;  danj^er.  We 
find,  for  cxam])lc,  in  certain  statisti<-al  tuliles  d<!alinfi:  only  with  indi\id- 
uals  above  the  i\^c  of  20  years,  that  the  average  a^e  at  d(uith  of  students 
is  iihout  2.'5  years,  while  that  >f  professors  exceeds  ')().  The  manifest 
absurdity  of  attempting  comparisons  oi'  the  healthfidness  of  these  two 
oc(;up;iti()ns  is  brouirht  out  still  farther  by  reversing  the  case,  and  sup- 
posing the  professors  to  die  oif  at  23  and  the  students  at  oO.  Sinrje 
even  advanced  students  in  tlie  professioiuil  schools  ])a-^s,  as  a  rule,  out 
of  the  student  (;lass  and  into  their  chosen  fields  of  usefulness  long  Itefore 
their  thirtieth  year,  it  cannot  cause  suqirise  that  those  wdio  die  before 
their  training  is  completed  do  uot  show  a  high  average  age  at  death  ; 
and,  on  the  other  hand,  since  men  of  learning  are  not  ordinarily  called 
ujion  to  assume  the  duties  of  professors  until  they  have  passed  through 
the  lower  grades  which  lead  to  that  rank,  it  is  to  be  exjiected  that  their 
average  age  at  death  will  be  fairly  high.  To  compare  lieutenants  and 
major-generals,  shipping-clerks  and  retired  merchants,  apprentices  and 
master  carpenters,  would  be  no  more  absurd.  The  average  age  at 
death  of  any  one  calling  must  be  largely  influenced  l)y  the  relative 
number  of  individuals  of  the  different  age  periods  engaged  therein,  just 
as  is  the  case  with  the  population  in  general. 

Another  fact  that  affects  the  age  at  which  work  is  undertaken 
is  a  very  low  wage  offered  even  in  times  of  prosperity,  so  low  as 
to  be  no  inducement  to  heads  of  families,  but  sufficiently  high  to  cause 
them  to  help  out  their  financial  condition  by  making  use  of  their 
offspring. 

Before  proceeding  to  a  classification  of  occupations  according  to  the 
circumstances  which  determine  their  healthfulness,  it  is  desirable  to 
consider  the  significance  of  the  somewhat  loosely  applied  term,  occupa- 
tion diseases.  Every  form  of  occupation  and  every  form  of  life  of 
leisure  has  some  attendant  circumstances  which  may  at  some  time,  in 
one  way  or  another,  bring  about  a  predisposition  to  some  form  of 
disease ;  and  to  regard  every  disease  of  an  artisan,  tradesman,  or  pro- 
fessional man  as  attributable  to  his  particular  calling,  is  to  fall  into  a 
common  inexcusable  error,  for  workers  and  drones  have  most  diseases 
in  common.  It  is  beyond  dispute  that  certain  pathological  conditions 
are  caused  and  others  promoted  by  certain  occupations,  and  it  is  equally 
true  that  most  diseases  already  acquired  may  be  influenced  for  better 
or  worse  by  one  or  another  cjilling. 


720  HYGIENE  OF  OCCUPATION. 

The  true  occupation  disease  is  tliat  which  in  all  probabilit)''  would 
not  have  been  acquired  bad  the  individual  not  engaged  in  his  par- 
ticular calling  or  some  other  in  Avhich  the  conditions  are  essentially 
similar.  As  an  instance,  may  be  cited  the  lead  jiaralysis  of  the  house 
painter,  potter,  compositor,  and  file-cutter.  Certain  diseases  of  com- 
mon occurrence  in  tlve  population  at  large  are  promoted  by  the  condi- 
tions under  which  various  callings  are  carried  on,  but  these  cannot 
properly  be  called  occupation  diseases,  since  the  exciting  cause  is  in  no 
way  a  part  of  the  business,  and  under  better  hygienic  management, 
combined  with  more  favorable  outside  influences,  might  be  avoided. 
As  a  conspicuous  instance  of  this  class,  may  be  cited  the  tuberculosis 
of  dressmakers,  cutlery  grinders,  and  operatives  in  the  cotton  and  flax 
industries,  promoted  by  overcrowding  and  inhalation  of  dust  while 
at  work,  and  by  all  extraneous  conditions  tending  to  lower  vitality. 
The  plying  of  the  needle  is  in  itself  in  no  way  inimical  to  the  in- 
tegrity of  the  lungs  ;  the  grinding  of  the  steel  implement  on  the  wheel 
and  the  running  of  the  loom  send  forth  none  of  the  specific  bacilli ; 
but  the  overcrowding  in  the  one  case,  and  the  unavoidable  inhalation  of 
irritating  dust  in  the  others,  bring  about  the  conditions  which  ofier 
fertile  soil  to  the  germ  of  the  disease. 

Certain  conditions  are  influenced  for  better  or  worse  by  different 
occupations,  as  has  been  stated.  Among  these  may  be  mentioned 
anaemia,  which  not  uncommonly  is  classed  among  the  diseases  of  occu- 
pation. Under  the  conditions  of  many  indoor  callings,  this  state  is 
easily  brought  about,  or,  if  already  existing,  increased ;  but,  on  the 
other  hand,  under  those  of  outdoor  occupation,  it  is  not  likely  to  be 
induced,  and,  if  already  existing,  may  be  made  to  disappear.  Many 
occujwtions,  for  easily  explainable  reasons,  draw  their  workers  largely 
from  that  portion  of  the  population  which  is,  if  not  already  diseased, 
predisposed  by  heredity,  habit,  and  home  surroundings  to  anaemia,  tu- 
berculosis, and  other  disorders,  the  onset  of  which  may  be  hastened  or 
delayed,  according  to  circumstances.  In  these,  and  in  occupations  in 
general,  it  is  not  an  easy  matter  to  determine  correctly  the  amount  of 
influence  properly  chargeable  to  the  calling  when  disease  appears,  since 
the  conditions  under  which  a  trade  is  carried  on  may  be  widely  vari- 
able, and  their  influence  for  good  or  evil  exceedingly  complex.  Among 
these  conditions  may  be  mentioned  indoor  confinement,  nature  of  ma- 
terials, geographical  location,  and  wages  paid. 

Whether  an  occupation  is  carried  on  indoors  or  outdoors,  is  of  much 
importance,  for,  other  things  being  equal,  outdoor  employment  is  far 
more  conducive  to  health  than  is  confinement,  even  in  well-venti- 
lated fiictories,  in  which,  with  the  best  of  systems,  the  air  cannot  be 
maintained  in  the  condition  of  purity  which  obtains  outside.  Even 
those  callings  which  subject  their  followers  to  great  vicissitudes  of 
weather  appear  to  be  more  conducive  to  robustness  than  those  carried 
on  indoors,  particularly  if  tlie  nature  of  the  work  is  such  as  to  call 
for  freedom  of  movement  and  great  bodily  activity.  The  sailor,  the 
letter-carrier,  or  the  farm   hand,  for  example,  working  in  the  open 


(![.A,SSlI<'l('y\'l'I(>N   OF  OCCIJI'ATIONS.  721 

;uf,  in  liciil  ;iii<l  ''old  ;iimI  in  ;ill  kinds  of  wciiflicr,  is  \u-\[iv  rircnni- 
s(.iinc,<'(l  in  in;niy  vv:iys  lli;in  (lie  lo()ni-(<!ii(lcr,  tlic  cnlry  clr-rk,  nn<l 
tlio  Hil.l(^snlilll  ill  I  lie  riKhon  connhr.  Ilr'  works,  jicrli;i|».-,  in  a  liioil- 
in^  Hiin,  miller  lliaii  in  an  ovcilnatcil  romn  filled  will)  iiiipiin'  air; 
(,li(^  air  lie  inhales  (tonlaiiis  some  dii-l,  |ierlia|ts  niiieli,  hut  it  is  a 
l(iss  liarnirnl  <liisl,  less  ahiiiidaiil,  and  not  eonliniioiis.  TJie  air  of"  flu; 
Ijictoi'y  and  workshop  inav  he  ainio.-l  as  jiiire  as  lliat  out  of  door.-,  or  if 
may  h(^  laden  with  fiinies,  ^ases,  foul  odors,  or  dii.'-t,  of  a  s)te<;ial  nainn-, 
ae.eordiiie^  !<»  I  he  nialerials  used.  '\'\\i-  outdoor  worker  i.s  al,sf»  nmeh  icHt 
o|)|»ress(ul  by  (he  monolony  \vhi(!li  is  so  (■oiis|»i(MioiisIy  a  eoiieomif;iiil  of 
indoor  work.  lie;  can,  a(  least,  see  some  part  of  his  world  in  ever- 
clian^'int;-  eondilions,  while  ihe  mill  operative  tends  his  niachin(;,  of 
whieh  li((  is  perha|)S  onl}'  a  minor  [)art,  day  in  and  day  out,  H('.v\\\\r  it  do 
the  same  thiii<;-  with  nieeiiaMii^al  exactness  so  many  limes  jmt  ininiito  or 
per  hour,  with  no  moi'e  sense  of  i'es|)oiisil)ilit \'  than  might  reside  in  an 
automaton. 

Geographical  location  ol'  the  place  of  employment  lias  an  impf)rtiint 
.sanitary  hearing  on  the  condition  of  the  workers,  since  it  determines 
very  largely  the  outsider  influences  to  w'hich  they  an;  sul)){!ct«l.  Lrtca- 
tion  in  country  districts  is  likely  to  insure  better  and  cheaper  homes 
than  can  be  found  in  crowded  cities,  with,  perhaps,  a  patch  of  garden 
which  may  be  worked  for  pleasure,  profit,  and  variety  in  the  diet.  It 
is,  furthermor(\,  farther  removed  from  the  influence  of  the  ti])j)ling-sliop 
and  other  unhealthy  inlluences  of  the  city. 

The  wages  })aid  affect  the  health  of  the  working  classes  in  several 
ways.  A  small  wage  means  necessarily  a  small  expenditure  for  rent, 
clothing,  and  food  ;  it  means  overcrow'ded  tenements,  lack  of  ventila- 
tion, insufficient  protection  of  the  body  by  clothing  of  inferior  quality, 
inadequate  food — usually  imjiropcrly  prepared  and  hastily  bolted — 
personal  and  general  uncleanliness  and  other  conditions  which  lower 
the  mental,  mcn'al,  and  physical  well-being  of  the  workers  and  all  who 
are  de])eudent  upon  them.  It  means  more  beside  :  it  means  the  utili- 
zation of  child-labor  and  the  breaking-down  of  women,  who  perform 
the  double  duty  of  looking  after  the  home  and  assisting  in  its  main- 
tenance. All  these  circumstances  promote  the  morbidity-  and  mortalitA^- 
rates,  and  the  particular  occupations,  perhaps  intrinsically  Avholesome, 
aiC  then  said  to  be  inimical  to  health,  when  it  is  not  the  nature  of  the 
callings,  but  the  attendant  circumstances,  that  are  at  fault.  Thus,  it 
often  happens  that  the  conditions  leading  to  the  most  serious  evils  may 
be  traced  to  some  circumstance  or  combination  of  circumstances  which 
are  wholly  external. 

Classification  of  Occupations. — In  a  general  way,  we  may,  from  a 
sanitary  standpoint,  classify  occupations  as  follows  :  1.  Those  which 
are  hitrinsically  dangerous  to  health  by  reason  of  the  nature  of  the 
materials  involved.  2.  Those  which  are  carried  on  under  conditions, 
avoidable  or  unavoidable,  which  promote  susceptibility  to  disease.  3. 
Those  Avhich,  involving  exposure  to  mechanical  violence,  are  dangerous 
to  life  and  limb  rather  than  to  health.  4.  Those  neither  iutrinsically 
46 


722  HYGIENE   OF  OCCUPATION. 

dangerous  to  health  or  life  nor  carried  on  necessarily  under  peculiar 
avoidable  or  unavoidable  circumstances. 

The  lirst  and  second  of  these  classes  are  of  esjiecial  interest  to  the 
sanitarian,  Avhose  elforts  are  directed  toward  the  removal  of  all  unsani- 
tary influences  of  whatsoever  kind  attending  any  and  all  occupations. 
The  third  class  includes  occupations  which  involve  the  possibility  of 
injury  due  to  circumstances  bearing  no  relation  to  hygiene.  Thus,  no 
effort  of  the  hygicnist  can  prevent  a  brakeman  from  falling  beneath  the 
wheels  of  a  train  or  the  operatives  in  a  dynamite  industry  from  being 
blown  uato  eternity  by  the  force  of  an  explosion  due  to  carelessness. 
The  fourth  class — and  this  includes  a  great  variety  of  perfectly  color- 
less callings — presents  nothing  of  especial  hygienic  interest,  since  the 
physical  condition  of  the  individual  would  be  essentially  the  same 
whether  he  were  engaged  in  one  or  another  of  the  different  fields,  and 
only  those  which  are  carried  on  under  peculiar  conditions  can  be  studied 
to  advantage.  Therefoi'e,  only  the  first  two  classes  will  be  considered 
here,  and  since  the  dividing  line  between  the  two  is  often  difficult  to 
define,  and  since  some  occupations  may  be  said  to  belong  to  both,  the 
two  may  be  merged  into  one  for  the  sake  of  convenience,  and  then 
subdivided  as  below  : 

The  occupations  which  are  of  particular  hygienic  interest  embrace 
those  which  involve  exposure  to — 

1.  Air  vitiated  by  respiration. 

2.  Irritating  and  poisonous  gases  and  fumes. 

3.  Irritating  and  poisonous  dusts. 

4.  Infective  matter  in  dust. 

5.  OflPensive  gases  and  vapors. 

6.  Exi;remes  of  heat. 

7.  Dampness. 

8.  Abnormal  atmospheric  pressure. 

Of  distinct,  but  minor,  importance  are  those  which  involve — 

9.  Constrained  attitude. 

10.  Over-exercise  of  parts  of  the  body. 

11.  Sedentary  life. 

Some  occupations  are  conducted  under  such  conditions  that  they 
may  very  properly  be  regarded  as  belonging  to  a  number  of  these 
groups.  Mining,  for  example,  may  be  considered  under  groups  2,  3, 
6,  7,  9,  and  10,  and  cigar-making  under  groups  1,  2,  3,  9,  and  11. 

To  attempt  to  describe  the  conditions  which  surround  each  individual 
industry,  and  to  give  the  details  of  the  countless  processes  involved, 
would  be  beyond  the  scope  of  a  work  of  this  nature,  and  quite 
unnecessary  for  a  general  understanding  of  the  relation  of  occupation 
to  health.  Therefore,  in  the  following  pages,  only  the  most  conspicu- 
ously characteristic  examples  will  be  cited  by  way  of  illustration  of  the 
dangers  to  which  workers  are  exposed. 


IRRITATIN(J    AND    I 'O  ISO  NO  (IS  (lASHS  AND    h'lJMKH.  72.'J 

1.  Occupations  Involving-  Exposure  to  Air  Vitiated  by 
Respiration. 

'^riiiw  c.liiss  iiiiiy  Ik'  iikmIc  Io  iiicliidc  ;iii\'  iihIikii'  ciilliii;.'  r';iiiic<l  dii  in 
ovonirowdcd,  ill-v<'iilil;iliil  idoius,  in  \vlii<'li  llif  air'  is  vitiiitcd  only  hy 
i\\(\  |)ro(',(!HS('S  of  (Ji(i  l)(»(ly,  an<l  not  l»y  adventitious  ^ascw  or  diiKt.  TIjcfHc 
occupations,  f licrcf'on!,  arc  not  in  tli(!niHclvoH  daiif^crons,  hut  arc  made 
so  by  a.  |)rcvcnlablc  (^•lnsc. 

Am  cxajn|)lcs,  niaylx'  '-itcd  the  callings  o("  lailoiin^^  and  'li(--tnal<in^'-, 
wlii(;li,  only  1,00  coninionlv,  arc  <-(in(lii('l(il  in  looms  in  wliidi  I'rcsli  air 
and  cnbic  space  per  capita-  are  at  a  rnininnnn.  'I'Ik;  \vorl\ci'>  arc  |»ackcd 
into  (piai'tcrs  no  larj^cr  tliun  absobitcly  necessary  for  IIk;  pcrCorinanfM; 
of  their  daily  task,  impossible  of  ])ro|)er  ventilation  witliont  an  exj)cn- 
sivc  incclianical  system,  so  great  is  the  overcrowding,  and,  as  i.s 
naturally  to  be  supposed,  overheated.  Here,  tlie  unfortunatcH  sjKjnd  a 
fairly  long  day,  leaving  at  night  to  go  to  homes  |)erliap.s  no  less 
unsanitary.  If  not  already  so  when  they  begin,  they  ix'come,  aft<^r  a 
time,  anaiuiic,  dyspeptic,  and  depressed,  these  conditions,  as  in  many 
other  callings,  being  promoted  by  lack  of  ex(u-cise,  by  ill-chosen  and 
badly  cooked  food,  and  by  absence  of  licahhful  recreations.  They 
become  greatly  susce])tiblc  to  cold,  and  hen(-e  opposed  to  the  admission 
of  fresh  air  from  without.  Breathing  cxcremental  air  l)y  day  and 
night,  denying  themselves  proper  food,  their  minds  (lci)resscd,  it  is  not 
to  be  wondered  at  that  their  condition  invites  disease,  more  particularly 
the  one  which  stands  forth  conspicuously  as  a  consequence  of  over- 
crowding; namely,  ]iulmonary  consumption.  The  onset  is  insidious. 
Beginning  with  a  cold  that  resists  being  "  thrown  off,"  the  cough  be- 
comes chronic ;  they  continue  to  lose  weight  and  strength,  and  the  end 
can  be  foreseen.  It  is  not  to  be  understood  that  these  callings  are 
always  or  even  usually  associated  with  these  conditions ;  but  when 
they  are,  the  result  is  generally  the  same. 

2.  Occupations  Involving  Exposure  to  Irritating  and  Poisonous 

Gases  and  Fumes. 

This  class  includes  a  great  variety  of  callings  which  may  or  may 
not  be  intrinsically  dangerous,  according  t(i  individual  circumstances. 
In  many  cases,  the  danger  may  be  much  lessened  by  due  regard  to 
personal  hygiene  and  by  the  use  of  respirators.  These  are  simple 
pieces  of  apparatus  designed  to  remove  noxious  matters  from  the 
air,  on  its  way  to  the  respiratory  passages.  It  is  the  rule,  however, 
that  ^vorkmcn  refuse  to  wear  them  after  the  first  days,  even  though 
well  aware  of  the  possible  consequences  of  laying  them  aside.  One 
reason  for  this  is  that  not  one  of  the  several  forms  invented  can  be 
worn  with  any  degree  of  comfort.  They  demand  faster  respiration, 
soon  get  wet  with  expired  moisture,  and  cause  excessive  perspirati<^n. 
Furthermore,  they  cannot  be  made  to  fit  tightly,  and  so,  even  Avheu 
conscientiously  w^orn,  they  only  partially  perform  their  office.     The 


724  HYGIENE  OF  OCCUPATION. 

mnjoritv  of  them  are  designed  to  filter  out  dust,  but  all  are  made  on 
essentially  the  same  prineiple,  those  intended  for  noxious  fumes  con- 
taining spongy  or  other  absorbent  material,  wet  witli  agents  which 
exert  a  neutralizing  influence. 

One  form  consists  of  a  muzzle  of  fine  wire  gauze,  single  or  double, 
on  a  metallic  frame.  If  made  with  a  single  layer,  it  is  lined  with  cot- 
ton-Avool,  .kept  in  place  by  a  very  loosely  woven  fabric  stitched  to  the 
wire  meshes ;  if  made  double,  the  intervening  space  is  occupied  by  a 
piece  of  thin  flannel.  Another  form  is  made  of  woven  or  knitted  stuff, 
instead  of  wire.  This  is  said  to  be  even  hotter  than  the  first  mentioned, 
particularly  in  summer,  and  both  are  extremely  uncomfortable.  A 
third  form,  made  of  pieces  of  flat  sponge  large  enough  to  cover  the 
nose  and  mouth,  interferes  very  much  with  free  respiration.  Another, 
consisting  of  a  large  bag  of  fine  cambric,  is  said  to  be  less  objection- 
able, but  is  difficult  to  fasten  tightly. 

Aside  from  the  discomfort  caused  by  respirators  of  whatever  form, 
the  operatives  have  another,  a  senseless,  objection  to  their  use,  women 
complaining  that  they  are  made  to  "  look  ridiculous,"  and  men  being 
moved  to  discard  them  by  the  gibes  of  their  more  reckless  fellows. 

{a)  Irritating  Gases  and  Fumes. — As  examples  of  irritating  gases 
or  fumes,  may  be  cited  ammonia,  chlorine,  sulphur  dioxide,  hydro- 
chloric acid,  and  nitrous  fumes.  In  small  amounts,  they  cause,  per- 
hajjs,  no  more  disturbance  than  a  slight  tickling  cough,  but  in  large 
amounts,  they  bring  about  great  discomfort  and  acute  and  chronic 
catarrhal  conditions. 

Chlorine,  which  is  used  or  given  off  very  extensively  in  a  number  of 
industries,  is  unimportant  when  it  is  present  in  the  air  in  very  small 
traces ;  but  when  in  large  amounts,  it  is  said  to  cause  minor  catarrhal 
troubles  and  diminution  or  even  loss  of  the  sense  of  smell.  It  i^r  said 
by  Pettenkofer  that  from  1  to  5  parts  of  chlorine  in  100,000  of  air  are 
sufficient  to  affect  the  lungs ;  that  40  to  60  parts  in  100,000  will  pro- 
duce alarming  symptoms  ;  and  that  more  than  60  parts  will  cause  death. 
It  is  given  off  in  the  processes  of  making  and  using  bleaching  powder, 
in  the  operation  of  glazing  bricks,  and  in  various  other  processes. 
Among  the  workmen  who  make  use  of  bleaching  powder,  the  occur- 
rence of  bronchitis,  asthma,  and  caries  of  the  teeth,  is  noticeably 
frequent. 

Hydrochloric  acid  fumes  are  given  off  in  various  industries,  and  es- 
pecially from  alkali  works,  the  immediate  neighborhood  of  which  is 
likely  to  be  barren  of  vegetation  in  consequence  thereof.  They  are 
given  off  also  in  the  process  of  galvanizing  iron,  the  first  part  of  the 
work  consisting  in  "pickling"  the  iron  in  the  acid  to  clean  it  and  to 
prevent  the  presence  of  oxide  on  the  surface  when  it  is  dipped  into  the 
molten  zinc.  These  fumes  act  much  less  energetically  on  the  respira- 
tory passages  than  chlorine.  Pettenkofer  states  that  as  much  as  1  part 
in  1,000  of  air  can  be  borne  without  difficulty  by  men  who  are  accus- 
tomed to  it,  but  that  this  amount  cannot  be  exceeded.  In  the  galvan- 
izing process,  the  workmen  are  exposed  also  to  the  dense  fumes  arising 


I'OISONOaS   (I ASKS  AND    FUMhlS.  725 

from  tlui  Kill  iuninoiiiiKt  wliirli  is,  IVoiri  (iiiic  lo  litiic,  lliivtwn  ii|k»ii  tlw 
HurfiKH!  ()("  IIk!  iiiollcii  /inc.  'I'licsc  urc  more  iii.'^ii|)|»iiil;il)|<-  than  llic 
a(!i(I   Cnnics. 

Snl|)linf  (lioxiflc  is  csoKcd  in  llic  snicli  inn  of  \;iiiriii-  orcH,  in  pn-- 
|):u'in,tj;'  Intps,  in  (lie  niMiiiiliicI  mi<'  <>('  -iil|iliiiric  ;i<'iil  ;mmI  oI'  <»r<linarv 
tnaic-lics,  and  is  used  cxlcnsivcly  as  a  lilcadiin^'-  a;:(ii(.  In  j-niall 
ainonnls,  il.  canscs  (-(MI^Ii,  and,  by  those  nnaccnslonicd  to  it,  cannot  he 
tolci'atcd.  Those  who  arc  c.\  posed  to  il  in  their  daily  work  CHt'ihlish  :i 
^raxhiaJ  fcohirancc  and  t;d<c  ii<i  notice  \\h;ilc\-er  of  an  attnosphr-rc  in 
whic.li  it  is  |)r('scnli  to  such  an  exient  lh;il  persons  nnaccnstotncd  to  it 
Ciiiinot  hrealiie  \i.  The  \vei<;ht  of"  (!videnc(!  coneernin^^  the  relation  of 
this  gus  to  healtli  iiidicales  that  its  elfeets  are  neither  serious  nor  last- 
ing, iind  are  exerted  more  on  the  difrestive  than  on  tiie  respiratory 
function.  In  some  indi\'i(hials,  a  small  amount  in  the  atnio-phero 
cauHcs   c[)i^astrie   pain   and   liearthiirn    very   (piic^Uly. 

Bromine  is  exeee(Iin<;ly  irritatinjj^  to  the  respiratory  passages  and  to 
other  mucous  membranes  with  wliieh  it  may  come  in  contact.  In  small 
amounts,  it  causes  cough,  dizziness,  and  a  feeling  of  general  malaise ; 
in  large  amounts,  spasm  of  the  glottis  and  asphyxia.  Bronchial 
asthma  is  commonly  observed  among  those  constantly  ex])osed.  The 
fumes  of  iodine  act  practically  in  the  same  way,  although  to  a  much  less 
marked  extent.  In  occupations  in  which  these  two  substances  are 
used,  men  with  a  tendency  to  pulmonary  troubles  should  not  be  per- 
mitted to  work. 

There  is  no  evidence  that  amn^onia  in  small  amounts  produces  any- 
thing more  than  temporary  irritation  of  the  air-passages,  but  it  is  a 
general  belief  that  it  is  conducive  to  emphysema. 

Nitrous  fumes,  given  off  in  a  nundoer  of  processes  involving  contact 
of  metals  with  nitric  acid,  arc  also  of  no  very  great  importance  in  small 
amounts,  but  it  is  said  that  those  who  are  exposed  ai"c  esjiecially  sub- 
ject to  phthisis,  in  the  causation  of  which  it  is  conceded  that  the  con- 
strained attitude  and  lack  of  ventilation  have  a  large  influence.  It  is 
noted  that  the  tendency  is  greatest  in  those  exposed  to  the  largest 
amounts. 

(6)  Poisonous  Gases  and  Fumes. — This  class  includes  a  very  large 
number  of  occupations,  since  poisonous  gases  are  an  incident  of  proc- 
esses without  number. 

Carbon  mon<^xido  is  one  of  the  most  important  of  the  poisonous 
gases,  and  this  is  given  off  in  many  manufacturing  o]icrations,  usually 
in  company  with  other  gases,  and  it  is,  therefore,  not  always  an  easy 
matter  to  determine  what  proportion  of  the  effects  noticed  are  due  to 
any  one  constituent  of  the  mixture.  The  constant  inhalation  of  even 
very  small  amounts  of  carbon  monoxide  causes  disturbances  of  the 
digestive  function,  geuend  weakening  of  the  system,  and  diminished 
mental  power.  The  one  class  in  which  one  would  natuj-ally  expect  to 
find  the  greatest  evidence  of  injury,  namely,  laborers  in  gas  plants, 
yields  very  little. 

Carbon  disulphide  is  much  used  as  a  solvent  for  fats,  but  its  chief 


726  HYGIENE  OF  OCCUPATION. 

use  is  as  a  solvent  aud  vulcanizing  agent  for  India-rubber.  The  very 
peculiar  effects  produced  upon  the  operatives  in  rubber  factories,  espe- 
cially when  the  Avork  is  carried  on  in  imperfectly  ventilated  rooms,  have 
been  attributed  o-enorally  to  the  use  of  this  agent.  There  is  at  first  a 
dull  headache,  which  increases  much  in  severity  toward  tlie  close  of 
day ;  sight  becomes  somewhat  confused  ;  vertigo  and  epileptiform  con- 
vulsions, pains  in  the  extremities,  and  formication  are  common.  In 
the  early  stages,  an  unrestrainable  inclination  to  talk  is  almost  invari- 
ably observed,  and,  coincidently,  a  stinudation  of  sexual  desire.  Soon, 
the  victim  becomes  moody,  irritable,  and  subject  to  violent  outbreaks 
of  anger ;  vision  becomes  further  impaired ;  the  sense  of  smell  is  much 
diminished.  During  this  stage,  obstinate  insomnia  is  the  rule.  Next 
occurs  a  stage  of  depression,  in  which  the  loquacity  and  increased  sex- 
ual desire  give  way  to  impaired  memory,  feebleness  of  mind,  taciturn- 
ity, aud  diminution  of  sexual  desire  aud  power  even  to  complete  abol- 
ishment, with  intense  headache,  either  somnolence  or  w^akefulness,  and 
local  areas  of  anaesthesia.  Sometimes  cough,  dyspnoea,  and  paraplegia 
are  observed.  As  a  rule,  however,  no  permanent  injury  is  caused, 
since,  from  the  very  nature  of  the  symptoms,  the  victims  are  unable 
to  continue  to  w^ork  ;  and  removal  from  the  cause,  with  appropriate 
medication,  in  which  phosphorus  is  highly  regarded,  usually  brings 
about  a  perfect  cure.  This  train  of  symptoms  seems  to  be  peculiar  to 
workers  in  rubber  factories  ;  and  since  the  evidence  at  hand  shows  that 
those  who  make  carbon  disulphide  do  not  suffer  in  the  same  way,  it  seems 
reasonable  to  suppose  that  other  agents  than  this  one  are  to  be  consid- 
ered in  the  etiology.  It  happens  that,  in  this  same  industry,  naphtha 
is  very  much  used  as  a  solvent.  The  vapors  of  this  substance  cause 
embarrassment  of  respiration,  and  also  dizziness  and  mental  confusion. 
In  France,  the  employment  of  women  under  eighteen  in  rubber  fac- 
tories, and  in  any  work  which  exposes  them  to  the  combined  fumes  of 
naphtha  and  carbon  disulphide,  is  prohibited.  Santesson  ^  has  reported 
9  cases  of  naphtha-poisoning,  4  of  which  were  fatal.  They  occurred 
in  a  rubber  factory  where  a  solution  of  rubber  in  naphtha  was  used. 
The  symptoms  were  headache,  dizziness,  vomiting,  palpitation,  and 
hemorrhages.  In  those  cases  which  recovered,  the  symptoms  lasted 
several  weeks.  All  the  victims  were  young  women.  In  1  fatal  case, 
the  autopsy  showed  fatty  degeneration  of  the  heart,  liver,  kidneys,  and 
other  parts.  Naphtha  is  used  very  extensively  also  in  cleansing  wool- 
len and  other  unwashable  clothing,  and  young  women  employed  in 
establishments  devoted  to  this  kind  of  work  suffer  from  dizziness, 
nausea  and  vomiting,  headache,  insomnia,  and  hysteria.  They  find  it 
necessary  to  go  frequently  into  the  open  air  in  order  to  avoid  hysteri- 
cal outbreaks. 

Another  much  more  poisonous  substance  is  nitrobenzol,  which  is 
very  insidious  in  its  effects.  It  is  used  in  making  aniline,  like  which 
it  is  a  narcotic  poison,  and  in  the  manufacture  of  roburite  and  other 

^  Gazette  hebdomadaire  de  Mddecine  et  de  Chirurgie,  August  26,  1897. 


POISONOUS   (lASKS   AN/)    FUMES.  I'll 

of  tiK!  iK^wcr  explosives.  [low^r  cxiiosiiic  (o  sMi.'iII  aiiioiirils  prorliic*--  a 
train  of  syinptoins  vvliicli  incliidc  licadiu'lic,  <lys|»ii(c;i,  drowsinch'-,  di/,- 
zinoHS,  naUH(!ii  Mild  vdinitinn,  ;iiid  lo--  dC  unr^cidiir  stniii^lh,  and  wliirfi 
terminate!  in  sl,ii|)i>i-  niid  nol  iMri((|ii(iil  ly  in  dcatli.  I)catli  hu\\u>{\i\m^ 
occnrs  witliin  a,  (cvv  lioin's  <i("  I  lie  oiiscf.  Aniliiu;  vapor  itself  is  dan- 
gerouH  to  liealtli  when  present  in  tlie   air  to  the  cxleiit  of  0.1   per  c-ent. 

The  most  [)rominent  of  all  the  poisonons  vapors  in  rnannfhctnrin/^ 
processes  are  those  of  I iiereiiry  and  pliospliorn:-.  it  i~  hardly  neces- 
sary here  to  entnnerate  th(!  eireets  of  ex|)osure  to  ihese  j)oison,s,  since 
they  are  so  nniversally  well  known  ;  hnt  it  is  not  so  eommonly 
recojjjnized  that  operatives  in  in(lnsti'i<'s  in  which  metallie  merenry  is 
used  extensively  a))p(!ai'  to  he  very  subject  to  phthisis,  and  that,  among 
the  women,  miscarriage  is  vc;ry  common.  It  is  said  that  the  ofrsf)ring 
show  the  eff('(!ts  of  the  poison,  and  that  two-tliirds  or  more  <»f  those 
born  at  term  die  without  eonipleting  a  year  of  life?;  but  it  is  well  to 
consider  that  among  the  classes  from  which  the  o])eratives  for  this  and 
similar  occu))ations  are  (h"awn,  child  life,  at  best,  labors  vnider  great 
disadvantages. 

Mercury  is  conunonly  su])posed  to  be  used  chiefly  in  the  manufact- 
ure of  mirrors,  and  in  gilding  and  silvering.  This,  however,  is  far 
from  being  the  case.  In  fact,  the  processes  of  making  mirrors  and  of 
gilding  have  been  so  revolutionized  that,  in  these  industries,  mercurial 
affections  have  been  practically  eliminated.  At  present,  one  of  the 
most  common  sources  of  mercurial  poisoning  is  the  industry  of  felt- 
ing, in  which  it  has  been  discovered  that  the  coney  and  other  hairs 
used  make  better  felt,  if  they  have  a  preliminary  treatment  in  a  bath 
of  mercuric  nitrate.  lu  a  later  process,  the  raw  product  is  heated  to  a 
temperature  sufficient  to  volatilize  the  mercury.  Other  occupations  in 
which  mercury  is  used  extensively  include  the  manufacture  of  ther- 
mometers, barometers,  and  certain  forms  of  electric  batteries,  and  the 
bronzing  of  plaster  casts  with  an  amalgam  containing  tin,  bismuth,  and 
mercury. 

Phosphorus  is  a  substance  of  much  more  importance  to  the  public 
health  than  mercury.  The  only  industry  of  any  magnitude  in  which 
phosphorus  is  used  extensively  is  that  of  match-making,  in  which  in- 
dustry the  operatives  suffer  from  the  well-known  lesions  Avhich  phos- 
phorus produces.  This  is  a  danger  which  has  received  much  legisla- 
tive attention  in  England  and  other  European  countries,  and  much 
has  been  done  to  avert  it  by  more  strict  attention  to  hygiene  and  the 
introduction  of  machinery  to  take  the  place  of  human  beings.  In 
Switzerland,  indeed,  even  the  use  of  any  matches  other  than  those 
made  with  amorphous  phosphorus  is  absolutely  forbidden. 

Common  phosphorus  gives  off  poisonous  fumes  at  ordinary  temjiera- 
tures,  provided  the  air  contains  moisture.  Amorphous,  or  red,  phos- 
phorus is  not  poisonous,  and  gives  off  no  fumes  under  usual  condi- 
tions. It  cannot  be  used  iu  the  same  way  as  common  phosphorus, 
and  is  employed  only  in  the  manufacture  of  matches  that  strike  only 
on  the  box  or  on  a  specially  prepared  surface;   this  is  obviously  a 


728  HYGIENE  OF  OCCUPATION. 

disadvantage,  since  a  match  that  will  strike  anywhere  is  ranch  more  con- 
venient. It  is  said  that,  in  England  alone,  no  less  than  60  tons  of  white 
phosphorus  are  consumed  annually,  against  4  tons  of  the  red  variety. 

Itr  is  a  verv  connnon  notion  that  most  of  the  workmen  suffer  exten- 
sively from  the  effects  of  the  poisonous  fumes,  and  that  necrosis  of  the 
jaw  .  is  exceedingly  common.  It  appears,  however,  that,  while  this 
class  of  workmen  are  in  general  ansemic  and  l)adly  nourished,  the  ex- 
tensive lesions  that  formerly  were  noticed  have  been  of  late  years  much 
less  connnon.  In  1897-8,  in  the  United  Kingdom,  more  than  1,500 
persons  were  engaged,  but  in  the  four  years,  1894-8,  only  3G  cases  of 
necrosis  of  the  jaw  were  recorded,  21  of  which  occurred  in  1890 ;  but 
possibly  more  may  have  occurred.  This  reduction  is  due  to  precautions 
taken  to  carry  oti'  the  fumes  by  thorough  ventilation,  and  to  prevent 
their  production  as  far  as  possible  by  the  use  of  substances  fike  tur- 
pentine, and  by  drying  the  matches  as  quickly  as  possible  after  they 
have  been  dipped,  since  the  fumes  are  given  off  only  in  the  presence 
of  moisture.  Again,  much  of  the  work  of  dipping  is  done  in  closed 
hoods.  It  is  said  that  the  most  difficult  part  of  prevention  lies  in  the 
handling  of  the  work-people  themselves,  since  they  are  of  a  class  that 
can  rarely  be  made  to  understand  the  importance  of  cleanliness  and  of 
attention  to  the  condition  of  the  teeth.  Persons  with  decayed  teeth 
should  be  excluded  from  the  business,  since  caries  is  known  to  increase 
enormously  the  risk  of  poisoning.  They  cannot,  for  reasons  already 
explained,  be  persuaded  to  use  respirators. 

In  the  industry  of  brass-founding,  fumes  are  given  off  which  cause 
what  is  commonly  known  as  "  brass- founders'  ague,"  which  is  a  dis- 
order occurring  sooner  or  later — usually,  within  a  very  short  time — to 
all  engaged.  The  trouble  begins  with  a  feeling  of  malaise,  headache, 
stiffness,  great  muscular  pain,  and  soreness  of  the  chest.  A  chill  comes 
on,  which  lasts  generally  about  a  quarter  of  an  hour,  after  which  the 
patient  falls  into  a  profuse  perspiration.  The  symptoms  then  begin  to 
abate  and  within  a  day  or  two  disappear.  Although  this  train  of 
symptoms  does  not  commonly  recur,  a  more  or  less  marked  chronic 
poisoning  is  common,  in  which  the  most  prominent  symptoms  are 
anaemia,  cough,  tachycardia,  headache,  neuralgia,  disordered  digestion, 
progressive  emaciation,  and  annoying  eruptions  of  the  skin.  The  acute 
and  chronic  poisoning  suffered  by  this  class  of  workmen  are  supposed 
by  some  to  be  due  to  zinc,  by  some  to  copper,  by  some  to  both  together, 
and  by  others  to  arsenic,  which  is  an  important  constituent  of  some 
kinds  of  brass  and  an  impurity  of  others.  Some  incline  to  the  belief 
that  brass-founders'  ague  is  a  true  infection,  for  which  the  poisoned  air 
prepares  the  ground  and  paves  the  way. 

Fumes  of  arsenic  are  given  off  in  various  smelting  operations,  but 
the  chief  danger  from  this  substance  is  met  with  in  occupations  to  be 
considered  later,  in  which  it  is  given  off*  in  the  form  of  dust.  A  pecu- 
liar source  of  poisoning  by  arseuiuretted  hydrogen  has  been  brought  to 
public  notice  by  Maljean,^  who  observed  a  number  of  cases  of  icterus 
^  Archives  de  M^decine  militaire,  February,  1900,  p.  12. 


POISONOUS    DIIS'IS.  729 

anion^  tli((  hulloonisls  (tl"  ;i  rc^iiiK-nt  oC  cniriiiccrs.  Tlic  {■^iiiHc  waH 
tra<!C(l  \)y  liiiii  (o  (Jic  liy<li(i<icii  <_';is  used  in  (illiii;.'^  the  l»;ill<»ons,  wliidi 
WUH  ni{ul(!  by  tlu;  iKition  of  ordiiiiiry  (•(piiiiii(i'ci;il  -iil|)liiiiic  ;ici(|  on  rorii- 
ni(!i"(!iiil  /iiKi,  l)()lJi  <»('  wliicli  <'oiil;iii)  jir.-cnif  in  \;iii;il)l('  jiiiioinif.-,  in 
C(>ns(!(jii(^n(i('  of  wliic.li  IIk'  |>r(i(ln<'t  (•(int;iin(<l  ;ii'scninr('tlc<l  liy<lro^M-n. 
'V\w.  inij)iir((  ^iis  \v;is  lilxTiilcd  (liroiitjii  llic  \;il\c  oC  tlic  Icillofm,  hnt 
tli(!  main  sonrcc;  of  (liin^i'cr  \\;is  llic  Imhil  (i(  -nidlinji-  ;it  tlic  j-lo|»roc|< 
(lurinj!;  filling,  to  nsccrliiin  win  n  llic  :iir  in  llic  pipes  liad  hccn  cxiulN-d 
by  tl<(\  <jja.s.  In  tli(!  (rases  ohsci'vcd,  llic  onscl  was  niiirkcd  liv  ^rcat 
malaise,  lieiulaelie,  naiisen,  stidness  (if  llic  joints,  jnnndiee,  ;ind  liMrnf>- 
globinuria.  The  symptoms  snbsidcd  in  ;i  lew  days,  leavin;.'-  llic  jcilicnts 
in  a  condition  of  aiiiumia  and  pronoinK-ed  malnntrition. 

The  vapors  of"  wooil  ak',ohol  have  within  reeent  years  attnicted  eon- 
sich'rabh'  nttention  by  renson  of  their  disjistrons  eneds  npon  vision. 
Since  1<S1)}),  many  cases  of  blinchiess  have  lu-en  reported  in  the  jonrnals 
devoted  to  ophthahiioh)gy  as  (hie  to  the  vapors  ;in<l  to  the  Inic  iikiI  nse 
of  preparations  sneh  as  essences  of  •••infjer,  ])e])])ciinint,  etc.,  which  arc 
very  connnonly  made  witli  wood  ;dcoliol,  and  extensively  consnmcd  in 
places  where  the  sale  ol"  ]i(|nor  is  ])roliibited.  A\'hen  wood  aleojiril  as 
such  is  consumed,  as  it  often  is,  with  fatal  results,  it  will  be  noted  that 
the  victims  are  generally  quite  blind  before  death  approaches.  Wiir- 
demann  '  has  reported  a  case  of  wood-alcohol  blindness  due  to  the  in- 
halation of  fumes  from  varnish.  The  suliject  was  a  moderate  user  of 
tobacco  and  stimulants,  whose  sight  had  always  been  good.  After 
wn)rking  six  days,  he  was  obliged  to  quit  work  on  account  of  nausea, 
dizziness,  and  severe  frontal  headache.  On  the  following  day,  he  had 
dimness  of  sight,  and  then  became  totally  blind  for  twenty-four  days, 
\vhen  his  sight  began  to  improve.  In  another  case  reported  by  Patillo,^ 
and  quoted  by  Wiirdemann,  the  material  worked  with  was  the  same, 
and  total  blindness  occurred  on  the  sixth  day.  This  lasted  a  week, 
then  sight  improved,  but  in  two  weeks  it  began  again  to  fail.  Inhala- 
tion of  the  vapor  is  believed  to  cause  retrobulbar  neuritis,  producing 
partial  atrophy  of  the  optic  nerve,  especially  of  the  central  tibers. 

3.   Occupations   Involving  Exposure   to   Poisonous   and 
Irritating  Dusts. 

Dust  is  of  very  great  importance  in  its  influence  on  health.  Its 
production  is  a  prominent  feature  of  many  occupations,  in  some  of 
which  so  much  is  caused  as  to  be  of  the  highest  possible  importance. 
It  may  be  divided  into  poisonous  and  irritating,  and  the  latter  may  be 
subdivided  into  mineral,  metallic,  vegetable,  and  animal. 

(a)  Poisonous  Dusts. — The  most  important  of  the  poisonous  dusts 
are  arsenic  and  lead. 

One  of  the  most  dangerous  of  arsenical  trades  is  the  grinding  of  the 
well-kuow'u  green  pigments,  Scheele's  green  (arseuite  of  copper)  and 

•  American  Medicine,  December  21,  1901,  p.  995. 
2  Ophthalmic  Eecoi-d,  December,  1899,  p.  599. 


730  HYGIENE  OF  OCCUPATION. 

Schweinfurt  green  (aceto-arsenite  of  copper).  These  and  many  other 
arsenical  colors  are  used  in  ])rintino-  wall-papers,  cretonnes,  and  other 
decorations,  and  in  the  nianutacturc  ol"  artiticial  flowers.  The  latter  is 
an  especially  dangerous  occupation,  since  after  the  leaves  have  been  cut 
to  the  proper  shape,  they  are  smeared  with  gum,  the  green  pigment  is 
then  dusted  on  from  a  dredging-box  and  much  of  the  substance 
becomes  susjiended  in  the  air.  Much  of  the  green  glazed  paper  used 
for  covering  boxes  is  made  with  these  pigments,  and  other  papers  and 
articles  of  paper  in  green  and  other  colors  (playing  cards,  etc.),  are 
made  with  arsenical  pigments.  Arsenite  of  sodium  is  a  very  common 
mordant,  and  white  arsenic  is  much  used  in  taxidermy.  In  fact,  the 
list  of  processes  in  which  arsenic  is  used  is  almost  endless.  The  symp- 
toms produced  may  be  acute,  but  ordinarily  are  chronic  in  character. 
Workmen  of  this  class  frequently  suffer  from  eczematous  sores  and 
obstinate  ulcers.  The  symptoms  of  chronic  poisoning  are  too  well 
known  to  need  description. 

Lead  is  infinitely  more  disastrous  in  its  effects  upon  health,  and  is  by 
far  the  most  important  of  all  industrial  poisons,  because  of  the  great 
diversity  of  its  use.  Among  the  many  occupations  in  which  it  figures 
may  be  mentioned  all  the  processes  involved  in  obtaining  lead  in  its 
commercially  pure  state  from  ores,  the  making  of  white  and  red  lead, 
the  glazing  of  many  kinds  of  papers  ;  type-founding  and  setting,  glass- 
cutting  and  polishing,  file-cutting ;  enamelling,  dyeing  and  printing, 
working  in  weighted  silk ;  plumbing,  painting,  leather  varnishing ; 
making  artificial  flowers,  leaves,  and  jewels  ;  and  several  of  the  proc- 
esses used  in  the  making  of  earthenware  and  china.  In  many  of 
these,  the  lead  gains  access  to  the  system  through  inhalation,  and  in 
some  it  is  carried  into  the  mouth  by  the  soiled  fingers.  The  latter 
method  of  introduction  is  very  commonly  the  case  with  compositors, 
plumbers,  workers  in  lace  and  silk  weighted  with  lead  acetate,  and 
others. 

In  Paris  alone,  it  is  said,  there  are  more  than  30,000  of  the  working 
classes  following  callings  which  expose  them  to  this  very  deleterious 
substance.  In  England,  the  great  importance  of  the  subject  of  indus- 
trial lead-poisoning  has  led  to  extensive  investigations,  resulting  in 
stringent  legislation;  and  in  the  year  1895,  it  was  required  that  all 
cases  of  lead-poisoning  should  be  reported  to  the  authorities.  During 
the  year  1897,  the  number  reported  was  1,124,  and  in  1898,  1,278. 
The  largest  number  of  cases  are  reported  from  the  china  and  earthen- 
ware trades.  It  appears  to  be  a  fact,  wherever  the  matter  is  inves- 
tigated, that  women  suffer  less  than  men.  This  is  explainable  in  two 
ways  :  first,  that  women  are  naturally  more  cleanly  in  their  habits  ; 
and  second,  that  women  are  more  likely  to  give  up  their  work  after 
the  occurrence  of  the  first  symptoms  and  before  the  affe(!tion  becomes 
chronic.  Men  appear  to  be  able  to  work  longer  without  showing 
evidence  of  injury. 

Particular  attention  has  been  given  of  late  years  in  England,  France, 
and  elsewhere  to  the  pottery  industry,  in  which  lead  is  used  in  the 


TO  ISO  NO  I  IS   DdSTS.  7.'il 

gl:iZ(!S,  tlio  flux  hciii^  Mi;i(l(!  ol"  lilliiic^a',  cluy,  niid  fliiif.  Miirli  atten- 
tion liiis  \)vv\\  \r^\\{'\\  to  (lie  |)().ssil)ilily  of  liiKliiif.'  ;i  ir\;v/.c  svliicli  hliall 
b(!  f'nit!  from  \v;u\.  In  llic  nijinufiicliirc  of  ocilinary  wliiu*  jionvlaiii,  no 
IcJid  ^lazc  is  rccjniicd,  and  (lu!  danger  of  l('ad-j>oisoiiiiij^  ariwH  almost 
wlioUy  in  the  W(»ik  of  decoration,  the  ])ovv(J(;r  which  i.s  diiKt<!<J  on  and 
oir  th(!  transfer  paper,  (tontaininj^  h-ad  (compounds.  y\cef»rdin}r  to  a 
report  of  a  (U)mmil(ce  of  tlie  master  potters  of  Statfonf'-hire,  it  is  not 
])OSsil)h!  to  snbstitutc  a  lea-dhiss  f^hize  ['ov  ordinary  eliina  and  e;irlheii- 
ware,  but  this  is  said  to  be;  only  |)artly  frne. 

In  Limoges,  vvljcre  10,()0{)  peo|)k!,  of  wliom  2,oO()  are  eliilihcn,  are 
em])h)yed  in  sixteen  |)oltery  <'stablishinents,  the  workers  are  mnch  \vm» 
subject  to  lead-poisonin<^  than  tliose  in  Staffordshire,  and  in  one;  of  the 
establishments  wliere  the  ware  produced  is  of  the  name  kind  an  made 
in  Staffordshire,  the  }2;laze  contains  only  8  per  cent,  of  lead  carbonate 
against  18  to  24  in  that  used  in  Staffordshin!.  It  has  been  pointed 
out  that  where  lead  glazes  are  necessary,  the  danger  can  be  verv  nnich 
diminished,  if  the  lead  is  used  in  the  form  of  a  double  fritted  silicate. 
In  the  Limoges  factories,  the  lead  is  used  in  this  condition,  and  to  this 
fact,  part  of  the  difference  in  the  amoinit  of  poisoning  is  probably  due. 
In  English  potteries,  the  tendency  is  toward  the  ai)andonment  of  the 
old  methods  and  the  adojition  of  fritted  lead. 

Lead  is,  however,  not  the  only  danger  to  health  with  which  w(jrk- 
men  in  potteries  have  to  contend.  In  certain  of  the  operations,  large 
amonnts  of  mineral  dust  are  given  off,  and  in  consequence  they  suffer 
from  the  effects  of  not  only  poisonous,  but  irritating,  dust ;  in  fact,  the 
occupation  is  regarded  from  a  sanitary  standpoint  as  one  of  the  least 
desirable.  The  flint-grinders,  who  belong  to  this  class,  are,  according 
to  Hirt,  quite  low  down  in  the  scale  of  longevity.  It  is  said  that  the 
dust  which  is  given  off  in  the  operation  of  grinding  kaolin  is  unusually 
irritating  to  the  lungs — worse,  even,  than  steel  dust.  The  most  com- 
mon diseases  among  potters  are  bronchitis,  phthisis,  rheumatism,  and 
lead-poisoning. 

As  another  example  of  an  industry  in  which  the  workmen  suffer 
largely  from  lead-poisoning  may  be  cited  that  of  lilc-making,  in  which, 
as  in  pottery-making,  the  operative  is  subjected  to  the  action  of  dust 
both  poisonous  and  irritating.  The  best  files  are  those  cut  by  hand, 
no  machinery  having  yet  been  invented  to  produce  so  satisfactory  an 
article  as  the  hand-made.  ^Vhile  being  cut,  the  file  is  held  upon  a 
leaden  bed,  called  the  "  stiddy,"  which  offers  sufficient  resistance  to  the 
blow,  without  at  the  same  time  being  so  unyielding  as  to  cause  a 
recoil.  As  fast  as  it  is  cut,  it  is  brushed  off,  and  the  air  becomes 
charged  with  a  combination  of  steel,  lead,  chalk,  and  charcoal,  and 
granite  from  the  block,  or  "stock,"  upon  which  the  "stiddy"  is 
secured.  The  danger  of  lead-poisoning  is  thus  always  present,  and  its 
occurrence  is  hastened  by  the  careless  habits  of  the  workman,  who,  in 
handling  the  leaden  bed,  constantly  wets  the  thumb  and  forefinger  of 
his  left  hand  with  his  tongue.  Doubtless,  if  more  attention  were  paid 
to  personal  hygieue,  a  smaller  proportion  would  suffer  from  colic  and 


732  HYGIENE  OF  OCCUPATION. 

paralysis  of  the  extensor  muscles  of  the  wrist  and  thnmb.  It  is  said 
that  a  robust  tile-cutter  is  rarely  seen  ;  as  a  class,  they  are  sallou, 
aufeniic,  and  dull,  and  the  majority  show  the  blue  line  of  chronic  lead- 
poisoning. 

A  more  modern  industrial  danger  is  that  involved  in  making  and 
charging  storage  batteries  of  a  certain  kind.  Dr.  Talamon  '  relates 
that,  during  a  single  year  of  hospital  service,  he  saw  30  cases  of  lead- 
poisoning  among  workmen  so  engaged.  The  work  consists  largely  in 
spreading  red  lead  and  litharge  over  lead  plates  with  the  bare  hands, 
and  the  results  on  the  system  are  doubtless  due  in  greatest  part  to 
absorption  through  the  alimentary  tract,  the  lead  being  conveyed  to  the 
month  by  the  hands.  The  symptoms  come  on  much  more  rapidly  and 
are  much  more  acute  than  with  painters,  type-setters,  and  others.  Many 
of  the  men  fall  victims  within  three  or  four  weeks  from  the  beffinnino; 
of  their  service. 

(6)  Irritating"  Dusts. — The  irritating  dusts  act  with  variable  inten- 
sity, according  to  their  nature.  It  is  generally  thought  that  that  of 
vegetable  origin  is  the  most  irritating  of  all ;  then,  in  order,  metallic, 
animal,  and  mineral.  The  disease  which  is  conspicuously  common 
among  dust-workers — more  common  than  among  any  other  large 
class — is  phthisis,  a  predisposition  to  which  is  favored  by  constant 
irritation  by  the  dust,  assisted  by  poor  ventilation,  constrained  atti- 
tude, and  other  unsanitary  circumstances.  In  general,  the  first  effects 
of  an  abnormal  amount  of  dust  in  the  air  are  couffh  and  increased 
secretion  of  mucus.  Then  the  cough  becomes  chronic,  and  when 
the  soil  has  been  properly  prepared,  the  specific  bacillus  finds  a 
lodgement  and  soon  produces  its  results.  Many  of  the  dust-M^orkers' 
disorders  are  traceable  not  to  a  single  kind  of  dust,  but  to  a  mixt- 
ure. Thus,  the  condition  formerly  known  as  "  grinders'  asthma " 
is  superinduced  by  a  mixture  of  metallic  particles  from  the  imple- 
ment ground  and  mineral  matter  from  the  stone,  and  to  which,  if  either, 
of  the  two  kinds  the  prepondering  influence  belongs,  cannot  be 
stated. 

The  relative  frequency  with  which  diseases  of  the  lungs  occur  in  the 
different  classes  of  dust-workers  and  in  those  whose  occuj^ation  creates 
no  unusual  amount  of  dust  was  determined  by  Hirt  ^  from  a  large  mass 
of  material,  in  which,  of  course,  the  value  of  the  primary  factors  can 
hardly  be  determined  ;  nor  that  of  collateral  circumstances,  such  as 
habits,  heredity,  and  locality.  But  his  facts,  which,  to  say  the  least, 
are  coincidences  of  occupation  and  disease,  show  that  the  different 
classes  of  dust-workers  suffer  from  pneumonia  and  phthisis  in  varying 
degrees,  and  much  more  frequently  than  those  not  exposed  to  dust,  and 
that  in  the  frequency  of  diseases  of  the  digestive  system,  on  the  other 
hand,  there  is  practically  no  difference.  In  the  following  table,  com- 
piled from  his  figures,  the  relative  frequency  of  these  diseases  per  100 
workmen  is  shown  : 

^  La  Mddecine  modeme,  Feb.  7,  1900. 

^  Die  Krankheiten  der  Arbeiter,  Breslau,  1871. 


IlililTAriNd   DUSTS. 


73'} 


Worlaii'H  in  iiict!illi('  (IiihI  .    .    . 

"  "     ItlillCl!ll         "        ... 

"  "  V('>^(!l;il)l(^  "... 

"  "  iuiirniil  "... 

"  "  riii.xcil  "... 

"  "  iioii  iliist  V  I  i';i(lcs 


I'neumonla. 


17.4 
O.i) 
«.4 

7.7 

r,.o 
•I.e. 


I'hthlNlii. 

28.0 
2.').'2 

20.8 
22.fi 
II. I 


I>lgMtive  dborden. 


17.8 
16.6 
l.'i.7 
20.2 
10,2 
16.0 


Willi  i'ct;;ir<l  li>  IIk'  iiiniiciicc  uC  t  lie  (IIITcrcnl  kinds  of  dust  occw- 
jKitioiis,  one  iiiiisl  not  lose  .sinlit  of  llic  liict  that  <|ii;intity  a.s  well  a.s 
([uality  sliould  he  considered,  and  that  hieal  eoiiditioiiH  of  ventilation 
luivc  a,  V(My  decaded  hearing. 

Ainoni>'  th(^  <)c,('n|)ations  in  which  nielalhc  (hi.-t  i.s  ^iven  off  in  not- 
able anionnts,  that  which  stands  foitii  most  con.sj)ic;nonsly  a.s  dan- 
gerous is  stcel-o^rinding.  In  this  work,  the  (hmgor  varies  invcr.sdy 
with  the  si/e  of  the  object  ground  ;  that  is  to  .say,  the  smaller  the 
object,  the  greater  the  danger.  This  is  because  largo  objects  can 
be  ground  in  the  wet  way,  but  very  small  ones,  as  needles,  must  be 
ground  dry  and  require  constrained  attitude  and  close  inspection,  and 
thus  the  grinder  constantly  inhales  the  very  fine,  sharp  particles  of 
steel  that  are  thrown  off  in  the  process.  These,  by  constant  irritation 
of  the  mucous  meml)ranes  of  tlie  air-passages,  prej)are  them  for  the 
reception  of  the  specific  organisms  of  pneumonia  and  phthisis.  At 
first,  the  cough  is  dry,  but  in  a  short  time  is  accompanied  by  expectora- 
tion. Among  those  individuals  who  have  followed  the  work  for  a  year 
or  longer  under  the  usual  conditions,  a  sound  man  is  rare.  Their 
average  age  ;it  death  is  stated  variously  between  twenty-five  and  forty 
years.  The  danger  may  be  much  reduced  by  the  use  of  respirators, 
and  by  the  employment  of  a  blast  of  air  to  carry  the  dust  away  from 
the  grinder  into  an  a])propriate  exit. 

Not  all  metallic  dust  is  as  irritating  as  that  given  off  in  cutler^-- 
grinding,  and  in  some  occu])ations  in  which  it  is  given  off  even  more 
abundantly,  there  is  no  noticeable  tendency  to  phthisis,  although,  perhaps, 
the  subject  has  not  been  investigated  with  sufficient  thoroughness.  In 
the  operation  of  bronzing  in  the  manufacture  of  show  cards,  Christmas 
cards,  and  the  like,  the  br(Hize  powder,  which,  under  the  microscojic 
shows  sharp  angles,  is  applied  to  the  pattern,  printed  in  sizing,  by  means 
of  a  soft  pad  worked  largely  by  hand.  The  dust  adheres  tenaciously 
to  the  skin  and  causes  much  local  irritation,  and  is  inhaled  and  causes 
catarrh  of  the  upjier  air-passages.  In  addition,  the  workers  suffer 
from  headache,  bad  taste  in  the  mouth,  anorexia,  nausea,  vomiting,  and 
diarrheea,  from  absorption  and  local  action  in  the  alimentary  canal. 
When  the  operations  of  dusting  on  and  off  are  done  by  machinery,  the 
evolution  of  dust  is  very  much  lessened. 

The  dusts  of  many  of  the  metallic  salts  produce  more  or  less  serious 
local  effects,  aside  from  the  results  due  to  absorption  into  the  system. 
In  the  manufacture  and  use  of  potassium  dichromate,  for  example, 
great  irritation  of  the  nasal  mucous  membrane  is  caused,  followed  by 
ulceratiou,  which  in  most  instances  ends  in  perforation  of  the  septum. 


734  HYGIENE  OF  OCCUPATION. 

Ulcers  are  produced  wherever  the  skin  is  abraded,  and  especially  on  the 
scalp,  where  action  is  ])roraoted  by  the  scratching  which  the  irritation 
calls  forth.      Xo  local  effects  appear  to  be  caused  in  the  lungs. 

As  an  example  of  a  calling  in  which  mineral  dust  is  given  off  in 
abundance,  that  of  glass-grinding  may  be  mentioned.  This  is  much 
like  cutlerv-grinding,  in  a  general  way,  and  the  dust  produced  is  nearly, 
if  not  quite,  as  sharp  and  irritating.  In  addition,  the  workmen  are 
often  subject  to  lead-poisoning,  due  to  the  use  of  putty  powder  con- 
taining 70  per  cent,  of  lead  oxide.  It  is  as  rare  to  find  sound  men 
among  this  class,  as  among  needle-grinders.  Gem  polishers  and 
potters  belong  in  this  same  category.  Stonecutters  and  quarrymen 
are  exjjosed  to  coarser  kinds  of  mineral  dust,  but  their  work  being 
conducted  in  the  open  air  or  in  open  sheds,  they  are  by  no  means 
so  prone  to  diseases  of  the  lungs.  Some  stone  is  much  dustier  than 
others,  and  hence  may  cause  more  marked  effects.  Mica  dust  is 
exceedingly  irritating,  and,  like  the  sharp  particles  of  glass  and  steel, 
prepares  indoor  workers  for  the  reception  of  the  bacillus  of  tubercu- 
losis. In  the  wall-paper  industry,  it  is  applied  to  obtain  the  effect 
of  "  frosting,"  and  assists  or  is  assisted  in  its  action  on  the  opera- 
tives by  another  very  fine  dust  made  of  finely  chopped  or  ground  lambs' 
wool,  which  is  applied  to  the  pattern  printed  in  size  in  much  the  same 
manner  as  obtains  in  bronzing  cards.  The  workei^s  are  very  prone  to 
phthisis. 

Vegetable  dust  is  of  very  many  varieties,  which  affect  the  system 
with  varying  degrees  of  intensity.  Ordinary  wood  dust  appears  to  be 
quite  innocent  of  injurious  action  on  the  lungs  of  carpenters,  whose 
employment  is  very  largely  out  of  doors,  and  of  cabinet-makers,  who, 
on  the  other  hand,  work  in  confinement.  Grain  threshers,  millers,  and 
many  others  exposed  to  vegetable  dust  present  no  great  evidence  that 
their  callings  are  markedly  inimical  to  health.  Certain  others,  how- 
ever, offer  important  and  interesting  facts,  indicating  that,  either  alone 
or  as  one  of  a  group  of  influences,  some  of  the  vegetable  dusts  are  as 
disastrous  in  their  effects  as  some  of  the  most  irritant  of  those  of 
metallic  nature.  Among  the  most  unhealthy  classes  of  workpeople 
are  those  engaged  in  cotton  and  linen  factories.  Cotton  dust,  or  ''  flue," 
is  very  irritant  to  the  upper  air-passages,  and  causes  dryness  of  the 
throat,  followed  by  cough  and  expectoration.  In  some  operations,  a 
sized  cotton  thread  containing  kaolin  is  used,  and  then  the  air  is  laden 
also  with  this  very  irritating  substance.  Flax  dust,  or  "  ponce,"  is  even 
more  irritating  than  cotton. 

In  the  linen  factories  of  Belfast,  which,  according  to  G.  H.  Ferris,^ 
employ  30,000  persons,  five-sixths  of  whom  are  women,  the  deaths 
from  phthisis  and  other  respiratory  diseases  have  been  shown  to  out- 
number those  from  all  other  diseases  by  about  two  to  one.  Among 
the  women  below  thirty  years  of  age,  the  death-rate  from  phthisis  is 
three  or  four  times  as  high  as  among  women  of  the  same  ages  engaged 
in  other  employments.  In  1892,  the  phthisis  death-rate  reached  the 
^  Journal  of  State  Medicine,  March,  1895, 


EXPOSnilK   TO    /NFJ'XrnVh'   MATTKIL    [N   DUST.  7.*55 

enormoiiH  luti^lil  <•("  ll.l  |)(i-  1 0, ()()(),  ;ijr;iir)sf  11.0  for  flu-  wliolc  nf 
En^Iiuid  ;ui(l  VViih^s,  ;iii<i  '1\J\  (or  ;ill  Ircl.-iiul.  Apart  from  tin;  iiitriii- 
sk;  (lunger  of  flic  o<'cii|);il  ion,  lio\\(\cr,  il  imi^f.  Iif  riolcrl  flmf  tin;  (;ity 
itHolf,  from  I. lie  iniliuc  of  the  soil  :iii(|  cliin.'ilc,  (•niiiiot  he  ;i  licalthy 
pljMX!,  hilt,  on  (Ik;  other  liaiid,  it  must  Im;  said  that  ov(rr<;ro\v(liii^,  whiefi 
is  HO  p^n^at  a,  factor  in  (he  causation  of  the  disease,  cannot,  jr»  thin 
in.stuncc,  he  char^csd  with  ;iii  iuhihi.iI  ;inioiuit  of  inlhienr;(;,  ninct!  in  no 
other  city  in  (<r(;at  Britain  and  Inland  are  there  ><<  many  houses  in 
proj)(>rti()n  to  tiu^  ))oj)ulation. 

Workers  in  tohnccc)  arc  exposed  not  alont;  to  irritatinjr  .'ind  poisonouH 
(hist,  but  to  fumes  as  well.  'I'hey  an;  nnich  subject  to  nasal  and  bron- 
chial catarrhs  and  disorders  of  the  di^cstivi;  ai)paratuH  and  nervouH 
system.  The  women  eni;aocd  arc  said  to  abort  very  commonly,  on 
account  of  the  death  of  the  fictus.  Many  assert  tliat  the  r»ccupation  in 
itself  is  not  an  unhealthy  one,  and  (hat  it  possesses  certain  advantaj^OH 
in  that  it  renders  the  individual  less  susceptible  to  infective  agents. 
As  evidence  of  this,  it  is  said  that,  during  the  great  eholeia  ej)idemic  at 
Hamburg,  in  181)2,  there  were  but  8  cases  of  the  disease,  with  4  death.s, 
among  the  5,000  cigarmakers  there  resident. 

Animal  dust  is  given  oif  in  the  numerous  industries  in  wliich  wool, 
silk,  feathers,  fur,  bristles,  hair,  horn,  bone,  shell,  ivory,  and  other  sub- 
stances of  animal  origin  are  used.  These  substances  are  irritating  to 
different  extents,  as  would  naturally  be  supposed  frf>m  their  verj' 
diverse  character,  some,  as  wool,  feathers,  and  silk,  resembling  in  action 
cotton  and  flax,  and  others,  as  shell,  bone,  and  ivory,  acting  more  like 
the  mineral  dusts.  The  operatives  in  woollen  mills,  a})pear,  on  the 
whole,  to  be  rather  less  subject  to  phthisis  than  those  engaged  in  the 
cotton  and  flax  industries.  Among  the  others  of  this  class,  those 
making  brushes  and  buttons,  especially  pearl  buttons,  are  regarded  as 
taking  greater  risks  than  the  rest.  Most  statistics  of  these  industries 
are  faulty  and  inconclusive. 

4.  Occupations  Involving  Exposure  to  Infective  Matter  in  Dust. 

This  class  includes  those  having  to  do  with  rags,  wool,  horsehair, 
hides,  and  other  materials  likely  to  be  infected.  The  importance  of 
rags  as  a  vehicle  for  infection  has  been  much  overrated,  but  the 
danger  is,  nevertheless,  a  real  one,  as  the  experience  of  paper-makers 
has  often  demonstrated.  The  only  method  of  insuring  freedom  from 
infection  through  the  handling  of  rags  is  thorough  disinfection,  a  proc- 
ess involving  an  expense,  it  is  asserted,  much  disproportionate  to  the 
results  achieved. 

The  most  common  disease  connected  with  infected  raw  material  is 
anthrax,  or  '^  wool-sorters'  disease,"  the  spread  of  which  is  often  traced 
to  horsehair,  wool,  and  hides.  Nichols  ^  reported  26  cases  of  this  dis- 
ease as  occurring  in  one  curled  hair  flictory  in  three  years.      Ravenel' 

'  Second  Annual  Report  of  the  State  Board  of  Health  of  Massachusetts,  p.  86. 
'^  Keport  and  Papers  of  the  American  Public  Health  Association,  Vol.  24,  p.  302. 


736  HYGIENE  OF  OCCUPATION. 

collected  12  cases  occurring  in  men  and  60  iu  cattle  in  three  localities 
in  Peunsylvania,  during  the  summer  and  autumn  of  1897.  All  of  the 
men  worked  in  tanneries,  and  all  of  the  cattle  were  pastured  in  mead- 
ows watered  by  streams  which  received  waste  products  from  tanyards. 
The  skins  at  fault  came  from  China. 

According  to  Dr.  S.  Leduc/  imported  horsehair  is  the  most  danger- 
ous material  brought  into  France.  The  French  market  is  su})plied  by 
South  America,  whence  it  is  shipped  in  bales  compressed  by  hydraulic 
pressure.  Unpacking  the  bales  and  sorting  the  contents  according  to 
color  are  alike  regarded  as  dangerous.  After  being  sorted,  the  hair  is 
beaten,  and  in  this  process  much  dust  is  caused.  It  is  then  carded 
and  spun  into  ropes.  The  precautions  to  be  taken  include  removal  of 
dust  by  special  blower  apparatus,  perfect  cleanliness,  and  great  watch- 
fulness. Disinfection  of  the  hair  without  impairing  its  commercial 
value  or  unduly  increasing  its  cost  is  said  to  be  impracticable. 

Naturally,  the  danger  of  infection  by  the  spores  of  anthrax  on  hides, 
hair,  and  the  many  kinds  of  wools  coming  from  countries  where  the 
disease  is  common  cannot  in  any  individual  case  be  foreseen.  From 
ordinary  sheep's  wool,  the  danger  is  slight,  and  from  native  wools  is 
practically  non-existent.  When,  for  any  reason,  danger  is  appre- 
hended, M^orkmen  with  sores,  cuts,  or  abrasions  on  their  hands,  arms, 
faces,  or  necks,  should  not  be  employed,  ventilation  should  be  thor- 
ough, and  all  precautions  should  be  taken  to  prevent  dissemination 
of  the  dust. 


5.  Occupations  Involving  the  Inhalation  of  Offensive  Gases 

and  Vapors. 

This  class  of  occupations  includes  a  great  variety  of  what  are  known 
as  "  offensive  trades,"  having  to  do  with  organic  matter  largely  of 
animal  origin,  such  as  tanning  and  currying,  soap-making,  glue-making, 
fertilizer-making,  fat-rendering,  bone-boiling,  keeping  animals,  etc. 
While  there  can  be  no  doubt  that  these  offensive  trades  are  a  frequent 
source  of  nuisance  to  the  community  at  large,  evidence  of  injurious  in- 
fluence on  the  health  of  those  actively  engaged  and  of  the  population 
in  the  immediate  vicinity  of  the  works  is  decidedly  slender.  There 
can  be  no  doubt  of  the  disadvantage  of  having  such  establishments 
located  in  the  midst  of  thickly  settled  communities,  and  hence  their 
supervision  constitutes  a  most  important  part  of  the  duty  of  public 
autliorities.  The  workmen  are  likely  at  first  to  suffer  from  nausea, 
vomiting,  loss  of  a])petite,  and  headache,  but  these  evidences  of  dis- 
turbance disappear  within  a  short  time,  and  do  not  recur. 

Contrary  to  general  opinion,  these  occujjations  not  only  do  not 
appear  to  shorten  life,  but  from  such  facts  as  are  presented  by  the 
mortality  statistics  of  occupations,  it  may  be  inferred  that  they  con- 
duce to  longevity,  for,  as  a  class,  their  average  age  at  death  is  quite 
1  Public  Health  Eeports,  May  25,  1900,  p.  1306. 


EXP()Sinii<:  TO  aunohmm.  ATMosriiiinKi  I'Iikssure.     I'M 

hi^li.      li,   is   liiirdly  iicccssMry    l.o  j^k   inlo  llif   <l<l;(ils  of"  llic   prorithHf-H 
iiivolv(!<l  in  tii(!  <lin'(!rci)(,  cjillingK. 

(I.  Occupations  Involving-  Exposure  to  Extremes  of  Heat. 

l<jX|»()Siir(!  1()  (!.\(.r(!in(!  li(!iit  is  u  c.oiKroiiiiliiiiL  of  u  iiiiiiilx'r  of  other 
iiiisMiiitaiy  indiK^iiccs  wliicli  ;i(rc(!l-  \\\v.  lifiiitli  of  tlic  worker  in  a  variety 
of  ()('(Mi|)at.ions,  wliidi  include  (lio.se  of  enginccrH,  HtokefH,  cook.s,  hakcFH, 
miners,  loundrynien,  \ve;ivers,  employees  in  rolling  mills,  wire  niillH, 
8iif^ar  rciineries,  jrlnss  faefories,  and  others.  The  effects  of  irreat  heat 
alone  are  exhanstion  and  thermic  i'v.wv,  and  when  lo  tliesr>  .nc  nddcd 
those  of  vitiated  air,  dnst,  irritating  fumes,  and  dampness,  the,  conse- 
quences may  be  very  ^rave.  Sndden  chilling  of  the  body  and  pro- 
longed exi)osnre  without  intervals  of  rest  are  es|)ecially  to  be  guarded 
against.  The  woi'kmen  of  this  class  are  commonly  affeeti'd  with 
catarrhal  and  rhenmatie,  troubles,  diseases  of"  the  kl<ln(ys,  and  .-kin 
eruptions. 


7.  Occupations  Involving  Exposure  to  Dampness. 

Exposure  to  indoor  dam])ness  is  usually  only  one  of  a  nimdier  of 
debilitatiug  influeucH's,  the  effects  of  any  one  of  which  are  not  suscep- 
tible of  correct  measurement.  Outdoor  daiupness  is  probably  far  Ics.s 
influential  for  evil ;  but  continued  exposure,  coexistent  with  exhausting 
labor,  is  conducive  to  rheumatism  and  bronchial  troubles.  With  ordi- 
nary care,  however,  those  exposed  to  vicissitudes  of  Aveather  and  to 
wetness  from  other  causes — di'ivers,  boatmen,  fishermen,  and  trench 
diggers,  for  example — enjoy  good  health  and  are,  as  a  class,  long  lived. 

8.    Occupations  Involving  Exposure  to  Abnormal  Atmospheric 

Pressure. 

The  ])riucipal  calling  of  this  group  is  that  of  caisson  workers,  who 
.suffer  from  Avhat  is  known  as  the  caisson  disease,  the  pathology  of  Avhich 
is  by  no  means  clear.  A  caisson  may  be  defined  as  a  large  Inverted 
water-tight  box  in  which  work  is  performed  below  the  water-level,  as 
in  the  laying  of  foundations  for  the  piers  of  bi'idges.  It  is,  in  fact,  a 
diving  bell  on  a  large  scale.  It  is  provided  at  the  top  with  a  shaft  for 
ingress  and  egress,  communicating  with  which  and  with  the  Interior  is 
a  chamber  with  two  sets  of  doors,  known  as  an  air-lock.  Placed  in 
position  and  heavily  weighted  with  masonry,  It  sinks  into  the  mud 
beneath.  The  air  in  its  interior  is  compressed  by  the  action  of  the 
surrounding  water,  and  the  thereby  diminished  air  space  is  restored  by 
downward  displacement  of  water  through  the  agency  of  powerful  air 
pumps.  The  deejier  the  caisson  sinks,  the  greater,  of  course,  the  at- 
mospheric pressure  withiu.  As  the  work  of  excavation  progresses,  the 
apparatus  sinks  deeper  and  deeper,  being  assisted  in  its  downwaixl 
47 


738  HYGIENE  OF  OCCUPATION. 

movement  by  the  Aveiiiht  of  the  superimposed  masonry  ;  and  wlien  the 
proper  geological  formation  is  reached,  the  interior  is  tilled  Mith  con- 
crete, which  thus  forms  the  solid  foundation,  and  the  box  is  left  there. 
In  entering  the  caisson,  the  workman  goes  first  into  the  air-lock  and 
closes  the  door.  The  pressure  in  this  compartment  is  then  gradually 
equalizi'd  with  that  of  the  caisson  chamber  by  means  of  an  inlet  pipe 
controlled  by  a  valve,  after  which  he  opens  the  inner  door  and,  enter- 
ing the  chamber,  closes  it  again.  In  emerging,  the  process  is  reversed  : 
the  pressure  in  the  air-lock  being  raised,  he  enters  and  closes  the  door ; 
by  means  of  another  valve,  the  pressure  is  lowered  gradually  to  normal, 
and  then  the  outer  door  is  opened.  The  operations  of  locking  in  and 
out  must  be  conducted  gradually.  In  locking  out,  the  rule  is  to  allow 
at  least  one  minute  for  each  6  pounds  of  pressure  within  the  chamber. 
Attention  must  be  paid  also  to  the  lowering  of  temperature  which 
accompanies  the  expansion  of  the  air  within  the  lock. 

The  symptoms  of  the  peculiar  disturbance  do  not,  as  a  rule,  apj^ear 
until  the  pressure  equals  20  pounds,  and  some  time,  measured  in  min- 
utes or  even  hours,  after  emerging.  In  some  cases  in  which  cerebral 
and  spinal  symptoms  are  severe  from  the  beginning,  death  occurs  within 
a  short  time.  The  symptoms  include  headache,  pain  in  the  ears,  rapid 
pulse,  sweating,  severe  pains  in  the  legs,  back,  and  epigastrium,  and, 
later,  paralysis  of  the  motor  nerves,  generally  of  the  legs,  sometimes  of 
the  arms,  and  not  infrequently  of  the  bladder  and  rectum.  The  motor 
nerves  are  in  some  instances  involved  before  the  sensory  disturbances 
appear.  The  epigastric  pain  is  accompanied  sometimes  by  vomiting, 
more  or  less  severe  in  character.  Mild  cases  of  the  disease  last  from  a 
few  hours  to  a  week  or  longer ;  but,  whether  mild  or  severe,  complete 
recovery  is  the  rule.  Where  electric  lighting  is  not  employed,  irrita- 
tion of  the  bronchial  mucous  membrane,  cough  and  expectoration,  due 
to  soot,  are  not  uncommon. 

The  cause  of  the  main  symptoms  has  been  the  subject  of  consider- 
al^le  speculation,  and  whether  it  is  an  excess  of  oxygen  in  the  tissues, 
which  seems  ira]3roba])le,  or  congestion  of  the  central  nervous  system, 
or  some  other  condition,  appears  to  be  incapable  of  elucidation.  The 
use  of  intoxicants  appears  to  be  a  predisposing  influence ;  hence, 
drinking-men  should  not  be  employed.  Thin  men  are  much  less  sus- 
ceptible than  the  stout  and  full-blooded.  Work  should  never  be  per^ 
formed  on  an  empty  stomach,  and  periods  of  absolute  rest  should  be 
frequent  when  the  pressure  is  unusually  high. 

Submarine  divers  are  subject  in  a  lesser  degree  to  the  same  train  of 
symptoms. 

9.  Occupations  Involving  Constrained  Attitude. 

These  include  a  wide  variety  of  trades  leading  to  various  deformities, 
the  most  important  of  which  is  constriction  of  the  chest.  Vitiated 
air  is  a  common  coexistent  condition,  and  phthisis  is  a  frequent  cause 
of  death. 


OffffllfATfONS   INVOLVINd  SI'IDHSTA  liY    fJFh:  7.'{0 

10.  Occupations  Involving-  Overexercise  of  Parts  of  the  Body. 

The  ()(uMi|>:i.li()ii.s  <»("  lliis  clasH  briii^  ithitiit  u  varicly  ol'  <l((oiiiiif icH 
and  (»('  (iiliniK;  iiciii'ohcs  (iliaractctri/cd  by  (lishirhaiiftc  of  tlir-  f'liiK-tirdial 
adi.iviiy  oC  ^('(tiips  of  iniisclcs  Iniincd  hy  pcadirc  in  liij^lily  special iz<'<l 
C()(')r<liiia(.('(l  iiiovciiiciils.  'I'licsc  iiicliidc  sik^Ii  ('((iMlitifdis  an  tlic  frariipH 
of  writers,  tcl<\<;r;i|)|icfs,  pi.iiiisls,  violiuistH,  (jn^ravcrs,  KoanihtrcHWJH, 
and  otlicrs,  and  locMli/cd  |iarnly,s(s  :ind  tn-inDrs.  l'\]c  patlioln^y  of 
these  conditions  is  xcry  (ihscnrc  ;  l)nl  in  ccihiin  i,\'  I  lie  fa.sf'H,  cHperially 
those  in  which  the  larynx  is  overexereised,  (he  element  of  hvsteria 
enters  (o  a,  eonsidcrahle  extent.  These  ;il)norni;d  e(»ndifions  are  (»f  far 
less  hygie,ni(!  inipoi'taiice  lh:in  ;Miy  lh;il  h;i\-e  liceii  con.-idcred,  and  are 
of  interest  chielly  to  (he  specialisl. 

11.  Occupations  Involving  Sedentary  Life. 

Certain  eallin^^s  are  eoninionl}'  set  down  as  .scr/r/^^ar/y  occupation.s  ; 
but,  strictly  speaking,  this  chiss  is  eh>sely  interwoven  with  several  of 
those  already  mentioned.  For  instance,  a  very  large  nnmher  of  indoor 
0(v.n])ati()ns,  carried  on,  pei'ha])s,  under  conditions  ]ieenliar  to  them- 
selves, are  at  the  same  time  sedentary  in  their  natnre. 

The  abnormal  conditions  brought  about  by  sedentiiry  life  are  those 
induced  by  a  lack  of  general  exercise  of  the  body.  This  brings  about 
a  general  sluggishness  of  the  functions,  which  is  ordinarilv  most 
marked  in  those  of  the  abdominal  organs  and  heart.  The  eonscfjuences 
of  too  close  coniiuement  and  lack  of  exercise  are  too  well  known  to 
need  detailed  mention.  Ordinarily,  they  can  be  expressed  by  the 
term  "general  debility."  There  is  no  particular  reason  why  sedentary 
occupations  should  injure  health,  and  it  will  be  found  in  almost  all  in- 
stances of  impaired  function  that  the  sedentary  habit  is  not  peculiar 
to  the  individual  while  at  work,  but  during  both  work  and  leisure 
hours.  The  sedentary  worker  has  the  matter  of  prophylaxis  in  his 
own  hands,  and  should  take  a  reasonable  amount  of  exercise  daily, 
preferably  in  the  open  air.  It  is  common  to  include  brain-workers  in 
this  class,  and  to  attribute  to  the  sedentary  side  of  their  lives  the  con- 
sequences of  overexertion  of  the  mind.  It  must  be  remembered  that 
activity  of  the  mind  has  no  shortening  influence  on  life  ;  but  abuse  of 
the  mental  powers,  and  especially  mental  worry,  conduce  to  headache, 
insomnia,  and  general  breaking  down  of  the  nervous  system  and  of 
the  general  health. 

PROPHYLAXIS  IN  GENERAL. 

In  what  has  gone  before,  it  will  be  noticed  that  the  disastrous  effects 
attributed  to  occupations  are  in  very  large  part  due  to  non-observance 
of  the  ]>rinciples  of  general  hygiene,  and  chiefly  to  inattention  to  that 
most  important  sanitary  measure,  perfect  ventilation.  It  will  have  been 
noted  that  in  Groups  1,  2,  3,  4,  5,  and  ti,  the  conditions  which  bring 
about  impairment  of  health  may  be  reduced  very  largely  by  a  con- 
stant supply  of  fresh  air.     With  proper  attention  to  this  matter  and 


740  HYGIEyE  OF  OCCUPATION. 

improvement  in  the  home  and  home  influences,  greater  attention  to  the 
character  and  preparation  of  food,  and  a  more  general  observance  of 
the  beneficial  influence  of  active  outdoor  exercise,  no  very  great  differ- 
ences would  be  noted  in  the  health  of  the  various  classes  of  work- 
people, and  the  expression  occujjatioii  dlaeaacs  would  lose  whatever 
significance  it  now  has. 

Employment  of  Women  and  Children. 

In  view  of  the  dangers  and  conditions  incident  to  a  great  variety  of 
occupations  directly  or  indirectly  inimical  to  health,  it  is  of  the  utmost 
importance  to  protect  the  health  of  women  and  children  by  restricting 
them  in  the  daily  number  of  hours  which  they  may  give,  and  prohibit- 
ing their  employment  in  distinctly  dangerous  surroundings,  for  women 
and  children  are  more  delicately  organized  and  less  resistant  to  weak- 
ening influences.  Particularly  should  women  be  protected  during  the 
child-bearing  age,  so  that  they  may  be  insured,  so  far  as  is  possible,  a 
hetilthy  progeny.  It  hardly  needs  to  be  said  that  children  should  be 
protected  most  carefully  during  the  period  of  their  full  development,  in 
order  that  they  may  come  to  maturity  in  a  fit  condition  to  take  on  the 
responsibilities  of  the  family. 

Inattention  to  the  very  great  importance  of  conserving  the  health  of 
women  and  children  is  bound  sooner  or  later  to  result  in  degeneration, 
and  this  fact  has  received  the  attention  of  the  law-making  bodies  of 
all,  or  nearly  all,  civilized  countries.  In  this  country,  it  is  constitu- 
tionally a  matter  for  legislation  by  individual  States,  in  many  of  which 
not  only  is  their  physical  welfare  protected,  but  the  moral  aspects  of 
trades  as  well  receive  due  attention. 

As  an  example  of  such  protective  legislation  may  be  given  the  fol- 
lowing rules,  made  by  the  State  Board  of  Health  of  Massachusetts,  to 
conserve  the  health  of  minors  within  the  State.  By  reason  of  a  law 
passed  by  the  Legislature  of  1910,  the  State  Board  of  Health  was 
given  power  to  declare,  from  time  to  time,  whether  or  not  any  partic- 
ular trade,  process  of  manufacture,  or  occupation,  or  any  particular 
method  of  carrying  on  such  trade,  process  of  manufacture,  or  occu- 
pation, is  sufficiently  injurious  to  the  health  of  minors  under  18  years 
of  age  employed  therein  to  justify  their  exclusion  therefrom.  The 
processes  named  are  given  herewith  : 

I.     Processes  Involving  Exposure  to  Poisonous  Dusts  or  Sub- 
stances : 

1.  Processes  in  the  manufacture  of  white,  red,  orange,  or 

yellow  lead. 

2.  Processes  in  the  manufacture  of  lead  pipe,  solder,  and 

plumbers'  supplies. 

3.  Cutting  metal  articles  with  a  mixture  of  lead  and  tin,  or 

lead  alone. 

4.  Processes  involving  exposure  to  lead   and  the  dust  of 

plumbago  in  electrotyping. 


EMPfjOYMKNT  OF    H'Oy)//-;,V  ANh    dl I l.lillHy.  1\\ 

5.    I*r()r(!.s.s(!,s    iiiv(»l\'iii^'   (lie   li:iiHlliii^   of"  wliilc   lend  or  lr-;i(i 
tnoiioxidc  (lit liMrj^cj  in  nildicr  (";iclorics. 

0.  LcikI  piiini  LMMiidiiijr. 

7.  \jv\u\  workiiit;'  in  IIh'  ni;iniil;ict  nif  of  -toraM-c  haltfric-i. 

8.  File  (Milling'  by  IkiikI. 

\).    'rypcsctlliij^,     clcaiiinjj;     or     liandlinM     1\|)c    in     jtrintiii;^ 
olliccs. 
10.   (JIazinir  in  pottery  cstahli-liimnts. 

II.      Processes  Involvirifr  Ivxposnrc  lo  1 1  ritat  in;:  i)iists: 

1.  J'rocu'sses  involving  exposure  to   (lie  dnsl  of  ^rapliilc  in 

tli(!  inaniiiact(n"(;  of  stove  polish. 

2.  'V\u\  oj)eration  of  bronzing  in   tlic   lithographie  business, 

and  the  conse(|neiit  exposnre  to  bronze  ])o\vder. 

3.  Cutlery  i>;rin(lin<jj,  and  jrrindin^  or  j)olishin^  in  the  niann- 

facture  of  ma(!hinery,  machine  parts,  and  metal  suj)- 
plies ;  and  grinding,  glazing,  or  polishing  on  emery 
or  buffing  wheels. 

4.  Cutting,    boring,    turning,    planing,    grinding,    doming, 

facing,  or  polishing  j)earl  shell. 

5.  Tal(!  dusting  in  rubber  works. 

6.  Sorting,  dusting,  cutting,  or  grinding  rags. 

III.  Processes  Involving  Exposure  to  Poisonous  Gases  and  Fumes : 

1.  Spreading  rubber  on  cloth  and  the  consequent  exposure 

to  naphtha  in  the  manufacture  of  rubber  goods. 

2.  The  use  of  naphtha  in  cement  work  in  rooms  in  shoe 

and  rubber  factories  which  are  not  provided  with 
mechanical  means  of  ventilation  where  the  mixture 
containing  naphtha  is  allowed  to  remain  in  uncovered 
receptacles. 

3.  Processes  involving  exposure  to  naphtha  in  the  manu- 

facture of  japanned  or  patent  leather. 

4.  Exposure  to  escape  of  fumes  or  gases  from  lead  processes. 

IV.  Processes  Involving  Exposure  to  Irritating  Gases  and  Fumes : 

1.  Gassing  in  textile  factories. 

2.  Singeing  in  print  works,  bleaching,  and  dyeing  works. 

3.  Dipping  metal  in  acid  solutions. 

V.      Processes  Involving  Exposure  to  Extremes  of  Heat  and  other 
Conditions  which  Promote  Susceptibility  to  Disease  : 
1.   Melting  or  anuealing  glass. 

By  legal  enactment,  the  employment  of  women  in  certain  kinds  of 
work  is  prohibited  absolutely,  and  in  many  others  is  restricted  as  to 
number  of  hours,  according  to  the  nature  of  the  work.  The  very  great 
value  of  most  of  the  legislation  regulating  labor  by  children  and  women 
is  too  clear  to  need  demonstration. 


CHAPTER    XIV. 

VITAL   STATISTICS. 

The  science  of  vital  statistics  comprises  the  analysis  and  synthesis 
of  facts  concerning  the  life-history  of  populations.  It  points  out  where 
and  to  Avhat  extent  disease  and  death  are  on  the  inci'ease,  and  suggests, 
therefore,  the  inauguration  of  combative  sanitary  effort,  the  efficiency 
of  which  it  enables  us  to  measure.  It  furnishes  the  basis  for  the  study 
of  all  the  various  social  problems  which  affect  increase  and  diminution 
in  numbers. 

It  is  axiomatic  that  the  facts  employed  must  be  numei'ous  and 
accurately  stated  and  classified,  in  order  that  the  information  supplied 
therefrom  shall  be  trustworthy  and  of  value.  These  facts  comprise 
those  which  are  yielded  by  the  census,  as  numbers,  age,  sex,  color,  oc- 
cupation, and  conjugal  relations,  and  those  reported  to  and  recorded  by 
local  and  central  authorities  concerning  infectious  diseases,  marriages, 
births,  and  deaths. 

The  study  of  these  facts  and  their  correct  interpretation  are  by  no 
means  simple.  In  census  years,  it  is  not  difficult  to  obtain  practically 
accurate  information  of  the  size  of  the  population,  and  the  ratios  of 
births,  marriages,  and  deaths,  and  at  all  times  to  know  the  degree  of 
prevalence  of  notifiable  disease ;  but  the  intelligent  interpretation  of 
these  facts  is  often,  if  not  usually,  a  most  complex  problem.  In  the 
hands  of  those  who  understand  the  fallacies,  the  numerous  sources  of 
error,  the  corrections  to  be  applied,  and  the  comparative  values,  statis- 
tics can  be  made  to  yield  knowledge  of  immense  value  to  sanitary 
science ;  but  in  the  hands  of  the  unskilled  or  unscrupulous,  they  may 
be  more  productive  of  harm  than  absolute  ignorance,  for  it  is  better 
not  to  know  at  all  than  to  be  misinformed. 

It  is  well  known  that  it  is  often  possible  apparently  to  prove  two 
direct  opposites  with  the  same  statistics,  the  fallacies  being  unobserved, 
and  to  this  fact  is  due  the  low  estimate  in  which  all  statistical  studies 
are  held  by  those  incapable  of  distinguishing  the  false  from  the  true. 
Statistics  may  be  made  to  lie  while  they  appear  to  tell  the  truth,  and 
they  have  been  raised  to  superlative  rank,  therefore,  among  falsifiers 
of  all  degrees. 

As  has  been  said,  the  interpretation  of  statistics  is  no  simple  matter. 
It  requires,  in  fact,  a  mind  not  only  naturally  logical,  but  trained  in 
drawing  scientific  inferences,  in  the  recognition  and  avoidance  of  the 
influence  of  fallacy,  and  in  the  correct  estimation  of  the  value  of  dif- 
ferent factors  and  disturbing  influences.  But  even  with  several  such 
minds  working  on  the  same  mass  of  material,  decided  differences  may 
742 


TJIK  iJKNSlh'-i.  74.3 

bo  foimd  in  lluMr  n'S|)(!(;iiv(!  <!onc,lii,sioiiH,  HoriU!  JipjKirontly  .sriiall  fiu-t 
l)(;in^  overlooked  by  one  or  Ixiiri}^  eredihid  wifli  undue  iin()orl:iri<M;  by 
iuiotluir.  'V\\vvi'\\)Vi'.j  in  |)ultli.-;liin;^  liief.s  .ind  iii(efenex!,»,  it  in  well  to 
give  'iii^  inneli  ;is  |)o,ssible  oC  detiill.s,  :ind  l,o  brin;^  out  clearly  the  thrwid 
of  the  r(!!isoninn'  lending  to  llie  (iumI  eoncluHiouH,  for  then,  otiior  anal- 
ysts nuiy,  by  jxiinting  out  dehaliible  issiio.s,  a.sHi.st  in  dedueing  the 
}il)Solut(!  truth. 

The  Census. — TIk;  very  fbiuidjition  of"  vital  statisties  is  a  knowledg*; 
oC  th<!  si/(!  of  (he  j)o[)ulatiou  and  of  the  ages  of  the  units  of  which  it  \n 
composed.  In  census  years  this  may  be  regard(!<l  as  Hubst^mtially  ao- 
curalx! ;  but  in  tlu;  intxirvening  y(!;irs  it  is  ncicessary  to  make  estimat<« 
based  on  |)M,st  and  present  indications,  which  may  Ksad  to  wide  varia- 
tions (Voni  the  trnlji,  not,  sus(U'[)til)le  of  correction  until  the  next 
cnumei'ation.  Tiie  (lensus  is  taken  in  all  civili/ed  countries  at  «tated 
intervals,  usually  of  five  or  ten  years.  In  France  and  in  Germany,  it 
is  taken  every  five  years  ;  in  this  (country  ami  in  (ireat  Britain,  (;very 
ten  years.  In  this  country,  many  of  the  individual  States  have  an  in- 
dependent enumeration  in  the  middle  of  the  intercensal  period,  so  that 
the  census  is  virtually  quinquennial.  The  census  givas  the  poj)idation 
of  each  community,  and  also  imjwrtant  facts  as  to  age  distribution,  sex 
distribution,  race,  occujiations,  and  civil  state. 

From  the  very  nature  of  the  work,  dealing  in  a  very  short  time  with 
vast  numbers  of  individual  sources  of  information,  no  census  can  be 
absolutely  accurate,  but  under  present  methods  the  results  obtained 
may  be  regarded  as  being  as  ncjirly  accurate  as  possible.  It  is  prob- 
able that,  in  a  large  degree,  the  errors  counterbalance  one  another,  but 
how  far,  can  be  only  a  matter  of  conjecture. 

The  sources  of  error  in  census-taking  are  intentional  frauds  and  neg- 
ligence on  the  part  of  the  enumerators,  ignorance  and  wilful  misstate- 
ment on  the  part  of  those  interrog-ated,  absence  of  residents  when  called 
upon,  and  inclusion  of  transient  visitors.  In  1890,  it  is  well  known, 
in  certain  cities  gross  frauds  were  practised  in  "  padding  "  the  returns 
so  as  to  increase  the  fees  due  the  individual  enumerators  concerned.  In 
one  case,  a  hotel  register,  running  back  seven  years,  is  knr»wn  to  have 
served  as  an  aid  in  the  manufacture  of  population  returnefl.  During 
the  same  census,  many  complaints  were  made  that  whole  streets  and 
districts  were  omitted,  the  inference  being  that  the  enumerators  either 
did  not  regard  the  work  as  sufficiently  remunemtive,  or  made  u]>  their 
reports  regardless  of  the  facts,  and  without  the  disagreeable  necessity 
of  going  from  house  to  house  for  information  only  slowly  obtained. 

Ignorance  on  the  part  of  the  person  questioned  is  doubtless  a  more 
fruitful  source  of  error  than  intentional  misstatement.  Many  persons 
do  not  know  their  age,  and  give,  therefore,  only  a  guess,  which  is  most 
commonly  expressed  in  multiples  of  five  and  ten.  more  especially  the 
latter.  This  tendency  appears,  in  general,  only  after  the  twenty-fifth 
year,  and  is  showTi  graphically  by  means  of  the  accompanving  diagram 
(Fig.  108)  by  INIr.  R.  H.  Hooker,  taken  from  Xewsholme's  VitafSta- 
tistics.     Again,  many  data  concerning  the   occupants  of  a  house  are 


744 


VITAL  STATISTICS. 


given  by  persons  not  qualified  to  know  ;  thus,  the  returns  for  a  whole 
laiuily  may  be  based  upon  the  statement  of  a  servant  not  long  in  the 
place. 

Intentional  misstatement  is  most  common  with  regard  to  age  and 
occupation,  many  ^^•ishing  to  a})ix'ar  younger,  others  older,  than  they 
reallv  are,  and  many  being  reluctant  to  state  correctly  the  occupations 
of  themselves  and  of  members  of  their  households,  preferring,  perhaps, 
to  record  others  more  "  genteel  "  or  important.  Other  wilful  misstate- 
ments are  due  very  commonly  to  that  over-development  of  the  sense 
of  humor  that  disposes  its  unfortunate  possessor  to  regard  extravagant 
lying  as  the  acme  of  wit. 

The  intentional  misstatement  of  age  is  more  commonly  a  fault  of 
women  than  of  men.      Women  are  prone  to  understate  their  age  after 


Fig.  113. 

60  70 


NO.   AT 
EACH 
AGE 

'Al 

WJ\    l\             JL                            1000 

Number  of  persons  in  Tasmania  living  at  each  year  of  age,  according  to  the  census  schedule; 
showing  the  tendency  to  cluster  at  round  decennial  periods. 

passing  twenty-five;  with  men,  the  tendency  is  to  add  rather  than 
subtract.  After  twenty-five,  many  women  become  sensitive,  and  give 
their  ages  as  under  that  age,  and  do  not  progress  for  several  years. 
This  is  shown  statistically  by  the  British  census  returns,  from  which  it 
appears  that  the  girls  of  10  to  15  years  of  one  census,  who  become 
women  of  20  to  25  years  of  the  next  census,  reach  these  latter  age 
periods  without  suifering  any  loss  in  number  through  death  and  emi- 
gration ;  l)ut,  on  the  contrary,  with  an  augmentation,  while  the  women 
of  20  to  25  years,  who  become  30  to  35  years  old  at  the  next  census, 
show  a  very  great  diminution  in  number. 

Thus,  as  shown  by  Dr.  Farr,  the  Registrar-General,  in  1841,  the 
number  of  girls  of  10  to  15  years  was  1,003,119,  and  in  1851,  tl>e 
number  of  women  of  20  to  25  years  was  1,030,456,  or  27,337  more, 
while  the  women  of  20  to  25  years  in  1841  numbered  973,696  and 
yielded  in  1851  only  768,711— a  loss  of  204,985.    It  is  inconceivable 


ESTIMATI'll)    I'OI'tJLATION.  71-', 

that,  tli(»  loHHCH  amoTi^  tlu;  y<»uii^;('r  j^nmp,  <lii«;  to  dcatli  arxl  fniif/ralion, 
.should  hav<!  Ix'cn  iiioi'i;  than  olTsci  hy  itrirni^';i-;ilioii  lo  th<'  cxU-iit  of 
27,3.37,  and  tJuil-  [\n\  saiiu!  inllucrKtc  should  li;ivc  liiilcd  lo  the  cxfciit 
of  204,1)85  (()  do  th(;  saiiu!  tiling;  lor  tiiosc;  of  the  later  aj^f  jM'ri<»dH, 
'^riiis  dis(;rc|)aii(^y  is  .said  to  he  (;ii|)!il)l(!  of"  d(!rnoiistration  l>y  coriipari- 
Hon  of  th(!  nstiiriis  of  any  two  coiiMcciitivc!  siihscfjiKiut  cnnnicratioiiH. 
Cluldrcn'H  ajijcs  an^  vciy  (lotninonly  ovt!rstiitc<i  in  (he  earliest  y(xirH ; 
then,  us  the  limit  iA'  \\\ri\  lor  IVoe  transportation  in  pnhlie  conveyancoH  w 
])ass('d,  (hey  !H'<'  iindci'slatcd  as  lon^  as  possible.  I'inally,  when  the 
statutory  niinininm  of  a<:;e  is  (he  oidy  bar  to  (he  utilization  of  children 
in  the  various  trades,  the  years  held  hack  are  restored  with  some 
additions. 

Estimated  Population. —  In  inlen-ensal  years,  it  is  neces.sary  to 
estimate  as  nearly  :is  possihh;  the  growth  or  deelint;  of  a  population, 
making  use  of  such  iiu^tors  as  ean  be  obtained  by  eomparison  (;f  the 
two  preceding  enumerations  and  from  other  observed  influences.  This 
is  done  very  commonly  by  dividing  the  difference  between  the  figures 
of  the  two  by  the  number  of  years  of  the  interval,  thus  obtaining  the 
yearly  increase  or  diminution,  and  reducing  it  to  a  percentage  which  is 
assumed  to  be  the  rule  obtaining  until  the  next  census.  This,  of 
course,  is  merely  a  guess  which  may  be  near  or  very  wide  of  the 
truth,  since  very  many  influences  may  be  in  operation  to  bring  about 
conditious  actually  very  different.  But  one  must  work  with  the  best 
data  available  and  eliminate  as  much  of  error  as  possible  ;  hence  the 
ratio  of  increase  or  diminution  is  assumed  to  hold  until  the  next 
census,  and  iu  the  meantime  errors  must  be  diminished  as  much  as 
possible. 

One  of  the  first  errors  into  which  one  falls  is  in  assuming  a  fixed 
ratio,  based  upon  the  above-mentioned  method  of  calculation.  Let  it 
be  assumed,  for  example,  that  the  annual  increase  in  the  population  of 
a  city  of  100,000  inhabitants,  determined  by  a  comparison  of  the  two 
preceding  enumerations,  is  2  per  cent.  ;  if  we  reckon  that  in  5  years' 
time  the  population  will  have  increased  5  times  2  per  cent.,  that  is  to 
say,  from  100,000  to  110,000,  we  fall  at  once  into  error,  for  the 
increase  proceeds  not  by  simple  but  by  compound  interest,  since  iu 
reckoning  by  simple  interest  no  allowance  is  made  for  the  augmentation 
of  capital,  so  to  speak,  due  to  the  annual  increase  in  the  number  of 
persons  arriving  at  the  nubile  period. 

The  method  generally  adopted  is,  therefore,  based  on  the  assumption 
that  population  increases  in  geometrical  rather  than  arithmetical  pro- 
gression, and  the  formula  employed  is  P'=P(1-l /•)",  in  which  P' 
represents  the  estimated  population,  P  the  population  according  to  the 
last  census,  r  the  annual  rate  of  increase  per  unit  of  population,  ascer- 
tained by  comparison  of  two  successive  enumerations,  and  ?i  the 
number  of  the  iuterceusal  year  in  question.  On  the  basis  of  a  2  per 
cent,  annual  increase,  the  population  at  the  end  of  the  first  year  would 
be  102,000  ;  at  the  end  of  the  second,  it  would  be  102,000  plus  2  per 
cent,  or  10-4,040  ;  at  the  eud  of  the  third,  106,121  ;  at  the  end  of  the 

44 


746  VITAL  STATISTICS. 

fourth  108,243;  and  at  the  end  of  the  fifth,  110,408,  or  an  increase 
of  408  over  the  original  estimate. 

As  an  ilhistration  of  the  manner  of  applying  this  formula  in  the 
estimation  of  the  population  at  the  ex])iration  of  the  fifth  intercensal 
year,  in  this  instance  of  an  original  population  of  100,000  increasing 
at  the  rate  of  2  per  cent.,  the  following  may  serve :  The  formula 
is  P'=:  100,000  X  (1  +  0.02)^;  (1  +  0.02)^=  1.10408.  100,000  X 
1.10408  =  110,408  =  P'  as  given  above.  Much  time  is  saved  in  the 
calculation  by  recourse  to  logarithms.  For  a  proper  estimation  of  the 
population  at  any  particular  period  in  the  year  on  this  basis,  due  allow- 
ance should  be  made  for  the  fraction  of  the  uncompleted  year. 

Population  is  sometimes  estimated  by  using  as  a  factor  the  average 
number  of  jiersons  per  habitation  according  to  the  preceding  census 
returns,  and  multiplying  this  by  the  number  of  houses  found  to  be 
occupied  at  the  time.  Sometimes,  also,  the  number  of  registered  voters 
is  used  as  a  basis  of  calculation,  and  again  the  birth-rate,  and  again 
the  number  of  children  in  attendance  at  the  several  schools.  These 
methods,  however,  are  very  faulty,  and  often  even  quite  valueless. 

Whatever  the  method  adopted,  and  notwithstanding  the  calculations 
of  the  amount  of  influence  exerted  by  emigration,  immigration,  unusual 
prevalence  of  or  freedom  from  infective  diseases  and  other  factors, 
estimation  of  population  is  very  frequently  wide  of  the  truth.  Within 
recent  years,  for  example,  the  most  careful  estimate  of  the  population 
of  London  by  the  Registrar-General  was  found  by  the  census  returns 
to  be  no  less  than  a  quarter  of  a  million  in  excess  of  the  truth.  With 
errors  in  estimation  come  necessarily  errors  in  all  the  ratios  of  births, 
marriages,  and  deaths,  and  these  must,  therefore,  undergo  correction  at 
the  proper  time. 

Increase  of  Population. — The  growth  in  population  due  to  excess 
of  births  over  deaths  is  known  as  the  natural  increase.  That  which  is 
due  to  excess  of  births  plus  immigration  over  deaths  plus  emigration, 
is  known  as  the  actual  increase.  Fluctuations  in  natural  increase  are 
caused  by  changes  in  mortality-  and  birth-rates ;  thus,  a  decline  may 
be  dne  to  a  diminution  in  the  number  of  births,  or  to  an  increase  in 
the  number  of  deaths,  or,  more  markedly,  to  both.  Fluctuations  in 
actual  increase  are  caused  by  the  same  influences  plus  those  of  immi- 
gration and  emigration.  Growth  may,  therefore,  be  slow  or  fast,  and 
steady  or  varied  and  spasmodic,  according  to  ever-possible  changing 
conditions,  governed  largely  by  commercial  prosperity  or  depression. 
Decline  in  population  may  be  due  to  excess  of  deaths  over  births,  but 
is  commonly  the  consequence  of  emigration. 

Population  Constitution. — What  is  known  as  the  constitution  of 
a  population  shows  the  relative  proportions  of  males  and  females  and 
of  persons  of  different  age  periods.  These  facts  are  obtained  only  from 
the  census  returns,  and  are  commonly  accepted  as  holding  good  until 
the  next  census  gives  different  figures.  In  cities  and  large  towns, 
the  proportion  of  females  is  generally  considerably  higher  than  that 
of  males ;  while  in  country  districts  the  reverse  is  true  or  the  excess  is 


liFJllSTlLAtiS'    llF/rUIlNS.  717 

slij^'lil..  TIiIm  is  ('X|)l:iiiic(l  in  s<'vcr;il  vv.'iy.s  :  In  the  fifHt  placo,  women 
jiHi,  in  <jj(W)('rii,l,  lon^fi'  li\(<l  llinii  men;  iti  tlic  hc<!on<l,  irion  arc  more 
pronc^  (.iinii  women  (n  rclnrn,  wIkii  ;ii|\;iii<(  (|  in  ycjirH,  t/>  (iontitry  jIIh- 
tri(!l:H  (Voni  wliidi  liicy  orininiiliy  sprang;  and  a^^-iin,  iimlcr  (lie  eoii- 
(JitioiiH  ol)laiiiiii;j,  in  ciowdcfl  conimunilies,  men  wear  out,  mon-  rapidly 
than  women.  In  (lie  pi»|tnlalion  a(  l:ir<:;c,  males  are  more  nnmcroUH 
than   AMiiales. 

A.\fv.  (lis(iMl)iilion  lias  a,  very  impnrlani  beariiifi;  on  tiic  dralli-rate, 
Hincu,  aH  i,s  vvcill  Uiiown,  tlu;  lii^liest,  deadi-rates,  so  far  as  af^e  is  ef)n- 
ccrncd,  occur  always  in  tlie  earlier  aj^c  periods.  'J'liercfore,  the  prepon- 
derance of  individuals  of  one  and  aiiotlua'  age  period  haw  a  very  great 
influence  in  demonsiraliiio-  ap|>ai(n(  dilTcrences  in  salubrity  of  different 
localities,  wlusn  the  actual  sanitary  conditions  are  identical.  With  such 
agreement  in  sanitary  conditions,  a  community  which  includes  a  much 
larger  proportion  of  young  (children  will  show  a  larger  death-rate  and 
a  smaller  marriage-rate  than  another  in  w  hidi  the  population  i.s  made 
u|)  more  largely  of  young  aihilts.  In  consecjucnee,  it  is  necessar}-,  in 
instituting  comparisons  between  two  localities,  to  take  into  accoinit  (and 
make  corrections  therefor)  the  differences  in  age  distribution,  and  to 
reduce  the  res]X'ctivc  j^opulations  to  a  common  standard. 

Registrars'  Returns. — Returns  concerning  births,  marriages,  deaths 
and  causes  thereof,  and  cases  of  infective  diseases,  are  made  to  h)cal 
authorities,  such  as  boards  of  health,  and  city  or  town  clerks  or  regis- 
trars. In  conjunction  with  census  returns  or  estimates  of  population, 
they  reveal  the  sanitary  and  sociological  conditions  obtaining  from 
week  to  week,  month  to  month,  and  year  to  year,  in  any  community 
in  which  they  arc  made.  Through  tlicm  we  are  enabled  to  watch  the 
death-rate  from  all  causes  and  from  any  one  cause,  the  amount  of  pre- 
ventable disease,  the  probable  fluctuations  in  populations,  and  other 
facts  of  interest  concerning  communities  and  groups  thereof.  They 
convey  information  as  to  sanitary  conditions,  and  suggest  wherein 
improvement  in  various  directions  is  possible. 

The  individual  facts  must,  of  course,  be  accurately  observed  and 
stated.  This  is  particularly  true  of  causes  of  death  and  distribution 
of  infective  diseases.  The  importance  of  proper  groupings  is  well 
shown  by  the  worthlessness  of  the  lax  returns  not  infrequently 
observed.  For  example,  it  is  not  unusual,  especially  in  the  older 
tables,  to  find  "  di'opsy  "  standing  side  by  side  with  "  heart  disease," 
"  kidney  disease,"  Bright's  disease,   and  other  general  or  vague  terms. 

The  value  of  the  aggregate  facts  depends  very  largely  upon  the 
length  of  time  during  which  they  have  been  g-athered,  since  only  with 
the  lapse  of  time  can  comparisons  be  instituted  and  the  influence  of 
temporary  conditions  eliminated  or  minimized.  They  must  be  suffi- 
ciently numerous  to  yield  correct  averages,  for  the  larger  the  number 
of  facts,  the  smaller  the  fluctuations  caused  by  individual  units  ;  and, 
conversely,  the  smaller  the  number,  the  greater  the  influence  of  single 
units,  and  the  greater  the  chance  of  error  ;  or,  more  definitely  stated, 
accuracy  increases  as  the  square  root  of  the  nmnber  of  units.     Thus, 


748  VITAL  STATISTICS. 

400  units  will  yield  but  half  the  error  of  100,  aud  900  will  yield  but 
a  third.  In  no  way,  perha])s,  ean  the  great  iiifiueueeof  individual  eom- 
poneuts  of  a  small  aggregate  and  the  small  inliuenee  of  the  unit  when 
the  aggregate  progressively  increases  be  better  illustrated  than  by  the 
daily  Huetuatious  in  the  comparative  standing  of  a  number  of  athletic 
organizations,  such  as  ball  clubs  and  bowling  clubs,  in  competition 
among  themselves  for  a  ])rize  or  championshij).  In  the  beginning, 
single  events  mav  cause  entire  rearrangement,  aud  the  Huctuations  are 
wide  and  the  curves  most  irregidar ;  then,  as  the  number  of  events 
increases,  the  fluctuations  are  less  abrupt  and  the  changes  in  the  curves 
are  gradual. 

In  order  that  statistics  may  be  useful,  they  must  admit  of  compari- 
son with  similar  ligures  obtained  in  other  years  and  also  at  other  places. 
But  correct  deductions  can  be  drawu  only  when  the  conditions  are  at 
least  apparently  the  same  or  when  there  is  but  one  essential  difference. 
One  may  not,  for  example,  compare  the  death-rate  of  New  York  for 
the  winter  of  1898  with  that  of  Detroit  for  the  summer  of  1875,  and 
expect  to  obtain  thereby  information  of  value.  In  order  to  measure 
the  full  influence  of  any  one  important  condition,  the  other  conditions 
must  be  in  agreement,  or  it  must  be  possible  to  make  correct  allowance 
for  any  degree  of  divergence. 

Again  one  must  not  ignore  the  effect  of  temporary  local  conditions, 
such,  for  example,  as  an  accident  in  a  small  community  whereby  a 
number  of  persons  are  killed  at  once  and  others  die  later  from  the 
effects  of  their  injuries.  The  death-rate-  of  that  town  for  that  year 
would  be  abnormally  high,  and  the  sanitary  condition  of  the  place 
might  be  made  by  figures  to  appear  much  inferior  to  that  of  an  adjoin- 
ing one  where  sickness  and  death  from  preventable  diseases  are  much 
higher  all  the  time. 

Marriage -rates. — Statistics  as  to  marriage  vary  considerably  from 
year  to  year,  according  to  various  circumstances,  and  especially  with 
changing  conditions  in  the  prosperity  of  the  general  population.  The 
rate  is  commonly  greater  in  cities  and  towns  than  in  country  districts, 
not  that  country-bred  people  are  less  inclined  to  marry,  but  because 
large  numbers  of  them  are  attracted  to  populous  centers  after  arriving 
at  the  wage-earning  age,  aud  there  they  marry. 

The  marriage-rate  is  usually  expressed  as  so  many  per  1,000  of  pop- 
ulation ;  but  this  is  commonly  open  to  objection,  in  that  it  may  convey 
false  impressions  concerning  inclination  or  disinclination  to  assume  the 
new  responsibilities,  and  also  concerning  the  communal  prosperity. 
Here,  the  importance  of  the  population  constitution  as  to  age  periods 
and  sex  is  very  clear,  for  in  a  community  made  up  largely  of  old  per- 
sons, young  children,  and  domestic  servants  from  without,  the  number 
of  marriages  occurring  among  the  marriageable  element  might  be  very 
considerable,  and  yet  the  rate  per  1,000  of  population  would  be  low. 
Therefore,  a  more  instructive  method  of  expression  would  be  a  state- 
ment of  the  rate  obtaining  among  those  of  marriageable  age.  Again, 
the  number  per  1,000  of  population  does  not  admit  of  proper  compari- 


i{iiLTii-n.\Ti':s.  740 

son  of  (llfTrrciii  c-ornrrmiiitics  in  tliis    |»;iil  inilnr,  mile--  (licir  |)<)|)iil;itl<iii 
conslitiil.ioM  is  siihsduiliiilly  IIkj  hjiiiic. 

Fliic.liiMlioiis  ill  iiiarriii^(!-r;it('H  urc  due  to  other  cuiiHeH  lli.-iii  coriiriH'r- 
(iial  |)ros|)crity  and  dcpfcssidii.  Ft  lia.s  hcon  ol).s(!rv(;d,  for  ('xaiiiplc,  that 
a  (M)iidi(i()n  of  war  diiiiiiiishcs  (he  iai<!  by  withdniwin^  frofii  the  niur- 
riaf!;('aJ)l(^  ra,iil<s  oC  \va };•(•-( 'a riici's  lar^c  iiiiinhcrs  of  al)l<-l»odir-d  artivo 
lucii.  With  return  of'  |)eaee  and  ils  alten<i;inf  n^h.'aHC  of  the  troojw  to 
civil  life,  (he  rate  is  aJif^tiieiitcd.  'rhii-,  (hiiin^H  H7(),  when  France  and 
GcM'inany  wc^re  at  war,  lh(;  niairiaj^c-rales  sank  respectively  to  12.1  and 
14.8;  two  years  later  (1H72)  they  advanced  to  lO.')  and  20.7.  Ag(; 
constitntioii,  loo,  has  necessarily  an  iiii|)oiiant  inlhieiicc  in  c^-iiisin^- 
fluetnatioiis.  'rims,  in  a,  coniiniinity  lai"L''ely  made  ii|>  oC  youths  and 
maidens,  the  tinu^  comes  when  ;in  iiini.^na!  amoiinl  of  man-ia;_M-;il)I(; 
material   becomes  available,  and  the  rate  at  onc(!  advaiic<-s. 

A  period  oC  nmisnal  increase  in  the  rate,  from  whatev(!r  cause,  is 
connnonly  followed  by  a  correspondinir  decline,  just  as  bitsiness  pros- 
perity and  depression  arc  marked  by  re<:nl;ir  waves  ;  but  the  general 
trend  is  nmnistakably  toward  a  diminntion.  I'or  nearly  thirty  years, 
a  very  gradual  decline  has  obtained  in  nearly  all  highly  civilized  cf»nn- 
tries. 

That  more  women  marry  than  men,  sounds  ])aradoxiea],  1>ut  it  is, 
nevertheless,  true ;  for  men  are  more  prone  than  women  to  second  and 
third  marriages,  and  statistics  show  that  the  tendency  of  widowers  to 
marry  spinsters  is  nuich  more  marked  tlian  tliat  of  bachelors  to  marry 
widows. 

The  age  at  whi(^h  marriage  occurs  has  a  very  important  bearing  on 
the  natural  increase  of  population,  since  whether  a  woman  marries  early 
or  late  in  the  child-bearing  period,  determines,  other  conditions  being 
the  same,  the  extent  of  fruitfulness  and,  more  particularly,  the  interval 
between  successive  generations.  Statistics  indicate  that,  among  the 
native-born  of  this  country,  particularly  in  those  parts  longest  settled, 
and  in  Great  Britain  and  other  countries  in  which  the  highest  degree 
of  civilization  has  been  reached,  the  average  age  at  mamage  is  steadily 
increasing.  This  has  been  attributed  to  an  intelligent  selfishness, 
'ending  to  defer  the  assumption  of  responsibility  for  the  maintenance 
of  others,  thus  insuring  an  unrestricted  enjoyment  of  the  fruits  of  labor ; 
and  to  the  wider  opportunities  for  profitable  employment  of  women, 
with  consequent  lessened  dependence  upon  marriage  as  a  means  of 
support. 

Birth-rates. — Statistics  as  to  births  are  expressed  in  the  same  manner 
as  those  concerning  marriage ;  namely,  as  so  many  per  1000  of  popu- 
lation. This  ratio  is  known  as  the  crude  birfh-rafe,  and  conveys  no 
information  concerning  the  proportion  of  women  of  the  child-bearing 
age  who  have  added  to  the  population.  Here,  agjiin,  a  more  accurate 
and  instructive  method  of  expression  might  be  based  upon  a  comparison 
of  the  number  of  legitimate  births  with  the  number  of  married  women 
below  forty-five  years  of  age,  and  (^f  the  number  of  illegitimate  births 
with  the  number  of  single  women  of  the  same  limit  of  age.     Under 


750  VITAL  STATISTICS. 

any  system,  still-births  are  not  inchuled  in  either  the  births  or  deaths, 
although  they  are  cert i tied. 

Birth-rates  naturally  vary  very  greatly  in  diiferent  commimities,  the 
same  as  marriage-rates,  and  for  the  same  reasons.  Ordinarily,  they 
are  higher  in  cities  than  in  the  country,  and  during  and  immediately 
iulldwing  periods  of  prosperity  than  during  times  of  depression.  A 
higher  rate  iti  to  be  expected  of  a  manufacturing  and  commercial  center 
than  of  a  purely  residential  town,  >vhere  a  large  number  of  unmarried 
domestics,  employed  by  the  well-to-do  and  rich,  swell  the  population 
and  lower  the  rates  of  l)oth  marriages  and  births  in  the  manner  already 
mentioned.  In  the  latter  case,  the  married  inhabitants  may  be  unusu- 
ally prolific,  and  the  birth-rate,  expressed  per  1000  of  married  women 
below  forty-tive,  would  be  very  high ;  yet,  the  crude  birth-rate  would 
be  low.  So,  in  comparing  two  communities  in  respect  to  births,  accuracy 
demands  that  they  shall  be  reduced  to  a  common  basis. 

The  higher  birth-rate  in  cities  and  large  towns  is  due  to  the  greater 
proportion  of  women  of  child-bearing  age,  the  higher  marriage-rate, 
and  the  earlier  marriage  age  that  there  obtain  among  people  of  the 
lower  classes. 

Since  the  proportion  of  deaths  in  the  earliest  years  of  childhood  is 
very  high,  it  follows  that  a  high  birth-rate  is  always  associated  with  a 
high  death-rate ;  but  at  the  same  time,  a  high  birth-rate  implies  a  large 
proportion  of  married  persons  in  the  full  vigor  of  life  at  that  age  period 
which  is  associated  with  a  low  rate  of  mortality,  and  thus  the  influence 
on  the  death-rate  is  more  or  less  corrected.  A  continued  high  birth- 
rate necessarily  implies  a  large  proportion  of  growing  children  who, 
year  by  year,  swell  the  ranks  of  the  reproductive. 

A  low  birth-rate,  by  causing  a  relative  increase  in  the  proportion  of 
persons  of  the  age  periods  of  low  mortality,  may  bring  about  a  low 
death-rate ;  but  if  it  continues  long  enough  to  bring  the  population  to 
a  high  average  age,  it  will  be  succeeded  by  a  raj)id  increase  in  the 
death-rate  due  to  diseases  of  advancing  years. 

The  birth-rates  of  many  countries,  like  the  marriage-rates,  have  for 
some  years  shown  a  steady  decline.  This  is  due  somewhat  to  the  in- 
creasing average  age  at  marriage,  which  reduces  the  period  of  repro- 
duction, but  largely  to  artificial  restrictions  and  economic  considera- 
tions. The  great  decline  in  the  birth-rate  of  France  has  attracted 
widespread  attention,  and  has  become  the  subject  of  grave  concern  to 
the  authorities  and  other  thinking  people  of  that  country.  A  hundred 
years  ago,  \nore  than  a  quarter  of  the  population  of  what  are  known  as  the 
Great  Pc  vvers  was  French  ;  to-day,  notwithstanding  the  marked  disin- 
clination of  that  people  to  emigrate  and  seek  new  homes,  the  propor- 
tion has  fallen  to  about  one-eighth.  In  1891,  according  to  census 
returns,  of  every  hundred  families,  22  had  but  2  children,  and  24,  but 
1  child,  apiece.  The  decline  in  births  is  not  due  to  poverty,  for  it  is 
among  the  poorest  there,  as  elsewhere,  that  the  largest  families  are  raised. 
The  same  influences  appear  to  have  been  in  operation  for  some  years  in 
England  and  Wales,  where,  since  1876,  when  the  birth-rate  was  36.3, 


DEATII-liATI'lS.  7r>l 

it  ("(ill  |)f()^r(!Hsiv<'.]y  in  lw(!iil,y  yciu-H  to  2().7,  and  hIiowccI  in  \\\c  hiHt 
ycui's  of  Ui(!  <'cntiiry  a  nior'c  slrikinj^  dcciv-asc  llian  in  any  of  licr  ff»nntry 
of  I^jiiropc. 

Ill  our  own  coiiiitry,  aiiioiiH-  the  (|(;.i(;(;n(iant.s  (jf  the  orij^inal  colonistH 
and  cailici'  iiiiiiiinriuitH,  tlic  same  dwsliiie  is  most  (ividfiif.  Wlicn-aH  in 
colonial  tiiiK'S  and  in  (lie  earlier  years  of  nalional  iiKlependeiife,  farni- 
lieH  of  a  do/(Mi,  (ir((;en,  aii<l  inor(!  \ver(!  exceedingly  e<»innion  ;  nowa- 
days, oiH!  o("  six  or  eif^lil.  l)e(!onies  a  suhjcd  lor  eonirruMit,  surprise,  and 
even  ridicule!.  TIk;  lariat;  llunilies  <»!'  lo-d;iy  arc,  mainly  tlio'-<-  of  the 
more  re(!cntly  arrived  immigrants  and  of  llieir  first  {generation.  In  .M;ih- 
.  sacliusetts,  the  statistics  ior  1  !)()8  show  that,  the  ^rreatest  proj)  irtion  of 
the  numl)(!r  of  births  belongs  to  the  forei^ii-horn,  the  children  of 
native  parentayjc;  on  hoth  sides  re])rcsenting  .'{I.OH,  those  of  mixed 
parcntajj^e,  18.25,  and  those  of  foreign-born  parentage,  5(),.">1  percent, 
of  the  total  births.     The  crude  birth-rate  was  27,77. 

Death-rates. — Death-rates  are  ealeiilated  in  the  same  way  and  ex- 
presses! ill  the  same  terms  as  birth- and  marriage-rates,  that  is,  by  mul- 
tiplying the  number  reported  by  1000  and  dividing  the  product  by 
the  population,  or  by  dividing  the  reported  number  V)y  the  number  of 
thousands  of  population,  the  result  in  either  case  being  the  rate  per 
1000  of  population,  This  is  known  as  the  general,  gi'oss,  (»r  crude 
death-rate,  and  is  affected  by  so  many  factors  that,  without  careful 
study  and  due  allowance  for  disturbing  influences,  it  may  prove  to  be 
a  very  faulty  index  of  the  health  of  the  people  and  of  the  sanitary  con- 
dition of  the  place.  When  used  as  a  basis  for  comparison  of  different 
places,  the  death-rates  must  first  be  corrected  by  making  careful 
allowances  for  differences  in  age,  sex,  and  race  distribution,  and  for 
abnormal  influences. 

Influence  of  Sex. — Sex  exerts  a  decided  influence,  since,  in  general, 
females  live  longer  than  males  and  their  mortality  is  lower  at  all  age 
periods,  excepting  from  the  tenth  to  the  twentieth  year.  So,  of  two 
places  equal  in  sanitary  and  all  other  conditions  excepting  .sex  consti- 
tution, the  one  with  the  greater  proportion  of  females  will  have  the 
lower  death-rate.  Except  in  newly  settled  places,  there  is,  as  a  rule, 
a  preponderance  of  females  over  males,  although  everywhere  the  births 
of  males  exceed  in  number  those  of  females,  the  preponderance  being 
the  result  of  the  higher  mortality  that  obtains  among  males,  except  at 
the  age  periods  above  mentioned. 

Influence  of  Age. — The  influence  of  age  distribution  is  far  greater 
than  that  of  sex,  since,  for  example,  the  mortality  per  1000  of  chil- 
dren under  5  years  of  age  is  more  than  ten  times  that  of  persons 
between  5  and  25,  and  more  than  six  times  that  of  adults  between  25 
and  45,  Thus  it  may  be  seen  that  the  greater  the  proportion  of  popu- 
lation belonging  to  the  earliest  and  latest  periods  of  life,  the  higher 
will  be  the  death-rate.  One  would  expect,  for  example,  a  higher 
mortality  in  a  community  made  up  largely  of  elderly  people  or  young 
children  than  in  one  unusually  rich  in  young  adults,  or,  to  reduce  the 


752  VITAL  STATISTICS. 

matter  to  its  simplest  terms,  in  a  foundling  asylum  or  retreat  for  the 
aired  than  in  a  collecre  for  voung;  men. 

iBfluence  of  Race. — To  a  certain  extent,  racial  peculiarities  have  an 
influence  on  vitality,  and  especially  on  susceptibility  to  certain  diseases. 
Thus,  the  negro  is  far  less  prone  to  some  and  far  more  susceptible  to 
other  morbid  influences  than  the  white.  As  between  difl'ercnt  peoples 
of  the  same  race,  tlie  diflerences  are  not  so  wide.  In  those  parts  of 
this  country  where  the  negro  population  is  considerable  or  preponder- 
ant, this  influence  can  never  be  disregarded,  and,  indeed,  it  is  com- 
monly the  practice  to  calculate  separate  rates  for  the  whites  and  for 
the  blacks.  According  to  Hoffman,^  the  mortality  of  whites  and 
blacks  in  ten  southern  cities,  including  Baltimore,  Washington,  Rich- 
mond, Memphis,  Louisville,  Atlanta,  Savannah,  Charleston,  Mobile, 
and  New  Orleans,  during  the  years  1890—94,  was  expressed  as  20.1 
and  32.6,  respectively.  This  divergence,  it  is  pointed  out,  would  be 
still  greater,  if  correction  were  made  for  age  distribution. 

The  excess  of  negro  mortality  obtaining  at  all  age  periods  is  espe- 
cially noticeable  in  the  earlier  ones.  Thus,  in  1890,  in  Washington 
and  Baltimore,  the  death-rates  of  negro  children  under  5  and  between 
5  and  15  years  of  age  were  more  than  double  those  of  white  children 
of  the  same  age  periods ;  in  the  age  periods  from  the  fifteenth  to  the 
forty-fifth  year,  the  rates  for  both  races  naturally  diminish  very  much, 
but  the  ratio  is  nearly  the  same.  After  the  forty-fifth  year,  the  dif- 
ference begins  to  be  much  less,  but  the  excess  is  always  with  the 
negro. 

As  instances  of  the  differences  in  white  and  black  death-rates,  the 
following  are  presented  : 

f  December,       1899,  White,  23.49  ;  Colored,  28.59 
New  Orleans   ■    ■    ■    \  January,  1900,         "       28.28;         "        44.80 


Baltimore 


March,  1900,  "  22.50;  "  39.60 

November,  1899,  "  13.42;  "  22.30 

December,  1899,  "  15.00;  "  29.38 

-January,  1900,  "  17.90;  "  30.60 


L  Whole  vear,  1900,  "  17.48;  "  33.42 

Atlanta Whole  "vear,  1900,  "  11.59;  "  19.50 

Augusta,  Ga "      '"       1899,  "  10.50;  "  31.00 

5  wks.  ending  Jan.     6,  1900,  "  15.70 ;  "  33.23 


Charleston    ^  4      "         "       Feb.    3,  1900,         "       12.60 ;  "        27.50 

(,  2      "         "       Feb.  24,  1900,         "       19.81 ;         "        32.94 

The  difference  between  white  and  black  mortality  is  believed  to  be 
due  more  largely  to  race  degeneration  than  to  sanitary  conditions.  In 
the  North,  the  negro  shows  an  excess  of  deaths  over  births,  and  holds 
his  own  only  by  influx  of  recruits  from  the  South. 

According  to  Dr.  Scale  Harris,^  before  the  Civil  War  the  negro 
death-rate  in  the  South  was  less  than  that  of  the  whites.  For  exam- 
ple, in  Charleston,  S.  C,  from   1822  to  the  beginning  of  the  war  the 

*  Eace  Traits  and  Tendencies  of  the  American  Negro.  Publications  of  the  Amer- 
ican Economic  Association,  New  York,  1896. 

'  The  Futuj-e  of  the  Negro  from  the  {Standpoint  of  the  Southern  Physician,  Amer- 
ican Medicine,  Sept.  7,  1901. 


INFLUI'lXdl':   OF   DFSSITY.  7.)') 

avcni^f!  (!(';illi-r!it(!  oC  IIki  whiles  was  'J,~).UH,  uihI  of  Uic  l)l;u;ks  2  l.Oo  ; 
but  from  I  .SflT)  (,o  I  M!)  I,  alllioii^li  llic  rate  was  hut  nhghtly  hi^hf-r  iu 
the  case  of  the  vvliilcs  (20.77),  it  hnd  ncntly  «louhh;(l  (4'i.29)  with  the 
l)lu(!k.s. 

r^roui  what  has  hcfii  said,  it  iiiiisl  he  cviflcnl  th.il  ciiHic  dcath-ratcH 
(jauuot  h(!  I'clicd  upon  as  a  hasis  ol' uiortalily  (Mtuipariscui  of"  two  phux^, 
uulcss  th(!  n'S|)('(;(,ivc  populafious  ai'c  in  suhsfaiilial  a^rccuioiit  in  aj^e, 
race,  and  s(!X  (Muistilulion,  nor  (or  conipiirisoii  oi'  dn;  (;on<litionH  obtain- 
in}jj  at  the  sanu;  phicc  in  diU'crcnl  years,  uidcs.s  these  factors  are  prac- 
tically unchann'cd. 

Other  Influences. — (hauh'  death-rates  are  influcn(;<;(l  by  cjrrors  in 
estimated  j)o[)uhition,  l)y  the  [)resenee  of  various  kinds  of  public  insti- 
tutions, such  as  hosi)itals,  state  ahnsliouses,  and  asylums  for  foundlingH 
and  th(!  at^ed  ;  by  mioratory  movements  ;  by  <lensity  r»f  ])oj)ulalion,  and, 
as  has  been  stated,  by  the  birth-rate.  An  imj)ort;int  source  of"  error  lies 
in  the  return  of  persons  afllicted  witii  incurable  diseases  to  their  old 
homes,  where  they  die ;  their  deaths  are  ref2;istered  there,  instead  of  at 
the  places  where  the  causes  thereof  had  their  origin  or  where  the  .sani- 
tary conditions  were  sueli  as  to  favor  suseeptil)ility. 

Influence  of  Density. — Death-rates,  es])ecially  those  of  the  very 
young,  are  much  higher  in  crowded  localities  than  where  the  population 
has  plenty  of  room  ;  and  it  is  commonly  accepted  that,  other  things  being 
equal,  increased  density  means  increased  mortality.  To  a  certiiin 
extent  this  is  undoul)tcdly  true,  particularly  where  increased  density 
means  overcrowding  ;  but  it  is  uot  necessarily  true  of  a  large  population 
spread  out  over  a  territory  capable  of  accommodating  twice  as  many 
people  very  comfortably.  Thus,  in  Massachusetts,  for  example,  where, 
in  1855,  the  population  averaged  130  to  the  square  mile,  the  general 
death-rate  was  about  the  same  as  obtained  forty  years  later,  when  the 
average  population  per  square  mile  had  more  than  doubled,  the  slight 
difference  being  in  favor  of  the  later  period.  During  the  decenuiura 
just  prior  to  the  outbreak  of  the  Civil  "War,  the  average  rate  Avas  18.25  ; 
during  the  period  1887-1897,  it  was  about  19.50;  and  in  1908  the 
rate  was  16.51,  which  figure  was  surpassed,  however,  by  that  of  1904, 
which  was  16.36. 

In  densely  populated,  overcrowded  localities,  such  as  the  slums  of  large 
cities,  we  find  all  the  conditions  which  favor  a  high  mortality  ;  namely, 
poverty,  immorality,  ignorance,  intemperance,  unsanitary  hal^itations, 
high  birth-rate,  carelessness,  filth,  and  improper  and  insufficient  food. 
In  fact,  the  slums  are,  in  very  great  measure,  the  cause  of  the  differences 
observed  in  the  death-rates  of  small  and  large  communities.  In 
country  districts,  small  towns,  large  towns,  and  cities  situated  within 
the  same  district,  where  climatic  and  other  natural  conditions  are  essen- 
tially the  same,  it  is  commonly  observed  that  the  higher  average  rates 
obtain  in  the  larger  connnunities,  and  the  lower  in  the  smaller  places, 
where  slums  are  unknown  ;  while  the  very  highest  occur  in  manufact- 
uring centers,  where  the  main  population  consists  of  mill  operatives, 
who  work  by  day  under  unsanitary  conditions  and  pass  their  nights  in 
crow^ded  tenements.  So,  also,  higher  rates  obtain  in  old  mauufacturing 
48 


754  VITAL  STATISTICS. 

crowded  tenements.  So,  slso,  higher  rates  obtain  in  old  manufacturing 
places,  in  which  a  larger  proportion  of  population  of  a  weak  and  degen- 
erated type  is  to  be  found,  than  in  others  more  recently  established. 

Weekly  Death-rates,  etc. — The  death-rate  for  any  particular  Aveek  is 
obtained  l)y  multiplying  the  number  of  deaths  occurring  during  that 
period  by  52.14  (the  number  of  weeks  in  365  days)  and  dividing  the 
product  by  the  number  of  thousands  of  population  as  estimated  for  the 
middle  of  the  year.^  The  same  method  of  reckoning  may  be  employed 
for  determining  the  rates  for  other  fractious  of  a  year,  and  for  rates  of 
birth,  marriage,  zymotic  disease,  and  other  matters  of  statistical  inter- 
est. These  weekly  and  other  periodical  rates  are  highly  unreliable 
data  upou  which  to  base  comparisons  M'ith  those  of  other  places  and  of 
other  parts  of  a  year,  since  seasonal  influences  and  temporary  condi- 
tions must  not  be  ignored  ;  their  principal  value  is  in  comparing  the 
rates  obtaining  at  the  same  place  at  corresponding  periods  of  diflPerent 
years. 

In  the  same  way,  the  weekly  death-rate  from  any  given  cause,  or  the 
weekly  number  of  cases  of  any  particular  notifiable  disease,  such  as 
diphtheria,  scarlet  fever,  or  measles,  may  be  determined. 

Zymotic  Death-rate. — The  zymotic  death-rate  is  the  death-rate  due 
to  the  seven  principal  so-called  zymotic  diseases ;  namely,  smallpox, 
scarlet  fever,  measles,  diphtheria,  whooping-cough,  typhoid  fever,  and 
diarrhceal  diseases.  It  is  expressed  in  terms  per  1000  of  population, 
like  the  gross  death-rate.  The  rate  for-  any  disease  may  be  similarly 
obtained  and  expressed. 

Infantile  Death-rate. — The  infantile  mortality  is  not  expressed  in 
terms  per  1000  of  the  whole  population,  but  as  the  number  of  deaths 
of  children  under  one  year  of  age  to  each  1000  births  registered  during 
the  year.  It  is  assumed  that  the  efflux  of  living  children  whose  births 
have  been  registered  with  the  local  authorities  is  counterbalanced  by  the 
influx  of  others  whose  births  are  registered  elsewhere. 

Infantile  mortality  is  always  high,  owing  to  a  variety  of  causes,  and 
it  is  particularly  high  in  slums  and  in  manufacturing  towns  where 
women  are  largely  employed  in  factories,  and  so  are  unable,  even  though 
so  inclined,  to  give  that  personal  attention  to  their  offspring  as  is 
bestowed  by  mothers  whose  lives  are  purely  domestic.  In  Massa- 
chusetts, for  example,  the  infantile  death-rate  averaged,  in  the  decade 
1881-1890,  174.9  in  the  cities  and  129.5  in  the  country,  and  the 
extremes  for  the  cities  were  239.7,  at  Fall  River,  preeminently  a  "  mill 
town,"  with  all  that  the  term  implies,  and  111.9  at  Newton,  where 
manufacturing  is  at  a  minimum  and  overcrowding  practically  unknown, 
Lowell  and  Lawrence,  also  "miM  towns,"  showed  respectively  222.5 
and  213.9,  while  Boston,  commercial,  manufacturing,  and  residential, 
showed  188.2. 

'  Many  statisticians  employ  the  factor  52.17747,  the  number  of  weeks  in  the  solar 
year  of  365  days,  5  hours,  48  minutes,  and  46  seconds.  This  exaggeration  of  exactness 
in  small  things  seems  all  the  more  absurd  when  we  consider  that  the  estimation  of  popu- 
lation at  the  middle  of  the  year  is  nothing  more  than  a  fairly  reasonable  guess,  and 
often  proves  to  be  wide  of  the  truth. 


/NFANTIL/':   DHATU-IIATI':.  755 

Ti)  ilm  tliHic  ciiicw  willi  I  lie  lii^'licsi  r;it<!H,  K;ill  liivcr,  Low«'ll,  and 
\Aiwn'\\r,v,  \\\v.  popul.'ilioii  is  lai|.';<ly  I''r(;iirli-r";iti;uliaii  opr'nitivcs  oi' 
cotton  and  woollen  mills,  JKMiscd  in  crowded  tenements,  TIm;  Ko-fsiIlc<l 
".shoe  towns,"  I  Iiiverliill,  i\I;irll)oi-o,  P.i-(,el<t<ni,  :in<l  f/ynn,  have  u  very 
(lid'enMit  kind  ol"  |)o|)iil;il  ion,  inncii  heller  paid  ;ind  \\u\  inejincd  U)  a 
tcn(Mnent-honse  lili-,  and  show  respeetively  107.1,  lod.O,  I  Mi.lJ,  and 
1.40.7,  all  oC  which  rates  are  helow  that  of  tin-  SUite  at  lar^e,  lOO.  I.' 
Similarly,  in  Kn<;land  ;iiid  Walerf,  where  in  I  H!M  the,  rat<!  was  l.'i7,  and 
in  1<S9(J,  147.5,  Preston,  which  (!an  (;laim  onr-  of  the  bhickcst  records 
in  all  rospeotH  anion^  mill  towns,  showed,  in  tin'  former  year,  229,  and 
in  th(>  latter,  2(12,  whih;  in   London  the  rat(!  was  hnt  151). 

The  chief  fiictors  in  I  he  eansalion  of  lii^h  infant  mortality  are 
prcmatnre  births,  heredily,  inlemperan(;e,  early  marriages,  neglect, 
carelessness,  i<2;uoranee,  improper  food,  nnsanitary  surroundings,  indus- 
trial conditions,  illegitimacy,  and,  perbaj)s,  infant  life  insurancx;.  The 
immediate  causes  are  (!hie(ly  inanition,  diarrh(eal  diseases,  measles, 
whooping-cough,  and  other  infective  diseases,  and  viohiuce.  The  influ- 
ence of  prcimature  birth,  heredity,  neglect,  carelessness,  ignorance,  and 
unsanitary  surroundings  needs  no  elucidation.  Industrial  conditions 
figure  largely  in  the  neglect  of  infants,  since  mothers  in  employment 
return  as  soon  as  possible  after  confinement  to  their  work,  and  entrust 
their  offspring  to  the  care  of  older  childnin  and  others,  by  whom  they 
are  improperly  fed  and  looked  after.  During  pregnancy,  also,  the 
woman  remains  at  work  up  to  the  last  posbii)l(>  moment,  so  tliat  her 
absence  is  limited  to  that  period  during  which  she  is  absolutely  in- 
capacitated. 

The  age  of  the  parents  has  much  influence  on  the  vitality  of  infants, 
those  of  mothers  under  20  dying  off  appreciably  faster  than  those  of 
others  between  20  and  30.  Between  ?>0  and  35,  the  vitality  of  the 
offspring  is  still  greater ;  but  after  this  age  period  it  begins  to  decline. 
The  first  children  of  very  young  fathers  also  are,  as  a  general  rule, 
weaker  than  tiiose  begotten  later.  To  this  influence  of  the  parents' 
age,  conjoined  with  that  of  ignorance  and  inexperience,  may  be 
attributed  the  excessive  mortality  which  obtains  among  the  first-born. 

Illegitimacy  has  a  very  great  influence  on  the  chance  of  survival  to 
even  the  early  period  of  childhood,  for  the  infant  is  in  an  unfavorable 
position  as  regards  care  and  home  surroundings  from  the  beginning. 
Abandoned  by  the  mother  to  the  care  of  whomsoever  may  be  willing  to 
accept  the  charge,  or  "  farmed  out "  among  persons  whose  interest  in 
its  welfare  is  wholly  financial  and  subject  to  innnediate  decline  on  the 
cessation  or  tardiness  of  payments,  it  has  even  less  chance,  perhaps, 
than  when  kept  at  home,  an  unwelcome  addition  both  to  the  family 
circle  and  to  the  expense  account. 

Infant  insurance  is  generally  believed  to  be  an  influence  in  diminish- 
ing the  amount  of  care  and  solicitude  for  the  health  of  the  very  young, 

^  These  figures  are  taken  from  a  comnuinioation  from  Dr.  S.  W.  Abbott.  Secretary  of 
tlie  State  Board  of  Health  of  Massiichusetts.  on  "  Infant  Mortality  in  Massachusetts." 
Journal  of  the  Massachusetts  Association  of  Boards  of  Health,  December,  1S9S,  p.  13-L 


756  VITAL  STATISTICS. 

and,  therefore,  has  been  the  subject  of  considerable  legislation,  by 
which  the  maximum  amount  of  the  policy  is  kept  at  a  low  figure,  as, 
for  instance,  the  actual  expense  of  burial.  Whether  insurance  has  more 
than  an  insignificant  bearing,  cannot  be  determined  by  trustworthy 
statistics. 

Beyond  doubt,  the  most  fruitful  single  cause  of  high  infant  mortality 
is  improper  feeding,  due  partly  to  the  necessity  of  supplying  an  arti- 
ficial substitute  for  brciist  milk  and  partly  to  ignorance.  The  breast- 
fed infant,  carelessly  looked  after,  has  a  far  better  chance  than  the 
bottle-fed  more  carefully  tended.  The  former  receives  its  natural  food 
at  a  uniform  temperature  and  practically  sterile ;  the  latter  is  fed  upon 
another  kind  of  milk,  differently  constituted  and  of  a  different  degree 
of  digestibility,  which,  under  the  best  of  circumstances,  is  com- 
paratively rich  in  ordinary  bacteria,  and  is  administered  at  different 
temperatures,  sometimes  very  hot,  sometimes  cold.  AVith  lack  of  care, 
the  danger  is  increased,  for  the  milk  may  be  stale  and  dirty,  and  act  as 
the  vehicle  for  the  exciting  cause  of  cholera  infantum,  which  is  respon- 
sible to  a  greater  extent  than  any  other  morbid  condition  for  the  deaths 
in  mill  towns  of  infants  whose  mothers  are  employed  in  the  various 
industries.  Besides  dirty  and  stale  cows'  milk,  a  variety  of  cereal  and 
sugar  substitutes  are  provided,  which  may  or  may  not  be  digestible 
and  nutritiotis. 

Ignorance  of  what  is  proper  for  introduction  into  an  infant's  stomach 
is  responsible  for  much  infantile  mortality,  even  when  breast-feeding 
is  followed.  Who  has  not  seen  fond,  but  ignorant,  mothers,  in  public 
conveyances,  keeping  their  infants  quiet  with  bananas,  seed  cakes, 
cookies,  and  other  food  materials  unsuited  to  a  digestive  system  which 
can  have  difficulty  enough  with  milk  alone  ?  It  seems  unlikely  that 
such  practices  are  restricted  to  the  time  spent  in  travel,  when  consid- 
eration for  the  comfort  of  strangers  suggests  the  avoidance  of  fretting 
and  crying. 

Death-rates  of  children  under  five  years  of  age  are  expressed  in  the 
same  terms  as  infantile  mortality,  that  is  to  say,  as  the  proportion  of 
deaths  per  1000  children  of  that  age  period. 

High  and  Low  Death-rates. — In  the  absence  of  any  unusual  general 
unsanitary  condition  or  of  unusual  prevalence  of  epidemic  diseases,  an 
abrupt  rise  in,  or  a  very  higli,  death-rate  is  not  infrequently  only 
apparent,  being  based  upon  an  underestimated  population.  A  very  low 
death-rate  is  always  open  to  suspicion,  although  sometimes,  as  in  newly 
settled  communities  with  a  very  high  proportion  of  young  male  adults, 
for  a  limited  term  of  years,  it  is  perfectly  ])ossible  and  natural.  A  rate 
of  15  per  1000,  for  example,  in  large  cities,  is  so  low  as  to  suggest 
that  the  population  has  been  very  much  overestimated.  Within 
recent  years,  the  authorities  of  a  rapidly  growing  Western  city  noted 
with  great  pride  the  gigantic  strides  in  the  estimated  population,  and 
were  naturally  much  elated  to  find  that  the  death-rate  based  thereon 
entitled  the  city  to  a  position  in  the  first  rank  of  the  cities,  lai^ge  and 
small,  of  the  whole  world.     The  census  of  1900  dispelled  the  illusion, 


CORRKCTfON  OF  IU'lATU-llATES. 


tor  the  population  Ii;hI  Ix'cn  jrrosHly  cxii^^^cnilcfl,  ;iiii|  ilic  ;i((ii;i|  (Ic-itli- 
rat(!  w:iH  (soinparalivcly  liij^li. 

I)(iM(Ji-riii(!S  as  low  as  10  ;ui<l  \'l  iirc  soinctiiiic^  noted.  y\  continiifri 
rate  oC  10  in  a  st:ilionarv  population  would  mean  that  tlu;  inlial)ifaiitH 
would  av('r;i<j,'(!  100  yv.ivs  of  a<;('  at  dtiitli  ;  ono  of  \'l  would  lucau  an 
average  ag(!  of  over  x;;  ;  one  of  I  o  would  mean  an  average  of  nearly  'j7. 

As  exaui|)les  of  liigli  and  low  (hsitli-rates,  tlie  following  for  tlie.wame 
(piarter  of  the  sauu!  year  (18!J7}  may  be  cited  : 


UiK'll. 

l)iil)lin 80.9 

Moscow ;{().'.» 

Bucliiuost :i.'i.2 

Belfast :ii.:{ 

8t.  iviiTshuiL' :n.(t 


Low. 
Kninkfoit  on  tli(!  Main  .    .    .  15.6 

The  HaKuc 1G.2 

Berlin 17.0 

("liristiania 17.7 

Aiiist(T(l;ini 17.8 


The  iuHueuec  of  imj)roved  sanitation  in  tln'  lowei-ing  of  the  mort^ility 
of  any  given  place  cannot  be  disj)uted,  Imt  in  attributing  the  whole  or 
even  the  greater  })art  of  the  dilfcirence  in  the  rates  of  any  two  place?,  or 
of  the  same  j)la('e  in  diirerent  years,  one  should  be  careful  not  to  ignore 
factors,  already  mentioned,  that  exert  influences  beyond  the  control  of 
sanitary  authorities.  Permanent  decline  in  mortality-rate  is  a  matter 
of  slow  growth,  and  is  the  combined  result  of  sanitary  effort  and  miti- 
gation of  the  occupational  and  social  conditions  tending  to  lower  vital- 
ity. In  Elizabetluin  times,  the  death-rate  of  London  was  about  40  ; 
at  the  beginning  of  the  reign  of  Victoria,  it  was  24,  and  at  the  end 
of  the  century,  about   19. 

Correction  of  Death-rates. — The  impossibility  of  making  a  fair  com- 
parison of  the  death-rates  at  dilferent  ])laces  without  taking  into  con- 
sideration the  constitution  of  the  respective  populations  as  to  age,  sex, 
and  race,  has  been  suiiiciently  pointed  out ;  and  since  two  places  abso- 
lutely alike  with  regard  to  occupational  influences,  \\ealth,  density  of 
population,  climate,  soil,  watcr-sup]>ly,  sanitary  administration,  and 
general  sanitary  condition,  but  discrepant  as  regards  the  distribution 
of  the  sexes,  age  periods,  and  race,  may  show  very  different  death- 
rates,  perhaps  magnifying  the  salubrity  of  the  one  and  exaggerating  the 
unhealthiuess  of  the  other,  it  becomes  necessary  to  have  some  method 
of  bringing  them  to  a  common  basis.  In  the  matter  of  race  influence, 
the  best  plan  is  to  separate  the  statistics  absolutely,  having  one  set  for 
the  white  and  another  for  the  colored  population,  and  to  compare  white 
with  w^iite  and  negro  with  negro. 

The  method  commonly  recommended  for  correcting  according  to 
sex  and  age  is  the  one  in  use  in  the  oflfice  of  the  Registrar-General  for 
England  and  Wales  ;  this  may  briefly  be  described  as  follows  : 

The  mean  annual,  death-rate  of  the  country  for  each  sex  at  each  of 
the  eleven  age  periods,  namely,  below  5,  o-lO,  10—15,  15-20,  20—25, 
25-35,  35-45,  45-55,  55-65,  65-75,  and  75  and  upward,  during  the 
last  preceding  ten  years,  is  obtained  and  multiplied  by  the  number  of 
those  of  each  sex  at  each  corresponding  age  period  in  the  temtory 
under  consideration,   according   to  the   returns  of  the  last  preceding 


758  VITAL  STATISTICS. 

census.  Each  product  thus  obtaiuetl,  divided  by  1,000,  gives  the  cal- 
euhited  number  of  deatlis  for  the  respective  sex  and  age  periods. 
These  22  results,  added  together,  represent  the  calculated  number  of 
deaths  for  the  place  in  question  in  one  year.  The  total  calculated 
number  of  deaths,  divided  by  the  number  of  thousands  of  population 
or  multiplied  by  1,000  and  divided  by  the  population,  gives  the  i^tan- 
dard  dcdth'-ratc. 

The  next  step  is  to  obtain  a  factor  for  correction,  by  determining  the 
ratio  which  the  standard  death-rate  of  the  place  bears  to  the  death-rate 
of  the  whole  country.  This  is  obtained  by  the  rule  of  simple  propor- 
tion, the  second  mean  being  unity.  The  recorded  death-rate  for  the 
year,  multiplied  by  this  factor,  gives  the  corrected  death-rate,  which 
will,  therefore,  be  above  or  below  the  recorded  rate,  according  as  the 
factor  is  above  or  below  unity.  By  dividing  the  corrected  death-rate 
by  the  death-rate  of  the  whole  country,  and  multiplying  the  quotient 
by  1,000,  the  comparative  mortality  figwe  is  obtained;  that  is  to  say, 
the  number  of  deaths  which  Mill  occur  in  the  same  number  of  the  local 
population  as,  in  the  general  population,  will  yield  1,000  deaths. 

Classification  of  Causes  of  Death. — In  the  registration  of  causes  of 
death,  a  certain  amount  of  error  is  inevitable,  for  several  reasons.  In 
the  first  place,  even  the  most  competent  practitioners  are  not  infallible 
in  diagnosis,  and  it  is  not  always  possible,  when  one  pathological  state 
is  complicated  by  the  advent  of  another,  to  determine  which  was  the 
actual  cause  of  the  fatal  termination.  Next,  the  nomenclature  of  dis- 
eases is  still  faulty,  although  many  of  the  sources  of  confusion  have 
been  removed  by  the  adoption  of  the  international  classification  ^  of  the 
causes  of  death,  through  which  it  is  hoped  to  secure  uniform  and  com- 
parable statistics  of  the  causes  of  death  for  the  whole  world.  Again, 
the  true  cause  of  death  frequently  is  misrepresented  intentionally  for 
private  or  family  reasons ;  thus,  apoplexy,  instead  of  suicide,  and  peri- 
tonitis, when  the  actual  cause  of  the  peritonitis  is  criminal  interference. 

Lastly,  it  is  sometimes  the  case  that  no  cause  whatever  is  assignable, 
even  after  careful  autopsy,  and,  obviously,  such  cannot  be  classified. 
With  the  existence  of  an  indeterminate  amount  of  error,  it  follows  that 
caution  should  be  exercised  in  comparing  results  representing  a  series 
of  years,  and  allowances  should  be  kept  in  mind  with  changes  in 
nomenclature,  when  drawing  deductions  from  what  has  been  described 
as  the  classification  of  the  more  or  less  reliable  guesses  of  a  large  num- 
ber of  more  or  less  skilled  observers. 

Registration  of  Sickness,  if  it  were  possible,  would  afford  a  far  more 
efficient  index  of  the  sanitary  condition  of  the  j^opulation  than  the 
registration  of  deaths,  which  gives  us  simply  the  number  of  cases  of 
sickness  which  ended  fatally,  but  no  idea  of  the  duration  thereof  or  of 
the  number  of  persons  temporarily  incapacitated.  A  disease  ordinarily 
regarded  as  fairly  dangerous  may  prevail  very  extensively  in  a  mild 
form,  and  be  attended  by  a  very  low  death-rate,  and,  again,  may  exist 

1  This  classification  can   be  obtained  by  applying  to  the  Bureau  of  the  Census, 
Washington,  D.  C. 


Ml'! AN    DUliATION  OF  rJFK.  7 f>U 

to  a  leHsnr  o.xivnt,  l)ui  in  !in  iiiiiisdaily  Hc.vo.rc.  form,  witli  u  lii{.'li  propfir- 
tioii  of  (!i,l;ilil,ics.  Miiiiy  (lis(;:i,scH,  .-i^raiii,  urc  Icinponirlly  dihiililiiitr  and 
oflcn  widely  |»n;v:il<'n( ,  l.iit,  pl.-iy  ;i  ,sni:dl  |.;i(f  in  mortality  nturiiH. 
Toii.silliti.s,  for  cxunipli!,  is  rcsponHihlc  for  nin<li  di-fotrd'ort  and  loHt 
timo  :  ItH  prova,l('iw',(!  Iiuh  somh!  nuianiiifj:,  l)nl  it-  <\c:\\\\  roll  ih  oxcft'din^ly 
small.  IMicMmalism  is  mncli  more  widespread  than  mortality  returim 
wonld  nnply  ;  eliiek((n|)ox  is  nilat-ively  iinimportjint,  hut.  in  some  plae^iH 
its  noii(i(!iiti()n  is  recjiiircid  u.s  a  Hafe^nard  against  the  spnrad  of  .small- 
|)ox  in(!()rrcetly  diagnosed  as  varieella;  ironorrlia'a,  without  Ijcing  fuUii, 
does  more  harm  than  (u)minoiily  is  supposed  ;  and  sy|)liiliH,  aJHO  not 
inunedialely  and  directly  fatal,  s(!nds  its  vietims  into  th<'  mf)rtality 
returns  throut!;h  various  av(!nues.  I'ut  luAvever  desirahle  such  regis- 
tration may  he,  the  ohstaol(!S  in  the  way  of  its  ;i<-<'..inplishmcnt  art;  too 
numerous  to  admit  even  of  ho|)e,  and,  exe(!j)ting  in  the  case  of  infective 
diseases,  which  law  recpiires  shall  he  reported,  there  is  no  satisfactory 
method  of  ohtaining  an  accurate  idea  of  th(!  health  of  a  community. 

Duration  of  Life. — Several  ex|)ressions  and  methods  are  emf>loyed 
to  denote  and  measure  the  duration  of  life,  a  prohlem  with  which  the 
science  of  vital  statistics  is  largely  engaged.  One  of  the  most  falla- 
cious indications  of  longevity  and  sanitary  condition  is  the  ^fmn  arje  at 
Death  or  Mean  Lifefliiie,  which  is  the  sum  of  the  ages  at  deatli  divided 
by  the  number  of  deaths.  This  is  unreliable,  because  it  fluctuates  very 
widely,  according  to  age  distribution ;  for  in  a  community  containing 
a  larg(>  proportion  of  children  and  in  which  the  birth-rate  and,  conse- 
(pieutly,  the  infantile  mortality  are  high,  the  average  age  at  death  will 
be  lower  than  in  another,  equally  healthy,  in  w^hich  these  conditions  do 
not  obtain.  Hence,  it  can  only  be  employed  with  any  degree  of  safety 
where  the  population  constitution  is  uniform  in  all  respects,  and  when 
the  observations  are  carried  along  over  a  long  period.  The  mean  age 
at  death,  not  of  a  few  hundreds  or  thousands  of  individuals,  but  of  an 
entire  generation  of  population,  is  necessary  to  show  accurately  the 
mean  duration  of  life,  and  this  is  determined  only  by  means  of  life 
tables. 

Probable  Duration  of  Life  signifies  the  age  at  which  half  of  any  num- 
ber of  children  born  will  have  died,  so  that  they  have  equal  chances  of 
dying  before  and  after  that  age.  It  is  also  called  the  vie  probable  and 
the  equation  of  Life ;  but  all  of  these  terms  are  ill-chosen,  for  eveiy 
possible  duration  of  life  has  a  certain  probability,  which  may  be  deter- 
mined by  life  tables. 

Mean  Duration  of  Life  is  another  ill-chosen  term  with  which  the  last- 
mentioned  is  often  confounded,  but  which  has  an  entirely  ditlerent 
meaning.  It  is  meant  to  express  the  probable  duration  of  life  from 
the  date  of  birth.  In  an  ordinary  population,  subjected  to  the  usual 
disturbing  intiuences  of  migration,  it  means  present  age  plus  the  prol>- 
able  length  of  life  after  passing  a  given  point,  and  is  called  commonly 
the  expeetation  of  life  or  rnean  a/tcr-lifetime.  It  is  a  term,  which,  by 
reason  of  its  indefiuiteness  and  looseness  of  application,  it  would  be  well 
to  eliminate  alti>i>'ether. 


760  VITAL  STATISTICS. 

Expectation  of  Life,  or  Mean  After-lifetime,  is  the  average  number  of 
years  which  an  individual  at  any  given  age  will  continue  to  live,  as 
shown  by  a  life  table.  As  applied  to  whole  communities,  it  is  the 
mean  duration  of  life  of  a  generation  of  individuals  from  birth  to  death, 
and  is  regarded  as  the  only  true  measure  of  the  health  of  entire  popu- 
lations. Like  others  which  have  gone  before,  it  is  an  unfortunate 
exjiression  tending  to  confusion.  "  The  term  does  not  imply  that  an 
individual  may  reasonably  expect  to  live  a  given  number  of  years. 
The  excess  of  those  who  die  late  is  distributed  among  those  who  die 
early,  '  those  who  live  longer  enjoying  as  much  more  in  proportion  to 
their  number  as  those  who  fall  short  enjoy  less  of  life.'  Thus  the 
expectation  of  life  has  no  relation  whatever  to  the  most  probable  life- 
time of  any  given  individual."     (Newsholme.) 

"Expectation  of  life  is  an  incorrect  term  :  the  time  which  it  is  expected 
a  person  will  live  is  the  time  which  it  is  an  even  chance  he  will  live ; 
it  is  the  vie  probable  of  the  French,  and  is  correctly  expressed  by 
'  probable  lifetime.'  The  after-lifetime  can  only  be  the  same  as  the 
prolxible  lifetime  on  Demoivre's  hypothesis — that  the  surviving  form 
an  arithmetical  progression.  The  term  '  expec cation  of  life,'  first  used 
by  Demoivre,  is  correct,  on  that  supposition,  which  is,  however,  in 
itself  quite  erroneous.  The  idea  iatended  to  be  expressed  by  '  expec- 
tation of  life '  is  the  viean  time  which  a  number  of  persons  at  any 
instant  of  age  will  live  after  that  instant :  it  is  the  French  vie  moyenne  ; 
and  this  technical  idea  is  strictly  and  shortly  expressed  by  nfter-lifetime, 
a  pure  English  word,  formed  on  the  same  analogy  as  after-life,  after- 
times,  after-age,  after-hours.  The  after-lifetime  of  men  at  the  age  of  30 
is  33  years  by  the  English  Life  Table  :  33  years  is  not  the  precise 
time  probably  that  anyone  of  that  age  will  live,  but  the  average 
time  that  a  number  of  men  of  that  age  Mdll  live,  taken  one  with 
another.  Age  -f-  after-lifetime  =  Lifetime.  At  30  this  is  30  -f  33  =  63, 
the  average  age  which  men  now  aged  30  will  attain.  At  birth 
this  is  0  +  40  =  40 ;  when  lifetime  and  after-lifetime  are  the  same 
thing. 

"  The  lifetime  simply,  without  the  addition  at  a  given  age,  will 
serve  to  express  in  one  w^orcl  what  is  improperly  called  the  expectation 
of  life  at  birth  ;  thus  the  lifetime  of  males  in  England  is  40  years,  the 
lifetime  of  males  in  Manchester  is  24  years.  Those  who,  from  habit, 
prefer  '  expectation  of  life,'  can  always  substitute  it  for  after-lifetime ; 
from  the  use  of  which,  in  this  paper,  no  ambiguity  can  arise." 
(Dr.  William  Farr,  Eighth  Annual  Report  of  the  Registrar-General, 
p.  279.) 

Life  Tables. — A  life  table,  according  to  Dr.  Farr,  is  an  instrument 
of  precision.  "  It  may  be  called  a  biometer,  for  it  gives  the  exact 
measure  of  the  duration  of  life  under  given  circumstances. 
A  life  table  represents  a  generation  of  men  passing  through  time  ;  and 
time  under  this  aspect,  dating  from  birth,  is  called  age.  In  the  first 
column  of  a  life  table,  age  is  expressed  in  years,  commencing  at  0 
(birth),  and  proceeding  to  100  or  110  years,  the  extreme  limit  of 
observed  lifetime." 


1JFI-:  TAIUJ'X  761 

Til  order  to  eoiisiriif!!,  ;i  lidr;  lahl'-,  i(  is  essciili.-il  to  li;iv<',  jih  rii;it<;rial, 
a  lvii()\vl<;(l}:;(!  oCtlu'  size  of  the  |)o|»iilalioi)  and  its  age  and  h-x  <Ji.-tril)ii- 
tioii,  Jiiul  tli(!  rciiirns  of"  dcaili  for  a  y<af,  or  a  HoricH  of  yourn,  urrari^<;d 
according  to  a^i;  a(.  dcalli  and  sex  ;  and  for  tools,  wrtiiin  alwtruHe 
matlicnialical  forintda-  wliicli  it  is  hardly  iK'cessary  to  consider  here. 
'V\iv  |)rinei|)lc  upon  wliicli  tiic  tahNis  an;  based  is  that  if  a  lar^e  inirnlHrr 
of  |)ersons,  I  00, 000,  for  instance,  horn  at  th(!  satne  time,  were  ("ollowj-il 
from  hirth  to  tJie  ;;i'a\c,  and  I  hi  ii- deal  hs  re(rorded  in  th<;  usual  manner, 
the  avera<:;(!  a«^e  lived  eonld  he  ohiained  hy  dividing  th(!  sum  of  their 
agOH  at  death  \}y  their  ori<:;inal  nnml)(!r,  aiul  the  nnnd)er  of  dejitlis  and 
of  survivors  at  each  jxriod  wotdd  he  known.  Another  lot  of  the  same 
size,  observed  elsewhere  and  livinj^  imder  dilferent  eondifions,  would 
j^ivc  different  results,  and  thus  the  inlluenc{!  of  the  diserepant  eonditi<jn8 
could  l)e  measured. 

1\)  insure  as  j^rcat  a(;euraey  as  |)()ssil)le  in  eonstrnetin;^  life  tables,  it 
is  best  to  take  the  death  returns  for  th(!  entire  intere<-nsal  [)eriod  <»f  five 
or  ten  years,  and  the  mean  ])o|)ulation,  for  the  experience  of  a  single 
year  may  be  exceptional.  Tables  can  be  constructed  comprising  each 
year  of  life  or  according  to  quin([uennial  ])eriods,  and  are  made  for  each 
sex.  From  them  may  be  determined  the  ])robable  proportiftn  of  a 
given  number  that  will  arrive  at  different  ages,  the  probability  of  living 
a  given  time  at  each  year  or  period  of  age,  the  mean  after-lifetime  at 
the  end  of  any  given  year  or  period,  and  the  aggregate  future  lifetime 
of  the  survi\'ors  at  the  end  of  eacli  year  or  age  period,  or  what  is 
knowni  as  the  /i/e  cdpHdl,  of  the  entire  (community. 

The  probability  of  living  a  given  time  for  each  year  of  life  or  age 
period  equals  the  number  of  survivors  at  the  beginning,  into  the  num- 
ber at  the  end  of  the  year  or  period.  The  probable  number  of  sur- 
vivors at  each  year  or  period  is  obtainable  directly.  The  mean  after- 
lifetime  at  the  end  of  any  given  year  or  period  is  obtained  l)v  adding 
together  the  years  lived  by  the  w-hole  life-table  population  beyond  the 
year  or  period,  and  dividing  the  sum  by  the  numljcr  of  survivors  at 
that  particular  time.  The  life  capital  of  a  community,  divided  by  the 
population,  gives  the  average  future  lifetime  ;  and  into  a  hundred  times 
the  population,  gives  the  percentage  of  annual  expenditure  of  life  capi- 
tal, since  the  mean  population  equals  years  of  life  expended  in  a  year. 

For  further  information  concerning  this  branch  of  vital  statistics, 
and  for  further  consideration  of  statistical  methods,  values,  and  errors, 
the  reader  is  referred  to  the  many  staudaixl  works  dealing  with  the 
subject. 


CHAPTER   XV. 

PERSONAL   HYGIENE. 

Ix  addition  to  the  barriers  which  public  hygiene  interposes  for  the 
protection  of  the  health  of  comrauuities  by  protecting  water  supplies, 
disposing  of  sewage  and  other  wastes,  excluding  exotic  diseases  by 
means  of  quarantine,  providing  for  isolation  of  communicable  diseases, 
destroying  infectious  ma,tter  by  disinfection,  regulating  the  conduct  of 
dangerous  occupations,  providing  for  the  inspection  of  foods,  and  throw- 
ing out  other  safeguards,  the  individual  owes  it  to  himself  and  to  the 
community,  of  which  he  constitutes  a  more  or  less  valuable  unit,  to 
erect  such  other  barriers  for  his  own  protection  as  he  can,  by  due  re- 
gard to  such  habits  of  life  as  conduce  to  a  healthy  existence.  It  is  his 
duty  to  maintain  habits  of  personal  cleanliness,  to  regulate  his  diet, 
avoiding  all  excesses  in  eating  and  drinking  ;  to  protect  his  body  by 
suitable  clothing  ;  to  take  sufficient  exercise  in  the  open  air  ;  to  keep  his 
system  in  perfect  working  order  throughout ;  to  devote  a  sufficient 
part  of  each  twenty-four  hours  to  needful  rest  of  mind  and  body  ;  and 
to  keep  his  immediate  surroundings  in  as  cleanly  a  state  as  his  own 
person.     This  is  the  domain  of  personal  hygiene. 

Section  1.     CARE  OF  THE  PERSON. 

It  is  hardly  necessary  to  impress  upon  intelligent  people  the  impor- 
tance of  personal  cleanliness,  for  with  such  it  is  a  matter  almost  of  in- 
stinct. In  the  case  of  the  naturally  dirty,  the  attempt  to  educate  in 
this  particular  is,  as  a  rule,  a  hopeless  task,  and  with  such,  the  mainte- 
nance of  cleanliness  of  body  and  surroundings  can  be  obtained  only  by 
compulsion.  There  is  in  every  civilized  community  an  all-too-large 
proportion  of  persons  who  never  bathe,  and,  indeed,  regard  a  bath  as 
a  positive  danger  to  health,  as  every  physician  who  has  had  experi- 
ence as  a  hospital  interne  or  in  practice  among  the  ignorant  poor  can 
abundantly  testify. 

Bathing  is  of  importance  to  health,  both  for  its  action  in  removing 
dirt  and  infectious  matter  of  external  origin,  and  for  its  influence  in 
keeping  the  skin  free  from  waste  products  of  the  system  and  in  a  con- 
dition for  the  proper  exercise  of  its  natural  functions ;  for  the  skin  is 
one  of  the  most  important  natural  defences. 

Baths. — By  an  arbitrary  division  of  temperatures,  cold  baths  are 
those  in  which  the  water  has  a  temperature  below  65°  F.  ;  cool,  be- 
tween 65°  and  80°  ;  tepid,  between  80°  and  90°  ;  warm,  between  90° 

762 


CAiii':  OF  nil':  i'EUson.  70.'{ 

and  th(!  nomuil  t<!mj)('riiliirc  of  llic  body  ;  and  hot,  ahovf  tliis  limit  VM 
high  as  the  Hyslcni  (!iiii  Ixar.  < 'old  luithing  is  c.-.scntially  sliinnhmt : 
the  cutaneoiiH  vchhcIs  conlnid  al  oihc,  and  Hcnd  the  snjM'rlicial  I*Io(k1 
Hn|)|)ly  inward  ;  th(!  rcspiialion  is  rnonicnlarily  gasping  in  cliaracttir,  and 
th(!n  slowed  and  incTcascd  in  depth.  TIk;  whole  nc-rvous  HyHtiTii  and 
all  oi"  th(!  menial  (lu-nlties  receive  an  immediate  itowerfnl  stimnliiH. 
The  pidse  is  somewhat  slowed.  On  ("merging  I'nun  the  (rold  water,  the 
respiration  and  pnlse  redirii  lo  tlieii-  normal  raU's,  the  entaru^onH  vchwjIs 
relax  and  dilate,  and  the  return  of  the  hlood  in  increased  volume  to  the 
Hurfaec^  gives  a  sensation  of  warmth,  whieh  is  in(;reased  hy  the  pro(M.'H« 
of  '<  nibbing  down."      This  is  known  as  tin;  "  normal  reat-tion." 

The  cold  bath  is  taken  best  in  a  tub  in  which  the  whole  body  may 
be  immersed  ;  but  in  default  of  the  necessary  means,  a  sjwnge,  satu- 
rated with  water,  a|)plied  repeatedly  to  tlu;  various  i)art.s  and  squeezed 
out,  forms  a  desirable  substitute!.  A  shower  bath  is  better  still,  espe- 
cially one  admitting  of  regulation  of  the  tem|)erature. 

The  proper  time  for  cold  bathing  is  on  rising  in  the  morning;  never 
on  retiring  for  the  night.  Cold  baths  should  not  be  taken  by  those 
advanced  in  years,  in  whom  the  arteries  are  ath(!romatous,  nf)r  by  those 
with  abnormal  circulation,  who  do  not  quickly  re;ict. 

Not  the  least  in  importance  of  the  effects  of  cold  bathing  is  the  im- 
munity which  its  devotees  appear  to  enjoy  against  taking  cold.  Many 
of  those  who  practise  cold  bathing  the  year  round  have  no  experience 
whatever  with  colds,  and  can  withstand  exposure  which,  to  others,  is 
productive  of  much  illness. 

In  sea  bathing,  the  element  of  enjoyment  has  a  most  important  in- 
fluence. The  salts  are  commonly  supposed  to  be  the  chief  source  of 
benefit,  and,  in  consequence  of  this  belief,  many  persons  are  in  the 
habit  of  dissolving  in  their  daily  bath  in  the  household  a  quantity  of 
more  or  less  dirty  material,  sold  at  a  price  which  insures  at  least  a  fair 
pecuniary  return,  and  known  as  sea  salt.  The  influence  of  the  salts 
contained  in  sea  water  is  nil,  and  the  benefits  of  sea  bathing  are 
the  result  of  the  physiological  action  of  cold,  the  attendant  exercise  of 
swimming,  the  pure  air,  the  absence  of  domestic  and  business  cares  (if 
on  vacation),  and  the  sense  of  enjoyment. 

Warm  and  hot  bathing  cause  dilatation  of  the  cutaneous  vessels 
and  more  or  less  profuse  perspiration.  Respirati<in  and  pulse  are 
increased  in  frequency,  and  a  general  soothing  effect  is  pnxluced.  Hot 
bathing  is  a  most  grateful  means  of  reducing  soreness  of  the  muscles 
after  violent  exercise  and  a  valuable  assistant  in  the  treatment  of 
insomnia.  For  purposes  of  personal  cleanliness,  warm  and  hot  baths 
are  more  suited  than  cold,  since  they  can  be  borne  longer  with  comfort, 
and  the  relaxation  of  the  skin  whieh  they  induce  is  more  favorable  to 
complete  removal  of  the  adherent  matters. 

If  means  for  complete  bathing  are  not  at  hand,  the  individual  should 
in  any  event  give  daily  attention  to  careful  cleansing  of  the  axillse, 
groins,  genitals,  and  feet,  as  well  as  of  the  hands  and  face. 


704  PEESOXAL  HYGIENE. 

Section  2.     REGULATION  OF  THE  DIET. 

It  is  obviously  impossible  to  formulate  any  system  of  rules,  applic- 
able to  all  classes,  for  the  selection  of  diet  and  the  regulation  of  hours 
A\ith  reference  to  the  daily  duties  of  life,  but  general  rules  concerning 
some  aspects  of  the  question  may  be  laid  down.  The  suggestion  of 
light  breakfasts,  somewhat  more  substantial  luncheons,  and  hearty  din- 
ners at  close  of  day,  with  periods  of  mental  and  physical  rest  after  each 
meal,  is  easy  to  make  ;  but  the  busy  lives  which  the  great  majority  of 
the  population  lead,  and  the  widely  different  conditions  of  life  and  oc- 
cupation, make  its  general  acceptance  and  adoption  quite  beyond  the 
bounds  of  possibility.  It  is  a  common  habit  of  writers  on  personal 
hygiene  to  compose  menus  for  the  several  daily  meals,  to  suggest  the 
amount  of  time  which  should  be  devoted  to  the  consumption  of  each, 
and  to  reeonunend  the  avoidance  of  physical  or  mental  labor  for  vary- 
ing periods  before  and  after  each  meal,  in  order  that  the  digestive  appa- 
ratus may  proceed  with  its  work  under  the  most  favorable  conditions 
for  its  uninterrupted  completion. 

The  adoption  of  most  of  such  recommendations,  however,  presup- 
poses a  curious  state  of  the  conditions  of  life,  including  an  absence  of 
any  marked  preferences  in  the  matter  of  articles  of  diet,  a  complete 
mastery  of  one's  time  Avithout  reference  to  the  demands  of  occupation, 
and  pecuniary  independence. 

General  rules  may  be  offered  to  the  effect  that  the  diet  should  con- 
sist of  wholesome  articles  of  food  ;  that  these  should  be  consumed  in 
sufficient,  but  not  excessive,  amounts ;  that  they  should  not  be  hur- 
riedly bolted  ;  and  that  as  much  time  as  is  consistent  with  the  needs 
of  one's  occu])ation  should  be  allowed  after  each  meal,  before  proceed- 
ing to  a  continuance  of  work.  Obviously,  in  these  particulars  each 
person  must  be  a  law  unto  himself,  and  the  greater  the  observance  of 
general  hygienic  principles,  the  better  the  physical  and  mental  well- 
being. 

Section  3.     REST  AND  RECREATION. 

For  the  repair  of  the  daily  wear  and  tear  of  a  busy  life,  a  reasonable 
period  of  rest  of  body  and  mind  is  indispensable.  Nervous  and  mental 
breakdown  result  from  overwork  and  absence  of  recreation,  but  it  is 
impossible  to  make  any  rule  as  to  what  may  be  regarded  as  a  safe  limit 
of  the  amount  of  work  which  may  be  performed.  Monotony  of  life  is, 
perhaps,  as  potent  a  factor  in  mental  breakdown  as  overwork,  as  is 
evidenced  by  statistics  showing  the  high  percentage  of  insanity  among 
farmers  and  formers'  wives  in  sparsely  settled  districts.  Mental  worry, 
also,  is  far  more  potent  than  mere  mental  activity  in  causing  physical 
and  mental  degeneration.  Recreation  is  a  most  important  remedy, 
therefore,  for  the  prevention  of  monotony  and  Avorry. 

It  is  impossible  to  lay  down  any  rule,  governing  the  amount  of  sleep, 
that  can  apply  to  all  persons  indifferently,  since  active  minds  may  need 
much  less  than   what  commonly  is  regarded  as  a  minimum  general 


riiysi<:.\L  i'.xeikhsic.  7f;r> 

rc(jiiir(;rn(!iit,  ;ui(l  persons  of"  (:()iis))ic,iioii.-ly  low  mciiliil  cajKirily  may  n;- 
([iiin;  Miiicli  tnorc.  It  is  jrf^ncrally  accopUtd,  liovvcivcr,  that  for  tli<;  repair 
of  waste,  tli<!  a,vei'a<f(!  inari  ii(!C(ls  to  pass  at  Icjist  om-ilijid  of  his  Uuw, 
namely,  cij^ht  hours  a  day,  in  sh'cp. 

Section  4.     PHYSICAL  EXERCISE. 

It  is  t!HS(!iitial  to  the  niaiiiteiiaiK-c  ol"  a  coiiiph'tcly  iicalthy  conditioo 
that  a  well-nourished  body  siudi  be  exer(;ise<l  properly  in  all  its  partH, 
Th<!  nuiseuhir  ellbrf,  involved  in  what  we  «Iesijrii;i(<.  as  physical  exctreine 
and  in  the  |)ursiiit  (»!'  cerlMiu  eallinti;s  whic^h  nec^essitate  bodily  activity 
affects  not  alone  I  lie  ncneral  innseiil;il  lire,  but  all  the  orj^ans  of  the  bmly 
as  well;  tlu;  heart,  the;  lunus,  th<;  digestive  apparatus,  the  skin,  the 
kidneys,  the  brain,  and,  in  short,  every  part.  TIk'  heart  and  lungs 
beino;  stimulated  to  increased  action,  an  incnjjised  sii|)ply  of  (»xyj!:enate(l 
blood  is  sent  to  every  |)art,  l)rin<^in<;  with  it  the  essentials  to  full  nutri- 
tion and  conveying  to  the  eliminative  ehannels  the  ultimate  products 
of  metamorphosis.  The  special  stimuli  of  the  various  organs  are 
excited,  and  thus  the  several  functions  arc  mainfciined  in  a  normal  st^ite 
of  activity. 

In  order  to  gain  a  full  appreciation  of  tht;  benefits  of  j)hysieal  exer- 
cise, one  needs  but  to  compare  the  rugged  condition  of  the  well-nour- 
ished laborer  in  the  iiclds  or  of  the  student  or  man  of  business,  who, 
in  the  intervals  away  from  his  daily  work,  seeks  recreation  in  outdoor 
exercise  or  indoor  gymnastics,  with  that  of  the  pent-up,  sedentary 
operative  or  the  indolent  seeker  after  pleasures  involving  inaction. 
VVhether  the  work  of  the  individual  be  that  of  the  hands  or  brain,  it 
is  sustained  better,  if  the  system  is  kept  active  in  all  its  functions  and 
parts. 

Effects  of  Active  Exercise. 

Circulation  and  Respiration. — Muscular  effort  causes  the  heart  to 
beat  more  rapidly  and  with  greater  force,  so  that  more  blood  is  sent 
through  the  lungs  and  all  parts  of  the  body,  including  the  substance  of 
the  heart  itself.  Unless  the  exercise  is  excessive  in  duration  or  violence, 
the  increased  action  is  regular  and  equal,  and  cessation  of  the  exercise 
is  folloAved  by  gradual  sl(1^ving,  until  the  rate  is  below  the  normal ; 
and  then  by  return  to  the  natural  rate.  With  excess  of  muscular 
effort,  the  pulse  becomes  quick,  small,  and,  often,  more  or  less  irregular, 
and  even  during  the  fall  in  rate  in  the  interval  of  rest,  it  may  be  inter- 
mitteut.  Excessive  rapidity,  irregularity  in  pulsation,  and  inequality 
of  volume  are  indicative  of  the  necessity  of  rest  and  of  danger  from 
continuance. 

The  increase  in  the  pulmonary  circulation  is  accompanied  by  increase 
in  respiratory  action,  so  that  a  larger  volume  of  blood  is  forced  through 
the  lungs  and  comes  in  contact  with  an  increased  air  supply,  from 
which  it  receives  the  necessary  increase  in  oxygen  for  conveyance  to 
the  tissues,  and  to  which  it  gives  up  its  carbon  dioxide,  aqueous  vapor, 
and  other  waste  products,  for  x'emoval  from  the  body.     According  to 


766  PERSOSAL  HYGIENE. 

the  researches  of  Pettenkofer  and  Voit,  the  oxygen  absorbed  during 
an  ordinary  Avorking  day,  \vith  the  usual  interval  for  rest,  is  about  one- 
third  greater  iu  amount  than  during  a  day  of  inaction,  and  the  carbon 
dioxide  produced  and  eliminated  is  increased  about  two-fifths.  During 
exertion,  the  action  of  the  chest  should  be  impeded  as  little  as  possible 
bv  tiirhtlv  fittino;  clothino;  and  other  restrictions. 

Excessive  exerei.<e  causes  labored  breathing  and  sighing,  which  are 
indications  that  the  lungs  are  too  much  congested,  and  that  rest  is 
required. 

Continued  excessive  exercise  may  bring  about  palpitation,  dilatation, 
hypertrophy,  and  even  valvular  lesions  of  the  heart,  and  congestion  of 
the  lungs,  accompanied,  sometimes,  by  hsemoptysis.  Sudden  unusual 
etJbrt  may  cause  rupture  or  other  injury  of  the  blood-vessels,  and, 
rarely,  even  rupture  of  the  heart. 

Deficient  exercise  favors  weakening  of  the  heart's  action,  dilatation, 
and  fatty  degeneration  ;  and  in  those  with  inherited  predisposition,  the 
preparation  of  suitable  soil  for  the  reception  and  development  of  the 
organism  of  tuberculosis. 

Skin. — In  consequence  of  the  increased  blood  supply  sent  through 
the  cutaneous  vessels,  the  latter  dilate  and  the  skin  becomes  reddened. 
Heat  is  l)rought  from  the  interior  of  the  body  and  radiated  from  the 
surface,  and  a  farther  cooling  eiFect  is  caused  by  the  evaporation  of  the 
sweat  which  is  poured  out  by  the  sweat  glands.  Thus  the  excess  of 
heat  produced  in  the  system  through  exercise  of  its  various  parts  is 
eliminated  and  the  body  temperature  kept  in  a  state  of  equilibrium. 
The  amount  of  water  given  off  by  the  lungs  and  skin  during  a  day  of 
average  work  was  shown  by  Pettenkofer  and  Voit  to  be  nearly  twice 
and  a  half  that  eliminated  during  the  same  period  of  rest. 

With  the  water  of  the  sweat,  the  body  loses  salts,  especially  sodium 
chloride,  and  fatty  acids  and  other  organic  substances. 

During  exercise,  while  the  skin  is  active,  there  is  little  danger  of 
chill,  even  though  the  skin  be  lightly  covered  or  even  exposed ;  but  as 
soon  as  the  body  rests,  the  temperature  falls,  and  sweating  and  evapo- 
ration continue,  so  that  it  is  important  to  protect  the  body  against  sud- 
den checking  of  the  skin's  action  and  chilling  of  the  surface.  This  is 
done  best  by  means  of  clothing  of  low  heat  conductivity,  preferably 
woollen. 

With  normal  action  of  the  skin,  the  body  temperature  remains  fairly 
constant,  the  heat  of  the  blood,  even  during  most  violent  exercise, 
rarely  rising  much  more  than  a  degree  Fahrenheit  above  the  normal. 
During  work,  a  decided  rise  in  temperature  indicates  lessened  evapo- 
ration from  the  skin  and  points  to  possible  danger  from  heat  apoplcxj'. 

Nervous  System. — It  is  a  common  l:)elief  that  exercise  has  no  effect 
in  increasing  the  powers  of  the  mind,  this  belief  being  based  on  the 
supposition  that  the  greater  expenditure  of  nervous  energy  called  for 
in  the  exercise  of  the  muscles  is  opposed  to  intellectual  development  or 
accomplishment.  In  support  of  the  idea  that  great  muscular  power 
and  exertion  are  incompatible  with  marked  mental  attainments,  the 


i<:i''Fi<:(rr  (jj<'  kxicilcish  on  wfjoiit.  7B7 

Tiuit  is  ofltJii  cilcd  IJimI,  Ifniticd  ;i(IiI(!(,{!H,  ;i.s  piif^ili.st.s  ,'irnl  wrf?HtIr;rK,  arc 
(!()iis|)i(!ii()iisly  stupid.  Wnl  ;i<itnitliii^  fli;if:  this  is  true,  it  rn.'iy  al.so  Ik; 
said  l.liat  llicsc;  persons  ;ii-c  stupid  in  spite  oC  rallier  than  heeause  of 
tlieir  j)liysie;d  d((Velopnienl  and  ti'ainin^;  and  the  f;u;t  may  ho  pointed 
out  that  in  our  s(^hools  ;ind  <  oIle^cH  the  (jhoHcsn  atfilctic  reprcHentatives 
rank,  ;is  a  ehiss,  even  hi<i;lier  than  the  averaj^^e  of  llieir  non-afhl(;tio 
hr(^thren.  I  nlclh'<^tnal  ahihty  is  in(tornp;it  ihi(!  w  itii  the  ernhraeing  of 
piifj:;ilisni  :is  :i  eallin<i;,  hut  is  (piite  coiisisUint  with  a  hi^h  de^.'^rctj  of 
physical  periection  and  bodily  exercise,  l^'iirtherinore,  a  reawonablc 
degree  of  activity  ai)|)(!ars  to  bo  ncce.s.sary  to  the  perforniancc  of  men- 
tal liibor,  for  without  proper  nutrition  and  exereiso  of  the  system,  tlic 
nerv(!s  and  nerve  (!enters  nnist  sulfiir  with  otluT  parts,  even  as  they 
nnist  share  in  the  IxMUifits  of  healthy  and  vif^orous  living. 

One  part  of  the  general  system  cannot  monopolize  tlu;  bon(!fits  of 
training:  the  muscles,  for  example,  cannot  be  trained  without  the  par- 
ticipation of  the  nervous  system  in  the  good  residts,  nor,  on  the  other 
hand,  can  they  be  abused  without  injury  to  other  parts  as  well,  for 
motor  activity  is  the  result  of  nervous  encM-gy,  and  all  fatigue  is  nerv- 
ous fatigue.  As  evidence  of  the  beneficial  influence  of  exercise  on 
the  nerves  may  be  cited  the  greater  readiness  with  which  trained  mus- 
cles respond  to  volition. 

Deficient  exercise  is  a  common  cause  of  morbid  excitability,  mani- 
fested by  irritability  of  temper,  sensitiveness,  and  that  form  of  nervous 
unrest  commonly  known  as  fidgets. 

Digestive  Apparatus. — The  great  increase  in  the  excretion  of  car- 
bon dioxide  and  in  general  cellular  activity  causes  a  demand  for  food, 
and  the  appetite  is  increased,  especially  for  proteid  matter  and  fats. 
Digestion  is  assisted,  and  absorption  is  hastened.  The  volume  of  the 
excreta  is  lessened  by  reason  of  a  diminished  content  of  water,  due  to 
increased  elimination  through  the  skin  and  lungs.  Lack  of  exercise,  on 
the  other  hand,  tends  to  diminish  appetite  and  the  powers  of  digestion. 

Kidneys. — The  amount  of  urine  is  lessened  by  reason  of  increased 
loss  of  w^ater  through  the  skin  and  lungs.  The  inorganic  salts  are  com- 
monly incraised,  both  relatively  and  absolutely.  Urea  is  not  increased, 
and  may  eveu  be  diminished,  as  shown  by  Pettenkofer  and  Voit,  in 
which  case,  a  more  than  compensatory  increase  occurs  during  the  inter- 
val of  rest. 

Effect  of  Exercise  on  Weight. — The  effect  of  systematic  regular 
exercise  on  weight  is  by  no  n\eans  constant,  but  is  influenced  by  the 
condition  of  the  body  in  the  beginning,  and  by  the  amount  and  variety 
of  the  food  ingested.  ^Nlany  persons  shortly  after  beginning  a  course 
of  traiuiug  for  the  reduction  of  weight  or,  more  correctly,  of  size,  find 
that  a  rcduc^tiou  in  girth  is  accompanied  by  an  increase  rather  than  a 
diminution  in  weight.  This  means  simply  that  the  system  has  drawn 
upon  its  stored  fat  for  fuel,  this  fat  being  most  conspicuously  placed 
in  the  vieiuity  of  the  waist  line,  and  has  built  up  tissues  elsewhere  for 
the  increased  work  of  moving  the  various  levers  of  the  body.  This  in- 
crease has  its  limitations,  and  when  the  maximum  has  been  reached. 


768  FEBSOyAL   HYGIENE. 

the  foil  in  weight,  due  to  utilization  of  surplus  fat,  may  continue  until 
a  poiut  is  reached  when  the  curve  of  weight  apjiroxiniates  a  horizontal 
line,  and  the  person  may  be  said  to  be  in  i)erfect  physical  condition. 
The  marked  losses  in  weight  which  occur  during  violent  exercise  are 
soon  counterbalanced  by  ingestion  and  absorption  of  food  and  drink. 

Amount  of  Exercise  Required. — Since,  in  the  ordinary  routine  of 
life,  a  consiilerable  and  varying  amount  of  physical  work  is  performed, 
it  is  impossible  to  fix  any  rule  concerning  the  exact  daily  amount  of 
exercise  which  a  healthy  normal  adult  should  take.  With  the  vast 
majority  of  persons,  all  the  exercise  needed  is  taken  as  an  inseparable 
element  of  their  regular  occupation,  and  any  additional  work  is  per- 
formed as  a  means  of  recreation.  On  no  other  ground  can  be  explained, 
for  example,  the  evening  bicycle  ride  of  the  letter-can-ier  after  the 
monotony  of  his  daily  rounds  on  foot,  or  the  game  of  ball  begun  at  the 
close  of  the  day's  work  by  the  hands  from  the  mill  or  foundry. 

A  fair  day's  ^^'ork  for  au  adult  may  be  said  to  be  equivalent  to  about 
300  foot-tons,  a  hard  day's  work  to  400,  and  a  very  hard  day's  work 
to  500  foot-tons.  The  latter  is  about  the  amount  of  work  performed 
by  a  soldier  of  average  weight  marching  at  ease  with  his  kit  twenty 
miles  over  a  level  surface  at  the  rate  of  three  miles  an  hour. 

It  has  been  reckoned  by  Haughtou  that,  in  walking  on  the  flat,  one 
performs  an  amount  of  work  equivalent  to  raising  a  certain  proportion 
of  his  weight  through  the  distance  travelled,  the  proportion  varying 
according  to  speed.  The  work  performed  is  reckoned  by  the  fol- 
lowing formula  : 

{W±WZ1XD  ^  (7^  number  of  foot-tons. 
2240 

W      =  weight  of  the  person. 

TP     =  weight  carried. 

D       =  distance  in  feet. 

2240   =  number  of  pounds  in  a  long  ton. 

C        ^  coefficient  of  traction. 

The  coefficients  of  traction,  as  determined  by  Haughton  for  different 
rates  of  speed,  are  as  follows : 

Miles  per  hour.  Coefficient. 

^■^^^ '2^27 

1 
4.353 15.70 

10.577 •    • y^ 

From  these,  the  coefficients  for  any  rate  may  be  determined.  For 
two,  three,  four,  and  five  miles  per  hour,  they  are  approximately 
_i_^  _1_^  Jg.,  and  ^Ij,  respectively.  Thus,  a  man  weighing  175  pounds^ 
walking  10  miles  at  the  rate  of  4  miles  per  hour  and  carrying  25 
pounds,  would,  according  to  the  formula,  do  nearly  300  foot-tons  of 
work — 

(175  +  25)X52,80Q        1   _  295.25 
2240  '^  16 


KINDS   01''   EXKnCISh:     COLF.  70fj 

Tri  ;iS(!(!ii(liii^  ;i  li(:i<;lil,  :i  111:111  lifts  lii-  ciilJi-c!  wci^lil,  tliroii^li  tin; 
vorti(!;i,I  diKtuncc  tnivollctl.  Tlni-,  the  Mime  man,  rarryirig  tlic  wirne 
wciifj^lit,  cliiiibiiiji;  six  fli^lils  in  :iii  or'lin.'iry  olllrc  Imildiii^,  woiilfl  do 
about,  8  ("o()(,-l.(»iis  of  work,  rcr-koninj;   flic  dislancc  rlimhcd  a.s  00  fi-ct. 

Vuv  (,lio,s(!  wlio  do  no  rcjrii|;ir,  ordinary  pliysitral  labor,  it  lian  bcf-n 
cstiinatod  by  didorcnl  :nillioi-ilics  lli:i(  cxciv-i'^c  ((inivMlcrit  to  from  100 
to  150  foot-tons  is  snUicicnl.  for  ihc  iii;iiiil<ii;incc  of  a  fair  Htjite  of 
health,  I'ut  this  should  not  b(^  jjiishcd  to  the  extent  of  bein^  exhaiint- 
iufi;  or  ii'ksoine.  VV^heii,  in  tlu;  (M)urs(!  of  exercise,  the  body  begins  U)  Ik; 
fatigued  or  the  iuijirt  and  respiration  to  l)e  cmbarraswid,  rest  is  required  ; 
for  excessive!  (\\ercise  (confers  no  bciKifit.  Severe  j)ro]ong(!d  exercise 
may  cause  dilatation  of  the  heart,  aneurysm,  ;in<l    respiratory  disorderH. 

Kinds  of  Exercise. —  hixcrcisf!  as  a  hygienic  measun;  may  be  divided 
into  outdoor  \vori<,  including  walking,  I'iding,  and  athletic  sports,  and 
indoor  work,  or  systematic  gymnastic  exercises.  I'he  former,  j)referred 
by  all  English-speaking  j)eople,  are  carried  on  under  far  more  hcidthy 
conditions  and  bring  with  them  a  much  greater  measure  of  enjf)yment 
than  the  latter,  which  arc;  ])refcrred  on  the  Continent,  more  especially 
by  Swedes  and  Germans.  Indoor  work  in  the  gymnasium  is,  as  a 
rule,  purely  work,  without  the  element  of  pleasure  either  in  anticipation 
or  during  its  continuance,  and  is  performed  as  a  serious  duty.  It  is 
carried  out  from  day  to  day  for  a  longer  j^eriod,  if  done  in  company 
Avith  others,  as  in  a  class  ;  in  which  case,  emulation  may  stand  in  the 
])laco  of  actual  enjoyment.  But  ordinary  indoor  exercise  with  Indian 
clubs,  dumb-bells,  chest- weights,  and  similar  appliances,  carried  on 
alone  in  one's  room,  is  usually  most  unsatisfactory  in  its  results. 

There  are  some,  doubtless,  who  regularly  take  a  certain  amount  of 
this  class  of  exercise,  enjoy  it,  and  profit  by  it ;  but,  commonly,  the 
enthusiasm  wdiich  attends  the  purchase  of  the  appliances  declines  in  a 
marked  degree  by  the  end  of  the  third  or  fourth  day  of  use,  and  has 
disappeared  in  a  week.  Soon  the  exercise,  simply  a  duty,  develops 
into  a  bore,  for  the  monotony  of  this  kind  of  work,  into  which  no 
sense  of  achievement  enters,  except  that  from  the  accomplishment  of 
a  wearisome  round  of  strokes  measured  by  hundreds,  produces  a  dis- 
taste ;  and  soon  the  work  becomes  spasmodic,  the  intervals  growing 
longer  and  longer,  and  finally  is  abandoned  completely. 

Grolf. — This  exceedingly  popular  game  appears  to  be  an  ideal  form 
of  exercise  for  all  ages  above  early  childhood,  and  particularly  for  those 
whose  lives  are  essentially  sedentary  or  whose  age  precludes  them 
from  following  the  more  violent  g-ames.  The  amount  of  work  per- 
formed in  going  once  over  a  course  is  very  considerable,  but  it  is  done 
in  such  a  way  and  under  such  surroundings,  with  ever-changing  scene, 
that,  at  the  time,  it  is  hardly  appreciated.  The  mind  is  pleasantly 
engaged  in  s]ieculation  as  to  the  possibility  of  achieving  certain  results, 
and  is  filled  with  pleasurable  emotions  when  the  effort  is  crowned  with 
success  ;  the  body  is  gently  exercised  in  all  its  parts  by  a  form  of  work 
performed  because  it  is  so  essentially  a  means  of  enjoyment.    It  cannot 

49 


770  PERSOXAL  HYGIENE. 

be  abused  as  are  so  many  other  sports,  and  there  is  no  necessity  for 
quick  and  violent  action,  as  in  tennis  and  football. 

Wheeling. — Wheeling  involves  very  largely  the  entire  muscular  sys- 
tem, and  brings  into  play  groups  of  muscles,  the  existence  of  which 
has  not  before  been  appreciated  by  the  beginner.  With  the  wheel,  one 
may  take  any  desired  amount  of  gentle,  moderate,  or  violent  exercise. 
It  gives  a  constant  change  of  scene  and  the  })leasurable  sense  of  motion, 
both  of  which  are  of  value  to  the  tired  mind.  It  is  not  the  ]iarticular 
form  of  muscular  exertion  that  is  the  incentive  to  long  exercise  on  the 
wheel,  but  the  pleasure  which  it  gives  ;  for  no  more  monotonous  exercise 
can  be  devised  than  riding  a  stationary  bicycle  in  a  gymnasium,  while, 
on  the  other  hand,  many  who  would  regard  an  errand,  involving  a 
walk  of  a  mile,  as  a  hardship,  will,  wdthout  demur,  wheel  five  times 
that  distance  for  the  same  end. 

Tennis,  etc. — Tennis,  football,  baseball,  and  other  outdoor  sports  are 
comjiaratively  violent  for  the  majority  of  people.  They  bring  the 
whole  body  into  action  and  are  valuable,  if  not  pushed  too  far.  They 
do  not  admit  of  varying  the  pace  according  to  the  fatigue  of  individual 
players,  in  w'hich  respect  golf  and  wheeling  possess  an  advantage. 

Rowing  is  also  a  very  healthful  form  of  exercise,  but  the  violent  exer- 
tion requii'ed  in  the  sustained  effort  of  racing  is  not  always  a  benefit. 

Section  5.     CLOTHING. 

The  objects  of  clothing  are,  aside  from  motives  of  decency,  to  pro- 
tect the  body  from  the  sun's  rays  in  hot  weather,  from  the  chilling 
influence  of  winds  in  all  weathers,  from  rain  and  other  forms  of  wet, 
and  from  mechanical  and  other  external  injuries  and  discomforts  ;  to 
conserve  the  body  temperature  and  prevent  interference  with  the 
natural  functions  of  the  skin  ;  and,  finally,  to  adorn  the  person.  The 
proper  fulfilment  of  these  various  objects  is  dependent  upon  the  nature 
of  the  material,  the  looseness  of  its  texture,  its  color,  its  hygroscopicity 
and  heat  conductivity,  and  its  special  adaptability  to  some  particular 
purpose. 

Color. — The  heat  of  the  sun's  rays  is  absorbed  to  the  greatest  extent 
by  black  materials,  and  least  by  white.  Next  to  black  come  the  dark 
shades  of  blue,  and  then,  in  order,  green,  red,  and  yellow.  Heat  is 
reflected  most  by  white,  and  then,  in  order,  the  light  shades  of  yellow, 
red,  green,  and  blue.  The  color  of  undergarments  (not  exposed  to  the 
rays  of  the  sun)  exercises  no  influence  whatever. 

Texture. — The  looser  the  texture,  the  greater  the  amount  of  air  in 
the  interstices  ;  and  air  being  a  very  poor  heat  conductor,  other  things 
being  equal,  a  loosely  woven  fabric  prevents  loss  of  body  heat  in  a 
still  air  more  than  one  of  closer  texture.  Thus  it  is  that  a  thin, 
loosely  woven  garment  of  woollen  is  warmer  to  the  body  in  a  still, 
cold  atmosphere  than  an  equal  amount  of  closely  woven  material  of 
the  same  or  other  kinds.  The  same  result  is  attained  by  wearing  a 
puraber  of  garmeutSj  one  over  another,  so  that,  having  layers  of  con- 


^fA  T/'J/ifA  LS.  I  I  1 

fin(!(l  air  Ixitwoen,  tlioy  nvl  in  Uh!  Humf!  way  an  (]f»ii}»If'  windows  (»n  a 
houKo.  'I'Ik;  Viiliic  oC  furs  ns  conservators  of  lic;i(  is  largely  <Uu-  U) 
the  amouiii  (»r  ;iir  icl;iinc<l  Ixl  w  ccii  llic  Iiiili\  i<lii;i  I  liairs. 

rrnj)('iiiic;il)l<;  nialcrinls,  hcin^  al)H)liil(ly  \viii(l-j»roof,  and  li(;nr<'.  jxtr- 
niiliint;'  no  iial,iiral  v(!ntiliiiion  thron^li  tlK^ir  snhstaiK^;,  are  vory  warm, 
but  have  serious  (lisadviinlaii'cs,  th(;  most  irnporlant  of  uliifh  is  the 
retention  of  th(!  transpired  Mioistun;  ol'  tlie  hody,  whi<h  e(,ller;t.s  on  the 
surface  and  is  absorbed  only  in  [lart  by  the  ch)thin^  next  theret<>. 
Against  rain  and  eold  wiixls,  iinpi-rnu^bhi  niatiTials  aH'ord  very  grrjat 
protection.  Wiixls  act  in  two  ways  to  (;hill  the;  body  :  by  cf>n.stant 
removal  of  th(!  air  in  (jontac^t  with  th(^  body  and  warnn-d  by  nuison  of 
contact,  and  by  hastening  evaporation  of  tlie  moisture  within  the  .sul>- 
stancc  of  the  ch)thiug. 

Heat  Conductivity. — Materials  vary  widely  in  their  power  of  he^it 
conduction.  Atiiong  the;  textihis,  linen  and  cotton  are  by  far  the  be„st 
conductors,  and  wool  lUv.  j)()on!st ;  l)ut  since  the  conductivity  of  a  g;ir- 
mcnt  is  governed  mainly  by  the  looseness  of  texture,  it  follows  that 
the  same  amount  of  a  good  conductor,  loosely  woven,  may  be  warmer 
than  wool  woven  very  closely.  But  the  fabrics  made  of  the  best  con- 
ductors are  commonly  very  closely  woven,  and  of  wool  are  of  varying 
degrees  of  looseness. 

Hygroscopicity. — Fabrics  hold  moisture  in  two  ways  :  first,  by 
retaining  it  in  the  interstices  between  the  fibers  ;  and,  secondly,  by 
absorption  directly  into  the  substance  of  the  fibers.  The  moisture 
held  in  the  interstices  gives  the  sensation  of  dampness  or  wetness,  and 
may  be  largely  removed  by  pressure,  as  in  wringing;  that  absorlx^i 
into  the  fiber  may  be  very  large  in  amount  without  giving  any  sen- 
sation of  dampness,  and  it  cannot  be  expelled  by  pressure.  The 
latter  is  known  as  hygroscopic  moisture. 

Materials  of  animal  origin  are  more  hygroscopic  than  those  from  the 
vegetable  world,  and  while  they  absorb  water  readily,  they  part  with 
it  more  slowly  by  evaporation.  Thus  it  happens  that  a  person,  sweat- 
ing to  the  same  extent  and  under  the  same  general  conditions,  feels 
less  sensation  of  chill  on  resting  from  his  exercise  or  work  when 
clothed  in  woollen,  than  when  his  dress  is  linen  or  cotton.  In  the 
latter  instance,  the  moisture  is  held  more  largely  in  the  interstices, 
and  the  garment  may  be  distinctly  wet,  and  then  adheres  to  the  skin, 
which,  as  evaporation  proceeds,  becomes  chilled  through  ra])id  abstrac- 
tion of  the  heat  required  in  the  process  ;  whereas,  in  the  former,  the 
evaporation  is  gradual  and  the  chilling  much  less  perceptible  or 
unnoticeable.  But  here,  again,  a  hygroscopic  material,  very  closely 
woven,  may  be  incapable  of  holding  as  much  moisture  without  im- 
parting the  sensation  of  distinct  wetness,  as  one  of  a  loosely  woven 
substance  of  low  hygroscopicity. 

Materials. 

The  materials  employed  in  the  making  of  clothing  come  mainly 
from  the  animal  and  vegetable  worlds  ;  from  the  former  are  derived  the 


772 


PERSOXAL   HYGIENE. 


wools  of  various  kinds,  silk,  furs,  feathers  and  down,  and  leather ; 
from  the  latter,  the  principal  derivatives  are  cotton  and  llax  (linen), 
and,  of  lesser  importance,  straw,  hemp,  jute,  and  rubber. 

Wool. — AA'ool  of  various  kinds  is  yielded  by  a  number  of  different 
genera  of  animals.  That  in  conmionest  use  and  to  which  the  name 
is  very  generally  restricted  is  derived  from  the  sheep.  Other  kinds 
include  mohair  from  the  Angora  goat ;  kashmir,  or  cashmere,  from 
the  Thibet  goat ;  camel's  hair  and  alpaca,  from  Auchenia  pacos,  a 
cameloid  ruminant  of  South  America.  But  the  terms  mohair,  cash- 
mere, and  alpaca  commonly  refer  to  cotton  and  sheep's  wool  imitations 
containing  no  trace  of  either  of  these  more  expensive  wools. 

Under  the  microscope,  the  fibers  of  wool  are  seen  to  be  cylindrical 
and  translucent,  and  covered  with  small  imbricated  scales  which,  like 
those  of  a  fish  or  the  feathers  of  a  bird,  run  all  in  the  same  direction. 


Fig.  114. 


Woollen  fibers. 


They  are  sharpest  and  smallest,  and  hence  most  numerous,  in  the 
finest  sorts  ;  as  many  as  2800  and  as  few  as  500  to  the  inch  have  been 
counted  respectively  in  the  best  and  very  inferior  kinds.  They  give 
to  the  fibers  the  tenacity  with  which  they  cling  together  when  woven, 
and  the  readiness  with  which,  when  wet  and  subjected  to  pressure,  as 
rubbing  or  wringing,  they  mat  together  and  cause  shrinking  of  the 
fabric.  They  are  shown  in  Fig.  114,  which  is  drawn  from  a  specimen 
of  fine  Saxony  crewel. 

Woollen  goods,  being  poor  conductors  and  containing  much  enmeshed 
air,  are  the  most  valuable  of  all  textiles  for  general  purposes  in  all 
climates,  and  particularly  in  those  in  which  abrupt  wide  changes  in 
temperature  occur.  In  very  hot  climates,  they  are  inferior  as  outer 
garments  to  cotton  and  linen,  which,  being  better  conductors  and  re- 
flectors, assist  more  in  keeping  the  body  comfortably  cool.  But  for  un- 
dergarments, wool  is  much  better  as  a  protection  against  chilling  after 


sil.K.  77.'} 

active  (!X(!r(!iH(!,  on  uocoiint  of  ils  \\yiir<)i\r.()\)\c  proy)f'rt,ics  ;  the  vaynir 
from  tlu;  Ixxly  is  coiMhtiiscd  and  absorbed,  and  tii<;  licat,  wliicli  lK;<:oinf,H 
latent  wli<;n  iJic  nioisliin;  is  vaporized,  in  set  free,  and  the  evajKira- 
tion  from  tlu;  I'ahric,  to  ihv.  (;xt(:rnal  air  |)roceod.s  nlowly  and  without 
the  ohillinn;  AXvri  observed  when  on(!  sits  in  c\\\\^\u^  wet  eotton  or 
linen,  wiiicili  feels  cold  in  j)ro|)ortion  to  the  rapidity  with  whi*-h  it  dric^-. 

Woolhwi  fabries  are  niiieh  subject  to  adulteration  with  cotton  and 
other  eheaj)er  materials.  What  are  known  as  Hanneiettes  are  very 
commonly  made  wholly  of  (sotton  or  with  a  very  small  perc<jnt.'ige  of 
wool,  alliiou^di  the  name  is  inteixh^l  to  convey  the  idea  that  wool  is 
the  sole  or  chief  uialeiial  used.  What  some  are  pleased  to  desij^ate 
"sanitary  flannel"  is  often  larj^ely  or  wholly  cotton.  Shoddy  is  a 
fabric  made  with  varying  proportions  of  old  ravelled  woollen  and  other 
cloths  with  a  miniiimm  of  new  wool.  It  has,  as  may  be  snpj)osed,  a 
much  inferior  tensile  strength  and  less  uniformity  of  texture  than  wool- 
len of  good  (juality. 

Silk. — Silk  is  the  spun  fiber  produced  by  a  number  of  s|)ecies  of 
insects,  especially  the  larvae  of  the  bombycid  moths,  called  silkworms, 

Fig.  11"). 


Silk  fibers. 


to  form  cocoons  or  protective  coverings  when  about  to  assume  the 
chrysalis  stage.  The  cocoon  in  which  the  chrysalis  is  killed  yields  an 
exceedingly  tine  thread,  consisting  of  two  agglutinated  filaments.  This 
thread,  when  unwound,  measures  more  than  two  miles  in  length,  and 
when  spun,  yields  in  the  neighborhood  of  500  yards  of  silk  thread. 
The  outer  part  of  the  cocoon  is  of  inferior  quality,  and  is  known  as 
floss. 

Silk  is  very  hygroscopic.  It  is  a  poor  heat  conductor  and  a  perfect 
non-conductor  of  electricity.  It  lias  great  affinity  for  anilin  and 
other  dyes. 

Under  the  microscope,  the  fibers  appear  as  structureless  tulles,  and 
show  no  scales  or  surface  markings,  such  as  are  seen  on  wool.  They 
are  represented  in  Fig.  115.  Before  being  woven  into  fabrics,  silk  is 
commonly  weightai  with   salts  of  tin   and  iron,  with  which  it  forms 


774  PERSONAL  HYGIENE. 

stable  chemical  compounds.  Weighted  silk,  subjected  to  the  action  of 
a  Buusou  flume,  parts  ^vith  its  organic  constituents,  but  retains  its 
structural  appearance. 

Silk  is  very  subject  to  adulteration  with  other  fibers  and  to  complete 
substitution  by  artificial  preparations.  One  form  of  artificial  silk,  in- 
vented, in  1884,  by  a  Frenchman,  Count  Chardonnet,  is  made  from 
prepared  cotton  or  wood  fiber.  It  possesses  a  very  silky  luster,  and  was 
at  first  very  inflammable  and  even  explosive,  being  practically  nitro- 
cellulose ;  but  later,  the  product  was  subjected  to  further  chemical 
process  and  made  harmless.  Another  form,  invented  by  Fremery  and 
Urban,  is  made  from  cotton  waste,  and  is  produced  much  more  cheaply. 
Still  another  form,  invented  by  Professor  Hummel,  of  Leeds,  is  made 
from  gelatin  at  an  expense  of  about  $1.15  per  pound.  It  has  a  low 
tensile  strength,  but  may  be  employed  in  a  mixture  with  genuine  silk 
or  fine  linen  or  cotton  thread  to  make  a  durable  fabric. 

Silk  is  used  chiefly  in  the  manufacture  of  silks,  satins,  velvets,  crape, 
and  plush. 

Cotton. — Cotton  is  the  soft  woolly  fibers  appendant  to  the  seeds  of 
the  cotton  plant  (Gossypium),  consisting  of  cellulose,  and  varying  in 

Fig.  116. 


Cotton  fibers. 


length  from  a  half  to  two  inches.  It  is  contained  with  the  seeds  within 
the  boll,  which,  when  ripe,  bursts  and  allows  the  fibers  partially  to  es- 
cape. Microscopically,  the  fibers  appear  flattened  and  twisted  ;  they  have 
somewhat  thickened  borders,  and  some  show  a  central  canal.  They  are 
shown  in  Fig.  116,  They  are  freed  from  the  seeds  by  the  cotton-gin, 
then  cleaned  and  spun  into  thread,  and  woven  into  fabrics  of  various 
kinds,  including  what  is  known  commoniy  as  "  cotton  cloth,"  sheeting, 
towelling,  jean,  drill,  and  others.  For  the  purpose  of  giving  weight, 
stiffness,  and  improved  appearance,  starch  and  other  materials  are  com- 
monly employed  in  finishing.     Cotton  is  employed  also  with  wool  and 


LINEN  niififii'in. 


775 


oilier  rriiitcrialH  as  iin  ;i(liil(<i:inl  oi-  (d  fDrrihiiU!  tlu;  UHcfiil  propfrrf ics  of 
eacili,  UH,  for  ex.'irnplc,  in  incrino,  vvliiih  is  riiucli  uwid  in  tlu;  manufacture 
of  nnderelolhin^  and  stoeUinj^H.  (-'olton  in  very  durable  and  hard,  liaH 
low  liy<rn)se()|)i(Mty  and  lii;i,li  lieiit  condn^idvif y,  doris  not  hhrink  in 
wasliinjr,  ;ind  is  j)arliciilariy  ndaptifd  as  a  material  for  outer  ^rarmentH 
for  hot  weatli(;r. 

Linen. — fjinon  is  a  fal»ri<!  wovcmi  from  Hk;  Koil  silky  fiber  obtained 
from  th(!  outer  cov(!riu{r  of  the  .stalks  of  \\\r  flax  plant  {Llnuiii  UHiOitm- 
simuiii),  wliieli  are  allowed  to  rot  until  the  proper  sta^;e  of  deeompohition 
is  attained,  when  lliey  are  beaten  and  (larded.  They  yield  about  a  six- 
teenth of  th(!ir  weijrht  of  fiber.  Mieroseojjieally,  the  fibers  apfM;ar  an 
cylinders  markiid  at  re<i;ulnr  int(Tvals  by  .striie  indieatinf;  eell  division.s. 
(See  F'u^.  117.)  Twist(!(l  into  threjid,  they  are  used  in  weaving'  various 
fabrics  known  as  linen,  caiiibrie,  daniMsk,  diaper,  lawn,  and  huckaback. 
Linen  goods  are  smooth  and  lustrous,  heavier  tliiui  cotton,  durable  and 
hard,  of  low  hygroscopicity  an<l    high    heat   conductivity.     They  are 

Fio.  117. 


Linen  fibers. 


especially  suited  for  shirtings,  sheetings,  and  outer  garments  for  hot 
climates. 

Rubber. — India  rubber  is  a  product  derived  from  the  milky  juice 
of  various  tropical  plants.  It  is  soluble  iu  ether,  naphtha,  chloroform, 
and  carbon  disulphide.  Its  elasticity  is  impaired  and  destroyed  by 
long  exposure  to  the  air  and  by  extremes  of  atmospheric  temperature, 
but  is  made  lasting  by  the  addition  of  a  small  amount  of  sulphur  iu 
the  process  known  as  vulcanizingy  discovered  by  Goodyear  in  1844. 
This  process,  in  addition,  insures  increased  durability,  flexibility,  and 
impermeability  to  air  and  moisture.  To  the  latter  quality,  rubber  owes 
its  extensive  employment  iu  articles  of  dress,  including  galoshes  and 
other  foot  coverings,  and  outer  garments  made  of  rubber-sheeting  or 
waterproof  cloth,  known  as  mackintosh.  The  latter  is  made  by  ap- 
plying a  solution  of  rubber  in  successive  layers  to  cotton  or  other 
fabric,  so  that  it  shall  be  made  impermeable  to  water. 

Rubber  garments  are  a  very  useful  protection  against  wind  and  rain, 
but  are  objectionable  on  the  score  of  being  hot  aud  contining  the  watery 
vapor  given  off  by  the  skin,  thus  bringing  about  a  condition  of  great 


776  PERSONAL  HYGIENE. 

discomfort.  They  should,  therefore,  be  ventilated  as  much  as  is  prac- 
ticable, especially  if  worn  iu  moderate  or  warm  temperatures. 

Clothing  can  be  made  waterproof  and,  at  the  same  time,  permeable 
to  air,  by  a  number  of  processes,  and  such  material  has  an  obvious 
advantage  over  ordinary  mackintosh  and  other  impermeable  fabrics. 

Leather. — Leather  is  the  skins  of  animals,  chiefly  the  ox,  calf, 
horse,  sheep,  and  goat,  prepared  by  tanning  and  tawing.  In  tanning, 
the  skin  is  soaked  in  vats  containing  an  infusion  of  oak  bark  rich  in 
tannic  acid,  which  causes  the  formation  of  tough,  insoluble  tannates  of 
the  gelatinous  and  albuminous  constituents  of  the  skin.  In  tawing, 
mineral  astringents  are  used  instead  of  oak  bark  ;  the  end  is  attained 
more  quickly,  but  the  product  is  of  inferior  quality.  After  the  proc- 
ess of  tanning  or  tawing  is  completed,  the  skin,  now  tough  and  stiff, 
is  subjected  to  a  series  of  processes,  collectively  known  as  currying, 
whereby  it  is  made  soft,  smooth,  pliable,  and  ready  for  use. 

Leather,  being  hygroscopic,  takes  up  perspiration  from  the  foot  and 
gives  it  off  to  the  outer  air ;  but  if  it  is  made  impermeable,  as  in  the 
case  of  the  so-called  "  patent  leather,"  the  latter  office  cannot  be  per- 
formed. That  the  perspiration  of  the  foot  is  given  off  through  the 
boot,  is  sufficiently  proved  by  the  dampness  and  dull  appearance  of  the 
leather  of  a  well-polished  boot  after  half  a  day's  confinement  in  a 
rubber  overshoe.  Although  permeable  to  this  extent,  leather  is  suffici- 
ently waterproof  for  ordinary  use,  and  may  be  made  more  so  by  the 
external  application  of  grease. 

Fur. — Fur  as  an  article  of  clothing  presents  the  great  advantage  of 
impermeability  to  wind  with  that  of  very  low  heat  conductivity,  due 
in  greatest  part  to  the  large  volume  of  air  retained  between  the  hairs. 
No  other  kind  of  material  is  comparable  as  a  protection  against  wind 
and  cold. 

Felt. — Felts  are  made  from  the  hairs  of  various  animals,  but  the 
best,  such  as  are  used  for  hats,  both  soft  and  stiff  (the  Derby,  for  ex- 
ample), are  made  from  the  hairs  of  the  cony.  They  are  made  without 
weaving,  the  hairs  being  blown  against  a  revolving,  perforated,  metallic 
cone  of  large  size,  connected  with  an  exhaust  blower.  When  a  thin 
coating  has  formed,  a  jet  of  steam  is  directed  against  the  cone,  and  then 
the  felt  in  its  first  stage  is  stripped  off  in  a  coherent  mass,  held  together 
by  the  minute  imbrications  on  the  individual  hairs.  By  means  of  fur- 
ther processes  of  steaming  and  steeping,  the  mass  is  reduced  iu  size  and 
increased  in  wall  thickness  through  shrinkage. 

Adulteration  of  Clothing. 

Fabrics  are  much  subject  to  adulteration  by  admixture  of  fibers  of 
lower  value,  as  of  cotton  or  shoddy  to  wool,  and  by  starch  and  mineral 
matters  to  give  weight.  Many  of  the  cheapest  of  cotton  fabrics  are  so 
heavily  sized  that  a  single  washing  Avill  convert  a  stiff,  apparently 
close-woven  piece  of  goods  into  a  worthless,  coarse,  flimsy  material  fit 
only  for  sieves. 


P()IS()N()!JS   DY/'X  777 

Chemical  analysis  of  (iihric.s  is  not  iilw.'iys  to  ])('  rflicd  upon, 
iiltlioii^li  (ilx'r's  ol"  v<'<;<'(;il)I(;  orij^in  hclmvc  vci'v  did'crcnlly  from  tlio.-><' 
from  tli(!  :uiim,'il  world;  iind  iiny  ;ilt(iM[)l  on  llw  |):irl  of  an  in«-x[M'- 
ri(!n(',(Hl  |>('rson  lo  (lcU;rmin(!  tlic  p('Vi'ci\i;\^<-  of  <lilf(;rcnl  kinds  o(  (ilx-r 
in  ii  mixture  is  siin^  to  lead  liim  (o  two  (tondnsions,  namely,  tliat  lie  liaa 
wasted  liis  time,  and  lliat  mneli  of  what  lias  been  written  eoneerning 
tl\(!  Ixiliavior  of  <liirei'(Mit  libers  when  tre^ited  with  -irong  chemicals  ii* 
nunai'kahlo  only  for  its  small  measure  of  truth. 

Microscopical  examination  is  a  iiir  sim|)l(r  and  nnieh  more  satis- 
iiu^tory  method  of  determinint!;  tlu!  composition  of  a  faWrie,  A  few 
threads,  teased  apart  and  examined  with  a  moderately  hi^-h  power,  will 
reveal  the  naruix;  of  the  libers  and  yi(;ld  approximately  accurate  <jnan- 
titativG  residts'.  Shoddy  comnioidy  shows  fibers  of  wool  of  ditt'crent 
shades  of  color,  but  this  liiidin<j^  is  by  no  means  to  be  a(;cej)led  as  eon- 
elusive  (^videncu' that  a  specimen  of  fabric  under  examination  is  >hoddy, 
since  only  plain  goods  of  a  solid  eoior  yield  fibers  all  of  (jne  sha<le. 
But  if  the  fibers  show  abrupt  changes  in  diameter  and  partial  obliter- 
ation of  the  imbrications,  it  may  be  safely  concluded  that  the  specimen 
is  shoddy,  since  fresh  wool  is  fairly  regular  in  diameter  and  shows 
sharply  marked  imbrications. 

Poisonous  Dyes. — In  the  dyeing  of  textiles  and  other  articles  of 
clothing,  a  great  variety  of  substances  of  vegetable  and  mineral  origiu 
are  used,  and  many  of  them  have  been  known  to  produce  serious 
results.  Among  them  may  be  mentioned  potassium  diehromate,  zinc 
chloride,  compounds  of  arsenic  and  antimony,  and  certain  of  the 
anilins.  An  outbreak  of  34  cases  of  acute  dermatitis,  occurring  among 
a  number  of  workmen  who  had  just  donned  new  overcoats,  is  rej)orted 
by  Taunton.^  On  the  first  wet  day,  when  the  coats  were  worn,  the 
wrists,  where  they  came  in  contact  with  the  edges  of  the  wet  sleeves, 
became  inflamed.  In  1  case,  the  legs  were  similarly  affected,  the 
trousers  being  wet  and  rubbed  against  by  the  skirt.  In  3  cases,  the 
arms  were  affected.  On  soaking  the  cloth  in  water,  it  yielded  free 
zinc  chloride. 

According  to  U.  S.  Consul  Hughes,  of  Coburg,  in  a  communication 
to  the  De})artment  of  State,  under  date  of  April  23,  1901,  Dr.  Adolph 
JoUes  has  demonstrated  before  the  Vienna  Medical  Society  the  harm- 
ful effects  of  wearing  p(>arl-gray  silk  stockings,  colored  by  repeated 
baths  in  a  solution  of  zinc  chloride.  It  was  shown  that  a  large  amount 
of  the  salt  was  present  in  the  finished  goods  when  packed  for  the 
market,  and  that  the  danger  therefrom  by  absorption  was  very  great. 

A  serious  case  of  poisoning  by  anilin  black  is  quoted  by  Cartaz,^ 
from  a  report  of  Landonzy  and  Brouardel  to  the  Academy  of  ^ledicine 
of  Paris.  A  child  of  seventeen  months  became  suddenly  unconscious 
and  apparently  asphyxiated,  and,  although  restored,  remained  very  ill 
for  forty-eight  hours.  Then  the  brother  of  the  child  and  a  number  of 
other  children  were  seized  in  the  same  way.  All  of  the  victims  wore 
shoes  which  gave  off  a  peculiar  penetratiug  odor,  and  were  found  to 
*  Lancet,  December  6,  1898.  *La  Nature,  August  4,  1900. 


778  PERSONAL  HYGIENE. 

have  been  dyed  with  aniliu  black.  Animal  experimentation  proved 
that  absorption  of  this  by  the  skin  is  favored  by  heat  and  moisture, 
which  conditions  are  present  in  a  tightly  laced  shoe,  and  may  bring 
about  alteration  of  the  blood  corjiuscles  and  asphyxia. 

Another  case  is  reported  by  Besson/  of  a  child  of  six  years,  A\ho, 
after  wearing  a  pair  of  new  shoes  during  the  forenoon  while  at  play, 
became  cold  and  cyanoscd  in  the  afternoon,  but  Avas  relieved  by  heat 
and  stinuilants  Avithin  twenty-four  hours.  The  shoes  had  been  pol- 
ished Avith  a  preparation  Avhich  had  a  distinctly  nauseating  odor,  and 
contained  91   per  cent,  of  anilin, 

Laurent  and  Guillemin-  report  still  another,  in  which  six  children, 
all  of  one  family,  were  seized,  after  wearing  new  shoes  upon  which  the 
anilin  polish  had  not  completely  dried,  with  sudden  symptoms  of 
poisoning,  which  included  pallor  of  the  face,  bluish  discoloration  of  the 
lips  and  nails,  dilated  pupils,  headache,  vertigo,  albuminuria,  great 
muscular  weakness,  slow  pulse,  slight  convulsive  movements,  and 
unconsciousness.      Kecovery  occurred  in  from  one  to  three  days. 

It  is  commonly  believed  that  arsenic  in  dyed  and  printed  textiles  is 
present  as  an  accidental  impurity  of  various  anilins,  but  this  is  far  from 
being  the  truth,  since  white  arsenic  itself  is  used  in  several  processes  for 
the  purpose  of  adding  brilliancy  to  the  colors.  Thus,  in  the  so-called 
arsenite  of  aluminum  process,  the  dye,  dissolved  in  acetic  acid  or  water, 
is  mixed  with  acetate  of  aluminum  and  white  arsenic  in  glycerin,  and 
the  mixture  is  employed  in  printing  the  pattern  ;  next,  the  printed 
fabric  is  subjected  to  moist  heat,  and  the  anilin,  in  combination  with 
the  arsenite  of  aluminum  formed,  is  fixed  in  the  fibers  in  an  insoluble 
form. 

Selection  of  Clothing. 

The  properties  of  the  various  materials  used  in  the  manufacture 
of  textiles  have  already  been  given  in  some  detail,  and  further  con- 
sideration of  underclothing  and  outer  garments,  beyond  a  word  of 
caution  against  unnecessary  weight  of  clothing  and  undue  constric- 
tion of  any  part  of  the  body  is,  therefore,  unnecessary.  In  the 
matter  of  constriction,  no  part  of  the  human  body  is  so  abused 
as  the  foot,  especially  that  of  woman.  Boots,  shoes,  and  stockings 
should  fit  the  foot,  and  there  should  be  no  such  thing  as  the  agony 
which  many  people  expect  as  a  matter  of  course  in  the  process  of 
"  breaking  in."  The  toe  should  be  neither  pointed  nor  cut  square,  and 
the  whole  sole  should  follow  the  natural  outline  of  the  foot.  The  sole 
should  project  a  reasonable  distance  from  the  upper,  in  order  to  give 
firmer  support  and  increased  protection  to  the  soft  parts  from  contact 
with  loose  stones  and  other  objects.  The  heels  should  be  low  and 
broad  High  heels  are  worn,  not  for  comfort  in  walking,  but  to  in- 
crease the  height  of  the  body  and  diminish  the  apparent  length  of  the 
foot.     For  purposes  of  successful  deception,  they  take  about  equal  rank 

'  Journal  des  Sciences  medicales  de  Lille,  1901,  No.  10. 
'■^  Journal  des  Praciciens,  March  2,  1901. 


HKlJCariON   OF  CLOTIIINd.  771i 

with  liair  <ly(;H  mikI  ;ii(ifH'i:il  cotiiplcxioiis.  TlK-ir  iis<'  coikIuc^'m  to 
weukncHH  of  tlic  -.m^x,  ;ilro|.liy  <>("  (Ih'  imisrlcs  of  llic  li-{r,  ini'l  !i  variety 
of  other  ul)ii(>nM;ilili(s.  'I'Ik'  Ii<<I  of  ilic  I'-..,!  -houM  lit  .simjrly  in  itH 
|)liu;(!  within  Ww,  shoe,  l)iil  I  he  loc-  slioiild  hiiv«:  .-iinicicrjt  room  for 
frcddoin  of  inovoin(!i)t,  y<'(  ii(il  cik.iiliIi  to  citnHf  (rhnfirif.';  and  cxooriatioiiH. 
Th(!  n|)|)(!r  siioiild  (it-  snn-^dy,  hut  n(»t  l(.o  ti-rhfly,  :d)oMt,  the  aiikh-  and 
over  th(!  iiiHt(!|);  othorwi.sc,  i\w.  foot  will  drive,  forward  ari<J  oranii)  the 
tocH. 


CHAPTER    XVI. 
INFECTION,   SUSCEPTIBILITY,   IMMUNITY. 

Exciting-  Causes  of  Disease. — The  exciting  causes  of  infectious 
diseases  are  parasites  belonging  to  both  the  animal  and  the  vegetable 
kingdoms.  They  gain  access  to  the  system,  and  if  the  individual  be 
receptive  or  "  susceptible,"  proceed  to  bring  about  disturbance  of 
function,  some  by  mechanical  obstruction,  some  by  destroying  the  blood 
corpuscles  which  they  invade,  some  by  methods  still  unknown  ;  but 
mostly  through  highly  toxic  substances  which  they  produce  and  which 
act  locally  or  generally,  as  the  case  may  be.  Most  of  those  which  have 
been  discovered  belong  to  the  vegetable  kingdom  (bacteria) ;  some  are 
animal  organisms  (protozoa).  Of  many  of  the  common  diseases,  nota- 
bly the  exanthemata,  the  still  undiscovered  causes  belong  probably  to 
the  latter  class,  if  we  may  reason  by  analogy  from  the  discoveries 
relative  to  smallpox  by  Councilman  and  concerning  the  cause  of 
scarlet  fever  by  Mallory. 

Disease  germs  are  endowed  with  life  ;  and  for  its  continuance  and  for 
multiplication  within  the  tissues,  certain  favoring  conditions  are  nec- 
essary ;  invasion  of  a  system  offering  hostile  conditions  begets  no 
disease.  Introduced  in  sufficient  numbers,  and  finding  their  environ- 
ment favorable,  they  multiply,  as  a  rule,  and  eventually  make  their 
presence  manifest  through  the  symptoms  produced  by  their  toxic  prod- 
ucts or  because  of  their  power  to  obstruct  or  destroy.  They  differ 
essentially  from  poisons  in  the  ordinary  sense  ;  for  poisons,  although 
causing  disturbance  of  function,  resulting  likewise  even  in  death,  do 
not  reproduce  themselves  within  the  tissues.  An  injection  of  aconitine, 
or  of  morphine,  or  of  tetanus  toxin,  or  of  snake-venom  does  not  grow  in 
the  system,  and  hence,  if  not  sufficiently  powerful  to  cause  disturbance  of 
function,  it  will  not  become  so  with  lapse  of  time  ;  but  the  introduction 
of  a  few  streptococci,  for  example,  may  be  followed  by  rapid  multiplica- 
tion in  geometrical  progression  and  result  eventually  in  a  fatal  sep- 
ticsemia. 

Channels  of  Infection. — Of  the  various  channels  of  infection,  the 
most  important  are  the  respiratory  and  alimentary  tracts  (tuberculosis, 
influenza,  diphtheria,  typhoid  fever,  cholera,  dysentery,  etc.) ;  but  some 
of  the  most  devastating  of  human  scourges  are  spread  through  inoculation 
into  the  skin  (malaria,  yellow  fever,  etc.).  Invasion  of  the  tissues  by 
disease  germs  may  be  followed  by  localized  infection  with  general  dis- 
turbance of  the  system  due  to  their  toxic  products  (as  in  diphtheria  and 
tetanus),  or  by  general  infection  and  disturbance  (as  in  the  septicsemias). 
780 


susaicr'i'inii.i'i'Y.  7H1 

Infection   and   Contagion.  -  Tlif  icrnis  iiifrr/lftm  ;iii<l  ronitKiiouH 

liMVc  ^ivcii  rise  lo  iiiiicli  coiidi^ioii.  I'ntjtcrly  hj»c:ikiii^-,  (licotH-  iiirliidfH 
tlu!  <»Ui(!r,  lor  :ill  (U)iil,;i[;i()iis  <li,sc:i,s(!S,  lliaL  is  to  wiy,  tliosc;  (toriiriiiinir'atcf] 
by  (lirccl,  coiilacl  willi  iIk'  patient  or  vvilli  (ornitcH  (iiH  scarlet  fever  and 
smallpox),  are  inCeelidiis;  Itiit  riiaiiy  infectious  (liKCUHCH  that  aro  Hprcad 
tliroii}:;li  the  a|;;eney  ol"  eoiitainiiiated  water  or  food  (as  typhoid  fever  and 
cholera),  or  hy  (Ik;  hites  of  insects  (as  yellow  fever  and  inalariaj,  art;  not 
contagions,  l»nl  an^  eoniinnniealed  IVoin  man  to   man   indirectly. 

Susceptibility. — When  the  exeitinir  cause  of  an  infedious  (Jist^hij 
either  directly  or  iinlirectly  oomninnicahlc  is  introduced  into  a  Cf>m- 
ninnity,  not  all  of  those  whos(!  systems  an;  invaded  become  stricken 
with  the  disea.se,  even  thoniih  they  may  receive  the  sanu;  dose  of  the 
organisms.  Of  a  do/cn  children  exposed  at  the  same  time  and  for  a 
like  period  to  a  pre-existint;-  v\\^q  of  .scarlet  fesc^r,  perhaps  one,  or  tliree, 
or  six,  or  none  at  all  may  be  .seized  ;  of  a  hundred  consiimerH  of 
typhoid-infected  milk,  ])erliaps  a  dozen  may  ])e  infected  ;  in  an  entire 
community  of  a  hundred  thousand  jx'rsons,  all  drinking  water  from  a 
common  sup|)ly,  a  few  hundreds  or  thousands  may  be  stricken  with 
cholera  in  the  event  of  extensive  specific  ])ollution  of  the  supj)ly,  the 
rest  of  the  population  esca])ing  with  no  .symptoms  whatever.  The 
reason  for  this  lies  largely  in  diflf'ering  susceptibility:  one  person  may 
be  very  susceptible  and  others  wholly  resistant,  regardless  of  the  extent 
of  exposure  or  of  the  number  of  exposures :  some  may  resist  a  few 
exposures  and  later  succumb.  Some  may  be  exposed  without  any 
resulting  invasion.  A\  hether  or  not  a  given  individual  will  be  attacked 
may  depend  also  upon  the  number  of  organisms  which  enter  his  .'sys- 
tem ;  for  while  a  few  disease  germs  may  be  overcome  and  destroyed,  a 
larger  dose  may  secure  a  foothold  and  cause  injury.  On  the  other  hand, 
what  might  be  an  overwhelming  dose  to  one  may  be  doubled  and  trebled, 
and  yet  be  ineffective  against  another. 

Susceptibility  is  influenced  by  a  number  of  conditions,  including  age, 
race,  family  ])redisposition,  cold,  fatigue,  etc.  A  person  who  to-day 
is  insuscej>tible  may,  a  few  days  hence,  acquire  susceptibility  through 
any  one  of  a  number  of  causes  which  bring  about  a  depressed  condition 
of  the  system,  such  as  lack  of  proper  food,  exposure  to  cold  or  extreme 
heat,  exhaustion  from  overexertion,  mental  disturbance,  loss  of  sleep, 
abuse  of  alcohol,  overcrowding,  mechanical  injury,  and  constitutional 
disease.  A  person  may  carry  virulent  pneumococci  in  the  respiratory 
tract  and  not  be  affected,  because  of  the  natural  defensive  properties  of 
his  cells  ;  he  may  for  the  .>^arae  reason  escape  an  attack  of  Asiatic 
cholera,  although  large  numbers  of  the  specific  organisms  have  gained 
access  to  his  intestinal  tract ;  and  yet,  in  the  foi'mer  case,  a  bad  cold, 
and  in  the  latter,  a  derangement  of  digestion,  may  overcome  his  defence 
and  he  falls  a  victim. 

An  individual  who  is  insusceptible  to  the  influence  of  a  particular 
pathogenic  organism  is  said  to  be  immune,  or  to  enjoy  inmi unity.  Im- 
munity may  be  either  natural  or  acquired,  and  acquired  immunity  may 
be  active  or  passive.     Natural  immunity  is  the  inherent  ability  to  resist 


782  INFECTION,  SUSCEPTIBILITY,  IMMUNITY. 

infectioD  when  the  system  is  invaded  by  disease  germs  :  for  example, 
the  insusceptibility  of  man  to  hog  cholera  and  rinderpest ;  of  carnivora 
to  tuberculosis  ;  of  rats,  dogs,  and  birds  to  anthrax  ;  of  horses  and  cattle 
to  typhoid  fever  and  cholera.  In  these  and  in  many  other  instances 
that  might  be  given,  the  respective  organisms,  on  being  introduced,  find 
themselves  opposed  by  conditions  which  are  inimical  to  their  existence 
and  multiplication,  and  they  soon  succumb  to  the  hostile  influences. 
This  form  of  immunity  is,  however,  not  always  absolute  :  it  can  be 
overcome  in  various  ways.  Thus,  while  birds  are  naturally  imnume  to 
anthrax,  it  has  been  shown  that  certain  species  may  be  rendered  sus- 
ceptible by  starvation  or  cold  ;  and  rats  lose  their  immunity  to  the  same 
disease  when  they  are  fed  wholly  on  a  vegetable  diet. 

Acquired  immunity  is,  as  stated,  of  two  kinds  :  active  and  passive. 
Active  acquired  immunity  follows  recovery  from  an  attack  of  a  disease 
which,  except  in  rare  instances,  occurs  but  once  in  the  same  person  (as 
yellow  fever,  scarlet  fever,  smallpox  and  chicken  pox) ;  or  from  a 
disease  of  an  allied  nature  (as  immunity  to  smallpox  after  cow  pox) ; 
or  it  can  be  induced  artificially  by  the  injection  of  increasing  doses  of 
bacterial  toxins  or  of  bacteria  which  have  been  killed  by  heat  or  dimin- 
ished in  virulence.  It  can  be  acquired  not  only  against  diseases,  but 
against  certain  proteid  vegetable  poisons  (ricin  and  abrin)  and  snake 
venoms  (rattlesnake) ;  but  it  cannot  be  acquired  against  the  numerous 
alkaloidal  poisons.  In  but  few  diseases  does  one  attack  confer  a  lasting 
immunity  ;  and  even  in  these,  second  and  even  third  attacks  may  some- 
times occur,  but  their  severity  is,  as  a  rule,  much  diminished ;  thus, 
smallpox  and  measles.  Witii  some  diseases  a  single  attack  confers  a 
temporary  immunity  (e.  g.,  pneumonia,  la  grippe,  and  diphtheria),  but 
subsequent  attacks  may  be  of  equal  or  greater  severity.  With  other 
diseases,  notably  malaria,  immunity  may  be  acquired  ^Vith  such  extreme 
slowness  that  increased  susceptibility  may  appear  to  become  established. 

Passive  acquired  immunity  is  that  which  is  brought  about  by  the 
injection  of  serum  obtained  from  the  blood  of  an  animal  that  has 
acquired  an  active  immunity,  the  serum  containing  specific  anti-bodies; 
and  it  may  be  acquired  also  through  the  milk  of  an  immune  mother, 
the  anti-bodies  being  secreted  therein.  Passive  immunity  is  acquired 
rapidly  and  with  practically  no  danger  or  discomfort,  but  the  protection 
conferred  is  only  transient.  On  the  other  hand,  active  imnumity  is  a 
matter  of  much  less  rapid  appearance,  but  its  protective  influence  is 
much  more  lasting. 

The  tolerance  which  the  system  develops  toward  a  specific  poison 
becomes  established  as  a  result  of  certain  processes  concerning  which 
we  have  practically  no  actual  knowledge.  While  we  know  that  certain 
means  employed  produce  certain  results,  the  various  changes  which 
occur  within  the  system  during  the  process  are  matters  concerning  which 
thus  far  we  can  only  theorize.  We  are  met  at  the  outset  by  the  fact 
that  protoplasm  is  a  substance  of  extraordinarily  complex  composition, 
which  defies  exact  analysis,  and  the  products  which  it  elaborates  are, 
(50  far  as  we  know,  of  equally  compleJi  nature.     It  combines  with  and 


KJlULICll'S   Til  1:011  Y.  783 

18  acted  upon  by  vurioiiH  matorinls,  whicli,  ncfonliiif^  to  llicir  nature, 
promote  or  di.stufl)  nictjiholi.srn  ;  c.  //.,  niilritivf  rnatt<'rs  and  toxinw. 
It  i.s  with  tli(!  latlci-  tliaf  problems  of  immunity  have  to  dral,  for 
idtlioufj;!)  under  some  eondilions  pro(opl;ism  is  by  them  destroyed  or 
di,sturb(!d  iti  its  I'lmetions,  under  others  it  i-  ;ible  not  only  to  witliHtand 
their  inlluenee,  but  (o  develop  antajionislir-  produets,  whieli  overeome 
them  (iomplelcly  and  thus  |)r(;vent  disease  or  pivirnote  reeovery. 

All  oin-  kuowleda;*'  of  what  oeeiu-s  in  the  establishment  of  immunity 
and  all  the  lliei'apeutl<'al  appliejitiouH  based  upon  this  knowled^^e  we  owe 
to  animal  ex|)erimenl:ilinn  ol  ;in  exeeedin^ly  ingenious  and  intercHting 
nature,  whi(^h  has  j:;iven  rise  to  several  th(;ories.  Of  these,  the  "reten- 
tion theory  "  of  Chativeau  and  the  "exhaustion  theory"  of  Pasteur 
have  h)iig  since  been  disproved  and  possess  now  merely  an  historical 
interest;  and  the  only  ones  which  have  withstood  the  t«'st  of  time  and 
investigation  are  the  "humoral  theory"  of  Ehrli('li  and  the  "cellular 
theory"  of  Metschnlkofl',  both  of  which  will  be  considered  below. 

EHRLICH'S    THEORY. 

Ehrlich's  lumioral  or  side-chain  theory,  which  had  its  inception  in 
1897,  explains  first  the  action  of  the  soluble  bacterial  toxins  and  their 
antitoxins,  then  deals  with  immunity  against  these  poisons  and  the 
bacteria  which  secrete  them,  and  finally  embraces  the  far  more  com- 
plicated question  of  immunity  against  those  pathogenic  organisms  which 
liberate  no  soluble  toxins,  but  bring  about  results  which  in  some  way 
are  dependent  u]>on  the  actual  presence  of  the  bacterial  cell.  The 
analogy  between  l)a('teriolysis  and  haemolysis  has  made  the  experimental 
work  much  less  laborious,  since  the  latter  can  be  employed  to  solve  the 
problems  of  the  former. 

Toxins  and  Antitoxins. — In  their  interference  with  metabolism, 
different  species  of  jiathogenic  bacteria  act  in  very  different  ways  ;  they 
produce  different  kinds  of  poisons  whose  actual  nature  is  as  yet  but 
little  known,  and  these  interfere  with  the  cell  functions,  each  in  its  own 
manner.  They  appear  to  possess  certain  definite  chemical  affinities,  like 
the  flir  simpler  inorganic  compounds  ;  they  are  precipitated  by  certain 
agents  and  redissolved  by  others  ;  they  combine  with  other  complex 
compounds  and  form  more  or  less  stable  inert  substances.  Whether 
the  bacteria  are  within  the  tissues  elaborating  the  poisons  and  sending 
them  to  distant  parts  of  the  body,  or  are  grown  in  artificial  culture 
media  outside,  the  poisons  which  a  given  species  produces  appear  to 
possess  the  same  properties,  so  far  as  they  can  be  studied. 

Bacterial  diseases  may  be  divided  into  two  classes  :  (1)  those  in  which 
the  infective  agents  are  localized  and  produce  their  effects  through  soluble 
poisons  which  they  secrete  and  send  through  the  system  in  the  blood 
stream  ;  and  (2)  those  in  which,  whether  localized  or  not,  the  infective 
agents  act  not  through  soluble  poisons,  but  in  some  manner  depeudent 
upon  their  actual  presence  in  the  tissues  and  yet  not  explainable  in  all 
cases  by  mere  mechanical  presence.     These  bacteria,  however,  contain 


784  IXFECTIOX,  SUSCEPTIBILITY,   IMMUNITY. 

poisons  united  Avith  their  protoj^lasm — intracellular  toxins,  some  of 
\vhich  have  been  separated  and  subjected  to  carefid  chemical  analysis; 
and  it  may  be  that  they  become  effective  on  liberation  from  the  bac- 
terial cells  when  these  die  and  are  disintegrated.  Indeed,  we  know  that, 
in  the  autolysis  of  cultures  of  B.  ti/phosus,  a  toxin  is  liberated  into  the 
culture  medium  ;  and  Vaug-han  and  Wheeler'  have  obtained,  in  soluble 
form,  highly  poisonous  material  from  the  cell  substance  of  colon,  typhoid, 
and  anthrax  bacilli.  That  the  last-named  organism  produces  an  intra- 
cellular poison  was  shown  first  by  J.  W.  Vaughau,^  all  prior  investiga- 
tion having  given  negative  results.  Intracellular  poisons  have  been 
demonstrated  also  by  Detweiler'  [B.  prodigiosus,  B.violaccus,  Sarcina 
lufca,  and  Sarcina  aurantica)  and  by  Gelston.' 

As  examples  of  the  first  class  may  be  cited  dij)htheria  and  tetanus ; 
and  of  the  second,  the  true  septicaemias,  in  which  the  bacteria  are  dis- 
tributed generally,  and  typhoid  fever  and  pneumonia,  in  which  the 
bacteria  have  a  selective  affinity  for  special  organs.  It  is  likely  that 
in  the  establishment  of  immuuity  to  both  classes  of  disease,  the  general 
principles  of  the  process  are  the  same,  although  the  details  may  diifer. 

In  the  diseases  of  the  first  class  (diphtheria  and  tetanus),  acquired 
immunity  depends  upon  the  formation,  within  the  system,  of  substances 
termed  Antitoxins,  which,  while  having  no  power  to  destroy  the  causative 
bacteria  themselves,  neutralize  their  toxic  products  (toxins).  In  the 
immunizing  process  a  very  small  part  of  what,  under  ordinary  circum- 
stances, would  be  a  fatal  dose  of  the  specific  toxin,  or  a  small  dose  of 
a  weakened  toxin,  is  given  subcutaneously  to  an  animal,  and  this  is  re- 
peated at  intervals  of  a  few  days.  After  a  time,  the  dose  is  increased, 
and  eventually  the  animal  is  capable  of  receiving  without  injury  a  nor- 
mally fatal  dose,  and  is  then  possessed  of  an  active  acquired  immunity.  If 
now  the  animal  be  bled  and  its  serum  be  injected  into  another,  it  will 
be  found  that  the  latter  can  resist  infection  by  the  organism  which  pro- 
duces the  toxin,  or  that  if  infected  before  treatment,  the  injection  will 
exert  a  curative  influence.  In  1890  Behring  made  this  discovery  as 
to  diphtheria,  after  he  and  Kitasato  had  found  it  to  be  true  of  tetanus. 
In  1891,  Ehrlich,  working  with  abrin  and  ricin,  found  that  these  toxins 
treated  in  vitro  with  the  serum  of  animals  immunized  therewith  became 
neutralized  and  incapable  of  causing  injury. 

The  protection  transferred  from  the  actively  immune  animal  to  the 
other  is  passive  acquired  immunity.  The  serum  of  the  immunized 
animal  differs  from  that  of  the  normal  in  that  it  contains  the  specific 
antitoxin,  which  is  a  substance  believed,  with  good  reason,  to  unite  in  a 
definitely  chemical  manner  with  the  specific  toxin  to  form  an  inert 
compound. 

How  the  antitoxin  is  formed  in  the  system  is  an  interesting  question, 
which  Ehrlich  explains  in  the  following  manner :  The  bacterial  toxins 
have  special   affinities  for  special   cells,  and  if  they  are  introduced  in 

^  .Journal  of  the  American  Medical  Association,  September  3,  1904. 
^  Transtictions  of  the  Association  of  American  Physicians,  1902. 
^  Ibidem.  *  Ibidem, 


Kiinijaii's  'nii.oiLY. 


785 


HiifUcii'Dt  ;un()iiM(,H  those,  cttlls  iirc;  destroyed  ;  hut  if"  not,  tliey  are  merely 
(Jiiriiiij^ed  by  IIk;  union  of  tli(!  toxin  with  ecTtiiin  utoni-^M-oufw  of  the 
eell  (or  wiiieh  it  })OHsesseH  tlie  H|)(!f!i;d  .'iflitiity.  Thr-  iitorn-j^roiij)  with 
which  th(;  toxin  unites  is  eiUled  n,  llccfjtlor  or  iSi/lr-r/inln.  'J'h(;  cell, 
|)einji;  d;un;ii;('d  by  the  loss  of  tiiis  portion  of"  its  Hnhst;UK;e,  proceeds  to 
r(!|)iiir  its(!l('l)y  rephuting  this  rec(!ptor  ;  hiil,  f"olh)Vvinj^  Weigert'.s  law  of 
8njK!re,oni|)(!ns;i(ion,  it  |)ro(hi(!os  un  (sxcchh  of  nieeptors,  whi(;h,  not  being 
needed,  an;  ciist  out  inio  \\h\  blood  slreani,  where  they  an;  f"n'e  fo  unito 
with  any  ("i-esli  portions  of"  toxin  with  which  they  may  efunc;  in  e<int;i<;t. 
"^rheso  free  I'ecieptors  are  the  :intiloxin. 

The  union  of  the  toxin  with  the  receptor  of  the  cell  or  with  tlie  fr(« 
receptor  (antitoxin)  is  ("ffected  l)y  an  atom-frroup  called  the  /Inp/ophf/re. 
When  the  toxin  be(!ornes  fixed  to  tlie  eell  by  this  f^roup,  it  may  j)rof;eed 
to  destroy  the  cell  by  its  poison  mole(!ul(!  or  Toxojiliorc ;  but  when  it 
unites  with  the  free  receptor  and  thus  satisfies  its  only  attaching  group, 

Fio.  118. 
..Toxopboye  qroxip 

Hjtpt'opnoYe  qroup 
T^i2  c  e  pfo  -r  & 


Y- Ant\ tox  \r> 


its  poison  molecule  has  no  cell  upon  which  to  work,  and  is  consequently 
unable  to  produce  harm.  The  receptor  thus  acts  in  two  ways  :  it  may 
attract  the  toxin  to  the  cell,  which  thus  may  suffer,  or  it  may  protect 
the  cell  when  it  is  no  longer  an  integral  part  thereof.  (See  Fig.  118.)' 
It  has  been  shown  by  Ehrlich  and  others  that  a  specific  proteid  toxin 
differs  in  one  very  important  respect  from  alkaloidal  and  other  common 
poisons,  namely,  that  the  latter  are  possessed  of  no  haptophore  groups 
with  which  they  can  form  chemical  combinations  with  the  body  cells 
or  with  substances  derived  therefrom.  A  dose  of  morphine,  for  exam- 
ple, no  matter  how  frequently  it  is  repeated,  is  incapable  of  causing  the 

^Figure  ll.'-!  and  the  succeeding  figures  in  this  chapter  are  purely  diagrammatic ; 
and  in-  order  tliat  no  erroneous  conception  nia_v  be  formed  concerning  the  various  sub- 
stances which  thev  represent,  shapes  have  been  adopted  which  are  not  likelv  to  sug 
actual  cellular  or  molecular  forms. 
50 


786  ISFECTIOy,  SUSCEPTIBILITY,   IMMUSITY. 

formation  of  a  substance  with  -which  it  can  unite  to  form  an  inert  body, 
although  it  can  establish  a  tolerance  for  larger  doses  ;  in  other  words, 
no  morphine  antitoxin  can  be  produced.  If  one  should  attempt  to 
immunize  an  animal  against  morphine,  the  serum  of  that  animal  when 
mixed  with  a  fatal  dose  of  mor})hine  would  not  deprive  the  latter  of 
its  power  to  poison  another,  as  will  an  antitoxic  serum  mixed  in  proper 
proportion  with  a  lethal  dose  of  its  corresponding  toxin.  Ehrlich  says 
that  the  term  toxin  should  be  applied  only  to  those  toxic  products  of 
metabolism  with  which,  by  animal  experimentation,  one  can  obtain  a 
specific  antitoxin.  As  examples  of  true  toxins  may  be  cited  those  of 
diplitheria  and  tetanus,  snake-venoms,  abrin  (from  the  jequirity  bean) 
and  ricin  (from  the  castor  bean).  In  the  case  of  any  one  of  these,  a 
reaction  occurs  in  the  body,  whereby  the  toxin  becomes  bound  firmly 
to  the  cell,  instead  of  entering  into  loose  combinations  which  are  easily 
broken  up,  as  in  the  case  of  alkaloids. 

It  must  not  be  supposed  that  the  so-called  receptors  or  side-chains 
are  concerned  merely  with  toxins  and  antitoxin  formation.  The  cell 
protoplasm  is  an  exceedingly  complex  substance  and  the  cell  is  some- 
thing more  than  a  mere  molecule  :  it  is  made  up  of  many  very  complex 
molecules.  It  is  unfortunate  that  attempts  to  explain  immunity  with 
the  aid  of  diagrams  lead  many  to  conceive  that  the  words  cell  and  mole- 
cule are  in  a  sense  synonymous.  The  smallest  possible  drop  of  water 
consists  of  many  molecules,  all  of  the  same  character ;  but  a  cell  is  an 
aggregation  of  complex  molecules  of  diverse  natures  and  functions. 
The  cell  possesses  certain  atom-groups  (receptors,  side-chains)  with  aiSni- 
ties  for  nutritive  materials  which  come  within  the  range  of  their  chemism, 
and  through  them  it  fixes  within  itself  that  which  it  needs  for  the 
carrying  on  of  its  functions.  It  possesses  affinities  also  for  the  proteid 
toxins,  which  are  believed  to  be  similar  to,  though  less  complex  in 
composition  than,  the  nutritive  materials.  Doubtless,  it  possesses  many 
other  atom-complexes  with  other  functions ;  and  doubtless,  also,  the 
number  of  each  kind  is  such  that  the  destruction  of  a  few  does  not 
necessarily  mean  the  death  of  the  cell,  which  under  favoring  conditions 
may  proceed  to  make  good  its  loss  by  processes  of  repair.  The  side- 
chains  which  are  concerned  in  the  fixation  of  toxins  and  which  are 
cast  oif  into  the  blood  stream  as  antitoxin  are  denominated  by  Ehrlich 
TJniceptors  ov  Receptors  of  the  first  order,  being  of  the  simplest  kind  and 
possessing  a  single  bond  of  attachment,  the  haptophore  group.  Other 
more  complicated  receptors  than  these  will  be  considered  presently. 

That  the  union  of  toxin  with  antitoxin  is  a  purely  chemical  process, 
is  believed  by  Ehrlich  and  most  other  investigators,  and  as  proof  are 
cited  a  number  of  facts.  Thus,  when  a  toxin  is  mixed  with  its  cor- 
responding antitoxin  in  proper  proportions  in  a  test  tube,  it  becomes 
neutralized  and  is  then  incapable  of  acting  injuriously  any  longer. 
Like  acids  and  alkalies,  the  two  can  be  titrated  against  each  other. 
Again,  as  with  most  chemical  reactions,  the  union  of  the  two  is  has- 
tened by  warmth,  and  occurs  more  readily  when  concentrated  solutions 
are  employed.     It  appears,  however,  that  with  tetanus  toxin,  at  least, 


I'liiiiLicirs  'I'lii'.onY.  787 

tli('  union  willi  luit-iloxiti  is  ai  lirsl,  ;i  sonicwliiit  lor).so  u."Hr)riation,  wliif-li 
can  l)(!  (lisiiiplcd  ;  and  tiiat,  as  titnc  j^ocs  on,  tlu;  combination  hccorrifs 
fixed.  Tliis  lias  been  wliovvn  in  an  iiitorcHtiii}^  cxiioririiont  by  A.  Wa»- 
scrinaiin,  vvlio,  Iiavinfjj  f'onnd  thai  a  niixtiin!  of"  Ictaiins  toxin  and  \i\\\xu".i- 
|)iii;-l)i'ain  cirnilsion  possc-sscd  tio  toxic,  action  for  ^'iiinca-ftifr-,  wiiilc 
niixttir'(!s  willi  cninlsions  of  oilier  oiLfiins  ol"  tli(;  hanie  anitnal  retained 
tlieir  power,  concluded  that  (lie  toxin  has  u  Kpccial  aflinity  for  tlic  n-Wn 
of  the  central  iicrvoii.s  systcitn,  and  thai  these  contain  nornmlly  the  anti- 
toxic; side-chains,  which  arc  the  same  as  those  existing  in  the  serum  of 
an  imnunii/ed  anitnal.  Jt  is  known  that  tli(!  tetamis  toxin  reaches  the 
cells  of  the  central  nervous  systcuii  thron<i^li  th(!  motor  axones,  and  that 
the  antitoxin  reaches  them  throngh  the  eireniation,  Wa.sHerniann  in- 
jected some  neutralized  toxin  into  the  liind-loot  of  a  guinea-pig  and 
saw  no  result.  Next  he  injected  some  adrenalin  into  the  hind-foot 
of  another  guinea-j)ig,  and  after  this  agent  had  caused  the  capillaries 
to  contract  he  injected  some  of  the  same  neutralized  toxin,  and  the 
animal  became  tetanized.  The  circulation  being  Kt(»ppcd,  the  antitoxin 
could  not  reach  the  central  nervous  system,  but  the  channel  of  ab.sorj)- 
tion  of  the  toxin  was  o])en,  and  the  conclusion  must  be  that  the  toxin 
broke  away  from  its  combination  and  was  al)Sorbed.  On  the  other 
hand,  when  the  mixture  of  toxin  and  antitf)xin  was  allowed  to  stand 
some  hours  and  was  then  injected  into  an  animal  after  adrenalin  treat- 
ment, no  symptoms  were  produced,  since  firm  union  had  become  estab- 
lished between  the  two  substances,  and  the  toxin  could  no  longer  free 
itself. 

Toxins  are  decidedly  unstable,  their  strength  diminishing  with  age. 
Ehrlich  found  that  a  single  antitoxic  unit  saturated  very  variable  amounts 
of  different  toxins,  and  that  a  neutralized  mixture  of  one  antitoxic  unit 
and  diphtheria  toxin  often  required  the  addition  of  many  minimum 
lethal  doses  (the  amount  necessary  to  kill  a  250-gramme  guinea-pig  in 
48  hours)  of  the  toxin,  in  order  to  produce  a  fatal  result.  The  com- 
bining pow'er  of  the  toxin  was  found  to  be  unimpaired,  but  its  toxic 
property  had  diminished,  and  from  this  fact  Ehrlich  concluded  that  the 
toxin  molecule  possesses  tw^o  independent  groups  of  atoms,  one  of 
which,  the  toxophore,  is  prone  to  undergo  alteration  of  structure,  while 
the  other,  the  haptophore,  remains  unimpaired.  To  this  degenerated 
toxin  molecule  Ehrlich  applied  the  term  Toxoid.  By  reason  of  the 
fiict  that  the  haptophores  of  the  toxoids  are  unimpaired,  an  animal 
treated  with  toxoids  can  elaborate  antitoxic  substances,  the  toxoids  at- 
taching themselves  to  the  cells  in  the  same  way  as  the  toxins.  Study- 
ing the  degenerated  toxins  further,  Ehrlich  found  in  addition  to 
To.roncs,  which  are  original  products  feebly  toxic  to  the  nerv'ous 
system,  a  number  of  moditications  possessing  weaker  affinities  for  anti- 
toxin and  for  cells  than  those  of  toxins,  but  capable  of  combining  with 
antitoxin  and  of  producing  slow  poisonous  eflects,  as,  for  example, 
paralysis.  To  these  intermediate  products  he  gave  the  name  Epi- 
toxoids.  He  found  also  other  modifieations  which  possess  greater  affinity 
for  antitoxin  than  has  toxin,  and  to  these  he  gave  the  name  Profofoxoids. 


788  INFECTION,  SUSCEPTIBILITY,  IMMUNITY. 

To  still  others  possessing  the  same  degree  of  affinity  that  toxin  has  for 
antitoxin  he  gave  the  name  Syntoxokh.  Further  research  by  Madsen 
and  Dreyer  and  Ehrlieh  has  demtnistrated  the  existence  of  Toxonoids, 
poisonous  for  one  species  but  not  for  another,  and  of  Proiotoxbi,  Dcu- 
terotoxin,  and  D'itotoxin,  possessing  ditfcrcnt  affinities  for  antitoxin,  and 
also  alpha  and  beta  modifications  of  each. 

Through  the  fact  that  toxoids  are  unimpaired  as  to  their  haptophores, 
so  that  they  can  link  themselves  to  the  cells  and  yet  cause  no  ill.  etfects, 
Wassermann  and  Bruck  were  enabled  to  prove  experimentally  the 
increased  production  of  receptors.  They  found  that,  using  an  old 
wholly  non-poisonous  tetanus  toxin  on  a  rabbit,  they  could  get  no 
antitoxin  production,  and  this  indicated  either  that  the  material  injected 
could  produce  no  physiological  action,  or  that  if  it  caused  the  prolifera- 
tiou  of  receptors  they  were  not  cast  oif  by  the  cells  into  the  blood. 
But  they  demonstrated  that  the  toxoid  did  act,  for  the  animal  could 
withstand  a  normally  fatal  dose  of  the  toxin,  the  toxoid  having  united 
with  the  cells  to  which  the  toxin  would  have  linked  itself.  On  wait- 
ing several  days  until  the  receptors  began  to  be  produced  in  overabun- 
dance, thus  increasing  the  number  of  points  of  attachment,  they  found 
that  the  animal  not  only  could  not  withstand  a  minimum  lethal  dose, 
but  was  killed  by  a  smaller  dose  than  is  required  to  kill  a  normal 
animal.  This  showed  that  the  receptors  were  produced,  but  not  cast 
oif;  and  being  retained  by  the  cells  they  gave  the  toxin  an  extra  num- 
ber of  points  of  attachment  through  which  to  poison  the  cells,  whereas 
had  they  been  cast  off  they  would  have  linked  themselves  to  the  toxin 
in  the  blood-stream  and  thus  neutralized  it.  It  appears,  therefore,  that, 
when  the  receptors  are  overproduced  they  require  for  their  liberation 
some  stimulus  which  the  haptophore  itself  is  incapable  of  supplying, 
and  that,  under  ordinary  conditions  of  immunizing  with  toxins  instead 
of  with  wholly  non-poisonous  toxoids,  this  stimulation  comes  from  the 
toxo])hore  group. 

A  true  antitoxic  serum  is  obtainable  only  by  injecting  soluble  toxins, 
and  it  happens  that^he  only  pathogenic  bacteria  that  produce  them  to 
any  considerable  extent  are  those  of  diphtheria  and  tetanus,  the  others 
retaining  their  poisons  in  apme  form  of  combination  with  their  proto- 
plasm. The  production  of  immune  serums  for  the  bacteria  of  the 
latter  class  requires  the  injection  of  the  bacterial  cells  themselves,  either 
living  or  killed,  the  latter  being  most  often  employed  for  the  first  in- 
jections. There  is  this  very  important  difPerence  between  the  serums 
obtained  through  the  injection  of  toxins  and  those  caused  by  the  in- 
jection of  the  bacterial  cells  themselves  :  the  former  are  antitoxic — 
they  neutralize  the  specific  poison  ;  the  latter  are  not  antitoxic,  but  they 
act  against  the  bacteria  themselves.  While  the  experimental  work 
along  the  line  of  production  of  bactericidal  serums  has  been  enormous, 
and  while  our  understanding  of  the  processes  which  go  on  in  the  body 
is  constantly  growing,  no  such  measure  of  success  has  yet  been  achieved 
as  in  the  case  of  the  diphtheria  antitoxin. 

Bacteriolysis. — In  1888,  Nuttall  discovered  that  normal  serum  and 


j/jaioLYsis.  789 

ViirioiiH  })<)(ly  fldid.s  li!iv(!  flu!  power  (,<»  kill  and  (li.-isolvc;  variouHKjMfricH  (^f" 
baclcriii,  aixl  lliai  llils  |)io|)(:rty  disappears  vvlieii  llie  j-ariie  are  lieated  tr> 
5r»"  ( /.  (  I.JI  "  V.)  or  allowed  t<)  Htaiid  lor  a  week  or  inoic.  This  j)ro[>- 
c.vty  was  awailn-d  hy  JJiieliiior,  in  1892,  to  tin;  iii(l(ieiiee  oC  HiihstaneeH 
wlii(;li  ho.  calhid  A/cxlim  (now  known  an  ('oinjilrnicnlyy  The  living 
animal  has  the,  same  power  when  the  organisms  aro  injeeted  In  not 
exeessive  nnnihers.  Tims,  one  can  injeet  small  do.-es  of  ehoh-ra 
organisms  indt  a  <;nin(a-pi<;  willioiit  eauHing  any  injnry,  and  if  the  dose 
bc!  gradually  increased  the  animal  heeomcH  so  resistant  that  it  can  with- 
Kland  a  single  dose  of  many  times  the  ainonnl  that,  in  an  nntn-atcd 
animal,  wonid  inevitahlv  oanse  death.  In  oth(;r  words,  the  animal 
becomes  immune  to  cholera  ;  its  .system  has  undergone  changes  which 
enable  it  to  destroy  the  specific  organism  in  ordinarily  overwhelming 
doses.  If  its  scrum  is  injected  in  very  small  amounts  into  other  guinea- 
pigs,  llui  latter  also  ae(juire  the  same  imnnmity.  It  was  shown  by 
Pfeiiler,  in  18!)-1,that  aniiuals  thus  ai'tificially  ininuuiizecl  could  receive 
without  harm  into  their  peritoneal  cavities  doses  of  cholera  germs, 
which  within  20  minutes  would  be  dissolved  by  the  peritoneal  exudate  ; 
and  he  asserted  that  the  result  was  due  to  a  substance  different  from 
JiiK^hner's  alexins  and  produced  in  the  body  during  the  j)rocess  of 
immunization.  He  showed  also  that  a  non-imnmnized  guinea-j)ig,  which 
would  be  killed  by  the  intraperitoneal  injection  of  a  certain  dose  of 
cholera  germs,  could  withstand  the  same  if  some  heated  immune  serum 
(thus  depi-ived  of  its  eonijilement)  were  introduced  at  the  same  time  ;  and 
he  concluded  therefrom  that  the  immuniziug  material,  although  it  had 
been  exposed  to  heat,  had  not  lost  its  bactericidal  ])roperty,  and  that  it 
had  influenced  the  organization  in  some  way  so  that  it  could  destroy 
the  bacteria.  I^ater,  it  w^as  discovered  by  Bordet  that  the  bactericidal 
power  can  be  restored  by  the  addition  to  the  heated  serum  of  a  small 
amount  of  normal  serum  from  anou-immunized  guinea-pig,  thus  she^v- 
ing  that,  for  the  solution  of  the  bacteria,  two  substances  are  required, 
one  of  which  (complement)  is  a  normal  constituent  of  the  blood,  and 
the  other  (immune  body)  a  substance  called  forth  by  the  immunizing 
process.  While  the  perfectly  fresh  immune  scrum,  like  fresh  normal 
serum,  has  power  to  dissolve  cholera  organisms  in  vitro,  so,  too,  on  keep- 
ing, it  loses  it ;  but  the  addition  of  some  fresh  normal  serum  or  of 
some  peritoneal  exudate  restores  the  property  ;  that  is,  it  reactivates 
the  inactive  serum.  This  was  shown  by  jNIetschnikoff  and  by  Bordet 
(in  1896)  prior  to  the  beginning  of  experimental  work  in  haemolysis. 
It  is  thus  evident  that,  with  both  normal  and  immune  serum,  two  .sub- 
stances are  involved  in  the  process  of  bacteriolysis  :  one,  the  comple- 
ment, is  thermolabile  (destroyed  at  55°  C.)  ;  the  other,  the  immune 
body,  capable  of  conferring  immunity,  is  thermostable  (resistant  to  heat). 
Haemolysis. — The  abandonment  of  transfusion  of  blood  was  aiused 
so  long  ago  as  1869  by  the  fact  that  marked  destruction  of  the  red 
cells  was  found  to  occur,  as  was  sho'^ni  by  the  ha?moglobinuria  which 
followed  the  (Operation  ;  but  transfusic^n  can  be  practised  without  injury 
between  animals  of  the  same  species  and  between  certain  animals  closely 


790  INFECTION,  SUSCEPTIBILITY,  IMMUNITY. 

related,  as,  for  example,  between  the  dog  and  the  wolf;  but  not 
between  unrelated  species,  as  the  dog  and  rabbit,  or  the  dog  and  horse. 
Rabbit  serum  will  dissolve  the  red  corpuscles  of  the  horse,  ox,  pig, 
monkey,  and  man,  but  not  those  of  the  hare  ;  guinea-pig  serum  acts 
against  the  corpuscles  of  rats  and  mice,  but  not  against  those  of 
rabbits  ;  human  corpuscles  are  dissolved  by  the  serum  of  the  horse, 
monkey,  ox,-  sheep,  etc.  Although  transfusion  was  abandoned  at  the 
time  and  for  the  reason  stated,  the  hemolytic  action  of  blood  serum 
attracted  but  little  attention  until  1898,  when  it  Avas  shown  by  Belfanti 
and  Carbone  that  the  blood  serum  of  horses  which  had  been  treated  with 
injections  of  rabbit  blood  was  poisonous  to  rabbits,  while  that  of  horses 
not  so  treated  had  no  such  property.  Later,  Bordet  announced  that 
guinea-pigs,  after  a  similar  course  of  treatment  with  rabbit  blood,  yield 
a  serum  which  will  dissolve  the  red  corpuscles  of  a  rabbit  with  great 
rapidity.  The  same  solvent  action  was  found  to  be  exerted  by  the 
serum  of  other  animals  treated  similarly  with  alien  blood,  and  it  was 
shown  that  it  is  a  specific  action  ;  that  is,  that  it  is  exerted  (with  certain 
few  exceptions)  only  against  the  red  corpuscles  of  the  particular  species 
whose  blood  is  used  for  injection.  In  other  words,  if  species  A  is 
injected  with  the  blood  of  species  B,  A's  serum  will  acquire  the  property 
of  dissolving  B's  corpuscles,  but  not  those  of  species  C  or  D.  This 
destruction  of  blood  cells  is  known  as  Hcemolysis,  and  the  agents  which 
bring  it  about  are  termed  Hcemolysins.  The  nature  of  the  h?emolytic 
substance  has  been  the  subject  of  much  investigation,  which  has  proved 
that  the  solution  is  effected  not  by  one  single  constituent  of  the  serum 
acting  alone,  but  by  two  acting  together,  each  being  powerless  in  the 
absence  of  the  other.  Ten  years  previously,  in  1888,  Nuttall  had 
pointed  out  that  many  normal  serums  possess  the  property  of  destroying 
bacteria,  and  that  this  ceases  on  exposure  of  the  serum  to  a  temperature 
of  55°  C.  (131°  F.).  Investigating  haemolysis,  Bordet  found  that  in 
this  process,  too,  the  property  disappears  at  this  temperature,  but  can  be 
restored  by  the  addition  of  a  very  small  amount  of  serum  of  another 
animal  of  the  same  species,  that  has  not  been  subjected  to  treatment ; 
that  is  to  say,  of  a  normal  animal.  Later,  it  was  discovered  that  an 
inactivated  normal  or  immune  serum  can  be  reactivated,  not  only  by 
normal  serum  from  the  same  species,  but  also  by  that  of  other  animals 
not  necessarily  nearly  related.  Thus,  goat  serum,  which  is  hemolytic 
for  guinea-pig  and  rabbit  blood,  loses  this  property  on  being  heated  to 
55°  C,  but  gains  it  again  on  the  addition  of  horse  serum,  which  itself 
has  no  action  whatever  on  rabbit  blood. 

It  was  clear,  then,  that  at  least  two  substances  are  required  in 
haemolysis;  one  unable  to  resist  exposure  to  55°  C,  but  existing  in 
both  normal  and  immunized  animals,  and  the  other,  resistant  to  55° 
and  even  65°  and  70°  C,  and  existing  only  in  the  serum  of  those 
immunized.  To  the  former,  common  to  both  kinds  of  serum,  Bordet 
applied  the  term  Alexin,  invented  in  1892  by  Buchner  for  the  bacteri- 
cidal substances  which  Nuttall  had  shown  to  exist  in  normal  blood  ;  to 
the  other,  found  only  in  the  serum  of  the  immunized  animal,  he  applied 


ll/KMOI.YSIS.  71)1 

tlio  U'vm  f^nhsfd/iice  HcnsihUiwiiricc.  Tlicsc  Icrnirt  ami  riiar)y  oIIkth  that 
hav(!  hrcii  coined  as  siil)sl iliit<!H  liav<!  lu'cii  Hii|)cr.-c(l<r(J  n'-pcclivoly  by 
CJonipicrncnt  (ICIirlidi  (.iiid  /  iii/iniinr.  hodi/  (I'icWVc.r)  or  A  mhorrj/l/jr  (KlirWch'). 
The  actual  solvciiL  ,siil)slaiicc  is  tlic  coriiplriiiciit,  hut  it  witinot  a<;t  unlr-HB 
the  imniuiK!  body  (;iiiiI)0(;(|>Imi)  [)i(j)ar(;H  tin;  rcfl  corpii.stjK.'.s  through  M»rne 
nicaus  of  its  ovvu,  fixing  itscK",  Mccordinji;  to  I^hilirh  aud  Morjrcriroth, 
in  th(!  r(!(l  ct^lls  Ihcinscivc^s.  'V\\(:  (;oiu|)h;in<'iit  is  not  only  lf;.s.s  n-.si.stant 
to  heat  than  tlu;  ininiiiiic  body,  but  is  less  persistent  on  Htonige  of  the 
serum.  Invcstiiration  by  JOhrli(!h  and  Morj^enroth  of  thr;  power  of 
normal  blood  seriun  to  dissolve  ali(!n  oorjuiscles  deraonHtrated  that  this, 
too,  does  not  dcjx'nd  upon  a  sint^de  sul)slancf,  as  was  maintained  by 
Konu!,  but  ujjon  two  substan(;es  acting  together,  as  had  Ix^en  proved  to 
be  the  case  with  immune  serum.  The  second  substance  analogou.**  to 
the  immune  body  is  now  known  as  the  JnUrhodii,  Go-hdveen,  or 
Zwischciikorpcr.  Ehrlieh  and  Morgenroth  proved  also  that  a  normal 
serum  whi(^h  will  destroy  tiu^  red  cells  of  more;  than  one  animal  sj)ecie8 
possesses  an  interbody  for  each  spe(ties,  and  dillerent  complements  as 
well. 

A  hemolytic  serum  is  intensely  poisonous  to  the  animal  spe<;ie8 
whose  blood  has  been  em])loye(l  in  its  produ(^tion,  injections  of  a  few 
cubic  centimetres  (causing  destruction  of  the  blood  cells  in  corpore. 
It  acts  like  a  toxin,  and  similarly  an  artificial  immunity  to  its  action 
can  be  produced,  an  antihsemolysin  being  formed  instead  of  an  anti- 
toxin. 

In  attempting  to  discover  the  relationship  of  the  active  constituents 
of  hemolytic  sernm  to  the  blood-cells  which  it  dissolves,  and  to  deter- 
mine upon  what  its  specific  action  depends,  Ehrlich  and  Morgenroth 
had  recoui'se  to  a  most  ingenious  experiment,  by  which  they  proved 
that  the  immune  body  combines  with  the  corpuscles,  and  that  the 
combination  is  of  a  chemical  nature  and  resists  attempts  to  break  it 
apart.^  The  specificity  of  the  union  was  shown  by  the  fact  that  the 
combination  does  not  occur  when  blood  is  used  other  than  that  for 
which  the  serum  is  hemolytic.  They  proved  also  that  a  similar  com- 
bination between  the  blood  corpuscles  and  complement  does  not  occur, 
and  that  the  immune  body  possesses  two  affinities  ;  one,  very  strong, 
for  the  corpuscle,  and  one,  less  strong,  for  the  comjilement.  Since  the 
latter,  as  proved,  has  no  combining  affinity  for  the  red  corpuscle,  its 
action  must  be  dependent  upon  the  interposition  of  some  agent  which 
has  ;  and  this  is  the  immune  body,  with  its  two  combining  groups. 
Therefore,  it  is  plain  that  the  function  of  the  immune  body  is  to  enable 

^They  destroyed  the  complement  of  a  goat  senim  tliat  was  haemolytic  for  sheep  blood 
by  heating  it  for  a  half-hour  at  5o°  C,  then  added  4  volumes  of  a  5  per  cent,  mixture 
of  sheep  blood  in  0.75  per  cent,  salt  solution,  and  after  letting  the  mixture  stand  for  15 
minutes  at  40°  C.  they  caused  all  the  corpuscles  to  separate  as  a  sediment  by  centrifu- 
gation.  That  none  of  the  inmiime  body  was  present  in  the  supernatant  fluid  they 
proved  by  adding  to  the  latter  some  more  sheep  blood  and  normal  serum  (containing 
complement)  and  tinding  that  the  corpuscles  were  not  dissolved,  as  they  would  have 
been  in  the  presence  of  the  immune  body.  The  sediment  of  corpuscles  which  had  com- 
bined with  the  immune  body  was  mixed  with  normal  (complement-containing)  serum, 
and  after  a  time  the  corpuscles  were  dissolved. 


792 


INFECTION,  SUSCEPTIBILITY,  IMMUNITY. 


the  complement  to  attack  aud  dissolve  the  corpuscle,  and  this  it  does 
by  acting  as  a  coupling-link  between  the  two.  Its  r6le  is  the  same  in 
bacteriolysis,  binding  the  complement  to  the  bacterial  cell  in  the  same 
way.  Diagrammatically,  it  may  be  shown  as  in  Figure  119.  It  will 
be  seen  that  the  same  relations  exist  between  the  immune  body  and  the 
blood  corpuscle  or  bacterial  cell  as  between  a  toxin  and  its  antitoxin. 
Both  the  immune  body  and  the  antitoxin  possess  haptophorcs,  which 
fit  respectively  the  receptors  of  the  blood  corpuscle  and  the  haptophore 
of  the  toxin.     They  are  analogous  products — free  side-chains. 


c 


Fig.  119. 

^ywoto;(ic    group 
-COMPLEMENT 


H»-pt"opbore 

-Corr)plemcT7topbile  qroup 
LIMMUNE   BODY 
_V~^_  -Cy^o  p  b  i  I  e     c/Youp 

J^eceproYs 


The  importance  of  the  study  of  the  phenomena  of  haemolysis  lies  in 
the  fact  that  analogous,  if  not  identical,  processes  occur  in  bacteriolysis  ; 
and  it  happens,  too,  that  experiments  with  blood  cells  are  more  simple 
and  convenient  in  several  respects,  among  which  is  the  fact  that  they 
can  be  carried  out  in  vitro,  and  they  are  also  better  adapted  to  accuracy. 
Although  the  study  of  bacteriolysis  antedates  that  of  haemolysis  by  ten 
years,  it  is  to  the  latter  that  our  knowledge  of  immunity  is  especially 
due. 

The  side-chain  theory,  which  originally  applied  to  the  production  of 
specific  antitoxins  and  was  then  extended  to  the  formation  of  specific 
bacteriolysins  and  haemolysins,  was  finally  broadened  so  as  to  apply  as 
well  to  the  production  of  all  other  antibodies  of  whatever  nature 
caused  by  the  introduction  of  any  substance  which  can  combine  with 
receptors  in  the  body  and  bring  about  the  overproliferation  and  setting 
free  of  the  same.  It  is  not  to  be  supposed  that  the  body  cells  are  of 
such  simple  structure  that  they  have  affinities  for  only  nutritive  mate- 
rials, toxins,  alien  bloods,  and  pathogenic  bacteria.  As  has  been  pointed 
out,  the  living  cells  are  enormously  complex  aggregations  of  exceed- 
ingly complex  molecules,  and  Ehrlich  holds  that  the  atom-complexes 
have  a  great  diversity  of  functions  and  combine  with  whatever  sub- 
stances, and  only  those,  for  which  they  have  receptors  ;  and  these  sub- 
stances naturally  must  possess  atom  groups  (haptophores)  which  can 
link  themselves  to  the  cell  receptors.  The  haptophores  of  the  im- 
munizing substances  are  quite  distinct  from  the  atom  complexes  which 


COMI'LEMICNTS.  703 

liavc  fuiH!tioiial  j)oculi;iriti('H  ;  for  example,  flie  ioxophorc  gronjj.s  (jf 
toxins,  and  the  zyinoplion;  groups  of"  leniiciits. 

Illustrative  of  the  (toinplcx  natiin;  of  body  eclls  and  of  iIk-  mnlti- 
plieity  of  ;itoin  {j^ronps  vviiiitli  tlu^y  jkihschs,  may  he  eit<(|  the  pioduetion 
of  vaiMous  oflicr  eyloloxins.'  Thus,  th(!  injcelion  of"  alien  s|M'rmato/^)a 
causes  the  ])r(KhH;tion,  in  the  serum  of  tiie  animals  injeeted,  of  f^fK-cific 
substances  termed  tSj/cniiof.o.vlnn,  which  have  the  prtwer  to  immohilizr', 
if  tluiy  do  not  dissolve,  tlie  spermatozoa  of  the  species  f"roni  which 
they  arc  derived,  and  also  to  iiu'iiioly/e  its  red  corpuscles.  A^'ain,  in 
the  same  way,  a  serum  can  he  ohlaiiK^d  by  injection  of  ciliated  epithe- 
lium from  the  trachea  of  the  ox  which  will  have  a  similar  action  on 
this  form  of  cells,  and  this  serum  also  is  iKcmolytic  (7rlrMolrixiii»).  By 
injeetin<]^  material  from  the  central  nervous  system,  from  the  liver,  from 
tile  kidneys,  from  the  mesenleric  tz;l:inds,  and  from  boiu;  marrow,  specific 
serums  have  been  obtained  which  are  j)oisonous  respectively  to  tiie  nerve 
cells  (^Neurotoxins),  liver  substance  {I[rpatotoxinn),  kidney  substance 
(^Nephrotoxins),  and  leucocytes  (^Leucotoxhifi).  Each  of  all  these  pos- 
sesses a  thermolable  complement  (destroyed  by  exj)osure  to  55°  C.) 
and  a  thermostable  imnume  body.  But  this  is  not  all.  The  study  of 
the  production  of  antibodies  has  gone  much  farther,  and  it  has  been 
proved  that,  proceeding  in  the  same  way  as  in  immunizing  animals 
against  toxins,  a  variety  of  antibodies  can  be  produced.  Thus,  by  be- 
ginning with  very  small  doses  of  specific  ha?molysin  and  gradually  in- 
creasing the  amount  of  the  injection,  an  antiha?molytic  serum  can  be 
produced,  which,  when  added  to  the  hsemolytic  serum,  will  inhibit  the 
latter's  action.  Investigation  has  demonstrated  the  existence  in  anti- 
haemolytic  serums  of  anticom])lement  and  anti-immune  bodies,  both  of 
which  are  specific.  In  the  same  way  can  be  produced  antispermo- 
toxins,  antileucotoxins,  and  even  antibodies  to  these  antibodies.  An 
enormous  amount  of  research  work  of  a  most  complicated  and  ingen- 
ious nature  is  going  on  constantly,  having  for  its  object  the  solution  of 
the  many  problems  of  immunity,  and  these  few  facts  are  given  merely 
as  examples,  for  a  general  survey  of  the  subject  in  all  its  branches  is 
beyond  the  scope  of  a  work  of  this  nature,  particularly  until  a  wider 
practical  application  can  be  made  of  the  numerous  discoveries. 

Complements. — The  elements  of  blood  serum,  which,  through  the 
intermediation  of  the  immune  body,  bring  about  the  destruction  of 
alieu  blood  cells  or  bacteria,  are  not  ]iroduced  as  a  result  of  an  immun- 
izing process,  but  are  normal  constituents  of  the  blood.  As  stated 
elsewhere,  Ehrlich  has  demonstrated  that  the  blood  contains  not  one, 
but  a  multiplicity  of  complements,  and  that  they  may  differ  in  their 
resistance  to  heat.  Thus,  the  serum  of  a  goat  immunized  with  sheep 
blood  lost,  on  being  heated  to  55°  C,  the  power  which  it  possesses 
normally  to  dissolve  rabbit  corpuscles,  but  was  baemolytic  for  sheep 

^"  Cytoiorin  is  used  for  anv  substance  in  serum,  venom,  or  bacterial  cultures,  or  of 
plant  origin,  which  destroys  cellular  elements,  either  animal  or  vegetable.  The  haemo- 
lysins  and  other  toxic  substances  which  kill  but  do  not  dissolve  cellular  elements  are 
included  under  CS'totoxins.  also  the  bacteriolvsins  (bactericidal  substance,  alexin)." 
Nuttall,  Blood  Immunity  and  Relationship,  p.  14. 


794  INFECTION,  SUSCEPTIBILITY,  IMMUNITY. 

blood  until  it  was  heated  to  65°  C.  Most  complements,  however, 
are  destroyed  at  the  former  tcmjiorature.  The  multiplicity  of  comple- 
ments is,  however,  a  matter  of  disagreement  between  Ehrlich  and  Mor- 
genroth  aud  others,  on  the  one  hand,  and  Gruber,  Bordet  and  their 
followers,  on  the  other ;  but  the  weight  of  experimental  evidence  ap- 
pears to  be  with  the  former,  who  maintain  that  a  diiferent  complement 
is  required  "to  link  itself  to  immune  bodies  that  are  specifically  haemo- 
lytic  for  difierent  kinds  of  blood  corpuscles. 

Complements  are  believed  to  exert  a  sort  of  digestive  fermentative 
action  upon  the  cells  (blood  or  bacteria)  to  which  they  are  linked  by 
the  immune  body.  They  lose  this  property,  as  a  rule,  when  they  are 
heated  to  55°  C.  They  are  believed  to  contain  two  imjiortaut  atom 
complexes  :  one,  the  haptophore,  with  an  affinity  for  a  similar  group  in 
the  immune  body  ;  the  other,  the  zymotoxic  group,  is  the  functional 
(digestive)  part.  It  is  the  latter  that  is  affected  by  exposure  to  55°  C, 
the  former  still  possessing  the  power  of  combining  with  the  immune 
body  and  of  stimulating  the  production  of  anticomplement  when  the 
heated  normal  serum  is  injected.  Complements  that  have  been  deprived 
of  their  zymotoxic  groups  are  analogous  to  toxoids,  and  are  known  as 
complementoids. 

An  immune  serum,  while  it  acquires  a  large  amount  of  immune 
body,  does  not,  as  a  rule,  gain  any  additional  amount  of  complement ; 
and  inasmuch  as  the  two  work  together,  it  cannot  exert  its  full  power 
in  test-tube  experiments  without  the  addition  of  a  sufficiency  of  com- 
plement, which  can  be  supplied  in  such  experiments  by  the  addition  of 
normal  serum.  In  the  practical  therapeutical  application,  however,  of 
a  bactericidal  serum,  the  necessary  complement  may  exist  already  in  the 
blood  of  the  patient ;  and  inasmuch  as  such  a  serum  may  contain 
many  thousand  times  as  much  immune  body  as  complement,  it  follows 
that  a  relatively  small  dose  will  be  sufficient  to  furnish  an  enormous 
number  of  linking  bodies  to  enable  the  complement  of  the  blood  to 
perform  its  office ;  but,  as  will  appear,  there  may  be  an  insufficient  sup- 
ply of  complement  for  the  attainment  of  the  desired  result,  and  in 
practice  the  deficiency  cannot  easily  be  made  up.  Moreover,  an  excess 
of  immune  body,  as  also  will  appear,  may  act  to  the  disadvantage  of 
the  subject.     (See  page  803-) 

As  to  the  source  of  the  complements,  there  is  considerable  disagree- 
ment. By  some  they  are  believed  to  be  secretory  products  of  the 
leucocytes  and  of  other  kinds  of  cells,  many  of  which  have  been  shown 
to  have  phagocytic  properties  ;  Metschnikoff  believes  that  they  are  not 
secretory,  but  decomposition,  products  of  the  leucocytes  ;  Pfeiffer  and 
others  believe  that  the  leucocytes  are  in  no  way  concerned  in  their  pro- 
duction, and  Wassermann  asserts  that  these  are  practically  their  only 
source. 

While  the  process  of  immunization  appears  to  have  no  influence  in 
increasing  the  amount  of  complement,  it  is  doubtless  the  case  that 
their  amount  in  normal  serum  is  subject  to  more  or  less  fluctuation  in 
the  same  individual  from  day  to  day  under  varying  conditions  of  health 


IMMUNIC   no  DIES. 


796 


Fk;.  VZO. 


COMPLE- 
riENT 


ANTICOMPLEr,  EMT 


and  (li.slm-bntHU' of  ilic  body  Cimclioiis.  Thus,  Klirlicli  and  M()r{.M-iirolh 
h;iv(!  proved  (lie  di.s;i|)|)(ai':MH;<;  of  coinitlcniciil  in  jxdhonin^  l>y  J)Ii«)h- 
plionis,  and  Mctsc.lmikon"  iLs  diniimilion  (ol lowing  .suppuration.  It  in 
j)(),ssil)lo  tlial,  rcducisd  Hisistance  Lo  iidcclion  may  dcfUTKl  upon  t\\e 
reduction  of  coinjjlcnicnt  hy  tlio  HpontiUKsoiiH  ])roduf;t.ion  of  anticom- 
plcnicnl,  in  iJu;  system.  Allliou^li  (liis  Kj)on(Mneous  prodiwtion  lias 
not  yet  been  d(;monstral(;d,  it  lias  been  proved  by  Wassermann  that 
the  injection  of  anticomj)lement,s  increaKcs  HU.sceptibility  to  infection. 
Anti(!()mph'inent  v.ux  be  produced  (]}ord(!t)  by  injection  of  cf)mj(Iement 
(normal  sei'um  of  another  spe(Mes),  thus  causing  the  production  of  a 
serum  which  is  antagonistic  to  ha-molysis  and  bactei-iolysis,  .since  the 
anticomplement  pos.sesses  a  haptophon'  ^rouj),  which  links  itself  to  the 
corre.spondinfr  group  of  the  complement  and 
thus  prevents  a  similar  union  of  the  com- 
plement and  immune  i)ody.  This  action  is 
shown  diajj^rammatically  in  Fi<j:ur(>  120. 

Except  in  those  ciises  in  which  the  com- 
plements of  the  two  species  possess  identical 
combining  groups,  the  anticomjilcmcnts  are 
specific  bodies  ;  that  is,  they  combine  only 
with  their  specific  complements.  The  union 
of  complement  and  anticomplement  is  very 
firm,  as  has  been  shown  by  Bordet,  who 
found  that  it  caniiot  be  broken  up  by  heat. 

Immune  Bodies. — The  immune  bodies, 
believed  by  the  Ehrlich  school  to  originate 
through  the  saturation  of  some  particular 
atom  complexes  (side-chains)  of  some  par- 
ticular cells,  are  specific  bodies  ;  for  exam- 
ple, that  which   links   complement    to    one 

kind  of  blood  cell  will  not  act  for  that  of  another  species  ;  that  \\  hich 
makes  possible  the  destruction  of  a  cholera  germ  will  exert  no  action 
against  the  bacillus  of  typhoid  fever.  That  they  exist  in  one  form  and 
another  in  the  system  under  normal  conditions  is  generally  admitted, 
for  in  the  normal  metabolism  of  the  cells  it  is  assumed  that  various 
substances — nutritive  substances,  for  example — stimulate  the  over- 
production and  liberation  of  side-chains,  among  which  may  be  some 
that  are  identical  with  those  which  originate  in  consequence  of  the 
introduction  of  alien  bloods,  bacteria,  and  other  foreign  substances. 

Whether  each  immune  body  is  a  single  definite  substance  or  a  com- 
bination of  substances  having  special  affinities  for  different  materials  is  a 
matter  in  dispute,  the  former  view  being  held  by  Bordet  and  Metschni- 
koff  and  the  latter  by  Ehrlich  and  Morgenroth,  who  bring  forward 
certain  experimental  proof  of  the  correctness  of  their  view. 

It  has  been  shown  that  different  kinds  of  blood  cells  possess  some 
similar  receptors,  and  that  each  cell  appears  to  have  these  atom  complexes 
in  great  variety,  so  that  a  given  cell  may  be  able  to  link  itself  to  the 
receptor  of  this  or  that  immune  body  and  not  to  tliat  of  some  other ; 


796  INFECTION,  SUSCEPTIBILITY,  IMMUNITY. 

aud  Ehrlich  and  Morgenroth  regard  the  immune  body  of  a  serum  as  the 
sum  total  of  its  athnities  for  diiferent  cells,  each  corresponding  to  one 
partial  immune  body.  A  particular  khid  of  blood  cell  or  species  of 
bacteria  introduced  into  an  animal's  system  may  or  may  not  find  corre- 
sponding receptors  for  each  of  its  many  different  combining  atom 
complexes  or  haptophores.  If  it  should  not  iind  them,  then  only  a 
part  of  the  possible  number  of  })artial  immune  bodies  will  be  produced 
by  the  animal.  In  another  species  of  animal,  other  receptors  may  be, 
and  are,  present ;  and  in  consequence  the  immune  bodies  produced  by 
the  two  must  differ  to  some  extent  in  their  composition,  each  containing 
certain  atom  groups  or  partial  immune  bodies  that  the  other  lacks,  and 
each  differing  in  similar  respects  from  those  produced  by  other  sj^ecies 
of  animals  subjected  to  the  same  and  to  different  stimuli.  If  Ehrlich 
and  Morgenroth  are  correct — and  the  weight  of  experimental  evidence 
appears  to  indicate  that  they  are — the  employment  of  bacteriolytiic 
serums  made  by  combiuing  a  number  of  serums  derived  from  different 
species  of  animals  ought  to  give  better  therapeutical  results  than  one 
derived  from  one  species,  and  hence  containing  a  smaller  assortment  of 
possible  combining  groups.  The  greater  the  variety  of  these  groups, 
the  greater  the  possibility  for  the  human  system  to  bring  its  complements 
into  action  ;  and  these  cannot  exercise  their  functions  unless  they  find 
the  necessary  intermediary  agents — the  immune  or  partial  immune 
bodies.  Indeed,  it  appears  certain  that  in  many  experiments  with 
lysins  a  number  of  different  immune  bodies  or  partial  immune  bodies 
are  concerned.  Inasmuch  as  the  atom  complexes  or  combiuing  groups 
of  the  molecules  that  make  up  the  bacterial  cell  may  not  be  absolutely 
alike  in  different  races  of  the  same  bacterial  species,  it  is  reasonable  to 
believe  that  an  immune  serum  produced  through  the  employment  of 
one  particular  culture  will  not  affect  all  different  cultures  of  that 
organism  equally.  In  fact,  that  is  what  often  is  seen  in  actual  prac- 
tice :  a  bactericidal  serum  is  active  in  a  certain  number  of  cases  and 
of  no  value  in  others.  Hence,  as  pointed  out  by  Wassermann,^  the  way 
out  of  the  difficulty  is  to  employ,  not  a  single  culture,  but  a  number  of 
different  cultures  of  the  same  bacterium  in  the  preparation  of  a  serum, 
in  this  way  securing  a  very  large  number  and  variety  of  partial  groups. 
Such  a  serum  Wassermann  would  call  multipartial. 

In  the  same  way  that  anticomplement  can  be  produced  by  the  injection 
of  normal  serum,  so,  also,  can  one  bring  about  the  formation  of  anti- 
immune  body  by  injecting  an  immune  serum  into  an  animal  in  small 
and  gradually  increasing  doses,  after  the  method  followed  in  immuni- 
zation. The  resulting  serum  will  contain  both  anti-immune  body  and 
anticomplement. 

Agglutinins. — It  was  observed  so  long  ago  as  1869  by  Creite,  and  in 
1875  by  Landois,  that  the  blood  serum  of  an  animal  when  mixed  with 
the  red  corpuscles  of  many  other  species  causes  them  to  come  together 
in  clumps.  In  his  experiments  in  haemolysis,  Bordet  observed  that  in 
a  hsemolytic  serum  this  property  is  increased  ;  that  the  agglutination 
'  New  York  Medical  Journal  and  Philadelphia  Medical  Journal,  October  15,  1904. 


A(j(;LirnNiN.s.  797 

prnondcH  tlu;  Holiilion  oC  I  Ik;  ca-.Uh  ;  uiid  tli.il  \\u-.  iiicrcM.sf!  in  a^^liitiiiiitiiif^ 
|tr()|)(!rly  i,s  s[)(!ci('ic, — llinl  is  t/»  wiy,  il  i-  iiicrcnsj-d  wiffi  r(')^\u-(:t  lo  the 
Isliid  (»('  l)l(»()(|  (•,(»i|)iis<;l('S  llijil  liiivc  l)C('ii  ciiiplriycd  ill  tlic  |)nKH'f-s  rif 
|)r()(lii<!in<;'  IJk;  lut'iiioiylif;  scniiii,  and  also  lo  some  cxU-Mi  for  that  of 
cJoHcly  r(tlut(!d  specieH.  Tlic  Md)st{inwj  wliicli  lnin^H  about  ihJH  phenom- 
enon is  culled  an  A</</hilhiiv.  It  is  not  destroyed  l>y  exposure  to  00°  C., 
and  it  may  resist  even  70"  (J.  ;  and  so  a  ha-molytie  sernm  whieh  hfw 
been  heated  to  tliat  temperatnre,  wiiiie  i(  loses  its  lia-niolylie  profierty, 
is  still  enpahic;  o("  eaiisinj:;  a^'ulnt inalion.  TIk;  exciting  canse  of"  its 
genesis  is  supposed  to  reside  in  tli(;  stroma  of  the  injected  corpiiHclcfl. 
Aeeordinii;  lo  Stewart,'  the  injection  of  the  stroma  oi'  an  alien  blood 
stiimdalcs  {\u\  |)r()dnction  of  a;z<J^lntinins,  whih;  the  cell  contents  stimu- 
late! more  especially  the  pi'oduclion  of  hicmolysins. 

'i^he  same  ag^lutinatini;-  |)()wer  is  possessed  by  some  mjrrnal  serums 
for  bacteria,  and  similarly  it  is  specifically  increased  in  bacteriolytic 
serums.  The  a <><>;luti nation  with  whicih  \vc  are  most  familiar  is  that 
which  is  cmj)loycd  as  a  means  of  diagnosis  in  susj)ected  typhoifl  fever 
— the  Gruber-Widal  n^action.  The  serum  of  a  person  ill  with  that 
disease,  diluted  with  bouillon  and  mixed  with  a  culture  of  typhf)id  germs 
will  cause  the  latter  to  clump  together.  This  happens  whether  the 
bacilli  are  living  or  dead.  The  agglutinin  may  ])ersist  in  the  system 
for  many  months  or  years  after  an  attack  of  typhoid  fever,  suggesting 
a  persistence  also  of  the  specific  bacilli,  which  we  know  to  be  often  the 
case,  since  they  may  be  discharged  in  the  urine  continuously  for  many 
months  after  recovery. 

The  bacterial  agglutinins  were  studied  first  by  Gruberwho  concluded 
that  in  some  way  they  affect  the  bacteria,  so  that  they  can  l)e  killed 
and  dissolved  ;  but  experimental  evidence  tends  to  show  that  they  are 
not  necessarily  injured,  and  that,  on  the  contrary,  they  can  even  continue 
to  multiply,  even  though  agglutinated.  It  has  been  shown  by  Bordet 
and  MalkofP  that  the  bacterial  agglutinins  and  the  haemagglutinins 
combine  with  the  bacterial  cells  or  blood  cells  in  the  same  way  as  the 
go-betweens  (Zwischenkorper)  of  normal  serum. 

The  agglutinins  are  comjilex  substances  ])ossessed  of  haptophores, 
which  combine  with  haptophores  in  the  blood  cells  and  bacteria,  and 
other  atom  groups  which  cause  the  clumping.  The  cells  ujion  which 
they  act  (blood  corpuscles  and  bacteria)  contain  what  is  called  ^'agglutin- 
able  substance,"  which  also  is  made  up  of  at  least  two  atom  complexes, 
one  of  which  is  a  haptophore,  as  mentioned  above,  and  the  other  is 
sensitive  to  the  atom  group  which  causes  the  clumping.  Thus,  the 
phenomenon  of  agglutination  is  analogous  to  the  chemism  of  haemolysis 
and  bacteriolysis  ;  but  the  one  is  apparently  not  dependent  upon  the 
other,  for  haemolysis  and  bacteriolysis  may  occur  without  agglutination, 
and  agglutination  may  occur  without  subsequent  solution.  Thus,  dog 
serum  will  agglutinate  but  not  destroy  anthrax  bacilli,  and  rat  serum 
will  destroy  but  not  agglutinate  them. 

'  American  Journal  of  Physiology,  XL,  Xo  3.,  June,  1904,  p.  250. 


798  IXFECTION,  SUSCEPTIBILITY,   IMMUNITY. 

Ehrlieh  reg-ard.s  the  ngglutinins  as  s])ecial  products  in  an  immune 
serum,  analogous  to  the  bactoriolysins  and  luemolysins. 

The  atom  complex  that  causes  agglutiuation  is  very  susceptible  to 
the  action  of  acids  and  other  substances,  and  when  it  is  deprived  of  its 
functional  power,  the  result  is  the  same  as  with  toxins  that  have  lost 
their  toxophore  groups  :  the  agglutinin  retaining  its  ha])to])}iore  group 
is  converted  to  an  agglutinoid,  just  as  a  toxin  becomes  a  toxoid  ;  it  still 
can  combine,  but  it  cannot  agglutinate. 

Precipitins. — If  the  serum  of  one  species  of  animal  be  injected  into 
an  animal  of  another  not  closely  related  species,  the  serum  of  the  latter 
will  acquire  the  property  of  precipitating  part  of  the  proteid  material 
of  that  of  the  former  when  the  two  are  mixed  together.  For  example, 
if  we  mix  normal  rabbit  serum  and  horse  serum,  we  observe  no  reac- 
tion ;  but  if  we  inject  a  rabbit  with  horse  serum  at  proper  intervals, 
after  a  time  its  serum  will  acquire  the  property  of  causing  a  precipitate 
when  it  is  mixed  with  horse  serum.  The  substance  which  is  developed 
in  this  process  of  immunization  and  which  brings  about  the  reaction  is 
known  as  a  Precipitin.  Precipitins  are  not  wholly  specific  in  their 
action.  A  serum  obtained  by  immunizing  with  the  serum  of  species  A 
may  precipitate  the  latter  and  also  that  of  some  other  closely  related 
species.  This  was  pointed  out  first  by  Nuttaiy  whose  extraordinarily 
extensive  researches,  conducted  with  hundreds  of  difi'erent  kinds  of 
blood  and  involving  the  making  of  many  thousands  of  tests,  have  been 
very  rich  in  results  valuable  alike  to  students  of  zoology,  physiology, 
and  immunity,  and  also  to  those  who  have  to  do  with  medico-legal 
investigation  of  suspected  blood  stains. 

The  use  of  these  facts  concerning  precipitins  in  the  detection  of  ani- 
mal flesh  of  various  kinds  has  already  been  referred  to  on  page  34  of 
Chapter  I.,  where  a  method  for  the  detection  of  horse-meat  has  been, 
described.  This  method  has,  however,  its  limitations.  For  instance, 
it  is  said  to  be  difficult,  if  not  impossible,  to  distinguish  by  this  test 
between  the  flesh  of  sheep  and  that  of  goats. 

Precipitins  have  been  found  in  certain  normal  serums.  Thus,  ox 
serum  will  precipitate  that  of  man  and  also  that  of  a  number  of  other 
species,  and  the  same  is  true  of  the  serum  of  dogs,  goats,  and  other 
animals.  They  have  been  found  also  in  the  serum  of  animals  immu- 
nized with  bacterial  cultures  ;  these  are  known  as  bacterio-precipitins, 
and  are  specific  for  the  culture  filtrates  of  the  germs  employed  and  for 
solutions  of  the  material  within  the  bacterial  cell. 

Precipitins,  like  agglutinins,  are  far  more  resistant  to  heat  than  the 
other  immune  substances,  their  functional  property  being  not  com- 
pletely destroyed  under  70°  C.  They  combine  in  a  definite  chemical 
way  with  the  substances  precipitated,  but  the  reaction  is  prevented  by 
acetic  acid.  They  are  believed  to  contain  two  essential  atom  groups  : 
one,  unstable  and  functional ;  the  other,  a  stable  combining  (hapto- 
phore)  group.     Precipitoids  analogous  to  agglutinoids  are  known. 

There  is  another  form  of  precipitin,  called  Coagulin,  which  is  de- 
^  Blood  Immunity  and  Blood  Jtielution&hip,  Cambridge,  1904, 


riii'iaii'i'i'is's. 


799 


volojMid  in  lli<!  j)r<K^(;,SH  of"  iinmiiniziii^';  uniirmls  with  (jtlior  alliiuninoijg 
Huhstiinccs.  Thus,  by  cinployiii^  niilic,  tln-rc  Ih  dovclopcfl  an  imrnnne 
l)()(ly  iliiit  will  coagulate  milk  of  flic  same  kind  as  used.  'I'lifsr-  laf;t'>- 
scrnms  are,  in  some  substano(!S,  also  spr-ei/icallv  hicrnolvtic  and 
sj)(!rn)otoxic. 

The  agglutinins  and  the  precipitins  are  more  fiomple-x  than  the 
toxins  and  less  so  than  the  haTnolysiriH  and  haoteriolysins.  Khrli(;h 
con(^eives  of  the  individuals  of  this  group  of  imrmme  suhstanees  UH 
])ossesse(l  of  two  atoin-eumpiexes,  on(;  of  whi<rh,  the  haptophore,  holds 
the  substance  acted  upon,  and  the  other,  tlx;  zymojihore,  exerts  a  fer- 
mentative action  which  brings  about  the  change.  (See  Fig.  121.) 
They  are  called  by  Khrlich  J\'('cr])lnrs  of  flic  .srcond  order.  The  recejjtors 
of  the  first  and  second  orders  are  known  also  as  Unicejdors. 

Fig.  121. 


Hakpto  pb  oyeS^^^^ 


_  Z  UTi9opV?or&   CjYOUp 


The  immune  bodies  concerned  in  haemolysis,  bacteriolysis,  and  other 
lyses  are  more  complicated  than  the  antitoxins  (receptors  of  the  first 
order)  and  the  precipitins  and  agglutinins  (receptors  of  the  second 
order).  In  this  third  kind,  one  haptophore  group  fixes  the  bacterium, 
blood  cell,  epithelium  cell,  food  material  or  other  substance  concerned 
by  the  corresponding  group  in  the  latter,  while  another  haptophore, 
represented    usually    as    another  arm,  links  to  itself  the   complement 


Fro.  122. 


^un7otoxio    qvoup 


HaptopVjoye 


Hapfopbore 
o-mplcYwentopbile 

CjYOUjO 


through  the  mutual  attraction  of  the  complementophile  (haptophore) 
group  of  the  immune  bodv  and  the  haptophore  group  of  the  complement. 
Both  are  held  separately  by  the  same  kind  of  at!inities,  and  the  comple- 
ment can  proceed  to  exercise  its  digestive  function  upon  its  companion 


800  INFECTIOX,  SUSCEPTIBILITY,  IMMUNITY. 

in  captivity.  This  is  shown  diagraniraatically  by  Fig:ure  122,  in  the 
use  of  which  and  of  the  others  presented  in  the  chapter,  it  must  be 
borne  in  mind  that  the  action  is  not  mechanical,  but  purely  chemical, 
and  that  the  figures  are  mere  diagrams  and  represent  bodies  which 
never  have  been  seen.  Figure  122  is  but  another  way  of  expressing 
the  same  idea  as  Figure  117. 

The  immune  bodies  of  this  class  are  known  as  Receptors  of  the 
tklrd  order.  When  they  are  formed  and  thrust  out  like  the  antitoxins 
into  the  blood  stream  in  consequence  of  some  immunizing  process,  they 
are  known  as  xbnhoceptors ;  and  those  which  are  not  so  caused,  but 
exist  normally  in  the  serum,  are  termed  Intermediary  bodies,  Zwischen- 
korper,  and  Go-betweens. 

From  the  fact  that  all  receptors  of  whatever  order  possess  hapto- 
phore  groups,  Ehrlich  calls  all  free  receptors  Hciptins.  There  are 
doubtless  many  more  varieties  of  haptius  tlian  have  yet  been  conceived 
of,  and  an  infinite  number  of  sub-varieties  of  each  kind. 


Wassermann's  Reaction  for  Syphilis. 

As  a  result  of  the  studies  above  detailed,  concerning  various  phases 
of  immunity,  a  test  was  devised  by  Wassermann  ^  for  the  diagnosis  of 
syphilis.  This  test  depends  upon  two  factors  :  first,  the  hsemolysis  of 
red  corpuscles  when  sensitized  with  appropriate  sera  and  treated  with 
complements  ;  and,  second,  to  the  fact  that  complements  become  an- 
chored to  antigens  which  have  been  treated  previously  with  their  specific 
amboceptors  or  intermediate  bodies. 

In  this  special  instance  we  have  two  systems  of  agents,  the  inter- 
action of  which  must  be  observed  in  order  to  determine  whether  or  not 
the  serum  of  an  individual  gives  a  syphilitic  reaction.  The  first  series 
consists  of  (a)  the  red  corpuscles  of  some  animal,  such  as  the  sheep ; 
(6)  the  serum  of  some  other  animal,  such  as  the  rabbit,  which  has  been 
injected  with  sheep's  red  corpuscles,  and  which  has  been  inactivated  by 
heat ;  and  (c)  fresh,  normal  serum  to  act  as  complement.  The  second 
series  consists  simply  of  syphilitic  antigen,  most  commonly  syphilitic 
liver  of  a  newborn  infant,  together  with  the  suspected  serum  (also  in- 
activated). 

In  carrying  out  this  test  the  syphilitic  antigen  is  added  in  proper 
proportions  to  the  serum  which  is  under  suspicion.  If  this  serum 
comes  from  a  syphilitic  individual,  the  syphilitic  amboceptor  in  that 
serum  becomes  anchored  to  the  antigen.  If,  now,  we  add  complement 
to  this  combination,  this  complement  in  turn  becomes  fixed  to  the 
antigen-serum  combination.  We  next  mix,  in  proper  proportions,  the 
red  blood-cells  of  the  sheep  and  the  inactivated  serum  of  the  rabbit, 
previously  inoculated  with  the  red  cells  of  the  sheep.  In  this  instance, 
also,  there  occurs  a  combination  between  the  red  cells  and  the  specific 
amboceptor  in  the  goat  serum.  Haemolysis  does  not  take  place,  how- 
1  Berlin  klin.  Woch.,  1907,  Nos.  50  and  61. 


Ar/<:TS(JIINIh'(JF/'\S   Tlir/iIiY.  801 

ovor,  bo(';iiiK(!  of  IIk^  iihsciH^n  of"  forriplc-nifiit,  Tlu*  (wo  hct\c-  ;irc  now 
mixed  io^ciilicr,  and  \\\o.  (iii;il  rcsiill,  of"  \\\c  Uwt  dnpfrid.s  upon  wliollicr, 
in  l.lii.M  (!oinl)iii;i,tioii,  liicinolysis  lii,i<(!S  pl;i<(  . 

II"  <li<^  snspcct.cd  scnim  is  sypliililic,  ;iii(l  ihc  coihIhiku ion  of  antigen 
scnini  ;ind  coniplcniciil  li;is  l;il<cn  |)l;icc,  I  Iktc  w  ill  lie  no  hcemolvHW, 
bc(;!Uis(;  IJic,  (rotn|»lonicnl  pnscnl  is  so  fixed  in  its  eornhination  lliaf  it 
cuiniot  act  upon  the  sensitized  slier-p's  corf)nsf!leK.  On  tlie  otiier  lianfl, 
if"tlio  suspeeted  serum  Ik;  Jiot  syphilitic,  <he  eomj)Iement  in  series  Xo.  1 
will  l)e  free,  will  act  on  the  sensitized  sheep's  corpUHcles,  and  lijemoiyHis 
will  lake  piacc. 

Metschnikoff 's   Theory. 

Metschnik()n"s  theory  of  I'liaoocytosis,  wliidi  dates  haek  to  1H84, 
holds  that  bacterial  invasion  of  Ihc  systcni  is  followed  by  either  attrac- 
tion or  rcjMilsion  of  the  leucocytes  and  oth(!r  |)hag'ocytic  cells  by  the 
bacteria,  which  in  the  former  case  become  absorbed  and  destroyed. 
In  case  the  pha,i2;ocytes  are  repelled,  or  if  the  attraction  is  oidy  partial, 
so  that  some  bacteria  escape,  nudtiplication  of  the  invaders  occurs, 
with  consequent  lesions.  The  property  of  being  attracted  or  repelled 
is  known  as  Chnninfaxis,  wln'ch  is  resp(^ctively  positive  or  negative. 
In  case  of  natural  in\munity,  the  ehemiotaxis  is  positive  and  the  cells 
move  toward  the  bacteria  and  englobe  them  ;  in  suscei)til)ility,  it  is 
negative  or  only  partially  positive,  or  the  phagocytes  may  n(jt  possess 
the  requisite  phagocytic  power.  In  the  acquirement  of  immunity,  the 
negative  ehemiotaxis  is  converted  to  the  positive  form  by  the  introduc- 
tion of  very  small  numbers  of  the  specific  bacteria  or  of  Aveakened 
cultures,  which  bring  about  a  tolerance  on  the  part  of  the  phagocytes, 
which  eventually  are  enabled  to  attack  and  destroy  the  organisms  in 
numbers  which  ordinarily  would  cause  death.  The  phagocytes  include 
the  mononuclear  and  polymorphonuclear  leucocytes,  certain  cells  in  the 
serous  cavities,  connective-tissue  spaces,  lymph  nodes,  nem-oglia,  splenic 
pulp,  and  in  the  lining  of  small  bloodvessels,  and  elsewhere ;  but  those 
chieHy  engaged  are  the  leucocytes. 

The  destruction  of  bacteria  by  the  phagocytes  is  attributed  to  the 
presence  of  digestive  ferments,  which  Metschnikoff  calls  Cjifascs,  and 
which  in  their  function  correspond  to  the  complements  of  Ehrlich. 

MetschnikoiF  believes  that  what  the  Ehrlich  school  calls  immune 
bodies  and  complements  are  produced  within  the  phagocytic  cell,  and 
that,  in  natural  immunity,  they  are  retained  within  the  cell  ;  while  in 
the  artiticial  form  the  iumiune  body,  but  not  the  complement,  is  liber- 
ated into  the  plasma.  He  explains  the  presence  of  the  two  substances 
in  an  immune  serum  as  a  consequence  of  disintegration  of  phagocytes 
(Pharjobffiis) ;  but  Wassermann  has  demonstrated  that  complement  exists 
naturally  in  the  free  state  in  the  blood.  He  believes  that  under  ordi- 
nary conditions  the  bacterium  is  englobed  by  the  cell,  which  produces 
both  substances  necessary  for  the  process  of  destruction.  In  what  is 
51 


S02  IXFECTION,   SUSCEPTIBILITY,   IMMUNITY. 

known  as  "  Pfeitfer's  phenomenon  "  (see  page  789),  Metsclniikoff  asserts 
that  the  phagocytes  are  broken  up  in  consequence  of  tlie  operation  on 
the  animal,  and  thus  the  cytase  (complement)  is  liberated ;  but  this 
alleged  phagolysis  is  denied  and  disproved. 

The  Metschnikotf  school  asserts  that  not  only  the  process  of  bac- 
teriolysis, but  also  that  of  hiemolysis,  is  carried  on  by  the  leucocytes ; 
that  they  also  absorb  and  destroy  the  soluble  toxins  ;  that  anticomple- 
ments  do  not  neutralize  complements,  but  merely  paralyze  the  leuco- 
cytes ;  and  that  the  circulating  blood  has  no  bactericidal  power. 

Opsonins. 

In  the  last  few  years,  especially  under  the  leadership  of  Sir  A.  E. 
Wright  in  England,  a  great  amount  of  work  lias  been  done  upon  the 
study  of  those  substances  in  the  blood  which  have  to  do  with  the  im- 
portant functions  of  phagocytosis.  These  immune  substances  are 
present  to  a  certain  extent  in  all  normal  sera,  but  are  developed  much 
more  extensively  and  specifically  through  the  result  of  natural  infection 
or  through  the  agency  of  artificial  immunization.  Although  it  is  held 
by  some  that  phagocytosis  is  due  to  the  fact  that  these  specific  immune 
substances  stimulate  the  leucocytes  to  increased  activity  through  the 
action  of  so-called  stimulins,  it  is  much  more  probable  that  they  in 
some  manner  act  upon  the  infecting  bacteria  themselves,  so  that  they 
are  more  easily  ingested  by  the  white  cells  of  the  blood.  The  fact  that 
the  amount  of  these  opsonins  in  the  blood  varied  very  much  in  health 
and  disease,  and  seemed  in  fact  to  correspond  to  the^  amount  of  immu- 
nity possessed  by  the  individual,  led  Wright  to  assert  that  in  the 
opsonic  index,  so-called,  we  had  a  measure  of  the  resistance  of  the  in- 
fected individual.  While  it  is  true  that,  carried  out  under  proper 
conditions  and  with  proper  precautions,  this  index  is  of  much  scientific 
interest  and  value,  it  cannot  be  said  to  have  justified  Wright's  claim 
for  its  common  use  in  medical  practice.  Together  with  the  work  of 
Wright  and  his  pupils  on  the  opsonic  index  has  developed  a  tremen- 
dous amount  of  literature  concerning  artificial  immunization  with  bac- 
terial vaccines,  and  although  results  have  not  been  so  remarkable  as  at 
first  claimed,  they  are  important  and  give  large  hope  for  the  future,  not 
only  for  the  prevention  of  general  and  local  infections,  but  also  for  the 
cure  for  those  infections  when  once  the  human  body  has  been  invaded. 


Practical  Applications  of  the  Results  of  Studies  in  Immunity. 

While  it  is  true  that,  in  spite  of  the  vast  amount  of  experimentation 
on  the  subject,  the  practical  application  of  what  has  been  thus  far  dis- 
covered to  the  prevention  and  cure  of  disease  has  made  comparatively 
little  progress,  it  must  be  borne  in  mind  that  the  problems  of  biochemis- 
try are  exceedingly  complex  ;  that  the  work  of  solving  them  is  of  quite 
recent  origin ;  that  the  pursuit  of  methods  for  their  solution  has  neces- 


lil'JSULTS   OF  STUDIES  IN  IMMUNITY.  803 

sitafc'd  llu!  itivcKti^.'itiori  of  many  yioiiits  of  ,'ij)})ar(;nlly  in(]in!ct  rr^lation 
to  llio  main  qiicHfion  ;  and  that  on(;  i.s  olili^nrl  io  n-ason  largely  from 
|)li('iioiii('ii;i,  wliicli  '.wi'.  \\\(\  oiilcomc  of  itror-chj-cs  wliidi  do  not  occur  in 
nature.  It  \\y.\y  l)c  s:iid  lli:i(  llic  whole  siihjeet  is  still  in  its  infancy, 
and  that  only  a  ,sni;ill  |i;iit  of  (lie  loninL-it ion  of  (lu;  final  Htriictiiro  haH 
yet  l)e(M)  liiid.  Tliiis  fir  iIk;  only  really  hriiliani  rcsnits  af;lii(!vcd  in  llic 
j)ra(!t-i(^id  ;i])|»lic;i(ion  of  I  he  discoveries  in  immnnity  arc  limited  to  one 
diseiise — I  )i|)hllieria — (he  toxica  ni;iferiMl  «if"  which,  hein^  soinhh"  and 
(!.\ti'a(;ellnlar,  nial<es  e:isily  |)ossiI)le  (he  prodnction  of  an  inuniinc  scrnin 
which  can  \n\  nsed  eidier  ;is  ;i  |)r(>|)liyl;K!tic  or  uh  a  cnrative  agent.  The 
)>;i(ho!^'enic,  or<;;niisnis  other  tli;in  those  (»f"  diphtheria  and  tetanus  n-tain 
their  toxins  within  their  cell  snhstance,  ;ind  the  innnnnc  scrnnrs  prodncr-d 
hy  theii"  introduction  into  livinjj:;  animals  arc;  not  antito.xic,  hnt  bac- 
teriolytic, and  exert  only  temporary  jjrotection  and  but  siigiit  curative 
a<^ti()n. 

The  lack  of  success  in  the  treatment  of  diseases  caused  by  this  class 
of  bacteria  is  due  probably  to  tlu;  disparity  in  the  amount  of  amijo- 
ceptor  and  complement  in  the  immune  serum.  As  has  been  pointed 
out,  a  bacteriolytic  immune  serum  contains  an  enormous  increa.se  in  the 
amount  of  specific  amboceptor  (sometimes  100,000  times  as  much), 
but  no  increase  in  complement.  Inasnmch  as  the  conjoint  action 
of  both  is  necessary  for  the  destruction  of  the  bacterial  cells,  it  follows 
that,  unless  the  patient  can  furnish  the  necessary  amount  of  complement, 
the  treatment  must  fail.  To  supply  the  needed  additional  complement 
is  not  an  easy  matter,  even  if  normal  serum  be  injected,  on  account  of 
the  multiplicity  of  complements  ;  for,  according  to  Ehrlich  and  Mor- 
genroth,  each  kind  of  amboceptor  re(piires  a  different  specific  comple- 
ment ;  and  hence  they  recommend  the  immunization  of  different  species 
of  animals  with  the  same  kind  of  bacteria  and  the  utilization  of  a 
mixture  of  the  several  serums,  thus  bringing  into  action  amboceptors 
and  complements  which,  although  differing  according  to  the  species  in 
w'hich  they  are  produced,  are,  nevertheless,  specific  against  the  same 
organism,  and  some  of  them,  at  least,  may  satisfy  the  needs  of  the 
human  system.  Not  only  does  a  deficiency  of  complement  in  itself 
present  an  insuperable  obstacle  to  successful  treatment,  but  the  excess 
of  amboceptor  may  also  work  injuriously  by  preventing  the  availal)le 
com}ilemeut  from  exercising  its  function,  as  has  been  shown  by  Xeisser 
and  Wechsberg,  who  proved  that  it  may  unite  directly  with  the  com- 
plement, which  has  a  greater  affinity  for  free  amboceptor  than  for  that 
which  has  linked  itself  to  the  bacteria  ;  whereas,  in  the  absence  of  an 
excess,  the  complement  will  unite  with  that  which  already  has  engaged 
the  bacteria.  Thus  it  happens  that  successful  treatment  depends  U]X)n 
the  very  difficult  problem  of  bringing  together  in  the  diseased  system 
the  proper  amounts  of  ambocejitor  and  complement  to  cope  with  the 
specific  bacteria.  An  excess  of  complement  is  not  to  be  thought  of, 
but  a  material  excess,  either  of  amboceptor  on  the  one  hand  or  of 
specific  bacteria  on  the  other,  is  fatal  to  success. 


80-4  IXFECTION,   SUSCEPTIBILITY,  IMMUNITY. 

DIPHTHERIA. 

As  has  been  stated,  the  disease  in  Avhieh  the  most  brilliant  results  have 
been  achieved  in  the  application  of  an  immune  serum  is  Diphtheria, 
against  which  the  agent  may  be  employed  either  as  a  means  of  cui'e  or 
as  a  prophylactic.  Its  introduction  its  a  curative  agent,  in  1894,  met 
at  first  with  much  adverse  criticism,  but  its  value  was  soon  firmly 
established,  and  statistics  of  cases  to  the  number  of  hundreds  of 
thousands  testify  that  the  mortality  has  been  reduced  from  about  40 
per  cent,  to  about  1 5  per  cent,  or  lower.  The  statistics  of  the  Boston 
City  Hospital  show  that  of  3067  cases  treated  during  the  period  1888- 
1894,  43  per  cent,  resulted  fatally  ;  while  with  antitoxic  treatment  the 
death-rate  of  14,910  received  during  the  period  1895—1904  was  but 
11.84  per  cent.  During  the  year  ending  December  31,  1904,  the 
death-rate  was  9.57  per  cent.,  and  if  those  cases  which  ended  fatally 
within  "twenty-four  hours  of  admission  are  eliminated,  this  figure  is 
reduced  to  6.95  per  cent.  Preventive  treatment  has  been  practised  exten- 
sively in  schools,  hospitals,  and  other  institutions  for  children,  but  the 
immunity  thus  conferred  is  but  transient.  In  a  children's  hospital  in 
which  an  outbreak  of  diphtheria  occurred,  Lohr^  immunized  460 
inmates  and  the  outbreak  was  checked,  no  cases  occurring  within  three 
weeks  of  the  operation.  Later,  a  few  cases  occurred,  wdiich  illustrated 
the  temporary  nature  of  the  immunity.  Of  99  patients  with  measles, 
treated  because  of  the  special  danger  of  diphtherial  supervention,  not 
one  was  attacked.  Similar  outbreaks  in  children's  institutions  have 
repeatedly  been  checked,  but  since  the  protection  conferred  is  so  tran- 
sient, reappearance  of  cases  is  likely  to  occur,  as  in  the  instance  cited ; 
and  tS"  guard  against  this,  it  is  advisable  to  remove  the  inmates  long 
enough  to  give  the  premises  a  thorough  disinfection. 

According  to  Xetter,^  immunity  begins  after  24  hours  and  wears  off 
within  3  or  4  weeks.  JHe  recommends  that,  when  a  case  of  the  dis- 
ease occurs  in  a  school,  hospital,  or  other  institution  for  children,  the 
other  inmates  be  treated.  The  treatment  is  advised  also  in  measles  and 
scarlet  fever  wards  as  a  preventive  of  possible  diphtherial  complication. 
An  instance  is  given  in  which  the  disease  was  a  frequent  complication 
in  a  measles  ward,  2  to  4  cases  occurring  during  each  of  4  months,  and 
19  in  the  next  succeeding  6  weeks,  after  which  period  each  child  was 
treated  on  entrance  and  no  further  cases  occurred.  The  employment 
of  the  immunizing  treatment  as  a  routine  practice  is  advocated  by  CailM' 
for  young  schoolchildren,  for  the  purpose  of  preventing  primary  infec- 
tion and  diphtherial  complication  of  scarlet  fever  and  measles.  He 
recommends  two  treatments  during  the  school  year. 

Fig.  123,  published  by  Park,  shows  the  extraordinary  influence  of 
diphtheria  antitoxin  upon  deaths  from  diphtheria  in  nineteen  large 
cities  of  the  world,  from   1878  to   1905.      It  will  be  noted  that  the 

*  .Jahrbuch  fiir  Kinderheilknnrle  und  physische  Erziehung,  September,  1896. 
'  Bulletin  de  I'Academie  de  Medecine,  March  18,  1902. 
3  Archives  of  Paediatrics,  October,  1903. 


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Deaths  per  100,000  from  croup  and  diphtheria  in  nineteen  hirgc  cities  (l.S7S-190.'.|.     (Park.) 

year  1894,  which  is  shaded,  was  the  year  in  which  diphtheria  antitoxin 
was  first  introduced. 

TETANUS. 

Like  diphtheria,  tetanus  is  due  to  extracellular  toxins  which  are 
produced  by  the  localized  bacilli.  They  are  conveyed  in  the  blood 
stream  to  the  cells  of  the  central  nervous  system,  for  which,  as  has  been 
shown,  they  have  a  selective  affinity,  and  with  which  they  form  a  very 
close  union.  Although  it  is  possible  to  ])roduce  an  antitoxic  serum 
which,  in  test-tube  experiments,  acts  equally  well  with  the  diphtheria 
antitoxin  in  neutralizing  the  specific  toxins,  the  antitoxic  treatment  of 
the  disease  luis  failed  signally  in  fulfilling  expectations.  This  is  because 
before  the  diagnosis  am  be  established,  the  injury  to  the  cells  has  been 
effected  beyond  the  possibility  of  repair.  The  antitoxin  is,  however, 
valuable  in  aborting  possible  attack,  and  its  injection  liys  become  a 
routine  practice  in  cases  of  gunshot  wounds  and  similar  accidents, 
especially  after  the  annual  observance  of  Independence  Day. 


HAY   FEVER. 

In  hay  fever  we  have  a  true  intoxication,  but  the  toxin  is  not 
of  bacterial  origin.  The  discovery  of  the  cause  of  this  exceedingly 
annoying  condition  is  due  to  the  investigations  of  Professor  AVilliam 


806  lyPSCTtON,  SUSCEPTIBILITY,  IMMUNITY. 

Dunbar,  of  Hamburg,  who  proved  that  the  disease  is  due  not  to 
bacteria,  but  to  the  poison  contained  in  the  pollen  grains  of  various 
grasses.  In  his  first  comnnmication  ^  he  showed  the  difference  in  the 
way  susceptible  and  non-snseeptible  persons  react  to  the  dissolved 
toxin  ;  9  of  the  former  subjected  to  its  influence  developed  typical 
symptoms,  and  20  of  the  latter  were  in  no  way  affected.  In  a  later 
paper-  he  showed  that  the  autinnnal  catarrh,  which  is  peculiar  to  this 
continent,  is  caused  by  the  pollen  of  goldenrod,  ragweed  and  other 
weeds  not  indigenous  to  Europe.  In  the  same  way  that  diphtheria 
antitoxin  is  produced,  Dunbar  obtains  a  horse  scrum  which  neutralizes 
the  pollen  toxin  completely.  This  toxin  is  so  powerful  that  one-forty- 
thousandth  part  of  a  milligram  (corresponding  to  2  or  3  pollen  grains) 
is  sufficient,  when  placed  in  the  conjunctival  sac  of  a  susceptible  per- 
son, to  cause  an  attack  lasting  several  hours,  but  it  will  yield  readily 
to  the  antitoxin.  Although  the  toxin  of  the  grass  pollens  differs  from 
those  of  the  pollens  of  goldenrod,  ragweed,  etc.,  the  grass-pollen  anti- 
toxin neutralizes  them  all.  Statistics  collected  by  various  writers 
abroad  and  in  this  country  show  most  favorable  results  of  treatment. 
Unlike  diphtheria  antitoxin,  Dunbar's  preparations  (liquid  and  pow- 
dered forms)  cannot  be  employed  subcutaneously,  but  are  applied 
locally.  The  serum,  evaporated  to  dryness  and  converted  to  a  fine 
powder  with  sugar  of  milk,  is  administered  as  a  snuff  in  very  small 
doses.  It  does  not  confer  lasting  immunity,  and  must  be  resorted  to 
during  the  season  at  intervals  of  a  day  or  two,  or,  if  the  outdoor  air  be 
unusually  rich  in  pollen,  at  intervals  of  a  few  hours.  For  application 
to  the  eyes,  the  serum  itself  is  preferred.  It  is  said  that  in  the  majority 
of  unsuccessful  cases  either  the  antitoxin  is  not  used  sufficiently  often 
or  is  taken  in  excessive  amounts,  which  aggravate  the  difficulty.  In 
some  cases  the  mucous  membranes  are  in  such  swollen  condition  as  not 
to  permit  absorption. 

DYSENTERY. 

Specific  therapy  has  made  a  great  deal  of  progress  in  this  disease. 
Considerable  confusion  has  arisen  because  of  the  varying  types  of 
bacillus  found  in  different  epidemics.  The  Shiga-Kruse  variety  has 
been  found  to  be  more  virulent  than  the  Flexner  type  and  more  effi- 
cient in  the  production  of  an  anti-serum.  A  polyvalent  serum  pro- 
duced by  inoculation  with  both  types  of  bacilli  has  been  suggested,  and 
would  seem  to  have  the  best  outlook.  The  serum  is  both  bactericidal 
and  antitoxic.  Good  results  cannot  be  expected  unless  the  patient  is 
injected  with  serum  corresponding  to  the  serum  infecting  organism. 
Bacteriological  diagnosis  is,  therefore,  very  important,  unless  a  poly- 
valent serum  be  available. 

As  to  the  efficacy  of  the  serum,  reports  from  Japan,  Austria,  France, 
Russia,  and  England  agree  in  according  it  marked  power.     Shiga  ^ 

1  Deutsche  medicinische  Wochenschrift,  February  26,  1903. 

2  Berliner  klinische  Wochenschrift,  June  15,  22,  and  29,  1903. 

3  Osier,  Modern  Medicine. 


TY 1-1 10 1 1)    FKVKR.  807 

tr('<'it(!(l  21)8  cuH(!H,  with  ii  dciitli-ratc  of  0  to  12  per  ccni.  Thr-  Icrifrth 
of  tli(!  <lis(!a.s(!  ill  tliosc  \vIm»  n;c()V(;r(;(l  vvuH  lw(;iily-fivc  dayn  ;  in  iIiom; 
who  (li(Ml,  .sixteen  duy.s.  In  212  eji-scs  t.r(;!it<<l  willi  <lni^.s  ilic  ni«>rtality 
was  22  to  2()  per  cent.  Tlio.sc  who  reeovereii  were  Hi(;k  I'orty  (Jayn ; 
those  who  (lied  eleven  dayw.  In  UiiHHiu  UoHenthul  guvc  Hcrum  treat- 
ment to  loT  <!a,ses,  with  only  H  deaths — 5.1   per  <tent. 

Shit^a  iM(teidat(!d  10, 000  peojjje  in  .Japan  with  a  mixtnre  of  dwid 
haeilli  and  specilie.  secnin.  Tlu;  inei<len(;e  of  the  disease  waw  not  inueli 
affcH'tcid,  hot  tlu!  niorlality  was  redn(M'd  from  20  to  oO  j)er  cent,  to  prao 
tieally  nothinijj.  Tnvitmeut  of  the  original  diseaise  with  HjHicific  vaccines 
has  bt^en  tried  in  a  few  eases  with  success. 

TYPHOID  FEVER. 

The  use  of  bacterial  va(;cines  in  the  prevention  of  tyi)hoid  fever,  es- 
pecially in  large  bodies  of  military  men,  has,  in  the  last  {cw  years,  be- 
come ({iiite  common,  and  represents  a  very  important  development  of 
the  practical  uses  of  artificial  immunization.  According  to  Russell," 
"since  1904,  60,000  men  have  been  vaccinated  in  India,  over  7000  in 
Southwest  Africa,  and  over  14,000  in  the  United  States,  and  in  no  case 
has  any  harm  followed  its  administration.  .  .  .  Among  the  14,000  per- 
sons vaccinated  in  the  United  States  Army  there  have  been  r<'port<-d, 
to  date,  6  cases  of  typhoid  with  1  death,  while  among  the  remainder 
of  the  army,  during  the  same  length  of  time,  there  have  been  4 1 H  cases 
with  32  deaths.  The  rate  per  thousand  among  the  vaccinate^!  is  0.4, 
while  among  the  unvaccinated  it  is  6,  or  15  times  as  high.  Only  one- 
sixth  of  the  force  has  been  immunized  ;  had  the  entire  army  been  vac- 
cinated the  same  rate  of  incidence  would  have  given  only  36  cases  rather 
than  418.  .  .  .  The  time  has  come  when  its  use  should  be  extended 
not  merely  in  the  military  services,  but  also  among  the  civil  population." 

In  this  connection  the  experience  of  the  writer  (M.  W.  R.)  and 
Spooner  may  be  quoted.  In  an  investigation  looking  to  the  prevention 
of  typhoid  fever  among  nurses  attendant  upon  typhoid  cases  in  general 
hospitals,  the  writers  gave  1588  inoculations  to  405  individuals.  "  As 
yet  there  have  been  no  untoward  results,  and  we  believe  that  the  inocu- 
lated individuals  have  acquired  an  increased  resistance  to  typhoid  infec- 
tion which  will  last  them  for  several  years  at  least.  We  have  strong 
faith  that  the  procedure  will,  within  a  short  time,  find  increasing  favor 
with  the  general  public,  which,  exposed  as  it  is  to  many  sources  -of 
infection,  is  in  great  need  of  specific  protection."  - 

In  the  serum  treatment  of  typhoid  fever  no  one  has  approached,  in 
experience  or  success,  Chantemesse  ^  in  Paris.  With  his  colleagues  he 
has  treated  1000  eases,  with  a  death-rate  of  4.3  per  cent.  Of  5621 
cases  who  were  given  routine  treatment  during  tlie  same  period,  17  per 
cent.  died.  Of  patients  who  were  given  serum  treatment  before  the 
seventh  day  Chantemesse  lost  not  a  single  one.     The  nature  of  Chan- 

"  Boston  Medical  and  Surgical  Journal,  Jan.  5,  1911.  •  Ibid. 

3  Hygiene  gen.  et  applique,  Paris,  1907,  577. 


808  lyFEcriox,  susceptibility,  uimvnity. 

temesse's  serum  is  difHcult  to  uiuk'rstaiul.  He  speaks  of  it  as  antitoxic 
and  as  produced  by  inoculation  of  horses  with  a  true  typhoid  toxin.  It 
does  not,  however,  act  directly  upon  the  toxin,  as  does  the  diphtheria 
antitoxin,  but  in  some  way  indirectly.  It  stimulates  the  spleen,  bone- 
marrow,  and  other  lymphatic  apparatus  to  increased  opsonin  production. 
The  sicker  the  individual  the  smaller  must  be  the  dose,  lest  too  many 
bacilli  be  destroyed  at  once.  There  would  seem  to  be,  therefore,  a 
strong  bactericidal  element  in  the  serum.  The  serum  treatment  is  com- 
bined with  the  cold  bath  treatment,  and  calcium  chloride  is  given  as  a 
routine  measure  to  prevent  hemorrhage.  Chantemesse's  results  have 
been  confirmed  to  a  certain  extent  by  the  Germans,  and  von  Leydeu'^ 
reports  3  cases  treated  with  antitoxic  serum  prepared  by  Meyer  and 
Bergell.2  These  cases  were  all  remarkably  short,  having  normal  tem- 
peratures on  the  sixteenth,  seventeenth,  and  nineteenth  days.  The 
serum  is  said  to  be  of  only  moderate  strength  and  to  be  both  bacterio- 
lytic and  antitoxic.  In  this  connection  it  is  important  to  bear  in  mind, 
as  suggested  by  von  Stenitzer,  that  an  antitoxin,  although  weak,  as  in 
dysentery,  may  be  of  great  service  in  tiding  over  critical  cases. 

Personally,  I  have  treated  132  cases  of  typhoid  fever  with  specific 
typhoid  products,^  serum,  bouillon,  filtrates,  and  the  non-toxic  residue 
of  the  typhoid  bacillus  as  prepared  by  Professor  Vaughan,  of  Ann 
Harbor.  The  results  were  largely  negative,  with  one  exception.  By 
continued  inoculation  during  convalescence  of  the  non-toxic  residue  the 
occurrence  of  relapses  was  cut  down  apparently  from  22  to  5  per  cent. 

ASIATIC    CHOLERA. 

Preventive  inoculation  against  Asiatic  cholera  actually  antedates  the 
antitoxic  treatment  of  diphtheria,  since  it  was  in  1890  that  HafFkine, 
inspired  by  Pasteur's  discovery  in  1880  that  chickens  could  be  ren- 
dered immune  to  chicken  cholera  by  preventive  inoculation,  discovered 
that  the  same  was  true  of  human  beings  in  respect  to  Asiatic  cholera. 
First  he  experimented  upon  himself,  and  then  made  70,000  injections 
of  living  cholera  germs  into  40,000  people  in  India  within  a  period  of 
two  years.  By  inoculating  only  a  part  of  any  given  population  where 
cholera  was  raging,  he  was  sure  of  a  control  by  which  he  could  judge 
of  the  value  of  his  work.  The  rate  of  attack  among  those  inoculated 
fell  to  about  one-twentieth,  and  the  mortality  in  about  the  same  pro- 
portion. 

Experimental  work  by  Kolle  led  to  the  conclusion  that  sterilized 
cultures  possess  the  same  immunizing  power,  and  on  his  recommendation 
that  such  be  used  in  place  of  the  living  organisms,  Murata^  adopted 
this  means  of  conferring  immunity  and  employed  it  most  extensively. 
Of  every  10,000  persons  so  inoculated,  6  contracted  the  disease,  against 
13  of  the  same  number  not  treated.     This  difference  in  the  number  of 

1  Med.  Klin.,  August  4,  1907.  2  Berl.  klin.  Woch.,  May  6,  1907. 

3  Boston  Med.  and  Surg.  Jour.,  October  3,  1907. 

4  Centralblatt  fiir  Bakteriologie,  etc.,  1904,  XXXV.,  No.  5. 


niJiiONic  PL  A  a  UK.  809 

Boiznres  is,  however,  liurdly  lurfro  ononp^li  to  bo  ropanlwl  as  having 
nmc.li  pr()l);itiv(i  forc(!,  hiii  it  is  \vi»rlliy  of  note  that  tlui  mortality  among 
the  inociiliitcd  was  (^on.sidciiilily  lower  aixl  the  Heverity  of  tLe  uttack 
was  less  marked. 

kSalambeni '  uscid  serum  treatment  for  cholera  e;ises  in  St.  Peterhhiirf^. 
Th(!  s(!rum  was  sopposcd  to  he  an  antitoxic  sernm,  and  was  jiroduced  hy 
injiKitiria;  horses  with  a  sohihlc  (cholera  toxin  ;  A'l  eases  wen-  trentcfj,  \\) 
of  thes(!  l)ein<r  very  s(!vere,  H)  severe,  7  moderately  serious,  and  <J  slifrht. 
The  nnmher  of  deaths  was  10,  giving  a  pere(!nt;ige  mortality  of  2.'i.8. 
The  ()(li(aal  returns  of  the  total  cholera  deaths  during  the  same  perifnl 
showed  a  mortality  of  4r).G  percent.  In  some  instances  anti-endotoxie 
sera  havc^  been  used,  and  have  been  thought  to  be  of  greater  potency 
than  the  antitoxic  variety. 

BUBONIC  PLAGUE. 

It  is  to  Flaffkine  also  that  tlie  prophylactic  treatment  for  bubonic 
plague  is  due.  II(i  discovered  that  imminiity  cDuld  be  attained  by 
injecting  sterilized  cultures  of  the  spccilic-  bacilli  (treated  at  70''-'  C. 
for  an  hour  or  longer).  The  injection  causes  slight  fever,  with 
enlargement  of  the  nearest  lymphatic  glands,  but  all  evidence  of 
reaction  disappears  in  from  2  to  8  days.  While  the  treatment  con- 
fers some  degree  of  imnmuity,  the  duration  thereof  is  very  uncer- 
tain :  it  may  be  two  days  or  several  months.  Hatfkine  asserts  that  it 
lasts  from  4  to  6  months  and  sometimes  for  as  long  as  2  years,  but  the 
weight  of  evidence  tends  to  indicate  that  it  is  not  safe  to  coimt  upon  a 
more  lasting  immunity  than  3  months,  and  hence  that  reinoculation 
every  3  months  is  advisable.  Calmette  has  called  attention  to  the  fact 
that  inoculation  of  persons  in  whom  the  infection  is  already  present  in 
the  incubative  stage  will  hasten  the  appearance  of  the  disease  and  con- 
duce to  a  fatal  result.  Personal  investigation,  in  India,  of  the  results 
obtained  led  B.  R.  Slaughter^  to  conclude  that  the  treatment  acts  within 
24  hours  and  renders  the  subject  immune  for  3  months ;  that  when 
applied  during  the  stage  of  incubation,  it  frequently  aborts  the  disease ; 
that  it  has  no  effect  on  other  diseases  excepting  eczema,  which  appears 
to  derive  benefit  therefrom  ;  and  that  the  chances  of  recovery  are  greatly 
increased  in  case  of  attack  in  spite  <if  the  inoculation. 

According  to  a  report  of  the  Plague  Commissioners  in  India,  of 
4,296  persons  inoculated  once,  only  45  contracted  the  disease,  and  of 
3,387  inoculated  twice,  2  were  seized.  Fifteen  of  the  former  and  1 
of  the  latter  died.  At  the  same  time,  among  the  non-inoculated  ]>ersons, 
no  less  than  057  per  thousand  died  in  a  single  week  (the  third  week 
of  September,  1899).  At  Kirkee  (India)  the  plague  broke  out 
in  a  small  camp ;  671  persons  were  inoculated  and  859  were  left 
unprotected.  Thirty-two  cases  occurred  among  the  inoculated  and  143 
among  the  uninoculated.  The  mortality  among  the  inoculatetl  was 
2.0v5,  and  among  the  uninoculated,  11.40,  per  cent.     In  another  camp, 

»  Ann.  de  I'Inst.  Pasteur,  Jan.  25,  1910. 

2  Bulletin  of  the  Johns  Hopkins  Hospital.  November,  1903. 


810  IXFECTTOX,   SUSCEPTIBILITY,   IMMUNITY. 

324  persons  were  inoculated  and  300  left  unprotected.    Fourteen  cases 
occurred  among  the  uninoculated  and  none  among  those  protected. 

From  further  statistics  which  demonstrate  the  value  of  the  treat- 
ment, the  following  may  be  quoted  :  In  the  Bombay  Presidency,  in  one 
connnunity,  among  3G5  persons  who  were  inoculated  there  Avere  13 
cases  with  3  deaths,  Avhile  among  413  not  inoculated,  there  were  48 
cases  with  36  deaths.  In  another  community  thei'c  were  7  deaths 
among  5,184  inoculated,  and  177  among  8,146  not  inoculated.  At 
Lanowli,  among  323  who  were  inoculated,  there  were  14  cases  with 
7  deaths,  and  among  377  not  inoculated,  78  cases  Avith  58  deaths. 

Immunity  appears  to  be  prolonged  by  a  second  inoculation  within 
ten  days  of  the  first,  as  is  shown  by  the  following  figures  :  At  ShaAvar, 
among  5,614  persons  not  inoculated,  there  Avere  957  cases  with  756 
deaths;  among  5,712  Avho  Avere  inoculated  but  once,  there  Avere  69 
cases  Avith  31  deaths;  but  among  3,349  who  were  inoculated  twice, 
there  were  only  9  cases  with  5  deaths. 

Prior  to  the  discovery  of  the  Haifkine  prophylactic,  Yersin's  anti- 
pest  serum,  Avhich  is  the  only  knoAvu  remedy  for  the  cure  of  the  disease, 
was  employed  as  an  immunizing  agent,  but  the  duration  of  immunity 
Avas  found  rarely  to  exceed  tAvo  Aveeks,  and  hence  the  treatment  must 
be  repeated  cA^ery  fourteen  days  in  order  to  insure  protection.  It  is 
claimed  by  Calmette  that  the  serum  confers  an  immunity,  certain  and 
ciFectiA'c,  almost  immediately  after  the  injection  ;  that  the  injection  is 
not  painful  and  is  never  harmful ;  and  that  the  serum,  properly  pre- 
pared, retains  its  poAver  almost  indefinitely.  On  the  other  hand,  the 
disadvantages  are  the  short  duration  of  immunity,  the  great  cost  of 
production,  the  difficulty  of  obtaining  a  supply  sufficient  for  the 
repeated  treatment  of  entire  populations,  and  the  difficulty  of  inducing 
the  natiA'^es  to  submit  even  once  to  the  operation.  It  takes  from  seven 
months  to  a  year  to  immunize  a  horse  to  the  point  that  his  serum 
acquires  preventive  and  curative  properties,  and  many  of  the  horses 
die  before  the  process  of  immunization  is  completed.  According 
to  Assistant  Surgeon-General  Greenleaf,  protective  inoculation  by 
means  of  the  Yersin  serum  is  not  practical  for  the  following  reasons  : 
The  enormous  plant  necessary  for  the  production  of  the  material ;  the 
large  Avorking  force  necessary  for  conducting  the  inoculations ;  the 
opposition  of  the  people  to  the  treatment ;  and  the  short  duration  of 
the  benefit  conferred. 

Cairns,^  Avho  used  the  serum  Avith  some  success  in  the  treatment  of 
cases  at  Glasgow,  concludes  that  it  is  both  antitoxic  and  bactericidal, 
and  that  it  produces  its  best  effects  when  the  injection  is  made  early 
and  both  subcutaneously  and  intravenously,  the  total  initial  dose  rang- 
ing from  150  to  300  cc,  according  to  the  circumstances  of  the  case. 

Both  the  Yersin  serum  and  the  Haffkine  prophylactic  are  very  un- 
popular with  the  natives  of  India.      The  Hindoos  suspect  that  the 
materials  are  of  animal  origin,  and  the  injection  of  such  matters  into 
the  body  constitutes  an  offence  against  their  religion. 
1  Therapeutische  Monatshefte,  May,  1904. 


ANTIHTni<:i"r<>(!()(!(ins  SKIHIMS    TUI'.EIiaULOSIS.  811 

ANTISTREPTOCOCCUS    SERUMS. 

Ant.iHtr(>{)t()(;()(!(;iis  scrurus  of"  various  kinds  have  l)<(rii  (■rn[)l')V«''i  in  tlie 
treatment  of  Erysipelas,  Puerperal  Sepsis,  Malignant  Endocarditis  and 
other  Htniptoeocfiie  infections  and  Scarlet  Fever,  hut  thns  far  they  have 
not  fi^iven  nvsnlts  that  in<li(uil<i  that  they  are  of  rnneh  vahie.  'I'hey  have 
been  pn^pared  by  ino(Milatinj^  with  livitifr  (;ul(iircs  of  stref>t<K;oe<:i  and 
with  the  inlracelliilar  substaJi(!e  of  killed  etdfiires,  and,  on  aeeonnt  of 
the  assert(!d  dilleniiiees  in  the  organisms  according  to  the  nature  of  the 
pathologic  processes  in  which  they  are  a  fact^>r,  with  cultures  obtained 
from  a  numlxM'  of  subjects  with  difT'crcnt  diseases,  and  also  with  cul- 
tures taken  directly  from  a  nnnilx-r  of  individuals  with  the  same  disease, 
as  is  the  method  followed  by  Moscr  in  the  preparation  of  his  jKjly- 
valent  serum  for  scarlet  fever.  They  have  been  prepared  als^»  by 
inoculating  with  organisms  rendered  unusually  virulent  by  being  passed 
througli  a  series  of  animals. 

How  these  various  serums  produce  such  results  as  have  been  observed 
Is  a  matter  of  some  disagreement.  It  is  believed  by  some  that  they 
are  bactericidal,  but  this  is  denied  by  others,  who  believe  that  they  act 
as  stimuli  to  the  j)hag()cytic  cells.  However  they  may  act,  the  hoped- 
for  results  have  not  been  attained,  and  innnunity  to  streptococcic 
invasion  is  evidently  a  very  complex  problem. 

The  use  of  streptococcus  vaccines  in  the  prevention  of  scarlet  fever 
has  been  practised  very  extensively  in  Russia,  following  lines  laid  down 
especially  by  Gabritschewsky  and  other  Russians. 

They  point  out  that  the  streptococcus  is  present  in  many  scarlet  fever 
throats ;  that  streptococcus  vaccines  cause  scarlatiniform  eruptions ; 
that  complement  deviation  shows  streptococcus  amboceptors  in  scarlet 
fever  blood  ;  that  the  mortality  in  scarlet  fever  has  been  markedly  re- 
duced by  the  use  of  a  serum  jiroduced  by  inoculation  of  a  scarlet  fever 
streptococcus  (Moser) ;  and,  finally,  that  by  inoculation  of  streptococcus 
vaccines  efficient  prophylaxis  against  scarlet  fever  has  been  secured. 

This  whole  subject  was  reviewed  by  Smith,^  who  concluded  that  from 
the  published  accounts  it  would  seem  that — 

1.  The  streptococcus  vaccines,  used  as  advocated  by  Gabritschewsky, 
have  some  influence  in  controlling  epidemics  of  scarlet  fever. 

2.  Their  use,  with  proper  care,  is  attended  by  no  harmful  results. 

3.  They  should  be  given  a  wider  application  in  this  country  to  prove 
or  disprove  the  contentions  of  the  Russian  physicians. 

TUBERCULOSIS. 

Through  ignorance  of  its  dangers,  sjiecitic  therapy  in  tuberculosis 
received  in  its  infancy  a  setback  which  it  has  taken  years  for  it  to  recover 
from.  Gradually,  however,  its  laws  and  limitations  have  become  better 
known  and  its  great  value  is  now  recognized  the  Morld  over.  The 
favorable  opinion  refers  now  especially  to  active  immunization  produced 
by  direct  inoculation  of  the  tubercle  bacillus  or  its  products. 
1  Boston  Med.  and  Surg.  Jour.,  Feb.  24,  1910. 


812  INFECTION,  SUSCEPTIBILITY,  IMMUNITY. 

It  makes  little  difference  apparently  what  variety  of  tuberculin  is 
useil.  More  depends  upon  the  method  and  skill  of  the  physician.  In- 
asmuch as,  in  animal  experimentiition,  inoculation  with  the  living-  bacillus 
produces  the  strongest  immunity,  we  should,  theoretically  at  least,  aim 
to  approach,  as  nearly  as  possible,  these  conditions  in  human  treatment. 
This  would  lie  secured  approximately  by  a  combination  of  living  filtrate 
(Tuberculin  B.  F.  of  Denys)  with  bacillary  emulsion  (Tuberculin  B.  E. 
of  Koch).  Corresponding  tuberculins  of  the  bovine  type  are  much  used 
by  Spengler,  who  claims  that  there  is  a  mutual  antagonism  between  the 
two  varieties  of  bacilli  and  their  pathological  processes.  Thus,  he  says, 
puiJmonary  tuberculosis  is  the  result  of  infection  with  the  human  types 
ofbacillus  and  must  be  treated  with  bovine  tuberculin,  whereas,  tuber- 
culosis of  bones,  joints,  and  glands,  being  due  to  bovine  bacilli,  is  best 
treated  with  human  tuberculin.  Be  that  as  it  may,  bovine  tuberculins 
may  be  tried  in  those  cases  which  do  not  improve  on  the  human  varieties. 

The  whole  question  of  tuberculin  treatment  has  been  much  clarified 
through  the  work  of  Denys  and  Trudeau,  and  has  been  well  summed  up 
by  Ringer  in  the  dicta  that  "  time  and  tolerance "  are  the  essential 
things,  and  that  the  word  "  haste  "  has  no  place  in  treatment  with  tuber- 
culins. Although  in  the  past  a  careful  selection  of  cases  for  tuberculin 
treatment  has  been  deemed  essential,  the  opinion  seems  to  grow  that 
practically  any  case  can  be  inoculated  if  sufficient  care  be  exercised. 

Allen  has  recommended  in  tuberculosis  a  vaccine  made  from  tuber- 
culous sputum.  Such  a  vaccine  has  a  number  of  theoretical  advan- 
tages. It  is  a  mixed  vaccine,  contains  primary  and  secondary  invaders, 
the  bacteria  concerned  are  autogenous,  and  their  fighting  powers  have 
not  been  diminished  by  artificial  cultivation. 

Specific  antisera  have  been  used,  especially  in  Europe.  The  best 
known  are  those  of  Marmorek  and  Maragliano.  Opinions  of  these  in 
their  own  countries  have  been,  on  the  whole,  favorable,  but  as  tried  in 
this  country,  at  the  Phipps  Institute  and  at  Saranac,  the  results  Lave 
shown  them  to  be  of  doubtful  value. 

CEREBROSPINAL  MENINGITIS. 

In   no  disease   has   serum   treatment  made  more  advance  in  recent 

years  than  in  cerebrospinal  meningitis.    Most  important  in  tiiis  advance 

has  been  the  work  of  Flexner  ^  and  his  associates.      Briefly,  the  serum 

is  produced  in  horses  by  subcutaneous  inoculation  of  dead  cultures,  living 

cultures,  and  autolysates  of  dead  cultures.     Many  different  strains  of 

the  meningococcus  are  used.      After  a  year  of  immunization  the  serum 

of  such  a  horse  has  been  used  intradurally  after  lumbar  puncture  in  130 

cases,  with  35  deaths,  a  mortality  of  27  per  cent.    The  dose  is  20  to  30 

cc,  and  may  be  repeated  daily  for  four  to  five  days  if  necessary.    When 

cases  are  treated  within  the  first  twenty-four  hours  the  results  are  most 

brilliant.'      The  serum  seems  to  act  by  stimulating  phagocytosis,  which 

destroys  cocci  and  renders  harmless  their  endotoxins. 

^  Flexner  and  Jobling,  Jour.  Exper.  Med.,  1908,  No.  1. 
^  Dunn,  Boston  Med.  and  Surg.  J^ur.,  March  19,  1908. 


(lI'ULl'lUnosriNAI,  MENINdlTlS.  Mi;j 

Qiiiio  Kiriiil.'ir  n^siills  liavc  Itccii  sffti  in  Ofrniaiiy.  I'or  iii.-laii<«-, 
L(!Vy/  iisinjf  u  scniin  |>r<'|)ar<il  hy  \\'a.-:-cntiaiiii,  lia<l  a  (leaf li-nif<;  of 
only  Il.7(!  ix-r  ccnl.  in  17  cases  in  wiiicii  iIk-  Hcnini  was  j.MVfii  iiilra- 
diimlly.  In  M  untroalod  cuses  llic  niorlalily  wuh  78  jut  cent.  V'My 
interoslin*!;  is  a  (;;ise  of  cerebroHpinal  MKiiinjrjtj.s  dcHorilxKJ  hy  Pc.'ibody,^ 
The  iM(('(;lin<i;  organism  was,  in  fliis  case,  \\\v  strfptofocniK.  Six  intni- 
(liiral  incxMilutions  of  sln'plococcns  scnnn  in  dctscs  of  10  w.  facli  won' 
given  in  cit^lii  (lays.  After  the  second  inoeiilalion  the  spinal  llnid  he- 
came  stcril(!  and  remained  so.  Clinically,  the  patient  improved  raj)idly 
and  recovered. 

This  Hueecss  with  a  sireptoeoccie  meningitis  KUggesis  immediately,  of 
conrse,  tlu;  treatment,  of  other  haeterial  invasions  of  the  meninges 
(pnemococcus  or  tyj)hoid  IkkmHus)  with  corresjMxling  antisera.  It  is 
more  than  probable  that  su(Oi  sera,  although  of  donbtful  valne  when 
given  subcutaneonsly,  might  show  valnable  ])roj)erties  if  applied  in  con- 
centrated form  at  the  very  seat  of  infection. 

Bacterial  vaccines  have  been  nscd  in  cerebrospinal  meningitis  with 
success  by  McKenzie^and  by  Rnndle  and  Mottram,^  but  in  the  presence 
of  such  encouraging  serum  theraj)y  their  use  does  not  seem  likely  to  be 
extensive.  Unique  is  the  experience  of  Radman,^  who  inoculates!  two 
patients  subcutaneonsly  with  8  cc.  of  their  own  cerobrospinal  exudate. 
No  harm  was  done,  and  lladman  thinks  this  form  of  sjiecific  therapy 
has  a  hopeful  future. 

1  Dent.  mod.  Woch.,  January  2.">,  1908.  2  Med.  Record,  Marcli  11,  1008. 

3  Brit.  I\red.  .Jour.,  Juno  15,"  1907.  ■♦  The  Lancet,  July  27,  1907. 

6  Miincli.  med.  Wocii.,  July  4,  1907. 


CHAPTER    XVII. 

VACCINATION  AND  SMALLPOX. 

Prior  to  the  discovery  of  vaccination  by  Jenner,  toward  the  close 
of  the  eighteenth  century,  smallpox  -vvas  one  of  the  principal  scourges 
of  the  world.  It  killed,  on  an  average,  nearly  half  a  million  people 
in  Europe  alone,  and  about  once  in  three  years  was  more  than  ordi- 
narily severe.  In  England,  Germany,  France,  Sweden,  and  other 
countries  of  Europe,  the  yearly  mortality  from  smallpox  was  about 
two  thousand  per  million  inhabitants.  More  than  half  the  cases  of 
blindness  throughout  Europe  were  attributed  to  the  disease,  and  about 
a  third  of  the  population  showed  in  their  faces  evidences  of  having 
had  it. 

It  was  well  known  that  those  who  recovered  enjoyed  protection  from 
recurrence  of  the  disease,  and  consequently  it  had  long  been  the  prac- 
tice to  produce  immunity  by  causing  the  disease  intentionally  by  inocu- 
lation when  it  prevailed  in  a  modified  form,  favorable  to  recovery. 
For  more  than  a  thousand  years,  the  Chinese  and  other  Eastern  peoples 
had  produced  the  disease  by  blowing  dried  smallpox  matter  in  pow- 
dered form  into  the  nostrils.  The  discovery  that  the  inoculation  of 
material  from  a  smallpox  pustule  was  more  certain  and  quick  in  its 
results  led  to  the  widespread  practice  of  inoculation.  This  was  begun 
in  England  in  1721,  and  toward  the  end  of  the  century  was  em- 
ployed very  extensively ;  and  even  after  the  discovery  of  the  beneficent 
results  of  vaccination,  was  practised  to  a  certain  extent,  until,  in  1840, 
it  was  prohibited  by  law. 

The  first  successful  vaccination  was  performed  by  Benjamin  Jesty,  a 
Dorsetshire  farmer,  who  inoculated  his  wife  and  two  sons  from  the 
teats  of  cows  aflflicted  with  cowpox.  The  inoculation  was  successful 
in  all  three  cases,  although  the  wife  had  a  badly  inflamed  arm.  Fif- 
teen years  later,  the  two  sons  were  inoculated  with  smallpox,  but  noth- 
ing resulted.  It  is  said  that  Heim^  had  noted  as  early  as  1763  that 
the  accidental  inoculation  of  cowpox  was  followed  by  smallpox 
immunity.  The  practice  of  vaccination  is,  however,  due  to  the  w^ork 
of  Jenner,  who,  on  May  14,  1796,  performed  his  first  successful 
operation.  After  some  very  strong  opposition,  intelligent  people  began 
to  adopt  the  practice,  and  the  uneducated  classes  began  to  fall  gradually 
into  line.  The  practice  was  adopted  in  America,  France,  Germany, 
and,  in  fiict,  the  entire  civilized  world,  and  everywhere  proved  to  be  of 
the  greatest  benefit.  In  1802,  the  English  Parliament  awarded  Jenner 
^  Nothnagel's  Specielle  Pathologie  and  Therapie,  ly,,  H.  2. 
814 


VAddrNATION   AND  SMAfJJ'OX.  HIO 

4,000  pounds  .sicrlliiu;,  ;in<l  hilcr,  ii  still  l;iij.nr  |fi;iiit,  was  made,  liut 
the  |)ioii('('r,  .I(^sty,  w;is  iml  lost  si^^lit  of,  and  in  1  HOr>  ho  wjw  tlie 
honorcid  <^\U'.si.  oC  the  .Icniicrian  S(»ci<;ty. 

TIk!  |)ra(!(i(^(  was  in(r(»du(;cd  info  this  counlry  l>y  I>i".  I><ii.janiin 
WatcM-honsc,  rrolcssor  oC  I'hysicU  in  Harvard  IJiiivorHJty,  who,  on 
Jidy  8,  1800,  va(vinalcd  lii.s  hc.vv.u  cliildnii,  with  six  |K»Hitiv(!  rcsidtM. 
About  tho  Hamo  lime  il  was  introdncr d  info  I'liilad<'lj»hia  l»y  John 
K('(hiian  ('oxc,  who  Narciiiatcd  his  eldest  (rhild  and  then  ex|Kis«-d  him 
to  smallpox  without  result.  In  lioslon,  in  Auj^ust,  1802,  ]U  hftys 
worn  vaooinatcd  snceessf'ully  at  a  t(3mporary  hoHpituI  on  \(»ddie  Islan<l 
(now  Kast  Boston),  and  in  Nov(!mb(!r,  these  and  one  other,  who  harl 
been  vacnunated  two  years  |)reviously,  w(!re  inoradated  with  smallpox, 
but  in  no  <iase  was  the  disease  produeed.  Two  unvaeeinat<'d  boys  were 
inoculated  at  the  sam<!  time,  and  l)oth  developcjd  the  disease.  In  1800, 
Thomas  Jefferson,  wiio  was  the  first  to  introduce  the  practice  in  the 
South,  wrote  to  Jenner  :  '*  You  have  erased  from  the  calendar  of  human 
adlietions  one  of  its  fjreatest.  Yours  is  the  comfortable  reflection  that 
mankind  can  never  f()ri>;et  that  you  have  lived.  Future  nations  will 
know  by  history  alone  that  the  loathsome  smallpox  has  existed,  and  by 
you  has  been  extirpated." 

The  beneficent  results  of  the  introduction  of  vaccination  into  this 
country  are  well  shown  by  a  comparison  of  the  conditions  ol)tainin<:^  in 
the  early  part  of  the  eio:htcenth  century  and  in  the  correspond iiif^  perif>d 
of  the  nineteenth  in  Boston.  In  1721,  Boston,  with  a  population  of 
about  11,000,  had  5,989  cases  of  smallpox  with  850  deaths.  In  17:30, 
in  a  population  of  about  15,000,  there  were  about  4,000  cases  with 
509  deaths  ;  but  between  1811  and  1830,  in  a  very  much  larger  popu- 
lation, there  were  but  14  cases  of  the  disease. 

In  London,  during  the  third  quarter  of  the  seventeenth  century,  the 
average  annual  mortality  from  smallpox  per  million  was  4,000.  A 
hundred  years  later,  between  1770  and  1780,  it  was  more  than  5,000  ; 
in  the  first  years  of  vaccination,  it  was  more  than  2,000  ;  by  the  mid- 
dle of  the  nineteenth  century  it  fell  to  about  500,  and  in  the  last  decade 
of  the  century,  to  less  than  75.  In  the  whole  of  England,  during  the 
peroid  of  optional  vaccination,  the  mortality-rate  fell  from  about  2,000 
to  417,  and  after  the  practice  was  made  compulsory  in  1850,  it  fell  to 
53.  In  August,  1898,  the  "conscientiously  believes"  clause  was  en- 
acted in  deference  to  the  anti-vaccinationists,  and  by  December  31, 
230,147  persons  were  exempted.  The  result  of  this  modification  of 
the  law  has  recently  been  shown  in  extensive  epidemics  in  London 
and  elsewhere. 

In  Sweden,  where  very  accurate  records  have  been  kept  since  1774, 
the  average  mortality  per  million  of  population,  between  1774  and  1801, 
Avas  2,045.  During  the  yciirs  of  optional  vaccination,  1802—181(3, 
it  fell  to  480.  In  1817,  when  vaccination  was  made  obligatory,  the 
rate  began  to  fall  still  lower,  and  up  to  1893  the  average  mortality  was 
155.  During  the  last  nine  years  of  this  period,  under  more  stringent 
regulations,  it  was  never  more  than  5,  and  in  one  year  it  was  as  low  as  0.2. 


816  VACCINATION  AND  SMALLPOX. 

In  Prussia,  during  the  period  of  optional  vaccination,  the  mortality 
rate  fell  from  more  than  2,000  to  about  300.  During  the  Franco- 
Prussian  War,  there  were  among  the  million  well-vaccinated  German 
troops  but  459  deaths,  while  in  the  smaller,  imperfectly  vaccinated 
French  army  there  were  no  less  than  23,400.  Between  1874,  when  vac- 
cination was  made  obligatory,  and  1896,  there  was  but  one  death  from 
smallpox  in  the  whole  German  array.  In  1899,  the  total  deaths  in 
285  German  cities  and  toM'ns,  Avith  a  population  of  nearly  16,000,000, 
amounted  to  only  4.  In  the  same  year,  in  France,  where  vaccination 
is  not  universal,  there  were  600  deaths  in  116  communities  with  a 
population  of  8,500,000. 

In  Austria,  Hungary,  and  Belgium,  where  the  practice  is  nf)t  re- 
quired, the  death-rates  were,  in  1886,  respectively  81,  687,  and  48  times 
that  which  obtained  in  Germany.  In  Spain,  where,  also,  the  practice 
is  optional,  the  death-rate  in  six  provinces,  in  1889,  was  12,050  per 
million  against  one  of  4  per  million  in  Germany. 

In  Denmark,  where  vaccination  was  made  obligatory  in  1816,  not  a 
single  case  was  known  up  to  1826. 

In  Porto  Rico,  before  the  Sijanish  War,  the  annual  mortality  from 
smallpox  was  about  600  ;  but  since  the  wholesale  vaccination  by  the 
United  States  authorities,  the  disease  has  virtually  disappeared. 

In  all  countries  where  vaccination  has,  at  different  periods,  been 
optional  and  then  required,  a  remarkable  drop  has  occurred  both  in 
morbidity-  and  mortality-rates,  and  those  countries  in  which,  to-day, 
vaccination  is  not  compulsory,  suffer  periodical  visitations  of  the  dis- 
ease and  lose  thousands  of  lives.  In  1889,  for  instance,  the  death- 
rate  from  smallpox  in  Spain  was  nearly  as  great  as  obtained  a  century 
before  in  the  principal  countries  of  Europe,  while  in  the  same  year,  in 
Germany,  the  disease  was  practically  non-existent.  In  France,  in  the 
tw^enty-five  years  from  1870  to  1895,  more  than  20,000  people  died 
from  smallpox  in  Paris  alone,  the  epidemics  of  1871  and  1872  being 
exceptionally  severe  and  fatal.  No  epidemic  has  occurred  in  Germany 
since  1871,  when  the  disease  was  brought  in  by  French  prisoners, 
although  a  few  scattered  cases  have  appeared  occasionally. 

The  Director  of  Health  of  the  Philippines,  in  his  annual  report  for 
the  fiscal  year  1907,  states  :  ^  "  During  the  year  there  has  been  unques- 
tionably less  smallpox  in  the  Philippines  than  has  been  the  case  for  a 
great  many  years  previous.  In  the  provinces  of  Cavite,  Batangas, 
Cebu,  Bataan,  La  Union,  Rizal,  and  La  Laguna,  where  heretofore 
there  have  been  more  than  6000  deaths  annually  from  this  one  cause 
alone,  it  is  most  satisfactory  to  report  that  since  the  completion  of  the 
vaccination  in  the  aforesaid  provinces,  more  than  a  year  ago,  not  a 
single  death  from  smallpox  has  been  reported.  So  thoroughly  are  the 
Philippines  saturated  with  the  contagion  of  smallpox  that  probably  25 
per  cent,  of  the  residents  would  soon  succumb  to  this  disease  if  it  were 
not  for  the  ability  to  protect  the  inhabitants  against  it  by  vaccination." 

1  Quoted  by  Trask,  American  .Journal  of  Public  Hygiene,  Vol.  XX.,  No.  1,  Feb., 
1910. 


VACCINATTON  ANT)  SMAIJ.I'OX. 


817 


III  spiles  <»("  ilic  i'ciii;iil<;il)lf  (fstiiiioiiy  (■(Hicfniinp  I  In  \;iliic  dC  v;ir- 
cination  in  Mi;il<iii^  ii,  r;iri(v  oC  \\li;i(,  waH  oikc  one  of  I  Ik-  piiiKipal 
H('(»iir<;('S,  \hvxv.  !ir(!  in  this  coiinlrv  hihI  in  oflicrs  wlicrc  laws  c-funjir-llinj^ 
v;M^(unMli(»n  luivc  hccn  cnMcfcd,  iiniiicroiis  riiiMjrniflcd  individual.-  who 
band  tlicinscKcs  looctlicr  inlo  .'i  lit  i-\;icciii;i(  ion  |f;i|riics  and  aft<'tnf)t  U> 
create.  ;i.  |M>|nil;ir  ;iiil;iniiiii,-,iii  to  llic  |»i:iclicc  ;iii<|  ff»  f{\'i-c\  rcfwal  of 
existing-  laws.  In  Faitjjland,  ;is  li:is  liccn  noted,  they  havn  Iwon 
partiiilly  sncccssfnl  in  coinpcllina;  the  p.-issn^c  of  a  l;i\v  wliicli  cxetnptH 
parents  who  have  "  consciciilions  scniplcH"  :ifrain.'«f  having.'  ihcir  chil- 
dren vaceinaled.  In  progressive  .Japan,  where  tlu;  government  lisw 
decided  io  coiii|»el  \';iceiiialionbcfbr(! thea^c  of"  fen  nionths,  and  revae- 
eination  at  I  lie  at;'c  of  .'-i.x  and  aL^'iin  at  twelve,  the  anti-vaeeiiiationlHt 
is   unknown. 

Tlu!  tbllowinji;  fable  shows  flic  smallpox  niortalify  of  the  several 
conntries  named,  in  which  vaccination  is  cither  not  comi)n].sorv  or  irn- 
porfectly  pcrtbrmed,  as  compared  with  that  ot'Ticrmany,  which  in  each 
year  is  represented  by  1  : 


Switzerland 

England  . 

France    .  . 

Austria  .  . 
Belgium 

Holland.  . 

Germany  . 


1898. 

1894. 

1895. 

1896. 

8 

96 

3 

17 

24 

108 

19 

23 

34 

261 

201 

1,176 

67 

132 

28 

177 

158 

145 

25 

57 

640 

81 

147 

i 

1 

1 

1 

1897. 


1898. 


16 
123 
247 

21 

7 
1 


25 
4 

22 
121 

86 
5 
1 


1889. 


42 
231 

67 
174 


It  cannot  be  claimed  that  vaccination  confers  absolute  immunity 
against  smallpox,  but  it  is  true  that  those  who  have  been  vaccinated 
and  then  acquire  the  disease  have  it  in  a  much  milder  form  and  are 
more  likely  to  recover  than  those  who  have  not  been  vaccinated.  In- 
vestigation of  11,036  cases  of  smallpox  in  England  showe<l  that,  for 
unvaccinated  and  vaccinated  cases,  the  I'ates  of  mortality  were  respec- 
tively 36.6  and  5.2  per  cent.,  and  that  for  all  cases  in  children  under 
ten,  the  rates  were  respectively  36.2  and  2.7  per  cent.  Among  those 
stricken  during  the  epidemic  at  Warrington,  England,  in  1891—92, 
21.8  ])er  cent,  of  the  eases  in  vaccinated  persons  were  confluent,  while 
among  the  unvaccinated  cases,  the  percentage  was  70. (j.  In  the  Shef- 
fleld  epidemic  of  1887—88,  1.55  per  cent,  of  vaccinated  and  0.7  of 
unvaccinated  persons  were  attacked.  Among  the  former,  the  death-rate 
was  0.7,  and  among  the  latter,  48  per  thousand.  Among  children 
under  ten,  the  rate  of  attack  was  o  and  101  per  thou.-^and,  resjiectively, 
for  vaccinated  and  unvaccinated,  and  the  death-rate  was  0.09  and  44. 

The  protection  conferred  by  vaccination  is  greatest  during  the  year 
succeeding  the  operation,  and  appears  to  diminish  gradually  during  the 
succeeding  five  or  six  years  ;  but  the  moditying  jiower  does  not  di- 
minish equally  fast.  The  protective  influence  can  be  reestablished  by 
a  repetition  of  the  operation,  and  during  epidemics,  or  when  about  to 
visit  eoimtries   where  vaccination    is    not  practised   and    smallpox   is 

5? 


818  VACCINATION  AND  SMALLPOX. 

endemic,  revaceination  is  always  advisable.  If  the  operation  is  negative 
in  its  results,  the  indiviilual  is  regiirded  as  iinnnme  or  partially  pro- 
tected; but  iu  the  case  of  a  first  vaccination,  it  is  customary  to  repeat 
the  operation  until  success  is  attained.  In  most  civilized  countries, 
vaccination  is  not  postponed  until  an  outbreak  of  smallpox  occurs, 
but    is  attended  to  in  the  first  few  months  of  life. 

Successful  primary  vaccination  within  three  days  after  exposure  to 
existing  cases  of  smallpox  will  prevent  tlie  development  of  the  disease, 
and  as  late  as  the  fifth  or  sixth  day  will  either  prevent  or  modify  an 
attack.  This  fact  has  been  utilized  in  many  cases  where  smalljiox  has 
broken  out  among  unprotected  people  with  a  prospect  of  unlimited 
spread,  and  has  been  the  means  of  ending  epidemics  with  some  sud- 
denness. Thus,  for  example,  at  Gloucester,  England,  in  1895,  after 
eight  years  of  practical  abandonment  of  compulsory  vaccination,  that 
is  to  say,  of  neglect  on  the  part  of  the  authorities  to  enforce  the  law, 
an  epidemic  of  smallpox  occurred  in  what  was  practically  an  unvac- 
cinated  community.  The  cases  increased  at  such  a  rate  that  great 
alarm  was  felt  and  extensive  measures  were  taken  for  general  vaccina- 
tion. In  the  closing  weeks  of  1895,  31  cases  occurred.  In  January, 
28  more  were  reported.  In  February,  tlie  number  increased  suddenly 
to  146,  and  during  March,  to  644.  Toward  the  last  of  that  month, 
the  authorities  gave  directions  for  enforcement  of  the  law,  and  work 
was  begun;  but  during  the  following  month,  no  less  than  744  cases 
occuiTcd.  During  the  last  days  of  April,  a  committee  undertook  general 
vaccination  of  the  city,  and  within  a  very  few  days,  every  house  had 
been  visited ;  by  the  end  of  June,  the  city  had  been  converted  from  a 
practically  unvacciuated  city  to  the  best  vaccinated  in  the  country. 
Nearly  36,000  persons  were  operated  upon ;  the  epidemic  began  at 
once  to  decline,  and  before  August  had  disappeared.  Nearly  450  per- 
sons, however,  had  died,  and  1,600  others  who  survived,  bore  the 
usual  lasting  evidence  of  the  disease  in  their  faces. 

As  showing  the  influence  of  revaceination,  the  following  figures 
from  a  study  of  the  statistics  of  the  Sheffield  epidemic  are  presented : 

Rates  of  attack  per  1,000  persons. 

Pei-sons  not  vaccinated      94 

Persons  once  vaccinated 19 

Persons  twice  vaccinated 3 

Death-rates  per  1,000  persons. 

Persons  not  vaccinated       51 

Pei-sons  once  vaccinated 1 

Persons  twice  vaccinated 0.08 

Similar  facts  are  yielded  by  investigation  of  all  epidemics  where 
there  is  a  large  class  of  vaccinated  and  another  of  unvaccinated 
persons,  and  yet  anti-vaccinatiouists  still  agitate  and  find  sympathetic 
listeners  to  their  arguments.  One  of  their  favorite  charges  is  that 
vaccination  not  only  has  had  nothing  to  dc»  with  the  decline  in  the 
amount  of  smallpox,  but,  on  the  contrary,  gives  rise  to  other  diseases. 
It  is,  indeed,  true  that  syphilis  has  been  conveyed  from  one  to  another 


VAddNA'nON  AND  .SMAI.IJ'OX.  819 

thrr)iifi:;li  ilic  prnrlicc  of  vJU'ciiKition,  Imt  ;il  flu;  pn'-ciil.  liiru;  tlif;  (lari^'f-r 
i*H  |)rii<^li<r:illy  ////,  ■Auvi'  jii'iii-to-anii  v;irciii;i(ioii  Ikik  fjilhii  info  flihiisc  ; 
but  while,  tlui  nrin-io-urin  prnclic-o  wuh  coiitiiiiicd,  tlu-rc  W(;n;  fu'rahifituil 
iiiHtJiiiccH  of  ^I'MVc  inilll•^'.  Tliiis,  soitic  yc-urH  niiKU',  if  li!i[)[)('i)f<l  that  a 
oom|);iiiy  (»('  I'^rciicli  iiil';iiili\ ,  |»iior  (o  hcin^  Hcnt,  to  Aly-irTH,  waH 
ViKU'iiiiifcd  \)\  fli(!  ;inii-lo-jiriii  mclliod,  mikI  very  ni;iii\'  of  flic  mcii 
WiU'e  (Jicrchy  iiio<'iil;ifc(l  wifii  sy))liilis. 

PiinsutH  Jirc  pi'oiic  lo  ;iscril)c  lo  \;ic(iii;i( ion  cscry  (liHturljuiicf!  whirh 
a  f'liild  niiiy  sulH'i-,  |);irliciij;irl\  if  iIhic  be  any  futaiiconK  cnipfirm. 
Soiiu'fimcM  -A  vcsicuilar  or  pnsfni.'ir  i:i-li  may  of!(;iir  aiui  spn-a<l  fnuii  llic 
\':i('ciiiMl('<l  arm  (o  ollicf  parts  oC  llic  l»o(ly  ;  somcfimcs,  ('rysi|iclas  and 
other  infections  occur  at  the  |)oint  of  \accinat ion  ;  hnf  tlies<-  are  no 
mor((  likely  to  oecnr  as  a  i-csiiil  of  \;icciiiat  i<iii  than  of  any  other  int^T- 
i'erenco  with  the  inte<jji'ity  of  the  skin.  Persons  of  dirty  hal)its,  livinfr 
in  nndcan  snn'oun(lin<;s,  are  more  likely  than  others  to  Kuffer  from 
ulceration  of  the.  vesicle!  and  Ironi  other  local  disturhanees  not  due  to 
the  influence  of  flie  virus  itsell". 

With  regard  to  the  assertion  that  the  three  weeks  following  vaccina- 
tion are  a  period  of  unusual  danger  from  tiie  various  zymotic  diseases, 
the  results  of  extensive  study  by  Dr.  Voight,  Director  of  Vaccination 
at  iraniburg,  are  of  interest.  According  to  his  records,  the  reverse  (jf 
this  assertion  is  true,  for  the  process  appears  to  exert  a  restraining 
influence  upon  the  development  of  practically  all  of  the  infectious  dis- 
eases. According  to  Dr.  J.  M.  Mackenzie,'  scarlet  fever,  whf)Oping 
cough,  influenza,  and  syphilis  are  favorably  influenced,  tuberculosis 
and  enteritis  may  be  unfavorably  influenced,  and  latent  eczema  and 
impetigo  may  be  excited. 

In  revaccination,  if  the  individual  has  become  again  wholly  sus- 
ceptible, the  local  manifestations  occur  earlier  than  in  the  primary  vac- 
cination, and  the  general  symptoms  are  usually  much  more  marked. 

^  British  Medical  Journal,  August  15,  1903. 


CHAPTER   XVIII. 
QUARANTINE. 

Quarantine  is  a  term  of  wide  sigiiiiicatiou.  Derived  from  the 
FreHch  quarante,  forty,  its  original  meaning  had  reference  to  the  num- 
ber of  days'  detention  to  which  vessels  and  their  personnel,  arriving 
from  places  infected  or  suspected  of  being  infected  with  tlie  plague, 
were  subjected  in  places  set  apart  for  the  purpose,  to  insure  against  the 
introduction  of  the  disease  into  the  country  or  port  of  arrival. 

The  usual  definitions  of  the  term  which,  in  a  composite  form,  may 
be  given  as,  "The  enforced  detention  of  vessels,  their  personnel,  and 
cargoes,  arriving  from  infected  ports,  or  having,  or  being  supposed  to 
have,  cases  of  certain  infectious  diseases  on  board,  and  interdiction  for 
a  fix^d  period  of  time  of  all  communication  therewith,"  are  wholly  in- 
adequate under  present  conditions.  Far  more  accurate  and  compre- 
hensive is  that  given  by  Dr.  Walter  Wyman,  U.  S.  P.  H.  and 
M.-H.  S.  :  "  The  adoption  of  restrictive  measures  to  prevent  the  intro- 
duction of  diseases  from  one  country  or  locality  into  another,"  for  the 
original  meaning  is  now  quite  lost.  To-day,  we  speak  of  port  quaran- 
tine, land,  interstate,  railroad,  munit;ipal,  house,  and  room  quarantine. 
Restrictive  measures  are  not  adopted  solely  against  human  diseases, 
but  also  against  those  of  the  lower  animals .  (cattle  quarantine),  and 
even  of  certain  fruits  and  other  important  crops. 

The  necessity  of  restrictive  measures  in  certain  cases  has  long  been 
recognized  ;  in  fact,  in  the  case  of  leprosy,  from  earliest  times.  The 
first  enactment  providijig  for  the  detention  and  isolation  of  travellers 
from  infected  places  dates  back  to  the  fifteenth  year  of  the  Emperor 
Justinian  (a.  d.  542),  but  quarantine  in  the  modern  sense  had  its 
origin  in  the  fourteenth  century  in  Italy,  where,  on  account  of  the 
ravages  of  the  plague,  local  authorities  at  different  times  adopted  pre- 
ventive measures.  Thus,  Florence  and  Venice,  in  1348  ;  Lombardy, 
1374;  Milan,  1399. 

The  first  maritime  quarantine  was  instituted,  in  t403,  at  Venice. 
A  lazaret,  the  house  of  St.  Lazarus,  was  founded  on  a  small  island, 
and  all  persons  from  the  Levant  were  there  detained  for  forty  days 
before  admissionvto  ^"he  city.  The  restrictive  measures  enforced  at 
Mediterranean  ports  and  elsewhere,  were  for  many  years,  and  at  some 
places  now  are,  unreasonable,  harsh,  useless,  and  a  great  injury  to 
trade.  Most  of  the  leading  countries  have,  for  a  long  time,  been 
strongly  opposed  to  the  oppressive,  arbitrary,  and  irrational  quaran- 
tine measures,  and  have  now  adopted  rules  and  regulations,  which, 
w'hile  effective  as  far  as  can  be  hoped  for  or  expected,  impose  the  least 

820 


(iHAIlAiS'TISE.  821 

|)(»Hsil)l(!  i'(!Mf,r'i(!lI()nH  upon  |i('i~oii:il  lilici-l y  and  fi-;i(l<-.  'Ilic  «lan^'<r  iw 
(!M(.inial('(l  a(^(;or<lin^  lo  iJic  condition  ol'  licaltli  ol  tlic  port  of  <l<'par- 
tur(!,  and  lliis,  with  tli(!  Hiiiiilury  history  of  tlic  vohhj;!,  ii|i  to  (Ik-  time 
of  arrival,  dclcrniincs  wliaf  incaHiircs,  if  any,  ;\.vo.  to  \h'.  tjikcn. 

'^riic.  p('i'io(ls  of  dctihlion  an;  fix(!(l  vvifli  rcfcn^tirc  to  tli(;  prol)al»l<"  in- 
(Mihalivc  pciiod  of  llic  disease;  in  (|ncsti(»n,  and  fjncHtiftns  of  ru-crcrihity 
of  disinft'c^lion,  and  of  niclliods  t«»  Ixi  followed  in  (-arrying  ont  tlu;  Hurnc, 
are  det(!rinined  l»y  the  eirennistjuuK^.s  of  eaeji  indi\idnal  Cinni.  C^iiar- 
jintincs  administered  witli  reason  do  iii\  alnaldc;  work  in  wiftin^  out 
infcM^tlon  and  protec-ting  the  pnl)li<-  li(allh  IVoni  exotic;  diw^iwjH,  wliieii, 
in  tli(!  al)sen(;(!  of  precautionary  in<'asures,  inij^lit  easily  ^'^lin  aecesH. 
At  the  same  time,  they  act  in  restraint  of  tra<le  to  the  sii^litest  jKwsible 
extent,  since  uninfected  vessels  are  not  unnecessjirily  det^iined. 

Unfortunately,  not  all  quarantines  are  administered  with  reason, 
and  it  often  hap|)ens  tiiat  \i:yv\\i  injusti(!c  and  unnecessary  ex)X'nse  are 
caused  hy  absurdly  tenacious  adherence  to  exploded  theories  and  routine 
practice.  As  an  example,  may  l)e  cited  the  case  of  the  J/e/cnc,  a  Ger- 
man vessel,  which,  arriving  in  an' English  port  in  August,  1893,  with 
two  cases  of  cholera,  was  disinfected  and  given  free  pratique  ;  nine 
months  later,  she  was  refused  pratique  at  a  South  Americiin  l>'>rt, 
because  in  P^ngland  she  had  not  been  held  for  a  definite  j>erir)d  at  quar- 
antine. As  an  example  of  quarantine  absurdity  of  a  minor  character, 
but  indicative  of  what  might  be  imposed  in  ease  opportunity  presented 
itself,  may  be  cited  an  experience  witli  the  municipal  authorities  at  a. 
Southern  port,  who  required  thorough  disinfection  oi'  a  Ijarrel  of  car- 
bolic acid  before  it  w^as  allowed  to  be  landed. 

Far  more  and  almost  incredibly  absurd  is  the  following  instance  :  On 
November  3,  1893,  the  steamship  Caho  Machichaco,  laden  in  part  with 
dynauAte,  blew  up  at  her  dock  at  Santauder,  Spain,  after  having  been 
on  fire  for  some  hours.  The  burning  cargo  was  thrown  about  in  all 
directions  and  started  a  general  conflagration.  It  happened  that  the 
entire  fire  department  was,  at  the  time  of  the  explosion,  engaged  in 
attempting  to  overcome  the  fire  raging  in  the  ship's  hold,  and  in  the 
ex]>losi(Hi  was  completely  wrecked.  Word  was  sent  to  Bilbao,  and  aid 
was  urgently  requested.  Two  steamships  were  sent  with  fire  engines, 
firemen,  surgeons,  nurses,  laborers,  and  others,  and  arrived  in  six 
hours.  The  provisional  governor  refused  to  jiermit  the  vessels  to  dock 
and  discharge  the  much-needed  apparatus  and  other  aid,  because  quar- 
antine had  not  been  observed,  and  he  insisted  that  they  should  comply 
with  the  regulations,  which  would  involve  several  days'  detention  out- 
side the  harbor.  It  was  several  hours  before  a  way  was  found  to 
overcome  the  strict  interpretation  of  the  rules. 

The  first  action  taken  by  any  official  organization  in  this  country 
looking  to  the  establishment  of  a  uniform  system  of  quarantine  regu- 
lations was  at  a  conference  of  boards  of  health  at  Philadelphia  in  1857, 
called  on  account  of  the  excitement  caused  by  the  breaking  out  of  yellow 
fever  at  Bay  Ridge  in  the  previous  year ;  but  in  spite  of  this  and  other 
attempts,   the  various  quarantines  of  the  country   were  administered 


822  QUARANTINE. 

with  no  uniformity  until  after  the  passage  of  the  Act  of  FeT^ruary  15, 
1893,  entitled  '^  An  Act  granting  additional  quarantine  powers  and 
imposing  additional  duties  upon  the  INIarine  Hospital  Service."  This 
act  established  a  national  system  of  quarantine,  but  in  no  way  limited 
State  and  municipal  authorities  in  their  right  to  prescribe  and  enforce 
additional  measures ;  and,  indeed,  it  is  beyond  the  power  of  Congress 
to  interfere  with  local  authorities  so  long  as  the  minimum  requirements 
of  the  national  law  are  complied  with. 

Quarantine  Law  of   1893. 

Section  1  makes  it  unlawful  for  a  vessel  from  a  foreign  port  to  enter 
any  port  of  the  United  States,  except  in  accordance  with  the  provisions 
of  the  act  and  Avith  such  rules  and  regulations  of  State  or  nuinicipal 
health  authorities  made  in  pursuance  of  or  consistent  therewith,  under 
penalty  of  not  exceeding  $5,000. 

Section  2  provides  that  a  vessel  at  a  foreign  port,  clearing  for  any 
port  in  the  United  States,  shall  obtain  from  the  consular  or  medical 
officer  of  the  United  States  at  that  place  a  bill  of  health  in  duplicate, 
in  the  form  prescribed  by  the  Secretary  of  the  Treasury,  setting  forth 
its  sanitary  history  and  condition,  and  that  it  has  complied  with  the 
rules  and  regulations  prescribed  for  securing  the  best  sanitary  condi- 
tion of  the  vessel  and  its  cargo,  passengers,  and  crew.  Penalty  for 
clearing  and  sailing  without  such  bill  of  health  and  entering  any  port 
of  the  United  States,  not  exceeding  $5,000.  By  an  amendment 
approved  August  18,  1894,  it  is  provided  that  the  provisions  of  this 
section  shall  not  apply  to  vessels  plying  between  foreign  ports  on  or 
near  the  frontiers  of  the  United  States  and  ports  of  the  United  States 
adjacent  thereto.  But  the  Secretary  of  the  Treasury  is  authorized, 
when,  in  his  discretion,  it  is  expedient  for  the  preservation  of  the 
public  health,  to  establish  regulations  governing  such  vessels. 

Section  3  directs  the  Supervising  Surgeon-General  of  the  U.  S. 
Public  Health  and  Marine-Hospital  Service  to  cooperate  with  and  aid 
State  and  municipal  boards  of  health  in  the  execution  and  enforcement 
of  the  rules  and  regulations  of  such  boards  and  of  those  made  by  the 
vSecretary  of  the  Treasury  to  prevent  the  introduction  of  contagious  or 
infectious  diseases  into  the  United  States  and  into  one  State,  Territory, 
or  the  District  of  Columbia  from  another. 

It  provides  that  all  rules  and  regulations  made  by  the  Secretary  of 
the  Treasury  shall  operate  uniformly  and  in  no  manner  discriminate 
against  port  or  place.  Where  no  State  or  municipal  quarantine  regu- 
lations exist,  and  in  the  opinion  of  the  Secretary'  of  the  Treasury  are 
necessary  to  prevent  the  introduction  of  such  diseases,  and  M^here 
existing  regulations  are  in  his  opinion  insufficient,  he  shall  make  such 
additional  rules  and  regulations  as  he  may  deem  necessary,  and  they 
shall  be  enforced  by  the  respective  sanitary  authorities ;  failing  which, 
the  President  shall  execute  and  enforce  the  same  and  adopt  such  meas- 
ures as   in   his  judgment  are  necessaiy,  and    may  detail  or  appoint 


QlfAnANTlNJ'J  LAW  OF  ixtifi.  «2.''» 

officicrH  for  iliut  i)ur|>()H(!.  TIk;  S(;c,r(!liiry  of  \\\i'.  TrciiHiiry  hIuiII  iiiak'- 
siicJi  rules  ;iii<l  rcfriihitioiiH  ;is  '.wv  iicccsHury  to  Ik-  ol)-crv<'<I  Wy  vr-hx-in 
;i(    llic  ynvi  oC   <lr|i;ii(  iiiv  ;in<l   on   lin'  VOyu^<!,  </»  Kcciii'c  l||c    bcHt  HUniUiry 

coiKJilJoii  of  Uiciiisclv<'-,  tli'ii'  r.iiMocH,  |>:i,sH(Mij^<'rK,  :iii<l  crcWH. 

S(H',ti()n  I  iiiakcH  \\  incnnil.i  nl  «>ii  I  Ik;  .SupcrviHluj;  Sur^e<>H-(jr«;nr'raI 
U)  |)(!r('(>nn  ;ill  llic  diilics  in  respect  to  (|ii:iniiit  iric  ami  (|ii:irantiiin  n-^rn- 
liiiioiiK,  !iii(l  to  ol)t:iiii  iiiCoriiiMtion  tlintii^li  coiisiihir  ofliccrs  of  tin;  sani- 
tary eondilion  oC  Corci^in  ports  :ni<l  places  from  wliieli  conta^^ioiis  and 
inCec^tions  <lise;ises  arc  oi'  iniiy  !><'  ini|)or<x;<l  into  the  rnit<'(l  StJit<-H.  'I'lic 
SecHitary  of  tlic  Tnjjistiry  is  rccpiircid  to  obtain  thn»n}.di  all  availabN? 
sources,  inc^ludini;  Stnte,  and  municipal  sanitary  authorities  throu^dif,ut 
the  United  States,  weekly  r(;|)orts  of  the  sanitary  condition  of  jxjrts 
and  plnces  within  the  United  States,  to  tnmsinit  to  collcctorH  of  cuh- 
tonis  and  to  State  and  municipal  health  oHieers  and  other  sanitarianH 
weekly  ahstnuits  of  th(!  cousuhu'  sanitary  reports  and  other  ])ertiiiont 
iuformatiou  received  hy  him,  to  procure,  throufrh  all  available  sourr^is, 
public  or  private,  information  relatiiif^  to  climatic  and  other  conditions 
aifcctin<r  the  public  health,  and  to  make  an  annual  rejwrt  to  Congress, 
with  such  recommendations  as  he  may  deem  im])ortant  to  the  public 
interests. 

Section  5  provides  for  the  issuance  from  time  to  time  to  the  United 
States  consular  and  medical  ollicers  at  the  various  foreign  j)orts,  of  the 
rules  and  regulations  made  by  the  Secretjiry  of  the  Treasury  to  be 
used  and  complied  with  by  vessels  in  foreign  ])orts  for  securing  the 
best  sanitary  conditions  before  dej)arture  for  the  United  States,  and  in 
course  of  the  voyage,  and  of  all  other  rules  and  regulations  as  shall  be 
observed  in  inspection  on  arrival  at  any  quarantine  station  and  for  dis- 
infection and  isolation,  and  treatment  of  cargo  and  persons  on  board,  so 
as  to  prevent  the  introduction  of  cholera,  yellow  fever,  and  other  con- 
tagious or  infectious  diseases.  No  vessel  shall  enter  a  port  or  dis- 
charge its  cargo  or  land  its  passengers  except  upon  a  certificate  rtf  the 
health  officer  at  such  quarantine  station  that  the  rules  and  regulations 
have  in  all  respects  been  observed  and  complied  with  both  by  him  and 
by  the  master  in  respect  to  the  vessel  and  its  cargo,  jiassengers,  and 
ere\v.  The  master  is  required  to  deliver  to  the  collector  with  the 
other  papers  of  the  vessel,  the  bills  of  health  obtained  at  the  port  of 
deixirture  and  the  certificate  above  mentioned. 

Section  6  provides  that  on  the  arrival  of  an  infected  vessel  at  any 
port  not  provided  with  proper  fai'ilities  for  treatment,  the  vessel  shall 
be  remanded  at  its  oavu  ex]>ense  to  the  nearest  national  or  other  quar- 
antine station  where  accommodations  and  appliances  are  provided  for 
the  necessary  disinfection  and  treatment  of  vessel,  passengers,  and 
cargo.  After  treatment  of  such  vessel  and  after  certificati<Mi  by  the 
United  States  quarantine  officer  that  vessel,  cargo,  and  passengers  are 
free  from  infectious  disease  or  danger  of  carrying  the  same,  the  vessel 
shall  be  admitted  to  entry  at  any  port  of  the  United  States  named  in 
the  certificate.      But  at  ports  where  sufficient  quarantine  provision  has 


824  QUARANTINE. 

been  made  by  State  or  local  authorities,  the  Secretary  of  the  Treasury 
may  direct  the  uudergoiug  of  quarautiue  at  said  statiou. 

Sectiou  7  provides  that  whenever  the  President  is  satisfied  tliat  by 
reason  of  the  existence  of  cholera  or  other  infectious  diseases  in  a 
foreign  country  there  is  serious  danger  of  the  introduction  of  the  same 
into  the  United  States,  and  that  notwithstanding  tlie  quarantine  defence 
this  danger  is  so  increased  by  the  introduction  of  persons  or  property 
from  such  country  that  a  suspension  of  the  right  to  introduce  the  same 
is  demanded  in  the  interest  of  the  public  health,  he  shall  have  power  to 
prohibit,  rn  \\hule  or  in  part,  the  introduction  of  persons  and  ])roperty 
from  such  countries  or  places  as  he  may  designate;  and  for  such  period 
of  time  as  he  may  deem  necessary. 

Sections  8  and  9  are  of  no  sanitary  interest. 

In  accordance  with  the  provisions  of  this  act,  certain  rules  and  regu- 
lations to  be  observed  at  foreign  ports  and  at  sea  and  at  ports  and  on 
the  frontiers  of  the  United  States  have  been  adopted  and  amended  and 
added  to  as  occasion  has  made  it  necessary  or  advisable.  These  rules 
are  subject  to  very  material  modifications  or  additions,  based  on  a  wider 
knowledge  of  the  causes  of  disease,  modes  of  infection,  etc.,  and  thus 
what  may  be  law  today  may  be  superseded  tomorrow.  Thus  the  very 
strongest  regulations  with  regard  to  yellow  fever,  which  were  made 
before  the  method  of  its  dissemination  was  known,  and  with  the 
idea  that  infection  could  be  conveyed  by  fomites,  merchandise,  bag- 
gage, etc.,  will  undoubtedly  be  changed  completely  in  consequence  of 
the  discovery,  by  Reed  and  his  associates,  that  infection  cannot  thus  be 
conveyed.  It  is  only  reasonable,  in  view  of  their  work,  that  quaran- 
tine restrictions  upon  passengers  and  cargoes  from  non-infected  ports 
should  be  very  greatly  modified,  and  that,  in  each  instance  of  vessels 
from  infected  ports,  the  incubative  period  of  the  disease,  the  possibility 
of  the  presence  of  infected  mosquitoes  on  board,  and  the  length  of  time 
a  mosquito  requires  for  the  acquirement  of  dangerous  properties,  should 
be  kept  in  mind.  Reed  believes  that  a  vessel  at  an  infected  ])ort  can 
be  loaded  in  midstream  by  lighters,  and  can  then  become  infected  only 
by  persons  who  have  been  exposed  on  shore,  since  the  probability  of 
mosquitoes  reaching  the  ship  by  flying  or  by  lighters  is  very  slight. 
If,  then,  a  vessel  thus  loaded  arrives  at  its  destination  free  from  dis- 
ease, the  non-immunes  aboard  should  be  quarantined  not  longer  than 
five  days,  and  the  time  consumed  by  the  voyage  should  be  included  in 
this  period.  The  cargo  may  be  allowed  to  be  discharged  without  treat- 
ment or  delay.  But  if  the  disease  should  occur  while  between  ports, 
the  sick  should  be  removed,  the  sleeping  quarters  disinfected  with 
sulphur  dioxide  in  order  to  destroy  all  mosquitoes,  and  then  the  vessel 
should  be  allowed  to  dock.  Under  some  circumstances,  it  may  be 
necessary  to  fumigate  the  hold,  for  mosquitoes  may  be  there  in  an 
active  condition  ;  although,  unless  they  have  access  to  moisture,  they 
will  not  live  longer  than  five  or  six  days.  Rosenau  has  kept  them 
alive  in  trunks  for  ten  days  and  longer,  but  moisture  was  provided. 

If  mosquitoes  are  found  on  board  a  vessel  from  an  infected  port,  the 


QJIAIiANTINI':   LAW   Oh'  IsufS.  825 

iioii-irnriiiMics  hIioiiI*!  Ix'  dcdiliic*!,  unless  mon;  fli;m  twenty  <lays  li;i\«' 
iilrcjuly  cl.'iiiscd  since  cIcMiinn.  'I'liis  period  will  he  siilVKMeiit  f<»  deriion- 
Htrat<^  liie  |»reseiiee  of  in  feel  Ion  in  I  lie  ni()Hf{llit()(rH,  by  tllO  0(;<MirrC'IUMr  of 
(!ilS(^s  diiiinj;'  I  lie  voyii^v.  If  more  lli:iii  tw(!lity  (liiy.s  have  elajtM'd,  tlien; 
(!iiM  \)v  no  dan<;'er,  and  neiilier-  passengers  nf)r  carj^o  shoidd  he  delain*^!, 

Sinco  IIk'  pnhliealion  oC  Reed's  residts  and  views,  many  ea'-e-  have; 
been  cited  in  (he.  medical  |)reHS  in  opposition  to  tin;  view  that  tlic  di.H- 
ease  cannot  be  .spread  by  ba^^^^a^;e,  fomit<!H,  and  car^ocw,  but  in  xm) 
instiUKH!  which  lias  lliiis  Car  lalleii  imkNt  th(!  anflior'n  obHorvation  (tan 
th(!  nios(|ni(<)  he  ignored.  Iii<leed,  in  many  oC  the  cas<'.s,  tin*  tliswiwi 
has  broken  oiil,  alter  an  un(!V(!ntf'nl  voyaj^e  jind  the  formalities  of" 
(quarantine,  in  |)laces  when;  the  .specific  yeihjw  iever  nio.s(jnito  i.s  known 
to  be  indigenous,  in  some  cases,  mention  is  made  of  the  fact  that,  in 
spite  of  the  very  nnmcrons  mos(|nitoes  presciiit  where  a  case  of  the  dis- 
ease has  been  brought,  no  extension  of  the  fever  has  been  ])rodiiced  ; 
but  it  is  not  stated  that  the  mcsquitoes  were  Stq/omyia  /(MciaUi,  which 
is  a  vital  point  in  the  arj^ument. 

In  view  of  the  jjrobable  extensive  changes  in  the  inles,  it  is  deemed 
best  not  to  reproduce  here  existing  rules  in  crtenso,  but  advise  one  to 
apply,  as  occasion  arises,  to  the  Treasury  Department  fV>r  a  j)rinted  copy 
thereof. 

As  they  stand  at  present,  the  regulations  prescribe  forms  for  bills 
of  health,  methods  of  inspection  of  passengers,  crew,  baggage,  cargo, 
food  and  water  supplies,  and  of  the  vessel  itself;  requirements  as  to 
cleanliness  of  vessels,  and  as  to  ventilation;  m(!thods  of  disposal  of 
bedding  ;  location  and  arrangement  of  the  "  sick  bay  " ;  what  may  not 
be  tidvcn  on  board  at  ports  infected  with  certain  diseases  ;  what  must 
be  di.siufected,  and  how ;  Avhat  persons  may  not  be  shipped,  and 
periods  of  detention  according  to  the  nature  of  the  disease  to  which 
they  have  been  exposed;  and  general  and  particular  rules  to  apply  in 
certain  cases.  The  regulations  prescribe,  also,  requirements  as  to  clean- 
liness and  ventilation  at  sea  ;  isolation  of  the  sick  ;  disinfection  and 
disposal  of  the  dead  ;  and  give  in  detail  the  methods  to  be  followed  in 
disinfection  of  all  parts  of  a  ship,  of  various  kinds  of  cargoes,  and  of 
personal  eifects. 

The  regulations  to  be  observed  at  ports  and  on  the  frontiers  of  the 
United  States  provide  for  the  establishment  of  quarantine  stations  at 
or  convenient  to  the  principal  ports  of  the  country,  and  prescril^e 
methods  of  inspection  according  to  the  circumstances  of  each  case,  as, 
for  instance,  for  vessels  from  healthy  or  infected  ports,  and  for  vessels 
suspected  of  being  infected  with  plague  or  yellow  fever.  Quaran- 
tinable  diseases  are  named  as  follows  :  cholera  and  cholerine,  yellow 
fever,  smallpox,  typhus,  leprosy,  and  plague  ;  and  rules  are  laid  down 
for  the  government  of  vessels  on  which  any  of  these  diseases  have 
occurred  (hiring  the  voyage,  and  for  the  treatment  and  detention  of 
passengers,  crew,  bagg-age,  and  cargo. 

Following  the  passage  of  the  quarantine  law  of  1S93  and  the 
promulgation  of  the    regulations   made    in   accordance    therewith,   at 


826  QUARANTINE. 

many  ports  the  quarantine  service  was  surrendered  voluntarily  to  the 
national  government,  and  at  others  it  was  taken  over  by  the  same  au- 
thority, because  of  non-compliance  with  the  regulations.  At  others, 
the  regulations  have  been  ado])ted  and  efficiently  enforced  by  the  local 
authorities,  but  these  and  all  others  are  inspected  regularly  by  the 
Public  Health  and  Marine-Hospital  Service,  to  insure  efficiency  of 
administration  aud  correction  of  faults  in  methods  and  defects  in 
ap])liauces. 

In  1900,  there  were  in  the  United  States  no  less  than  120  quaran- 
tine and  inspection  stations,  of  which  number,  81  were  on  the  Atlantic 
coast,  17  on  the  Pacific  coast,  and  22  on  the  Gulf  of  Mexico.  They 
vary,  naturally,  very  widely  in  importance  and  equipment,  the  most 
important  one  beiug  that  of  New  York,  the  chief  gate  of  entrance  of 
immigrants  aud  of  foreign  commerce,  and  the  least  important  being 
several  with  practically  no  arrivals  of  vessels  from  foreign  ports. 
Only  a  small  proportion  are  equipped  with  extensive  disinfecting  ap- 
pliances, aud  but  8  are  provided  with  quarters  for  the  detention  of 
persons   held  for  observation. 

Interstate  Quarantine. 

To  prevent  the  introduction  of  contagious  diseases  from  one  State  to 
another.  Congress,  on  March  27,  1890,  passed  an  Act  providing  that 
whenever  the  President  is  satisfied  that  cholera,  yellow  fever,  small- 
pox, or  plague  exists  in  any  part  of  the  United  States,  and  that  there 
is  danger  of  the  spread  thereof  into  other  States,  Territories,  or  the 
District  of  Columbia,  he  is  authorized  to  cause  the  Secretary  of  the 
Treasury  to  promulgate  such  preventive  rules  and  regulations  as  he 
may  deem  necessary,  and  to  employ  such  inspectors  and  other  persons 
as  may  be  necessary  to  enforce  them. 

These  rules  and  regulations  shall  be  prepared  by  the  Supervising 
Surgeon-General  of  the  Public  Health  and  Marine-Hospital  Service, 
under  the  direction  of  the  Secretary  of  the  Treasury,  and  any  violation 
thereof  entails  a  fine  of  not  exceeding  $500,  or  imprisonment  for  not 
more  than  two  years,  or  both,  in  the  discretion  of  the  Court.  In  the 
case  of  any  officer  or  other  person  employed  to  prevent  the  spread  of 
said  diseases,  wilful  violation  of  any  of  the  quarantine  laws  of  the 
United  States  or  of  any  of  the  rules  and  regulations  made  and  promul- 
gated as  above,  or  of  any  lawful  order  of  his  superior  officer  or  officers, 
the  penalty  is  a  fine  not  exceeding  $300  or  imprisonment  for  not 
exceeding  one  year,  or  both,  in  the  discretion  of  the  Court.  Any 
common  carrier  or  servant  thereof  who  shall  wilfully  violate  any  of  the 
same,  shall  be  liable  to  a  fine  of  not  exceeding  $500,  or  imprisonment 
for  not  exceeding  two  years,  or  both,  in  the  discretion  of  the  Court. 

State  Quarantine. 

The  national  quarantine  law  and  the  rules  and  regulations  made 
thereunder  are,  as  has  been  said,  intended  only  as  minimum   require- 


STATI-:  qi  J  AHA  NT  INK.  827 

monts,  to  vvlii<^li  St'iic!  or  iniiiiici|):il  iiiilliorily  may  rnako  siidi  a<l<litioiiH 
as  may  be  dcdiicd  lU'ccHsary  I'ti-  the  pri'sci'valioti  of"  \\\v.  Iic^iltli  of  i\w. 
p(!opl<!  wilJiiii  ils  jiiri.s(li(!lioii.  Siidi  addil ioiml  i(<|iiirein('ntH  may  1)0 
ostablisluid  ("oi-  s|K'cifi(;  periods  or  wiflioiit  limit  ol'  time,  and  to  m<«d 
{general  (!oiidilioiiH  or  a  special  class  of  eases.  Ah  an  e,\am|»le  of 
special  re<j;'ida.(ioris  made  ['i>y  a  llmilid  p(  ri(jd,  ili<'  following-,  ad(»pte<l  by 
the  Stat(!  Hoard  of  lleallli  ol"  l>oiiisiaiia,  with  releTeiic«;  to  vessels  cn- 
^'A\r,vx\  in  the  tropical  iriiit  trade;  durinjr  tin;  Heason  of  1899,  may  l>e 
eited. 

"All  vessels  eno-a^cd  in  (lie  tropical  I'niit  trade  between  Central 
Ameriean,  South  Amcriean,  and  West  Indian  ports  and  New  Orleanw 
will  bo  allowed  to  pass  tiio  MisslHsipjn  Jiiver  (inarantine  Stjition  with- 
out detention  Ion<^er  than  is  m^eessaiy  for  a  thoron^di  inspection  by  day 
by  the  (piarantine  ol1i(u'rs,  so  lonjr  as  a  proj)erly  aeer<;dit<'d  me<lieal 
aji^ent  of  this  board  (U'rtilies  that  such  ports  and  places  are  free  from 
eontiij2;ious  or  infectious  disease,  and  |)rovided  said  vessels  shall  strictly 
conform  to  the  followinji;  conditions  : 

"1.  They  shall  not  be  allowed  to  l)rin<,^  to  this  j)oil  bedding  or 
household  effects  of  any   kind. 

"2.  After  leaving  New  Orleans,  said  vessels  may  t<ike  on  board 
passengers  during  any  part  of  their  trip,  and  bring  passengers  to  this 
port  as  herein  provided. 

"  Cabin  passengers  only  will  be  allowed  at  the  discretion  of  the  med- 
ical officer.  This  officer  must  satisfy  himself  that  the  ai)plicant  has 
not  been  in  any  infected  locality  in  the  past  thirty  days,  and  that  none 
of  his  effects  have  been  exposed  to  infection,  and  further  such  effects 
shall  have  been  fumigated  or  disinfected  before  going  on  board, 

"  Passengers  may  be  taken  on  board  from  one  healthy  ])ort  to  another, 
each  of  said  ports  having  a  medical  officer  representing  this  board  ; 
under  the  same  restrictions  said  passengers  may  be  brought  to  New 
Orleans,  Personal  effects  of  passengers  are  restricted  to  personal 
wearing  apparel,  and  should  as  much  as  possible  consist  only  of  clean, 
recently  laundered  clothing,  and  such  effects,  together  with  passengers' 
trunks,  bags,  valises  or  baskets,  must  be  fumigated  before  being  brought 
on  board, 

"The  medical  officer  will  refuse  to  permit  the  bringing  of  any  un- 
usual or  unnecessary  amount  of  baggage,  it  being  the  jnn'jiose  of  the 
board  of  health  to  facilitate  the  affairs  of  commerce  by  permitting 
passenger  commuuication  whereby  business  may  be  transacted  in  a  safe 
manner,  holding  highest  the  health  of  the  community  ;  and  it  is  insisted 
that  material  capable  of  carrying  any  possible  infection  should  be 
limited  to  the  least  possible  amount.  AVoollen  bags  or  carjx^t  sacks 
will  be  prohibited.  Trunks  should  be  of  metal,  wood,  or  ixij^er ; 
valises  of   leather  or  paper, 

"  The  medical  officer  will  make  a  personal  inspection  of  all  jvissengers 
and  of  every  member  of  the  crew  just  prior  to  the  dejiarture  of  the 
vessel,  and  give  a  certificate  to  the  master  o^  the  vessel  of  the  con- 
dition of  such  persons  examined,  marking  opposite  the  name  of  each 


828  QUARANTINE. 

person  on  the  list  furnislietl  him  by  the  officers  of  the  vessel  of  every 
person  on  board  such  observations  as  may  seem  to  him  to  be  advisable 
concerning  the  condition  of  said  person's  present  or  previous  state  of 
health. 

"  ^Medical  officers  will  invariably  assist  masters  of  vessels  in  treat- 
ment of  members  of  crew  or  passengers  taken  sick  on  board  vessels 
and  should  make  notes  of  such  treatment  in  writing;  to  be  sent  to  the 
quarantine  officer  at  home  ports. 

"  3.  Vessels  shall  not  touch  at  any  infected  port  or  have  any  com- 
munication with  any  vessel  during  their  voyage  except  in  case  of  dis- 
tress. 

"  4.  T^liey  shall  not  touch  at  such  ports  or  stations  as  are  not  men- 
tioned in  their  schedule,  which  latter  shall  be  communicated  to  the 
board  of  health. 

"  5.  They  shall  be  required  to  make  a  full  disclosure  when  arriving  at 
quarantine  station  of  all  ports  and  places  they  have  visited  on  their  voyage. 

"  6.  They  may  take  on  board  a  crew  of  laborers  after  inspection  by 
the  medical  officer  and  disinfection  of  clothinsi;  of  such  crew  for  such 
healthy  point  where  they  permanently  reside  and  remain,  the  crew 
being  as  nearly  as  possible  composed  of  the  same  men.  The  captain 
or  other  officer  may  go  ashore  only  for  the  purpose  of  entering  or  clear- 
ing vessels.  Any  further  communication  with  shore  or  natives  will  be 
considered  a  violation  of  regulations,  and  vessels  in  default  will  be 
treated  accordingly. 

"  7.  These  vessels  shall  be  cleansed,  and,  when  necessary,  disinfected 
in  the  city  of  New  Orleans  after  discharge  of  cargo." 

Sanitary  Cordon. 

What  is  known  as  a  sanitary  cordon  ("cordon  sanitaire")  consists 
of  an  extended  line  of  guards  thrown  about  a  district  to  prevent  access 
thereto  or  egress  therefrom  of  any  person  or  thing  which  may  act  as  the 
carrier  of  infection.  The  object  is,  in  other  words,  to  protect  the  dis- 
trict from  infection  from  the  surrounding  country  or  to  protect  the  lat- 
ter from  infection  from  the  district.  Sometimes  a  double  line  is  estab- 
lished, the  territory  intervening  being,  perhaps,  only  suspected  of  being 
infected.  Cordons  are  not  uncommonly  estaljlished  in  the  South  against 
yellow  fever,  but  are  practically  unknown  in  the  North.  In  California, 
in  1900,  a  cordon  was  maintained,  for  a  short  time  only,  against  a 
district  in  which  cases  of  bubonic  plague  were  believed  to  be  concealed. 

Municipal  Quarantine. 

Municipal  quarantine  comprehends  measures  for  isolating  those  sick 
with  certain  of  the  infectious  diseases,  such  as  scarlet  fever,  diphtheria, 
and  smallpox,  keeping  others  under  observation,  and  disinfecting  rooms 
and  houses  and  objects  contained  therein  which  may  be  capable  of  har- 
boring infection.  It  is  beyond  dispute  that  public  safety  requires  that 
certain  sick  should  be  shut  off  from  free  communication  with  the  out- 
side world.     This  isolation  is  most  complete  and  entails  less  hardship 


MdNK'IJ'AL   Q(//iIiANTrNE.  829 

whnn  it  cnn  ho,  carried  out  iit  ,'i  Hpcoi.'il  liosj)if!il  for  conta^'ioiiK  dis^-jisch, 
hilt  ^(^iicrally  it  in  enforced,  if  at  all,  at  the  palienl's  lioiiie.  Koorn  and 
lioiis(!  ((iiafaiitine.s  ar(!  comiiionly  diniciill  or  iiii|)os>il)l<!  of  enroreeinent, 
(!S[)(;e,ially  in  leneineiit  districts  aiiioiifr  llu'  very  poor,  for  it  is  arnon^ 
this  class  llial  danger  of  inrcdioii  is  lc;ist  iiiidfiv-loofj  and  mutual  help 
and  nei^hhorly  visilinn;  most  ext<-iisively  practised,  and  thus  thf;  foci 
of  infection  may  l)ec(>me  iiutreasod  indelinilcjy.  In  hospitals,  on  the 
otiier  hand,  whei'c  indiscriminate  ejrrcss  and  iiij^ress  are  under  control 
and  fa(;iliti(!S  for  the  disiiilrcli<iii  of  disciiar^es  are  af  hand,  tiie  danger 
of  spread  is  rediKU'd  to  a  miniiniim. 

Ks|)ecially  diniciiit  and  productive  of  hardship  is  the  isolation  not 
only  of  the  patient,  hut  also  of  the;  oth(!r  memhers  of  his  fiimily.  This 
is  conimoidy  pi'ac^tised  in  the  vnsa  of  small|)ox,  Imt  is  unnecessarv  if 
the  other  memhers  have  undergone  recent  successful  vac(;iuation,  and 
tlKiir  clotihini:;  and  other  eHects  are  disinfected  and  they  are  then  sepa- 
rated from  all  ])ossil)le  conta(!t  and  communication  with  the  jiatient. 
But  (>ven  then,  they  should  he  kept  under  surveillance  for  a  time  equal 
to  the  period  of  incuhation.  Jn  times  of  epidemics  of  yellow  fever  in 
the  South,  house  (piarantiuc  of  entire  fuuilies  has  proved  to  be  the 
cause  of  much  hardship  and  anythiuu;  hut  an  unqualified  success.  It 
causes  great  pojMdar  dissatisfiu^tiou,  l(>ads  to  (concealment  of  cases,  and 
tends,  tiierefore,  to  spread  rather  than  restrict  the  disease.  Treatment 
of  the  sick  in  isolatiou  hospitals  and  removal  of  those  who  have  been 
exposed  to  infection  to  camps  of  detention  for  five  full  days  have  Ix-cn 
found  to  give  far  better  results. 

In  some  outbreaks  of  infectious  diseases,  it  is  necessary  or  advisal)le 
to  conduct  a  house-to-h(nise  inspection  for  the  discovery  and  isolation 
of  unreported  cases.  When  such  a  course  is  undertaken,  the  visits 
should  be  repeated  at  intervals  equal  to  the  period  of  incubation. 

The  making  of  regulations  for  municipal  quarantine  and  inspection 
is  subject  to  no  general  rule,  each  local  authority  lieing  a  law  unto 
itself.  In  some  cities,  the  rules  governing  notification,  isolation,  and 
disinfection  are  exceedingly  thorough  and  strictly  enforced  ;  in  others, 
they  are  inadequate  in  varying  degrees  and  enforced  M-ith  laxity. 

Camps  of  Detention. — Camps  of  detention  are  places  set  apart 
for  the  reception  and  observation  of  persons  who  have  been  cx]i<ise<l 
or  who  are  under  suspicion  of  having  been  exposed  to  the  contagion 
of  smallpox  or  other  quarantinable  disease.  They  should  be  under 
strict  surveillance  and  governed  by  inflexible  rules.  Every  |-)erson 
should  be  examined  before  admission,  and  such  effects  as  he  mav  be 
permitted  to  bring  in  should  be  disinfected  thoroughly,  for  above  all 
things,  it  is  necessary  to  guard  against  the  introduction  of  infection. 
The  entire  personnel  should  be  mustered  in  quarters  and  examined  at 
least  twice  daily,  and  such  as  are  beginning  to  show  symptoms  must 
be  promptly  isolated.  Indiscriminate  ingress  and  egress  must  l>e 
strictly  prevented.  At  the  expiration  of  the  proper  ]>eriod.  in  each 
case  the  clothing  and  other  personal  effects  should  be  thoroughly  dis- 
infected before  dischariie. 


CHAPTER   XIX. 
DISPOSAL  OF  THE  DEAD. 

The  public  health  reqiures  that  the  bodies  of  the  dead  shall  be 
disposed  of"  in  such  a  way  as  not  to  be  a  menace  to  the  living,  and 
as  soon  as  possible,  with  due  consideration  of  the  feelings  of  those 
bereaved.  In  the  case  of  those  dead  of  infections  diseases,  disposal 
should  not  be  delayed  by  sentimental  considerations,  but  should  be 
accomplished  with  as  little  delay  as  possible,  on  account  of  the 
risk  to  which  the  living  may  be  subjected  by  the  retention  of  the 
body  in  the  home. 

Concerning  methods  of  disposal,  consideration  may  be  limited  to  the 
two  in  use  by  most  civilized  peoples  and  by  most  others  as  well ; 
namely,  earth-burial  and  cremation. 

Earth-burial. — Interment  of  the  dead  has  ever  been  the  principal 
mode  of  disposal  among  Christians,  Jews,  and  Mussulmans.  Within 
comparatively  recent  years,  the  results  of  overcrowding  of  ancient 
churchyards  and  cemeteries,  and  the  necessity  of  dedicating  great 
areas  of  valuable  land  to  be  held  in  perpetuity  for  the  accommodation 
of  the  dead,  have  brought  about  an  economic  sentiment  against  the 
practice,  and  to  it  has  been  added  a  feeling  of  danger  to  the  public 
health  from  the  decomposing  tissues,  particularly  of  those  who  have 
died  of  infectious  diseases. 

Buried  in  soil  of  suitable  character,  a  body  gives  off  for  a  number 
of  months — six  to  nine  may  be  regarded  as  reasonable  limits — foul 
gases  of  decomposition  which  are  not  evolved  in  the  later  stages.  The 
rate  of  decomposition  is  influenced  not  alone  by  the  nature  of  the  soil, 
its  pore  volume,  and  its  degree  of  moisture,  but  also  by  the  character  of 
the  coffin,  the  depth  of  interment,  and  the  processes  to  which  the  body 
has  been  subjected  before  burial.  After  some  years,  the  period  varying 
within  very  wide  limits  according  to  circumstances,  decomposition  is 
complete  and  but  little  remains  besides  bones,  more  or  less  crumbly  in 
character. 

It  is  charged  against  earth-burial,  that  the  places  used  for  the  pur- 
pose are  offensive ;  that  the  air  becomes  poisoned  ;  that  the  soil  be- 
comes laden  with  disease  germs  of  all  descriptions,  which  are  pre- 
served indefinitely,  and  that  water  supplies  are  converted  to  dilute 
poisons  of  great  potency ;  that  is  to  say,  cemeteries  predispose  to 
and  act  as  direct  causes  of  disease.  As  proof,  numerous  cases  which 
will  not  bear  close  scrutiny  are  cited,  but  the  whole  mass  of  what  is 

m 


J'JA  11  Til-  li  (nil  A  L.  H.'J  1 

r('|i;;if(l('(l  ;i,h  ((vidciicc  of  llic  coinicction  of  ffiiK't^-rifH  with  tlio  outhn-jik 
of  (IIh(:;is(!  Iiiis  hill  little  ir:il  wi'ImIiI  ;iii<|  is  iiiic.oiiviriciiif^.  It  lias 
boon  Siiid,  lor  cMiiiipIc,  tli;i(.  typliiis  :in<i  oilier  l(V(;rM  were  ]tr«'valr-iit  in 
tli('  iiniiKMliatc  iicjnliboilioofl  <•("  old,  overcrowded  cliiireliyardH  in  Lon- 
don when  it-  was  <Mi.sloiii;iiy  (o  kee|»  di.-tiirhin^'-  tiu;  Hoil  for  new 
interineiils,  reiiarfjiess  of  (he  niiiiiher  ;iiid  eondilion  of  tho.^c  alrcjulv 
hnried.  lOveii  Ihon^h  the  Hii|)|)osed  eonneetion  were  anyllnnj;  nior*; 
than  mere,  (roincidcncic,  it  may  he.  .said  liiat  nothing  of  ihcr  M.rt  ha.s  hcr-n 
noticed  within  njccnt  years,  and  never  anywhere  except  in  densely 
popniatcd  neijrhborhoods,  in  uhieh  densely  crowded  cemeteries  hap[M'n 
to  be  located. 

Cases  of  cholera,  yellow  lever,  scarlet-  fever,  and  r.ther  diHcaHes  have 
been  attributed  to  the  o|)eninw;  of  old  ji;raves.  In  (»ne  case,  often  quoted 
in  all  s(!ri()usness,  a  number  of  |)ers()ns  were  s(.'ized  with  scarl(;t  fever 
supposedly  from  di<;<;iiit;-  u|)  the  surface  of  a  burial  ^rf)und  where, 
no  l(vss  than  thirty  years  before,  a  number  of  victims  of  that  dis<;ase 
had  been  buried.  ,Sir  Henry  Thompson  has  said:  "The  poisons  of 
scarlet  fever,  enteric  fever,  smallpox,  (li|)htheria,  inalifrnant  cholera, 
are  undoubtedly  transmissible  through  earth  from  the  buried  body  by 
more  than  one  mode.  Ami  thus  by  the  act  of  interment  we  literally 
sow  broadcast  throuohout  the  land  innumerable  seeds  of  pestilencx- ; 
germs  which  long  retain  their  vitality,  etc.,  many  of  them  destined  at 
some  future  time  to  fructify  in  premature  death  or  ruined  health  to 
thousands." 

Such  broad  statements  are  easy  to  make,  but  exceedingly  difficult  or, 
indeed,  impossible  to  sul)stantiate.  If  true,  it  would  a])))ear  that  the 
earth,  instead  of  being  the  great  natural  resolvent  and  disinfectant  of 
all  forms  of  dead  organic  matter  deposited  below  the  surface,  is  a  mine 
of  septic  matter,  in  spite  of  which,  the  world  at  large  continues  to 
increase  in  health  and  the  average  length  of  life  to  extend  little  by 
little  with  every  decade. 

It  is  said  also  that  the  spores  of  all  known  species  of  pathogenic 
bacteria  are  very  resistant  and  retain  their  virulence  indefinitely.  But 
even  if  this  were  true,  and  it  is  not  true,  it  is  not  shown  that  the  spore- 
bearers  in  the  body  form  spores  after  death  occurs.  As  a  matter  of  fact, 
the  basis  of  the  bacterial  scare  concerning  the  dangers  of  earth-burial 
rests  on  no  more  solid  foundation  than  the  instance,  quoted  in  the 
chapter  on  Soils,  of  anthrax  spores  supposed  to  have  been  brought 
to  the  surface  by  earthworms  that  had  acquired  them  from  a  cow  buried 
two  meters  below,  which  instance  has  no  value  as  evidence  for  reasons 
already  explained. 

Comiug  to  a  consideration  of  the  actual  dangers  arising  from 
earth-burial  and  from  the  proximity  of  cemeteries,  it  must  be 
admitted  at  the  outset  that  merely  stinking  gases  are  inca^table  of 
transmitting  disease,  and  are,  nu^reover,  abse»rbed  and  de<xiorize<I  by 
the  soil  itself.  The  same  class  of  foul  odors  are  borne  without  injury 
by  those  engaged  in  the  numerous  offensive  trades.  There  is  no 
ground  for  supposing  that   the  emanations    from  graveyaixl  soil  are 


832  DISPOSAL  OF  THE  DEAD. 

dangerous  to  health,  for  if  they  were,  their  effects  should  be  most 
marked  among  grave-diggers,  a  elass,  who,  like  the  workmen  in 
sewers,  are  obstinately  lu^althy  in  spite  of  all  a  jjriuri  reasoning  to  the 
contrary. 

Whether  the  soil  becomes  seriously  polluted,  is  a  question  which  bears 
on  the  possible  contamination  of  the  ground-water.  This  possibility 
may  exist,  but  it  is  as  nothing  in  com})arist)n  with  the  pc^lluticm 
of  the  soil  and  its  contained  water  by  leacliing  cesspools,  into  which 
man  casts  yearly  several  times  his  weight  of  liquid  and  solid  excreta 
from  his  own  body,  and  there  is  recorded  no  single  well-authenticated 
case  of  outbreak  of  disease  due  to  water  contaminated  by  the  drainage 
of  a  graveyard. 

On  general  principles,  the  drainage  of  a  cemetery  should  not  be 
allowed  to  run  into  streams  used  as  water  supplies,  and  wells  should 
not  be  located  in  close  proximity  to  the  boundaries  of  land  used  for 
interments. 

AMiile  burial  too  near  the  surface  should  be  avoided  on  account  of 
the  possibility  that  the  body  may  be  exhumed  by  dogs  and  other 
animals,  it  is  to  be  borne  in  mind  that  the  nearer  the  body  is  to  the 
surface,  the  more  rapid  will  decomposition  occur.  In  order  to  shorten 
as  much  as  })0ssible  the  time  required  for  complete  resolution,  the  coffin, 
which  should  not  be  of  too  permanent  material,  should  be  placed  in 
immediate  contact  with  the  earth,  and  not  in  a  bricked  enclosure  or 
vault.  The  use  of  wicker  coffins  is  urged,  since  they  offer  less  obstacles 
to  the  natural  processes  of  resolution  than  any  other.  Metallic  coffins 
which  retain  the  products  of  decomposition  indefinitely  should  be 
jjrohibited.  The  top  of  the  grave  should  be  a  mound  of  earth  capable 
of  supporting  a  fairly  luxuriant  growth  of  vegetation,  which  assists  in 
draining  the  soil  and  makes  use  of  the  products  of  decay. 

Sites  for  Cemeteries. — In  the  selection  of  a  site  for  a  cemetery, 
particular  attention  should  be  given  to  the  nature  of  the  soil.  This 
should  be  dry  and  permeable  to  air ;  the  ground-water  level  should 
normally  be  well  below  the  bottom  of  the  deepest  grave ;  the  surface 
should  be  of  rich  loam,  which  acts  as  a  powerful  deodorant  and  provides 
for  an  abundant  growth  of  vegetation.  Clay  soils  are  objectionable  on 
account  of  dampness  and  impermeability,  which  prevent  rapid  decom- 
position of  the  bodies.  Rocky  soils  are  objectionable  on  account  of 
their  drainage  and  the  obstacles  to  the  digging  of  graves. 

Much  has  been  written  concerning  the  danger  of  pollution  of  water 
supplies  by  the  drainage  of  cemeteries,  and  this  danger  should  be  kept 
in  mind,  but  it  is  unlikely  that,  with  proper  locations  well  away  from 
habitations,  serious  pollution  Avill  occur.  Where  land  is  abundant  and 
cheap,  the  immediate  neighborhood  of  cemeteries  for  purposes  of  resi- 
dence is  generally  avoided,  but  it  is  always  well  to  pay  attention  to  the 
proper  drainage  of  lands  devoted  to  burial  purposes,  and  to  consider 
the  possibility  of  the  fouling  of  any  wells  already  present  or  likely  to 
be  sunk  in  the  surrounding  soil. 

Cremation. — Disposal  of  the  dead  by  burning  was  practised  in  very 


curly  tiiruiH  iiH  m,  irinrk  <»!"  n'S|iccl  hy  some,  or  oC  <li-li()ii(»r  l»y  otlicrn,  or 
from  motives  of  (^xpcdiciicy  alU-r  ^rcat  .slaii^'liti-r  in  warliin- ;  l)iif  flu; 
practi(;(!  of"  iiiciiicraiion,  based  on  eeonoinie  and  sanitary  eonsiderationH, 
is  of  (jnil,e  reeeni,  origin  anionLr  ^'lirih(i;in  lu-oples,  Tlic!  ar^iimeiitH 
urji^ed  in  its  favor  from  an  ee,onotni(;  slandpoint  are  indi-pntaMe,  for 
not  only  can  the  dead  Ix!  Ilins  disposed  ol"  nnieli  inor<'  cheaply,  hut  llie 
necessity  of  d(!Votin^  larj^^c  Iracts  of"  valnaLIc  Kind  for  pnrpo-c-  of 
burial  is  done;  away  witli. 

From  a  sanitary  sfandpoini,  llic  arL^niincnls  are  not  ho  Htronjr  and,  in 
facst,  are  easy  of"  n^fntaf ion.  It  is  nrj^cd  that  earth-hnrial  is  a  un;n;nii 
to  public  lieallh,  and  a  nun)l)er  of  sn|)posedIy  convineinj^  instjincx's  are 
cited  as  proof  (»f"  this  sialeineiil  ;  l)iit  these  cannot  withstand  th(!  tCHt 
of  careful  examination  and  uciirhin^  of  evidence,  and  it  must  be  ad- 
mitted, even  by  the  strontjjest  a(lvo(rat(!S  of  (cremation,  that  ih^xv.  is  no 
definite^  statistical  evidence  that  tlu;  (:;(!neral  death-rat^;  or  any  special 
(Icatii-rate  has  ever  been  influcnc(Ml  by  earth-burial. 

It  is  urged  also  that  earth-burial  is  repulsive  in  idea  and  horrible  in 
practice,  and  while,  in  the  minds  of  many,  this  statement  is  tnie, 
it  is  to  be  said,  on  the  other  hand,  that  in  the  minds  (»f"  far  more,  the 
arginnent  apj)lies  with  ii^rcater  force,  to  the  practice  of  incineration. 
From  the  time  of  the  early  Christians,  who  pructiscfl  interment  by 
stealth,  earth-burial  has  ever  been  the  one  method  of  disposal,  and  the 
sentiment  in  its  favor,  fostered  thr(Mi2;h  nineteen  centuries  of  practice, 
is  a  powerful  obstacle  to  the  trcneral  adojition  of  cremation,  and  can 
only  slowly  be  overcome.  A  stront^  feelino;  that  cremation  is  oj^posed 
to  Christian  doctrine  concerning  the  resurrection  of  the  body  can  only 
be  overturned  by  the  influence  of  the  clergy,  many  of  whom,  including 
Protestants  and  Roman  Catholics  of  eminence,  have  already  done  much 
in  advocacy  of  the  practice  as  a  rational,  economic,  and  sanitarv  means 
of  disposal. 

Aside  from  religious  feeling,  the  strongest  argument  urged  ag-ainst 
cremation  is  the  destruction  thereby  of  evidence  of  poisoning  in  cases 
in  which,  after  disposal  of  the  body,  susjiicion  of  foul  plav  mav  arise; 
but  when  one  considers  the  very  great  infrequency  of  exhumations  on 
this  ground,  and  the  still  greater  infrequency  of  positive  results  there- 
from, this  objection  can  hardly  be  regarded  as  entitled  to  much  weight. 
In  the  case  of  the  metallic  poisons,  the  evidence  Mould  still  be  present 
in  most  cases  in  the  ashes  ;  in  the  case  of  the  organic  cc^njiounds,  it 
must  be  borne  in  mind  that,  under  most  fovorable  conditions,  begin- 
ning the  analysis  before  the  onset  of  putrefaction,  their  detection  in 
the  small  amounts  commonly  employed  is  by  no  means  easy,  and 
afterward  is  extremely  difficult  and  more  oflen  impossilile. 

Furthermore,  it  must  be  borne  in  mind  that,  unless  suspicion  arises 
before  or  innnediately  after  death,  chemical  analysis  is  commonly  viti- 
ated by  the  universal  practice  of  embalming  the  body  with  strong  solu- 
tions containing  the  very  substances  sought.  In  every  case  of  doubt 
as  to  the  cause  of  death,  the  body  should  be  subjected  at  once  to  pro|>er 
examination.      In  some  States,  legal  provision  has  been  made,  forbid- 

53 


834 


DISPOSAL    OF  Tin-:  DEAD. 


diner  ernbalining  in  case  of  dcatli  by  violence,  until  the  body  has  been 
*' viewed"  by  the  proper  authority,  and  providing  ibr  proper  certifica- 
tion before  incineration. 

History  of  Modern  Cremation. — According  to  Ja])anese  authoi-i- 
ties,  crematiou,  as  at  present  practised  among  ci\ilized  nations,  had  its 
origin  in  their  country  many  years  ago.  Until  1871,  however,  no 
special  crematories  were  installed,  the  body  in  its  coffin  being  placed  on 
stones  surroui'ided  by  wood  or  other  inflanimable  material.  In  that  year, 
crematories  were  erected  ;  and  since  then,  the  practice  of  incineration 
has  increased  to  such  an  extent  that,  in  1897,  in  Tokio,  of  34,000  per- 
sons who  died,  15,000,  or  44  per  cent.,  were  cremated.  In  1898,  the 
percentage  was  about  the  same. 

In  this  country,  the  first  movement  in  favor  of  cremation  occurred 
in  New  York,  in  1873,  but  the  first  crematory  was  not  erected  until 

Pig.  124. 


187G-'83  'Si  '85  '8C  '4i7  '88  '89  '90  '91  ■'92  '93  '91  '95  '90  '97  '98 
YEAR 

Curve  showing  number  of  crematiDns  in  the  United  States.    (After  Abbott.) 


187G.  This  was  built  at  Washington,  Pa.,  by  Dr.  J.  T.  LeMoyne, 
for  the  disposal  of  his  own  body,  and  was  the  only  one  in  the  country 
until  1884,  when  another  was  established  at  Lancaster,  Pa.  During 
this  interval  of  eight  years,  the  use  of  his  crematory  was  allowed  by 
Dr.  LeMoyne  for  others,  and  25  incinerations  were  performed.  Be- 
tween 1884  and  1900,  the  number  of  crematories  increased  to  26, 
which  growth  indicates  a  steady  increase  in  public  sentiment  in  favor 
of  the  process.  The  number  of  cremations  performed  in  the  United 
States  from  1884  to  1899  is  shown  in  Figure  124  from  the  monograph 


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IllSTOliV   OF  MOIHCliN   CILKMATIOS.  8.'i7 

l)y  Dr.  S.'itriiicl  VV.  AhhoK,'  roritriWiitcd  hy  flu;  (.'oriirnoriwfaltli  of 
M!iss;i(!liiiH(!llH  l.o  tlu!  lliiilf'd  St.'ilcs  Social  Iv-onoiriy  Kxliibit  at  tin; 
Paris  Pjxpositioii.      Diiriiifj^  tliis  period  'S88r>  cniruatioiis  ofir.iirn^J. 

TIk;  tabic  oil  |).'if^o  "i^Wr)  shows  tin-  fiirtlicr  progrcsH  of"  tlie  luovcriicnt 
ill  tli((  Uiiitwl  States.  Tlic  ^rowlli  oC  the  inovctnoiit  in  Gn^at  IJrifain 
lip  to  11)10  is  sliowri  oil  paj^c  H.'iO." 

A  inovctncnt  toward  (TCMiialioii  Ix'gaii  in  Italy  in  1857  ;  liut  nothing 
was  ac(!oinplisli(!d  until  1807,  (line  years  after  legal  sanction  waH  rth- 
tained.  In  1JK)1  tluTc;  wen-  in  Ilaly  22  cr«imatorie.s  in  ofK^ration. 
Germany  liad,  in  11)01,  7  estaMislimcnts,  the  first  of  whi(;li  was  in- 
stalled at  Dresden  in  1871;  (Jreal  liritain  had  7,  the  first  of  whir-h 
was  eslahlished  in  London  in  1880;  I^'i-ance  had  2,  Switzerland  had 
3,  Sweden  had  2,  and  Denmark  had  1. 

According  to  Sir  Henry  Thomjison,'  there  were  in  tin;  United  States 
during  1901,  no  less  than  2,(505  incinerations;  in  Germany,  693  ;  in 
England,  445  ;  in  Paris,  297  ;  in  Italy,  at  12  of  the  22  institutions, 
243;  in  Switzerland,  at  2  of  tin;  .'>  institutions,  144. 

In  the  destruction  of  the  body,  the  apparatus  is  so  constructed  that, 
while  reduction  to  ashes  is  (iomplete  within  three  hours,  no  offensive 
fumes  are  given  off.  Commonly,  the  l)ody,  incloswl  in  a  simple 
wooden  cotlin,  is  placed  in  the  retort,  which  is  then  intensely  heated 
by  an  oil  ilanie,  with  which  air  under  pressure  is  mixed  ))y  a  blower. 

1  The  Past  and  Present  Condition  of  Public  Hygiene  and  State  Medicine  in  the 
United  States,  Boston,  1900. 

=  British  Medical  Journal,  Mar.  5,  1910,  p.  579. 
3  Tlie  Lancet,  July  5,  190'J. 


INDEX. 


AllDOMlNAt.  I);ui(1h,  01^2 

Ahywsiiii.'i.n  vvtIIh,  I5S7 

Acctylctid  Ki'M  '"  illiiiiiiriM.1  ion,  ')()() 

Acid,  l)<)ri(^  'i.lS 

cITccI,  of,  on  (iii^cslion,  'JtlO 
in  milk,  IIS 

delect  ion  of,  HiO 
(carbolic,  TjSI) 

hypochlorouH,  as  disinfcclanl,  T)?? 
oxalic,  24 

standard  solution,  304 
phonic,  as  disinfectant,  586 
salicylic,  2()l 

detection  of,  in  beer,  2:5:} 

in  wines,  240 
in  milk,  120 

detection  of,  KiO 
Acids,  mineral,  as  disinfectants,  585 

organic,  24 
Actinomycosis,  milk  afTected  by,  128 
Age  in  vital  stalistics,  751 

statement  of,  744 
Agglutinins  in  serum,  796 
Air,  269 

disinfection  of,  612 
examination  of,  297 

bacteriological,  314 
filtration  of,  493 
humidity  of,  relative  determination 

of,  299 
infection  carried  by,  290 
pollution  of,  through  lighting,  501 
saturation  of,  279 
in  soil,  329 
vitiated,  effects  of,  286 

occupations  exposing  to,  723 
in  water,  371 
water  capacity  of,  299 
Albuminoid  ammonia  in  water,  375 

detection  of,  445 
Albuminoids,  23 
Albumins,  20 

Alcohol  as  disinfectant,  591 
in  beer,  percentage  of,  223 
in  ration,  643 
in  tropical  hygiene,  685 
in  wines,  236 
Alcoholic  beverages,  distilled,  241 

fermented,  217 
Aldehyde  catalase,  105 
Alga\  destruction  of,  in  water,  412 
Alkaline  potassium  permanganate,  445 
soils,  3  IS 


Alkalinity  indicator,  304 

Alkaloid.s  in  b(;vc;rag(«,  210 

Allspic*!,  251 

Almonds,  194 

Aluminum  dilorido  iw  diHinfcctant,  5S1 

kitclicnwarc,  2(>H 

in  soil,  :>1.S 
American  wells,  3S7 
Ammonia  in  air,  275 

permanent  staiidard.s  of,  449 

in  soil,  319 

in  water,  373 

determination  of,  445 
Ammonia-fr(M!  water,  446 
Ammonium  chloride,  standard  solutions, 

445 
Amykose,  104 
Aniiin  orange,  160 

Ankylostomum  duodenalo  in  water,  442 
Annatto,  158 
Anthrax,  milk  affected  by,  128 

soil  relation  to,  349 
Antistreptococcus  serum,  811 
Antitoxins,  783 
Aiiplcs,  201 
Apricots,  202  _ 

Aqueous  vapor  in  air,  276  . 

determination  of,  298 
Arachnids,  relation  of,  to  diseases,  696 
Argand  burners,  498 
Argon  in  air,  272 
Arrowroot,  193 
Artesian  wells,  3S9 
Artichokes,  199 

Ascaris  lumbricoides  in  water,  441 
Aspirating  cowls,  480 
Aspiration  in  ventilation,  479 
Attitudes  in  hygiene,  738 
Aurate  of  sodium  as  disinfectant,  585 

B. 

Babcock  asbestos  test,  151 

centrifugal  test,  150 
Bacillol  as  disinfectant,  590 
Bacon,  smoked,  30 
Bacteria  in  air,  2SS 
in  milk,  105 

conditions  affecting,  110 
nvmiber  of,  107 
source  of,  110 
of  soil,  340 
in  water,  379 
Bacterial  action  in  purification  of  water, 
397 

S39 


840 


INDEX. 


Bacterial  diseases  in  animals,  45 

poisoning  of  foods,  Go 

toxins,  783 
Bacteriological  exaniiualion  of  air,  314 
of  soil,  302 
of  water,  462 
Bactcriolj'sis,  788 
Baler's  test,  104 
Baker's  chemicals,  246 
Baking  powders,  251 
Bananas,  204 
Bands,  abdominal,  632 
Barium  hydrate  solution,  303 
Barley,  180 

malt,  substitutes  for,  in  beer,  220 
Barracks,  652 
Bathing,  752 
Bath-tubs,  532 
Beans,  191 

Bed-bugs,  relation  of,  to  diseases,  695 
Bed  linen,  disinfection  of,  611 
Beef,  composition  of,  29 

good,  characteristics  of,  27 

poisoning  by,  84 

poisonous,  characteristics  of,  71 
Beer,  217 

acidity  of,  233 

adulteration  of,  222 

alcohol  in,  determination  of,  223 

barley  malt  in,  substitutes  for,  220 

composition  of,  222 
ash,  234 

extract  of,  determination  of,  232 

hops  in,  substitutes  for,  221 

manufacture  of,  219 

methyl  alcohol  in,  determination  of, 
229 

physical  properties  of,  222 

preservatives  in,  233 

specific  gravity  of,  224,  232 
Beets,  199 
Bernstein's  test,  163 
Berries,  204 
Beverages,  210 

alcoholic,  distilled,  241 
fermented,  217 
Bicarbonate  of  sodium,  264 
Bichloride  of  mercury  as  disinfectant,  582 
Bilharzia  haematobia  in  water,  442 
Biological  agencies  afTecting  soils,  328 
Birth-rates,  749 
Biscuits,  183 
Bisulphate  of  sodium  in  purification  of 

water,  403 
Blackberries,  204 
Blackboards,  school,  473 
Blankets,  waterproof,  632 
Bleaching  powder  as  disinfectant,  575 
Body  louse,  relation  of,  to  disease,  696 

measurements  of,  621 
Boiling  meat,  26 

in  purification  of  water,  404 

water  as  disinfectant,  568 
Books,  disinfection  of,  616 
Boots,  630 
Borax.     See  Boric  acid. 


Bored  wells,  388 
Boric  acid,  258 

elToct  of,  on  digestion,  260 
in  milk,  118 

detection  of,  160 
Bovine  tuberculosis,  human  tuberculosis 

and,  50 
Brand's  test,  233 
Brandy,  242 
Bread,  180 

pulled,  183 
Broiling  meat,  26 
Bromine  as  disinfectant,  577 

in  i^urification  of  water,  401 
Bubonic  plague,  air  as  carrier  of,  295 
immunization  in,  809 
soil  relation  to,  846 
Buckwheat,  189 
Burial  of  dead,  830 
Butter,  164 
Butyric  ferments,  107 
Butyro-refractometer,  171 


Caffeine,  210 
Calcium,  24 

chloride,  standard  solution  of,  453 

oxide  as  disinfectant,  580 
Cameron  tank,  554 
Camps  of  detention,  829 

military,  649 
Cane  sugar,  205 
Canned  fish,  38 

meats,  30 
Canning,  preservation  of  food  by,  254 
Canteen,  army,  644 

Capillarity  of  soil,  determination  of,  359 
Caramel,  159 
Carbohydrates,  22 
Carbolic  acid,  586 
Carbon  dioxide  in  air,  272 

determination  of,  303 
in  soil-air,  determination  of,  360 
in  water,  372 

monoxide  in  air,  280 

determination  of,  311 
Carbonate  of  sodium,  120 
Carbonates  in  soil,  218 
Carbonic  acid.     See  Carbon  dioxide. 
Care  of  person,  762 
Carrots,  199 
Cassia,  251 
Catalase,  105 
Cayenne  pepper,  251 
Celery,  typhoid  fever  transmitted  by,  64 
Cellulose,  23 
Cemeteries,  832 
Census,  743 
Cereals,  178 

Chafing,  care  of  and  prevention  of,  639 
Chairs,  school,  472 
Cheerfulness,  627 
Cheese,  173 
Chemical  agencies  affecting  soils,  328 

agents  as  disinfectants,  571 


iM)/':x. 


841 


Ohorriion,!  [)r(!f;ii)il,;i,(,i()ri  of  HowaKo,  fil'i 

l)iii'ili('.,'i,li()n  <>(  wii.lcr,  .'{9X 
Cluitnicids,  hiikcrH',  2U'> 

pn^HcrviiXioti  of  food  liy,  'jriCi 
of  inilk  hy,  IIS 
Ch(!rri((H,  202 
Ch(iHt,  r:\.])nc\ly ,  (^x.'Uiiinjilioii  of,  (i2() 

m(^iiHiir(;iii(M)l,H,  <'»2l 
(;ii(i.slrMit,H,  l!)4 
('liicory,  214 
Cliildrrti,  (lc;i,l,li-r;iJcH  of,  7r)(l 

(MiipioyifK^il-  of,  740 
(!lil(>ri(l(^  of  limn  iiH  <li,sinf(^c,t.:ui(,,  r)7r) 
Cliloiidcs,  24 

Cliloriiiiil.cd  liiuc  as  disiiifccliiril,  oTf) 
Chloi'iiH'  lis  (lisinfccl.iuit,,  .174 

ill  ))uri(ic,'il  ion  of  w.'ilcr,   10! 

ill  soil,  ;>iS 

ill  wa,ti'r,  ;i77 

(leUinirmal  ion  of,  452 
(lliocolal.o,  217 
CHiolcra,  air  as  carrier  of,  296 

food  as  l)(>arcr  of,  58 

iminunizalion  in,  SOS 

infantiiin,  mill<  as  licaivr  of,  144 

milk  as  bearer  of,  1  .'i7 

8oil  relation  to,  .'i4() 

wai.er  reflation  to,  4l!() 
Chroinates,  122 

deteetion  of,  in  milk,  162 
Cider,  240 

vine{i;ar,  247 
Cinnamon,  251 

Circulation  in  active  exercise,  765 
Clays,  316 

Cleanliness,  personal,  627 
Closets,  520 

disinfec^tion  of,  616 
Clothing,  770 

adulteration  of,  776 

disinfection  of,  611,  615 

selection  of,  778 

of  soldier,  628 

in  tropics,  687 

under,  631 
Clouds,  279 
Cloves,  250 

Coagulated  proteins,  21 
Coal-gas  in  illumination,  499 
Coal-tar  colors  in  wine,  detection  of,  239 
Cocoa,  215 
Cocoanuts,  194 
Coffee,  213 
Cold  as  disinfectant,  569 

preservation  of  food  bv,  254 
of  milk  by,  114 
Color  in  clothinc;,  629,  770 
Colostrum,  102  " 
Complements  in  serum,  793 
Condensed  milk,  124 
Condiments,  246 
Confectionery,  209 
Constitution  of  population,  746 
Constrained    attitudes,    occupations    in- 
volving, 738 
Contact  filtration  of  sewage,  550 


Contusion,  7HI 

( loritfrritrricrif ,  627 

(yorivectioii  in  vritilatinK,  4H0 

Cr)okiiig  rnc'ilH,  26 

Cop|)<;r,  forxl  r^oiitHminjilerJ  by,  2<>4 

Hulphiilc  iiH  (JiHitifcctarit,  5H2 
Cordon,  Hanitury,  H2H 
(;orri,  1H7 
('orncrd  b«'cf,  30 

Corrosiv*^  subliinate  ;lm  (liHinf'Ttunt,  5S2 
Cotton,  774 

rlotliiiig,  62S 
Cotlr)ri-H<'r-(|  oil,  19t> 
Cowls  for  ventilation,  479 
('rackcTH,  183 
(^raribf-rries,  204 
('r.'iwfisli,  tyjilioid  fever  tranHmittwl  by, 

64 
Cream,  124 

gclalin  ill,  detection  of,  16.''» 

sucrat,e  of  lime  in,  detection  of,  161 
Cremation,  832 

apparatus  for,  837 

history  of,  833 

statistics  of,  834 
Creolin  a,s  disinfectant,  589 
Cresol  jin^parations  a.s  disinfectants,  587 
Cucumbers,  201 
Currants,  204 

Cyanide  of  mercury  a.s  disinfectant,  584 
Cysticercus  in  meat,  39 

D. 

Dampness,  occupations  exposing  to,  737 
Dead,  disposal  of,  830 
Death,  causes  of,  758 
Death-rates,  751,  754,  756 

weekly,  754 
Dcceco  closet,  527 

Dengue,  relations  of  mosquitos  to,  714 
Densitj^  of  population,  753 
Desks,  school,  472 
Detention  camps,  829 
Dew-point,  301 
Dextrose,  23,  206 
Diarrhoea,  epidemic,  soil  relation  to,  354 

infantile,  air  as  carrier  of,  296 
Diarrhoeal  diseases  in  army,  669 
Diastase,  104 
Diet,  regulation  of,  764 

in  tropics,  684 
Diffusion  in  ventilation,  476 
Digestibility,  comparative,  of  meats,  28 
Digestion,  effect  of  exercise  on,  767 
Dioxide  of  sulphur  as  disinfectant,  577 
Diphtheria,  air  as  carrier  of,  295 

immunization  in,  804 

milk  as  bearer  of.  136 

soil  relation  to,  347 
Discharges,  disinfection  of,  611 
Disease,  air  as  carrier  of,  290 

butter  as  carrier  of,  167 

dissemination  of,  609 

occupations  exposing  to,  735 

exciting  causes  of,  780 


84-2 


INDEX. 


Disease,  food  as  bearer  of.  44 

insect  relation  to,  690 

soil  dampness  and,  342 
relations  to,  342 

susceptibility  to,  781 

water  relations  to,  420 
Diseases  of  sailors,  677 

of  soldiers,  665 

tropical,  6S8 
Disinfectants,  560,  571 

alcohol  as,  791 

carbolic  acid  as,  586 

chemical,  571 

cresol  preparations  as,  587 

essential  oil  as,  593 

fonnaldeh3'tle  as,  598 

iodine  as,  577 

metallic  salts  as,  581 

mineral  acids  as,  585 

non-metal,  572 

physical,  560 

soap  as,  594 
Disinfection,  609 

by  formaldehj'de,  599 

special,  610 
Disposal  of  dead,  830 
Dissemination  of  infectious  material,  609 
Distillation  in  purification  of  water,  404 
Distilled  alcoholic  beverages,  241 
Distilling  apparatus,  446 
Distomatosis,  43 
Domestic  filters,  404 
Dracunculus  medinensis  in  water,  441 
Drainage  areas,  391 
Drains,  504 
Dress  coats,  629 
Driven  wells,  387 

Drying,  preservation  of  food  by,  254 
Duration  of  life,  759 
Dust  in  air,  278,  288 

determination  of,  313 

poisonous,  729 

occupations  exposing  to,  740 
Dwellings,  470 
Dyes,  poisonous,  777 
Dysentery  in  army,  668 

immunization  in,  806 


Earth-btjrial,  830 

Eating  utensils,  disinfection  of,  611 

Egg-plant,  201 

Eggs,  91 

Ehrlich's  theory,  783 

Electric  lighting,  502 

Emergency  ration,  642 

Enamelled  kitchenware,  268 

Endocarditis,  immunization  in,  811 

Enteritis,  specific,  milk  affected  by,  128 

Epidemic  poisoning  by  food,  signs  of,  68 

Erysipelas,  air  as  carrier  of,  295 

immunization  in,  811 
Essential  oils  as  disinfectants,  593 
Evaporation  from  oil,  335 
Examination  of  recruit,  625 


Exercise,  765 

amount  required,  768 

kinds  of,  769 

over-,  of  parts,  739 

of  soldier,  63)5 
Expectation  of  life,  760 


Fabrics,  chemical  analysis  of,  777 

microscopical  examination  of,  777 
Fieces,  disinfection  of,  610 
Farinaceous  preparations,  193 

seeds,  178 
Fats,  22 

in  butter,  determination  of,  169 

in  milk,  97 

determination  of,  148 

vegetable,  195 
Fatty  seeds,  193 
Feces,  disinfection  of,  610 
Feet,  care  of,  638 
Fehling's  test,  152 
Felt  in  clothing,  776 
Fermented  alcoholic  beverages,  217 
Ferments,  butyric,  107 

lactic,  106 

of  milk,  103 

peptonizing,  107 

salol-splitting,  105 
Ferric  chloride  as  disinfectant,  581 
test,  161 

sulphate  as  disinfectant,  681 
Ferrous  sulphate  as  disinfectant,  581 
Field  ration,  641 
Figs,  204 

Filaria  sanguinis  hominis  in  water,  442 
Filarial  disease,  relation  of  mosquitos  to, 

712 
Filipino  ration,  649 
Filter  galleries,  393 
Filters,  404,  412 
Filtration  of  air,  493 

contact,  550 

of  public  water  supplies,  406 

in  purification  of  water,  404 

in  sewage  disposal,  548 
Fish,  35 

composition  of,  38 

disease  transmitted  by,  44 

parasitic,  transmitted  by,  38 

poisoning,  64 

preserved,  38 
Fitz's  test,  310 
Flame,  luminosity  of,  497 
Fleas,  relation  of,  to  disease,  694 
Flies,  relation  of,  to  disease,  691 
Flour,  adulteration  of,  184 

bleaching  of,  185 

wheat,  179 

preparations  of,  180 
Fluke  in  animals,  43 

life  history  of,  43 
Fluoride  of  sodium,  264 
Fluorides,  detection  of,  in  beer,  233 
Fog,  279 


INDEX. 


843 


FoK,  v\U-(:\H  of,  2!)7 

K()()(Ih,  juiioiiiit.  ii(!(;(!HHiiry,  IS 

.'iriiiri;i,l,  24 

oiiloriinclric!  v.'iliu-  of,   IN 

(•(niipo.sitioii  of,  I'.) 

colli, .■iiniiiii,!. ion  of,  l>,\'  iiicI.'lIs,  'Zi'A 

luil-rilivi'  v.'iliK^  of,  17 

|)r('|);uii,f ion  of,  (111 

l)r('M('rval  ion  of,  25.'$ 
(ilicinic!!,!  2r)() 

rations  of,  for  .sol(li<'r,  G.''.!) 

vcnc(.ii,i)!c,  177 
F()ot-a.n(l-tiioul  li  iliflcasc,  niilk  affcftfcd  l)y, 

127 
I'\)nnal(lchy<l<',  2(i2 

UH  (lisinfccl-anl,  HdS 

(li,siiif<H',fion  by  fnrni^ialion,  ;")•)'.) 
by  Holufion,  (id!) 

Korinicidal  proix'rfics  of,  (lOd 

ill  iiiillv,  1  IS 

(IrUH'tion  of,  1()() 

toxicity  of,  (')07 

in  wines,  (Ictoctioii  of,  210 
Fruit,  products,  201 
Fruits,  201 
Fryiiifj;  iiicat,  27 
Fuohsino  test,  KU 
Fumes,  irritating,  724 

occui)ations  oxposinp;  to,  741 

poisonous,  occu])ations  exposing  to, 
_  723,  741 
Fungi,  edible,  205 
Fur  in  clothing,  776 
Furnaces,  489 

a. 

Gaiters,  620 
Galactase,  104 
Galactose,  23 
Gai'bage  disjiosal,  556 

reduction  in,  559 
Garget,  milk  affected  by,  128 
Garrison  ration,  640 
Gas  burners,  498 

fixtures,  502 

pipes,  501 
Gases,  illuminating,  499 

irritating,  724 

occupations  exposing  to,  741 

poisonous,  occupations  exposing  to, 
723, 741 
Gasolene  gas  in  illumination,  501 
Gelatin,  detection  of,  163 
Gin,  245 
Ginger,  251 
Globulins,  20 
Glucose,  23,  207 

vinegar,  248 
Glutclins,  20 
Glycoproteins,  21 
Goitre,  soil  relation  to,  353 
Golf,  769 
Gooseberries,  204 
Grape  sugar,  206 
Grapes,  203 


(inivcjly  Hoil.M,  3IH 
(Jnivity  in  ventilation,  476 
(Jn'iiH(!-tra|)H,  514 
(jlroiirid-watcrH,  3r»5 

iLS  water  supply,  HS5 
Giiaiacol  tcHt,  162 
Guinea  wonriH  in  wati-r,  441 

H. 

IlAIUTATirjNH,  470 

Habits  of  life  in  tropical  hyKi<!nc,  Wi 
Ihi'inoglobins,  21 
Ibernolysis,  7x<.) 
I  lain,  siriokcd,  'M) 
I  larnptdii  tank,  554 
Ilaiwls,  disinfi'ction  of,  6|  | 
llardnesH  of  water,  detenninalion  of,  453 
effects  of,  413 
removal  of,  413 
Haversack  ration,  641 
llay  fever,  immunization  in,  S05 
Head  covering,  630 
Heart,  beef,  30 

veal,  31 
Heat  conductivity  in  clothing  materials, 
771 

as  disinfectant,  563 

occupations  exposing  to,  737,  741 
Heating,  4S7 

necessity  for  moisture  in,  491 

regulation  of,  490 

in  relation  to  ventilation,  485 
Hefelmann's  test,  233 
Height  and  weight,  621 
Herbaceous  articles,  200 
Herrings,  poisoning  by,  73 
Histones,  20 
Honey,  208 

adulteration  of,  209 
Hopper  closets,  525 
Hops,  substitutes  for,  in  beer,  221 
Horse  meat,  27,  32 

detection  of,  in  chopped  meats, 

34 
poisoning  by,  86 
Hot-water  heating,  489 
Housekeeping,  471 
House-maids'  sinks.  535 
House-service  tanks,  535 
Huckleberries,  204 
Humidifiers,  492 

Humidity,  relative  determination  of,  299 
Humus  soils,  317 
Huts,  military',  656 
Hydrogen  in  air,  272 

peroxide,  263 
in  air,  275 
as  disinfectant,  574 
Hydroquinone  test,  163 
Hygiene,  military',  617 

naval  and  marine.  671 

of  occupation,  716 

personal,  762 

of  ships,  679 

tropical,  681 


844 


INDEX. 


Ilygrophant,  302 

Hyj!;roscopic'ity  of  olotliinp:  fabrics,  771 
Hypochlorites  iu  puritication  of  water,  401 
Hypochloi-ous  acid  as  disinfectant,  577 


Ice,  443 

Illuminating  gases,  499 
Inihoff  tank,  554 
Imnunie  bodies  in  sera,  795 
Immunity,  780 

application  of  theories  of,  802 
Immunization,  802 
Increase  of  population,  746 
Infantile  death-rate,  754 
Infection,  780 

air  as  carriers  of,  290 
Infectious  material,  dissemination  of,  609 

occupations  exposing  to,  735 
Inosite,  23 

Insects,  relation  of,  to  disease,  690 
Inspections,  military,  059 
Interstate  quarantine,  826 
Iodine  as  disinfectant,  577 
Iron,  24 

action  of  water  on,  418 

content  of  yolk  of  egg,  variability  of, 
93 

in  purification  of  water,  402 

removal  of,  from  water,  414 

in  soil,  318 

in  water,  determination  of,  459 
Irrigation  with  sewage,  544 
Irritating  dusts,  732 

occupations  exposing  to,  741 

gases  and  fumes,  724 

occupations     exposing     to, 
741 


Jams,  210 
JeUies,  210 


K. 


Kefir,  101 

Kid  meat,  poisoning  by,  89 

Kidney,  beef,  30 

mutton,  31 

pork,  30 

veal,  31 
Kidneys,  effect  of  exercise  on,  767 
Kitchen  utensils,  food  contaminated  by, 

267 
Koumiss,  101 

L. 

Lactic  ferments,  106 

Lactose,  23,  98 

Lsevulose,  23 

Lamb,  characteristics  of  good,  27 

composition  of,  31 
Lard,  94 


Latrines,  military,  658 

Laundry  tubs,  535 

Law,  quarantine,  822 

Lawrence  tank,  554 

Lead,  action  of  water  on,  414 

food  contaminated  by,  266 

in  water,  determination  of,  456 
Leather  in  clothing,  776 
Lecitho-proteins,  21 
Leggings,  ()29 
Legumes,  190 
Lemon-juice,  249 
Lentils,  192 
Life,  duration  of,  759 

expectation  of,  760 

tables,  760 
Light  as  disinfectant,  560 

rays  in  purification  of  water,  403 
Lighting,  artificial,  497 

electric,  502 

impurities  given  off  by,  501 

natural,  495 

ribbed  glass  in,  496 
Lime  as  disinfectant,  580 

juice,  249 

in  soil,  318 
Limestone,  318 
Linen,  775 

clothing,  628 

disinfection  of,  611 
Lipase,  104 
Liqueurs,  245 

Liquor  cresolis  comp.  as  disinfectant,  588 
Liver,  beef,  30 

chicken,  32 

goose,  32 

mutton,  31 

pork,  30 

veal,  31 
Liver-rot,  43 
Loams,  317 

Louse,  relation  of,  to  disease,  696 
Luebert's  test,  162 
Luminosity  of  flame,  497 
Lungs,  beef,  30 
Lysoform  as  disinfectant,  598 
Lysol  as  disinfectant,  589 

M. 

Macaroni,  183 
Mace,  251 

Magnesia  in  soil,  318 
Magnesium,  24 
Malaria  in  army,  668 

prevention  of,  706 

relation  of  mosquitoes  to,  697 
of  soil  to,  348 
Malarial  parasite,  700 
Malic  acid,  24 

Malignant    endocarditis,     immunization 
in,  811 

oedema,  soil  relation  to,  348 
Malt  vinegar,  247 
Maltose,  23 
Mammitis,  milk  affected  by,  128 


iNi>i':x. 


845 


M,'ui(i;;uH!,s(',  in  soil,  I'. IS 

Miinihiii^!;,  ('):{:'. 

M:i,rii)(!  \\y\i^\v.w,  ()7I 

MiirlH,  'Ml 

M,•u•^i!W-^l,l.(^M,  7'1.S 

Mmitow,  Ix^cf,  ;>() 

MjimMUh,  mills  ;iJTcc(.(;(l  hy,  I2S 

Mill rl.n'SH(^H,  (lisiiirccl  ion  of,  015 

Mc:ui  ;i,ri,(T-lilr  l-iiric,  7<)() 

(liirjilion  of  life,  Tf)'.) 
M(',iisl(«  in  urrny,  (iCiU 
Mousurninrnis  of  hoily,  ('i21 
M(<a(.s,  25 

cliiinic.l.criHlif'H  of,  \vlii('li    (t;i,iisc    poi- 
Honinff,  70 

coinposiiion  of,  2S 

cooking  of,  crfcct  of,  20 

(lig(>siil)ilil.y  of,  compjiralivc,  25 

disease  1,ranHniiU,e(l  by,  44 

extracts,  83 

good,  charactorisl i(\s  of,  27 

inspection  of,  S*.) 

tubonMilosia  and,  4<S 

parasitica  disciase  transmitted  l)y,  .'>8 

poisoning,  04 

from  diseases  of  animals,  40 

powder,  33 

texture  of,  26 
Mechanical  filters,  412 

ventilation,  485 
Medicated  soaps  as  disinfectants,  590 
Melons,  203 
Meningitis,  epidemic,  air  as  carrier  of,  295 

immunization  in,  812 
Mercuric  chloride  as  disinfectant,  582 

cyanide  as  disinfectant,  584 
Metakaline  as  disinfectant,  598 
Metals,  foods  contaminated  by,  264 
Metaproteins,  21 
Metchnikoff's  theory,  801 
Methyl    alcohol,    deterniination    of,    in 

beer,  229 
Micro-organisms  in  air,  278,  283,  288 

in  soil,  319 
Military  hygiene,  617 
Milk,  95 

adulteration  of,  122 

analysis  of,  140 

bacteria  in,  105 

coiiditions  affecting,  110 
source  of,  110 

bactericidal  properties  of,  103 

biological  properties  of,  103 

condensed,  124 

constituents  of,  97 

cooked,  detection  of,  162 

detection  of  added  water  in,  154 
of  coloring  matter  in,  158 
of  preservatives  in.  160 

determination  of  ash  in,  153 
of  constituents  of,  151 
of  fats  in,  148 
of  specific  gravity  of,  147 

diseases  transmitted  by,  125 

ferments  of,  103 


Milk  from  diHf;iHed  rrowH,  127 

inffrctiotiH,  acute,  IranMinif ti'dby,  136 

I)l)yHi(;al  prri|)fTtifH  of,  99 

poiHorK)iiH,   125 

lircHcrviilion  of,  1 14 
clicfni(;al,   I  IS 

produclH,  10! 

rc'iction  of,  '.)'.) 

slrrilizalion  of,  1 14 
Mineral  acids  .-us  (\'\»\\\U'V.\m\\h,  5K5 

tiiatters,  diw^iiHf;  and,  421 
in  watfT,  37S 
Mist,,  279 

Moisture,  detfrmination  of,  by  w«-i((hinp;, 
298 

needed  in  healing,  491 

of  soil,  df^tenninalion  of,  359 
Mohisses,  207 

vinegar,  248 
Mos((uitoeH,  relation  of,  to  diseauo,  696 
Moulds  in  air,  288 
Muck  soil,  318 
Mulberries,  204 
Municipal  ciuarantine,  828 
Mushrooms,  205 
Mussels,  poisoning  by,  72 
Mustard,  2.50 
Mutton,  composition  of,  31 

good,  characteristics  of,  27 

N. 

Naphthol,  a-,  test,  103 

Nai)hthylamine  solution,  4.50 

Naval  hygiene,  671 

Nervous  system,  exerci.se  and,  eflfect  of, 

766 
Nesslerizing  tubes,  447 
Ncssler's  reagent,  445 
Nickel,  food  contamination  by,  267 

kitchenware,  268 
Nitrates  in  .soil,  319 

in  water,  375 

determination  of,  450,  451 
Nitrifying   organisms   in    purification    of 

water,  409 
Nitrite,  permanent  standards,  451 
Nitrogen  in  air,  271 

compounds  in  air,  275 

in  soil,  318 
Norton's  tube  wells,  387 
Nucleoproteins,  21 
Nutmeg,  251 
Nuts,  193 

0. 

Oatmeal,  187 

Oats,  186 

Occupations,  classification  of,  721 

hygiene  of,  716 

of  women  and  children,  740 
Oil,  cotton-seed,  196 

essential,  as  disinfectant,  593 

olive,  195 
Olein,  22 


84G 


ISDEX. 


Oleomargarine,  166 

Olive  oil,  U.  S.  Standard  for,  195 

Open  closets,  525 

fires,  4S7 
Opsonins  in  serum,  802 
Oranges,  202 
Organic  matters  in  air,  286 

in  soil,  detection  of,  360 
in  water,  372 
pollutions  of  water,  relation   of,  to 
disease,  423 
Overcrowding,  2SG 
Overexercise  of  parts,  739 
Oxalic  acid,  24 

standard  solution  of,  304,  454 
Oxidation  in  purification  of  water,  396 

in  soil,  319 
Oxytlascs,  105 
Oxygen  in  air,  269 

as  disinfectant,  572 
required  for  decomposition  of  organic 
matters  in  water,  determination  of, 
454 
Oxvuris  vermicularis  in  water,  441 
Oyster  plant,  199 
Oysters,  infection  transmitted  by,  58 

poisoning  by,  75 
Ozone  in  air,  274 

determination  of,  312 
in  purification  of  water,  402 

P. 

Pail  system  of  sewage  disposal,  541 

Palmitin,  22 

Pan  closet,  523 

Paper  coil  extraction  test,  148 

Paralysol  as  disinfectant,  598 

Parasitic  disease,  fish  and,  38 

meat  and,  38 

water  and,  441 
Parsnips,  199 

Pasteurization  of  milk,  114 
Peaches,  202 
Peanuts,  194 
Pears,  202 
Peas,  191 
Peat  soil,  317 
Pectin,  23 
Pectose,  23 
Pepper,  250 

Cayenne,  251 
Pepsin,  104 
Peptides,  22 
Peptones,  22 

Peptonizing  ferments,  107 
Perflation  in  ventilation,  479 
Permanganate  of  potassium  as  disinfect- 
ant, 582 
Permeability  of  soils,  320 

conditions  affecting,  323 

determination  of,  356 
Peroxide  of  hydrogen,  120,  263 

in  air,  275 

as  disinfectant,  574 
Peroxydase,  105 


Perry,  241 

Person,  care  of,  762 

in  tropics,  688 
Personal  cleanliness,  627 
of  sailors,  680 
hygiene,  762 
Phaseomannite,  23 
Phenic  acid  as  disinfectant,  586 
Phenol  as  (Hsinfcctant,  586 
Phenoldisulj^honic  acid  solution,  451 
PlK'nolphthulein  solution,  304 
Phloroglucin  test,  161 
Phosphates,  24 
in  soil,  318 
Phosphoproteins,  21 
Pike,  poisoning  bv,  75 
Pimento,  251 
Pin  worms  in  water,  441 
Plague,  air  as  carrier  of,  295 
immunization  in,  809 
soil  relation  to,  346 
Plumbing,  502 

testing  of,  537 
Plums,  202 
Plunger  closets,  524 
Pneumonia,  air  as  carrier  of,  295 
Poisoning  by  beef,  84 

by  carbon  monoxide,  281 

by  cheese,  177 

by  fish,  64 

by  herrings,  73 

by  horse  meat,  86 

by  kid  meat,  89 

by  meat,  64 

diagnosis  of,  69 

postmortem  appearance  in,   69 
symptoms  of,  68 
by  milk,  126 
by  mussels,  72 
by  oysters,  75 
by  pike,  75 
by  pork,  78 
by  potatoes,  198 
by  salmon,  74 
by  sausages,  87 
by  veal,  76 
Poisonous  bacterial  products  in  foods,  65 
beef,  71 
cheese,  176 
dusts,  729 

occupations  exposing  to,  740 
dyes,  777 
fumes,  occupations  exposing  to,  723, 

741 
gases,  occupations  exposing  to,  723, 

741 
milk,  125 
sausage,  71 
species,  64 
veal,  70 
Polariscopic  tests,  153 
Police,  sanitary,  660 
Pollution  of  air  by  lighting,  501 
of  soil,  338 

of  water,  disease  and,  423 
of  wells,  391 


INDEX. 


817 


P()|)iil;il.i()ii,  cHl-irii.'ilioM  of,  745 
Porc-voluirH;  of  Hoilw,  :'.  I'.» 

(l(!t.(U'initi;i,l-iori   ol',  '.'u)h 
Pork,  coinpoHit.ion  of,  ;>() 

(rood  (tluiDLct.criHlicH  of,  27 

jjoiHoriin^!;  by,  7.S 

NaJl,,  :i() 
PohI.h,  inilif.'U'v,  M\) 
PoUiHHiiiiii  clifoni;i,l,(^  Holul.ion,  4r)2 

iiiLraLc  .4(.!Ui(l;inl  Holulion,  451 

pcrmaiiKHiiaUi  \va  (lisinfcctMnl,  582 
Holulion,  454 

sulphaicr  IchI,,   I()2 
Polaiocs,  1<)() 

HWCCi,,    I'M) 
Poultry,  (toinposilioii  of,  'XI 
Pr(>c.ipit,!i(.ioii  in  ncwa|!;''  disiiosal,  542 
Precipitins  in  scrum,  7'.I.S 
Preparation  of  food,  (144 
Preservation  of  food,  253 
oheini(!al,  25(5 

of  milk,  114 

chcMTiical,  1  IS 
Preserved  (isli,  .'{S 
Pressure,  higli,  o(Huipa(iona  exposing  (o, 

7:37 

Prevent  ion  of  dissemination  of  infectious 
matter,  G09 

of  malaria,  70G 

of  yellow  fever,  71 1 
Probable  duration  of  life,  759 
Proportion  of  body  measurements,  621 
Protamines,  21 
Proteids,  19,  99 

in  soil,  319 
Proteins,  20 
Proteoses,  21 
Psychrometer,  299 

Puerperal  sepsis,  immunization  in,  811 
Pulled  bread,  183 
Pumpkins,  201 
Purification  of  water,  396,  404 

algir  in,  destruction  of,  412 
limitations  of,  401 
Pyrocatechin  test,  163 

Q. 

Quarantine,  820 

detention  camps,  829 

interstate,  826 

municipal,  828 

State,  826 
Quicklime  as  disinfectant,  580 

R. 

Rabies,  milk  affected  by,  128 
Race  in  vital  statistics,  752 
Radiation  in  ventilating,  486 
Radishes,  199 
Rain,  279 
Rain-water,  363 

stored,  3S2 
Raspberries,  204 
Rations,  naval,  672 

of  soldier,  various,  639 


Rations,  tro|)ical,  645 
R(!cr(!ation,  764 
Itecruit,  <)!9 

naval,  (»71 
ited  meatH,  28 
HiiductiiHCH,  105 

RcdiKttion   in   narba^e  diH{)OH!il,  550 
iicnistrar'H  retiirns,  747 
ll(!KiiiatinK  tcmpcratiin-,  \'M) 
Residencr;  in  tro|)icH,  (iS3 
Respiralioii  in  active;  exerclMC,  765 
Rest,  7()4 

Ribb(!<l  ^l.-usH  in  lightiriK,  490 
Rice    1S9 

iliiKlerpcst,  milk  alTcctcfi  by,  127 
Koastinn  meal ,  2() 
Room  (iisinfection,  612 
Roots,  19(),  199 
Rot  in  sheep,  43 
Rotary  cowls,  479 
Round  worms  in  water,  441 
Rowing,  770 
Rubber  in  clothing,  775 
Rum,  245 
Rusks,  183 
Rye,  185 


Sacchakine  preparations,  205 
Sago,  193 
Salicylic  acid,  261 

in  beer,  detection  of,  233 
in  milk,  120 

detection  of,  160 
in  wines,  detection  of,  240 
Salmon,  poisoning  by,  74 
Salol-splitting  ferment,  105 
Salt,  249 

inorganic,  24,  99 

pork,  30 

soils,  318 
Salting,  preservation  of  food  by,  2.54 
Sand  in  purification  of  water,  407 
Sand}^  soils,  316 
Sanitary  cordon,  828 

police,  660 
Sanit:is  closet,  527 
Saprol  as  disinfectant,  590 
Saturation  of  air,  279 
Sausages,  33 

coloring  in,  35 

poisoning  by,  87 

poisonous,  characteristics  of,  71 
Scarlet  fever,  immunization  in,  811 

milk  as  bearer  of,  13S 
School  furniture,  472 
School-houses,  471 
Sea,  discharge  of  sewage  in,  541 
Seal  of  traps,  511,  516 
Seat  worms  in  water,  441 
Sedentary  life,  739 

Sedimentation  in  sewage  disposal.  542 
Seeds,  farinaceous,  178 

fatty,  193 
Sepsis,  puerperal,  immunization  in,  811 
Septic  tanks,  554 


848 


INDEX. 


Serum,  antistrcptococcus,  Sll 
Service-pipes,  530 

-tanks,  house,  o3o 
Sewage  disposal,  538 

filtration,  548 

infection  of  shellfish,  61 

irrigation,  544 
Sewer  gas,  282 
Sewerage,  military,  657 
Sex  in  vital  statistics,  751 
Shellfish,  composition  of,  38 

infection  of,  b}-  sewage,  61 

varieties  of,  38 
Ships,  hvgiene  of,  679 
Shoddy,"  629 
Shoes,  778 
Silica  in  soil,  318 
Silk  in  clothing,  773 
Silver  compounds  as  disinfectants,  584 

nitrate  standard  solution,  452 
Sinks,  534 

militarj^,  658 
Siphon  closets,  520 
Skin  in  active  exercise,  766 
Slaughtering,  91 
Sleep,  764 

Sleeping  quarters,   sailors',   676 
Slop-sinks,  535 
Smallpox,  814 
Smoke  in  air,  297 
Smoked  ham,  30 

Smoking,  preservation  of  food  by,  254 
Soap  as  disinfectant,  594 

medicated,  596 

standard  solution  of,  453 
Sodium  aurate  as  disinfectant,  585 

bicarbonate,  264 

carbonate  as  disinfectant,  579 
solution,  445 

fluoride,  264 

hypochlorite  solution  as  disinfectant, 
577 

Tlitrite  solutions,  450 
Soil,  agencies  effecting  change  in,  328 

bacteria  of,  340 

bacteriological  examination  of,  362 

constituents  of,  318 

dampness  of,  disease  and,  342 

detection  of  organic  matter  in,  360 
of  volatile  matter  in,  360 

effect  of  vegetation  on,  337 

evaporation  from,  335 

examination  of,  354 

moisture  of,  determination  of,  359 

physical  properties  of,  319 

determination  of,  355 

pollution  of,  338 

relation  of,  to  disease,  342 

study  of,  316 

temperature  of,  326 

varieties  of,  316 

water-retaining  capacity  of,  325 

water-transmitting  capacity  of,  324 
Soil-air,  329 

determination  of  carbon  dioxide  in, 
360 


Soil-pipes,  504 
Soil-water,  332 

sources  of,  335 
Soldier,  hygiene  of,  627 
Solved  as  disinfectant,  590 
Spaghetti,  183 
Spices,  246 
Spirit,  ^•inegar,  248 
Springs  as  water  supplies,  385 
Sputum,  disinfection  of,  611 
Squash,  201 
Starches,  22 
State  quarantine,  826 
Statistics,  vital,  742 
Steam  as  disinfectant,  565 
Steam-pipe  heating,  489 
Stearin,  22 

Sterilization  of  milk,  114 
Stewing  meat,  27 
Stimulant  beverages,  210 
Stockings,  630 
Storch's  test,  163 
Stoves,  487 
Strawberries,  204 

Streptococcus  infection,  air  as  carrier  of, 
295 
immunization  in,  811 
Strongyloides  intestinalis  in  water,  442 
Sublamin  as  disinfectant,  584 
Sucrate  of  lime,  detection  of,  164 
Sucrose,  23 
Suet,  beef,  30 
Sugar,  236 

cane,  U.  S.  standard,  205 

determination  of,  in  wine,  238 

grape,  206 

maple,  206 

milk,  23,  98 

determination  of,  152 

varieties  of,  23 

vinegar,  247 
Sulfonaphthol  as  disinfectant,  590 
Sulphanilic  acid  solution,  450 
Sulphates,  24 

in  purification  of  water,  403 

in  soil,  318 
Sulphites,  262 

detection  of,  in  wines,  240 
Sulphur  dioxide  as  disinfectant,  577 
Sulphuric  acid  test,  161 
Sunstroke  in  army,  669 
Superoxydase,  105 
Surface-water,  364 

as  water  supply,  384 
Susceptibility  to  disease,  781 
Sweet  potatoes,  199 
Syphilis,  Wassermann  reaction  in,  800 
Syrup,  maple,  206 


Tanks,  house-service,  535 

Tapeworm,  varieties  of,  in  meat  and  fish, 

38 
Tapioca,  193 
Tea,  210 


IM)ICX. 


849 


T'oa,  adiiU.ornfion  of,  212 

(;()iri|)().Hit.i(Hi  of,  '1\\ 
'l"(;in|)(^rii,l,iirc,  rcnulaUou  «!',  'I'-X) 

of  Hoil,  iwr) 
'YmuM,  770 
'l\!iil,H,  iiiili(,;u'y,  (ir).''. 
TctaiuiH,  itMiiiiiiii/,;i,li()M  in,  S()5 

n^l.'il.ion  of  hoiI  (d,  -M^ 
'I\^x(,ur(!  of  (tloMiinn,  770 
'rhciiic,  210 
'Pli(M)l)roiiiiii(',  210 
Tlicrinoinclcr  in  (I<!l,(U-iiiinul.ioii  of  hiiniid- 

il.y,  29U 
'ricrUs,  rclMtioii  of,  t.o  (liH('u.s(!H,  ()9() 
Tin,  ucl.ion  of  wafer  on,  41!) 

food  confaininiiUMl  by,  207 
in  water,  (k-fcHiliou  of,  4r)<.) 
ToaHt,,  183 
'l\)iiia<,o(>s,  201 
Touffuo,  b(!(^f,  'M) 
ToxiiiH,  7S:} 
Traps  for  grc-'iso,  514 
pluinhinfT,  r,07,  510 
seal  of,  511,  516 
ventilation  of,  516 
Travel  ration,  641 
Tri(;hina  spiralis,  39 
Trichinosis,  41 

diagnosis  of,  42 
Trichocephalua  dispar  in  water,  442 
Tripe,  beef,  30 
Tropical  dietary,  648 
diseases,  688 
hygiene,  681 
rations,  645 
Trousers,  629 
Truffles,  205 
Trypsin,  104 
Tuberculin  tests  of  cattle,  47 

therapy,  812 
Tuberculosis,  air  as  carrier  of,  293 
animal  experimentation  in,  50 
in  animals,  46 
in  army,  666 
danger  from  carcasses  affected  with, 

49 
immunization  in,  811 
milk  affected  by,  130 
relation  between  human  and  bovine, 
50 
of  soil  to,  343 
Tubers,  196 
Tubs,  laundry,  535 
Turnips,  199 

Typhoid  fever,  air  as  carrier  of,  294 
in  army,  667 
celery  as  bearer  of,  64 
crawfish  as  carrier  of,  64 
food  as  bearer  of,  58 
immunization  in,  807 
milk  as  bearer  of,  139 
relation  of  soil  to,  343 
water-cress  as  bearer  of,  64 

supplies  infected  with,  425 
rates,  influence  of  water  supplies  on, 
426 

54 


U. 

l!i/t'itA-vif)r,KT    rayH    in    purification    of 

water,  403 
Ihicinaria  dufxifiialiH  in  wat<T,  442 
Uncin.iriaHiH,  relation  of  Hoil  t'),  350 
Underclotliinj^,  631 
llrinaJH,  530 

Urine,  disinfcfrtifjn  of,  610 
lltciiHilH,  dimnffrction  of,  611 

kitchen,  food  ctinturninatfwl  by,  267 


VAcriNATioN  aKairmt  smallpox,  S14 

Vanes,  480 

Va|)or,  afiueouH,  in  air,  276 

determination  of,  298 

tensions,  301 
Veal,  composition  of,  '■'>\ 

good,  27 

poisonous,  70,  76 
Vegetaljli!  fats,  195 

foods,  classification  of,  177 

marrow,  201 
Vegetal)l(!3,  disease  transmitted  by,  44 

fruit  products  as,  201 
Vegetation,  effect  of,  on  soil,  336,  337 

on  water,  397 
Venereal  disease  in  army,  670 
Ventilating  cowls,  479 

pipes  in  plumbing,  508,  516 
Ventilation,  473 

aspiration  in,  479 

diffusion  in,  476 

filtration  in,  493 

gravity  in,  476 

heat  conduction  in,  486 

inlets,  482 

mechanical,  485 

natural,  481 

outlets,  482 

perflation  in,  479 

radiation  in,  486 

rates,  475,  482 

determination  of,  493 

space  required,  475 

of  traps,  516 

of  vessels,  677 

with  heating,  485 
Vermicelli,  183 
Vessels,  ventilation  of,  677 
Vinegar,  adulteration  of,  248 

examination  of,  248 
Mnegars,  246 
Vital  statistics,  742 
Vitiated  air,  effects  of,  286 

occupation  exposing  to,  723 

W. 

Walnuts,  194 

Waring  system  of  irrigation,  547 

Wasli  basins,  530 

Washing  soda  as  disinfectant,  579 

Wash-out  closets,  525 


850 


INDEX. 


Wassermann  reaction,  SOO 
^\■aste  pipes,  509 
\\'ater,  363 

action  of,  on  metals,  414 
bacteria  in,  379 
diseases  related  to,  420 
examination  of,  444 

bacteriolofiic,  462,  467 

chemical  444,  467 

inferences  from,  459 
gases  in,  371 
hardness  of,  378 

determination  of,  453 

removal  of,  413 
mineral  contents  of,  disease  and,  421 

matters  in,  377 
organic  matters  in,  372 
parasites  in,  441 
physical  characters  of,  3G7 

determination  of,  455 
purification  of,  396 

by  boiling,  404 

chemical,  398 

destruction  of  algse  in,  412 

by  distillation,  404 

by  filtration,  404 

by  light  rays,  403 

limitations  of,  401 

removal  of  iron  in,  414 
reaction  of,  369 

determination  of,  455 
residue  in,  determination  of,  453 
sanitary  classification  of,  394 
in  soil,  332 

sources  of,  335 
substances  normally  found  in,  371 
supplies,  382 

filtration  of,  406 

military,  656 

naval,  675 

typhoid  infection  of,  425 
vapor  in  air,  276 

determination  of,  276 
Water-closets,  520 

connections  of,  529 
disinfection  of,  616 
flushing  apparatus  for,  528 
in  ships,  680 
Water-gas  in  illumination,  499 


\\'atcr-proof  blankets,  632 

Weight,  rlTcct  of  exercise  on,  767 
height  and,  621 

Wells,  386 

deep,  pollution  of,  393 
drainage  area  of,  391 
pollution  of,  391 

Welsbach  burners,  498 

Werner-Schmidt  test,  149 

Wheat,  178 

composition  of,  179 
flour,  179 

adulteration  of,  184 
bleaching  of,  .185 
preparations  of,  180 

Wheeling,  770 

Whip  worms  in  water,  442 

Whiskey,  243 

factitious,  244 

White  meats,  28 

Wind,  action  of,  330 

Wine  vinegar,  247 

Wines,  234 

acidity  of,  238 
adulterations  of,  396 
analysis  of,  238 
classification  of,  235 
coal-tar  colors  in,  237 

detection  of,  239 
composition  of,  236 
preservatives  in,  237 
detection  of,  240 

Wolpert's  test,  309 

Women,  employment  of,  740 

Wool  clothing,  628,  772 

Work.  633 


Yellow  fever,  prevention  of,  711 

relations  of  mosquitoes  to,  707 
of  soil  to,  348 


Zinc,  action  of  water  on,  418 
chloride  as  disinfectant,  581 
food  contaminated  by,  267 
in  water,  detection  of,  458 

Zymotic  diseases,  754 


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